Update version

Closes #917

.config/dotnet-tools.json

@@ -1,12 +0,0 @@
-{
-  "version": 1,
-  "isRoot": true,
-  "tools": {
-    "xamlstyler.console": {
-      "version": "3.2003.9",
-      "commands": [
-        "xstyler"
-      ]
-    }
-  }
-}

.github/FUNDING.yml

@@ -1,3 +0,0 @@
-github: Tyrrrz
-patreon: Tyrrrz
-custom: ['buymeacoffee.com/Tyrrrz', 'tyrrrz.me/donate']

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -1,25 +1,31 @@
-name: "\U0001F41E Bug report"
+name: 🐞 Bug report
 description: Report broken functionality.
 labels: [bug]
+
 body:
 - type: markdown
   attributes:
     value: |
-      - Please check existing issues (both opened and closed) to ensure that this bug hasn't been reported before.
-      - Refer to the [contribution guidelines](https://github.com/Tyrrrz/DiscordChatExporter/blob/master/Contributing.md) for info on how to file a good issue.
-      - If you want to ask a question instead of reporting a bug, use [**discussions**](https://github.com/Tyrrrz/DiscordChatExporter/discussions/new) instead.
+      🧐 **Guidelines:**
+
+      - Search through [existing issues](https://github.com/Tyrrrz/DiscordChatExporter/issues?q=is%3Aissue) first to ensure that this bug has not been reported before.
+      - Write a descriptive title for your issue. Avoid generic or vague titles such as "Something's not working" or "A couple of problems".
+      - Keep your issue focused on one single problem. If you have multiple bug reports, please create separate issues for each of them.
+      - Provide as much context as possible in the details section. Include screenshots, screen recordings, links, references, or anything else you may consider relevant.
+      - If you want to ask a question instead of reporting a bug, please use [discussions](https://github.com/Tyrrrz/DiscordChatExporter/discussions/new) instead.
 
 - type: input
   attributes:
     label: Version
-    description: "Which version(s) of DiscordChatExporter does this bug affect?"
+    description: Which version of DiscordChatExporter does this bug affect?
+    placeholder: ver X.Y.Z
   validations:
     required: true
 
 - type: dropdown
   attributes:
     label: Flavor
-    description: "Which flavor(s) of DiscordChatExporter does this bug affect?"
+    description: Does this bug affect the GUI version, the CLI version, or both?
     multiple: true
     options:
     - GUI (Graphical User Interface)
@@ -27,16 +33,32 @@ body:
   validations:
     required: true
 
+- type: dropdown
+  attributes:
+    label: Export format
+    description: Does this bug affect specific export format(s)? If not applicable, leave this field blank.
+    multiple: true
+    options:
+    - HTML
+    - TXT
+    - JSON
+    - CSV
+
 - type: textarea
   attributes:
     label: Details
-    description: "Clear and thorough explanation of the bug. If relevant, include screenshots or screen recordings."
+    description: Clear and thorough explanation of the bug.
+    placeholder: I was doing X expecting Y to happen, but Z happened instead.
   validations:
     required: true
 
 - type: textarea
   attributes:
     label: Steps to reproduce
-    description: "Minimum steps required to reproduce the bug."
+    description: Minimum steps required to reproduce the bug.
+    placeholder: |
+      - Step 1
+      - Step 2
+      - Step 3
   validations:
     required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -1,8 +1,14 @@
 blank_issues_enabled: false
 contact_links:
-  - name: "\U0001F4D6 Read the wiki"
+  - name: ⚠ Feature request
+    url: https://github.com/Tyrrrz/.github/blob/master/docs/project-status.md
+    about: Sorry, but this project is in maintenance mode and no longer accepts new feature requests.
+  - name: 💬 Discord server
+    url: https://discord.gg/2SUWKFnHSm
+    about: Chat with the project community.
+  - name: 📖 Wiki
     url: https://github.com/Tyrrrz/DiscordChatExporter/wiki
-    about: Find answers to most common questions.
-  - name: "\U0001F5E8 Ask a question"
+    about: Find usage guides and frequently asked questions.
+  - name: 🗨 Discussions
     url: https://github.com/Tyrrrz/DiscordChatExporter/discussions/new
-    about: Please ask and answer questions here.
+    about: Ask and answer questions.

.github/ISSUE_TEMPLATE/feature-request.yml

@@ -1,26 +0,0 @@
-name: "\U00002728 Feature request"
-description: Request a new feature.
-labels: [enhancement]
-body:
-- type: markdown
-  attributes:
-    value: |
-      - Please check existing issues (both opened and closed) to ensure that this feature hasn't been requested before.
-      - Refer to the [contribution guidelines](https://github.com/Tyrrrz/DiscordChatExporter/blob/master/Contributing.md) for info on how to file a good issue.
-      - If you want to ask a question instead of requesting a feature, use [**discussions**](https://github.com/Tyrrrz/DiscordChatExporter/discussions/new) instead.
-
-- type: dropdown
-  attributes:
-    label: Flavor
-    description: "Which flavor(s) of DiscordChatExporter does this feature request apply to?"
-    multiple: true
-    options:
-    - GUI (Graphical User Interface)
-    - CLI (Command Line Interface)
-
-- type: textarea
-  attributes:
-    label: Details
-    description: "Clear and thorough explanation of the feature you have in mind."
-  validations:
-    required: true

.github/workflows/CD.yml

@@ -1,71 +0,0 @@
-name: CD
-
-on:
-  push:
-    tags:
-      - "*"
-
-jobs:
-  build:
-    runs-on: windows-latest
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2.3.3
-
-      - name: Install .NET (v3.1)
-        uses: actions/setup-dotnet@v1.7.2
-        with:
-          dotnet-version: 3.1.x
-
-      - name: Install .NET (v5.0)
-        uses: actions/setup-dotnet@v1.7.2
-        with:
-          dotnet-version: 5.0.x
-
-      - name: Build & publish (CLI)
-        run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
-
-      - name: Build & publish (GUI)
-        run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
-
-      - name: Pack (CLI)
-        run: Compress-Archive -Path DiscordChatExporter.Cli/bin/Publish/* -DestinationPath DiscordChatExporter.Cli/bin/Publish/Archive.zip -Force
-        shell: pwsh
-
-      - name: Pack (GUI)
-        run: Compress-Archive -Path DiscordChatExporter.Gui/bin/Publish/* -DestinationPath DiscordChatExporter.Gui/bin/Publish/Archive.zip -Force
-        shell: pwsh
-
-      - name: Create release
-        id: create_release
-        uses: actions/create-release@v1.0.1
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          tag_name: ${{ github.ref }}
-          release_name: ${{ github.ref }}
-          body: |
-            [Changelog](https://github.com/Tyrrrz/DiscordChatExporter/blob/master/Changelog.md)
-          draft: false
-          prerelease: false
-
-      - name: Upload release asset (CLI)
-        uses: actions/upload-release-asset@v1.0.2
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          upload_url: ${{ steps.create_release.outputs.upload_url }}
-          asset_path: DiscordChatExporter.Cli/bin/Publish/Archive.zip
-          asset_name: DiscordChatExporter.CLI.zip
-          asset_content_type: application/zip
-
-      - name: Upload release asset (GUI)
-        uses: actions/upload-release-asset@v1.0.2
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          upload_url: ${{ steps.create_release.outputs.upload_url }}
-          asset_path: DiscordChatExporter.Gui/bin/Publish/Archive.zip
-          asset_name: DiscordChatExporter.zip
-          asset_content_type: application/zip

.github/workflows/CI.yml

@@ -1,39 +0,0 @@
-name: CI
-
-on: [push, pull_request]
-
-jobs:
-  build:
-    runs-on: windows-latest
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2.3.3
-
-      - name: Install .NET (v3.1)
-        uses: actions/setup-dotnet@v1.7.2
-        with:
-          dotnet-version: 3.1.x
-
-      - name: Install .NET (v5.0)
-        uses: actions/setup-dotnet@v1.7.2
-        with:
-          dotnet-version: 5.0.x
-
-      - name: Build & publish (CLI)
-        run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
-
-      - name: Build & publish (GUI)
-        run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
-
-      - name: Upload build artifacts (CLI)
-        uses: actions/upload-artifact@v1
-        with:
-          name: DiscordChatExporter.CLI
-          path: DiscordChatExporter.Cli/bin/Publish/
-
-      - name: Upload build artifact (GUI)
-        uses: actions/upload-artifact@v1
-        with:
-          name: DiscordChatExporter
-          path: DiscordChatExporter.Gui/bin/Publish/

.github/workflows/docker.yml

@@ -0,0 +1,55 @@
+name: docker
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Build container
+        run: docker build -f DiscordChatExporter.Cli.dockerfile .
+
+  deploy-latest:
+    if: ${{ github.event_name == 'push' && github.ref_type == 'branch' && github.ref_name == 'master' }}
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Login to DockerHub
+        run: docker login -u tyrrrz -p ${{ secrets.DOCKER_TOKEN }}
+
+      - name: Build container
+        run: docker build -f DiscordChatExporter.Cli.dockerfile -t tyrrrz/discordchatexporter:latest .
+
+      - name: Push container
+        run: docker push tyrrrz/discordchatexporter:latest
+
+  deploy-stable:
+    if: ${{ github.event_name == 'push' && github.ref_type == 'tag' }}
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Get release version
+        id: get_version
+        uses: dawidd6/action-get-tag@v1
+
+      - name: Login to DockerHub
+        run: docker login -u tyrrrz -p ${{ secrets.DOCKER_TOKEN }}
+
+      - name: Build container
+        run: docker build -f DiscordChatExporter.Cli.dockerfile -t tyrrrz/discordchatexporter:stable -t tyrrrz/discordchatexporter:${{ steps.get_version.outputs.tag }} .
+
+      - name: Push container (stable)
+        run: docker push tyrrrz/discordchatexporter:stable
+
+      - name: Push container (${{ steps.get_version.outputs.tag }})
+        run: docker push tyrrrz/discordchatexporter:${{ steps.get_version.outputs.tag }}

.github/workflows/main.yml

@@ -0,0 +1,154 @@
+name: main
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: windows-latest
+
+    env:
+      DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
+      DOTNET_NOLOGO: true
+      DOTNET_CLI_TELEMETRY_OPTOUT: true
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Install .NET
+        uses: actions/setup-dotnet@v2
+        with:
+          # Fixed version, workaround for https://github.com/dotnet/core/issues/7176
+          dotnet-version: 6.0.100
+
+      - name: Run tests
+        # Tests need access to secrets, so we can't run them against PRs because of limited trust
+        if: ${{ github.event_name != 'pull_request' }}
+        run: dotnet test --configuration Release --logger GitHubActions --collect:"XPlat Code Coverage" -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=opencover
+        env:
+          DISCORD_TOKEN: ${{ secrets.DISCORD_TOKEN }}
+          DISCORD_TOKEN_BOT: true
+
+      - name: Upload coverage
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+
+  package:
+    needs: test
+    runs-on: windows-latest
+
+    env:
+      DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
+      DOTNET_NOLOGO: true
+      DOTNET_CLI_TELEMETRY_OPTOUT: true
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Install .NET
+        uses: actions/setup-dotnet@v2
+        with:
+          # Fixed version, workaround for https://github.com/dotnet/core/issues/7176
+          dotnet-version: 6.0.100
+
+      - name: Publish (CLI)
+        run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
+
+      - name: Publish (GUI)
+        run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
+
+      - name: Upload artifacts (CLI)
+        uses: actions/upload-artifact@v3
+        with:
+          name: DiscordChatExporter.Cli
+          path: DiscordChatExporter.Cli/bin/Publish/
+
+      - name: Upload artifacts (GUI)
+        uses: actions/upload-artifact@v3
+        with:
+          name: DiscordChatExporter
+          path: DiscordChatExporter.Gui/bin/Publish/
+
+  deploy:
+    if: ${{ github.event_name == 'push' && github.ref_type == 'tag' }}
+    needs: package
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download artifacts (CLI)
+        uses: actions/download-artifact@v3
+        with:
+          name: DiscordChatExporter.Cli
+          path: DiscordChatExporter.Cli
+
+      - name: Download artifacts (GUI)
+        uses: actions/download-artifact@v3
+        with:
+          name: DiscordChatExporter
+          path: DiscordChatExporter.Gui
+
+      - name: Create package (CLI)
+        run: Compress-Archive -Path DiscordChatExporter.Cli/* -DestinationPath DiscordChatExporter.Cli.zip -Force
+        shell: pwsh
+
+      - name: Create package (GUI)
+        run: Compress-Archive -Path DiscordChatExporter.Gui/* -DestinationPath DiscordChatExporter.Gui.zip -Force
+        shell: pwsh
+
+      - name: Create release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          body: |
+            [Changelog](https://github.com/Tyrrrz/DiscordChatExporter/blob/master/Changelog.md)
+          draft: false
+          prerelease: false
+
+      - name: Upload release asset (CLI)
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_name: DiscordChatExporter.Cli.zip
+          asset_path: DiscordChatExporter.Cli.zip
+          asset_content_type: application/zip
+
+      - name: Upload release asset (GUI)
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_name: DiscordChatExporter.zip
+          asset_path: DiscordChatExporter.Gui.zip
+          asset_content_type: application/zip
+
+  notify:
+    needs: deploy
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Get release version
+        id: get_version
+        uses: dawidd6/action-get-tag@v1
+
+      - name: Notify Discord
+        uses: satak/webrequest-action@v1.2.4
+        with:
+          url: ${{ secrets.DISCORD_WEBHOOK }}
+          method: POST
+          headers: |
+            {
+              "ContentType": "application/json; charset=UTF-8"
+            }
+          payload: |
+            {
+              "content": "**DiscordChatExporter** new version released!\nVersion: `${{ steps.get_version.outputs.tag }}`\nChangelog: <https://github.com/Tyrrrz/DiscordChatExporter/blob/${{ steps.get_version.outputs.tag }}/Changelog.md>"
+            }

.gitignore

@@ -19,4 +19,7 @@ bld/
 [Oo]bj/
 
 # Coverage
-*.opencover.xml
+*.opencover.xml
+
+# Secrets
+*.secret

Changelog.md

@@ -1,3 +1,152 @@
+### v2.35.2 (08-Sep-2022)
+
+- Updated usage guide to mention the need to enable "Message Content Intent" to use a bot as a medium for exporting messages.
+- [CLI] Fixed an issue where passing an existing directory as the output path failed when exporting multiple channels (for example, when running `exportdm`). An ambiguous output path will now always be treated as a directory path if that directory already exists. If it doesn't exist, it will be treated as a file path, matching the previous behavior.
+
+### v2.35.1 (26-Aug-2022)
+
+- Added `~` character as an alias for `-` when negating a message filter. This should make it easier to use negated filters from CLI where the dash character already has other meanings.
+- Extended retry logic to encompass all server-side errors from Discord API, instead of only `500 Internal Server Error`.
+- [CLI] Attempt to export multiple channels will now fail if provided with an output path that is neither a directory, nor a file name template. Previously, this resulted in all channels being exported to the same file, overwriting each other.
+- Fixed an issue where a text message filter didn't work if it started with a character that's also the first character in one of the named filters (e.g. `from` or `mentions`).
+- Fixed an issue where a text message filter didn't work correctly if it was enclosed in parentheses.
+- Fixed an issue where categories were displayed alongside regular channels in the channel list, both in GUI and in CLI (when using the `guild` command).
+- [CLI] Fixed an issue where an output path starting with a tilde on Linux was not expanded properly into a full path. (Thanks [@TSRBerry](https://github.com/TSRBerry))
+
+### v2.35 (02-Jul-2022)
+
+- Added support for exporting text chat in voice channels. These channels are now also displayed when browsing in the GUI and in the CLI when executing the `channels` command.
+- [GUI] Direct message channels are now sorted by the timestamp of their last message, similarly to how they appear in the Discord client.
+- [GUI] Removed artificial grouping of direct message channels into "Private" and "Group".
+- [CLI] Added runtime bootstrapper capabilities to the CLI flavor of DiscordChatExporter on Windows. Now, if you attempt to run the application without the required prerequisites installed, you will be provided with an option to install them automatically.
+- [CLI] Fixed outdated information in the usage guide. (Thanks [@Clint Herron](https://github.com/HanClinto))
+- [CLI] Added whitespace padding to the output of `guilds`, `channels`, and `dm` to make the tables look more uniform.
+- [HTML] Added hyperlinks to message timestamps, which allows you to quickly copy a link to a specific message in the export. (Thanks [@Philipp C. Heckel](https://github.com/binwiederhier))
+- [HTML] Added minification. Chat exports in HTML format are now 30-35% smaller than before.
+- [HTML] Added support for rendering embeds of Twitter posts that contain multiple images. Previously, this resulted in multiple separate embeds instead of one.
+- [HTML] Added support for rendering embeds of YouTube Shorts videos.
+- [HTML] Text content is now hidden if the message only contains a link to an image and nothing else. The link itself is resolved as an image embed.
+- [HTML] Fixed an issue where some emoji that included a zero-width-joiner rune were not rendered correctly due to a wrong Twemoji URL being generated. (Thanks [@Ethan](https://github.com/ethanndickson))
+- [HTML] Fixed an issue where replies to a message that contained a quote (i.e. `>`) were not rendered correctly.
+- [HTML] Fixed an issue where code blocks with language highlighting did not have the correct background color.
+- Added file name template token that resolves to the current date (`%d`). (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- Updated the usage guide to replace the instructions for retrieving the user token with those that appear to work for more people.
+- Updated the usage guide to feature the TOS warning more prominently.
+- [Docker] Changed internal working directory from `/app/out` to `/out`. This was an unintended breaking change. Please update your volume binding configuration from `-v /path/on/machine:/app/out` to `-v /path/on/machine:/out`.
+
+### v2.34.1 (01-Jun-2022)
+
+- Improved retry policy to handle more transient errors. This should result in fewer errors exporting a channel due to timeout.
+- Added `has:pin` message filter. You can use it to limit exported messages to those that have been pinned. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- Fixed an issue which caused the export to fail when processing stickers that have no name.
+
+### v2.34 (10-Apr-2022)
+
+- [HTML] Reworked layout to be more consistent with Discord.
+- [HTML] Changed user profile picture dimensions from `128x128` to `512x512`. (Thanks [@Chris Helder](https://github.com/TheDude53))
+- [HTML] Improved image scaling for Chromium-based browsers. This should result in higher quality images across the entire export.
+- [HTML] Hovering over messages will now show short timestamps on the left, indicating the time that the individual messages of the group were sent.
+- [HTML] Using "download media" option will now also download scripts, styles, fonts, and other similar resources used by the export.
+- [HTML] Image attachments will now use the provided description as alt text.
+- [HTML] Fixed a few layout inconsistencies related to embeds.
+- [GUI] Added a few clickable links to the usage guide to make the process of locating tokens easier.
+
+### v2.33.2 (07-Mar-2022)
+
+- Actually fixed it this time.
+
+### v2.33.1 (07-Mar-2022)
+
+- Fixed an issue where the application silently failed to run if the system didn't have .NET Runtime 6.0.2 installed. If you continue seeing this issue, please uninstall all existing .NET runtimes from your computer and then try running the application again.
+
+### v2.33 (06-Mar-2022)
+
+- Added messages informing about war in Ukraine and available ways to help.
+- Added support for rendering stickers in HTML and JSON. Lottie-based stickers currently cannot be displayed in HTML exports (see [#803](https://github.com/Tyrrrz/DiscordChatExporter/issues/803)).
+- Added a new `reaction:` message filter which can be used to check if someone reacted to a message with a specific emoji. You can either pass the emoji name (e.g. `reaction:LUL`) or its ID (e.g. `reaction:41771983429993937`).
+- [GUI] Added auto-detection for dark mode. If your system is configured to prefer dark mode in applications, DiscordChatExporter will use it by default instead of light mode.
+- Fixed an issue which caused the export process to crash when downloading media files with extremely long file extensions. (Thanks [@Tomlacko](https://github.com/Tomlacko))
+- Fixed an issue which caused the export process to crash on invalid mentions.
+- [GUI] Fixed an issue where the time pickers used to specify export ranges always displayed time in 12-hour format, instead of respecting the system locale.
+
+### v2.32 (27-Jan-2022)
+
+- Token kind (user or bot) is now detected automatically. Removed the button to switch token kind in GUI. Option `-b|--bot` in CLI is now deprecated and does nothing.
+- Updated user token extraction guide to reflect the fact that devtools are no longer accessible in the desktop version of Discord client. The recommended workaround is to open Discord in browser. (Thanks [@Dhananjay-JSR](https://github.com/Dhananjay-JSR))
+- Fixed an issue which caused an error when parsing invalid date timestamps. Such timestamps are now rendered as "Invalid date", similarly to how the Discord client does it.
+- Fixed an issue which caused an error when parsing certain embed fields.
+- Fixed an issue which caused an error when parsing a mention to a user that has no username.
+- [GUI] Minor visual fixes.
+
+### v2.31.1 (15-Dec-2021)
+
+- Fixed an issue which caused an error when parsing certain custom emoji reactions.
+- [GUI] Improved user interface.
+
+### v2.31 (06-Dec-2021)
+
+- Changed target runtime of the application (both GUI and CLI) from .NET 3.1 to .NET 6. Those using the GUI version will not need to take any action as the application should install the necessary prerequisites automatically. Those using the CLI version will need to download and install .NET 6 runtime manually [from here](https://dotnet.microsoft.com/download/dotnet/6.0) (look for ".NET Runtime 6.0.x" section on the right and choose the distribution appropriate for your system).
+- [HTML] Updated layout design to match Discord more closely. (Thanks [@Artem](https://github.com/Scarg))
+- [HTML] Fixed an issue where markdown inside channel topic was not rendered correctly. (Thanks [@Emily](https://github.com/emillly-b))
+- [HTML] Fixed an issue where the layout was broken for messages containing text in right-to-left languages. (Thanks [@Emily](https://github.com/emillly-b))
+- Fixed an issue where text filters weren't matching content inside of embeds.
+- [GUI] Fixed a multitude of issues related to the bootstrapper.
+
+### v2.30.1 (28-Aug-2021)
+
+- [HTML] Changed user avatars to render using higher resolution images. (Thanks [@Chris Helder](https://github.com/TheDude53))
+- Fixed an issue where `has:file` message filter was not recognized. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- Fixed an issue where a unix timestamp marker with an invalid offset crashed the export process.
+
+### v2.30 (08-Aug-2021)
+
+- [HTML] Added special casing for Spotify track embeds to render them directly using an embedded player.
+- [HTML] Added special casing for plain image embeds to render them like image attachments.
+- [HTML] Added tooltip text for unix timestamp markers which shows the full date represented by the timestamp, regardless of configured date format.
+- [HTML] Updated the fallback text shown when the referenced message could not be loaded to make it more explicit.
+- [HTML] Updated styling of quoted text in markdown to more closely resemble how it looks in Discord.
+- [HTML] Fixed an issue where some file formats were not correctly recognized as image or video attachments, which affected how they were rendered.
+- [HTML] Fixed an issue where formatting inside named links (e.g. `[**Bold link**](https://example.com)`) was not being parsed.
+- [HTML] Fixed an issue where inline embed fields were missing horizontal spacing between columns.
+- [HTML] Fixed other minor styling issues.
+
+### v2.29 (19-Jul-2021)
+
+- Added support for message filtering, which is accessible as an additional export parameter in the GUI and as the `--filter` option in the CLI. Message filters use a special syntax similar to Discord's search query syntax to allow specifying which messages should be included in the export. For example, you can limit the export to only include messages that contain image attachments (`has:image`) or messages from a certain user (`from:Tyrrrz`) or messages containing certain words (`hello world`), etc. You can also combine filters together (`hi mentions:Tyrrrz`, `from:Tyrrrz | from:96-LB`, `(mentions:Tyrrrz | from:Tyrrrz) has:image`) or negate them (`-has:link`). More thorough documentation coming soon. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- Added support for rendering mentions of voice channels, in addition to text channels.
+- Added support for rendering unix timestamp markers. Currently, style markers are ignored and timestamps are always rendered with the format configured in settings (or provided via `--date-format` option).
+- Updated in-app instructions for obtaining a user token. (Thanks [@Yudi](https://github.com/Yudi) and [@virtuallyvlad](https://github.com/virtuallyvlad))
+- [HTML] Improved visual appearance of the reference symbol (Г-shaped line in replies) to make it more closely resemble Discord's styling.
+- [HTML] Added more specific fallback text used when rendering referenced messages that contain no text content but have attachments or embeds.
+- [HTML] Fixed an issue where a broken embed author icon occupied visual space, ruining the embed layout. (Thanks [@Cliff J.](https://github.com/CliffJameston))
+- [GUI] Improved handling for fatal errors that may occur when attempting to export a channel. These errors are now displayed in a popup, allowing the user to try again instead of having the application crash completely.
+- [CLI] Fixed an issue where an attempt to export a channel resulted in `NotSupportedException` when the default encoding was set to `UTF8`.
+- [CLI] Fixed an issue where providing an incorrectly formatted partition limit via `-p|--partition` option resulted in a non-descriptive and unhelpful error.
+- Improved "Requested resource does not exist" error message by including the ID of the requested resource.
+
+### v2.28 (19-Jun-2021)
+
+- [HTML] Added special casing for YouTube video embeds to render them directly using an embedded player. (Thanks [@quentinmay](https://github.com/quentinmay))
+- [HTML] Added support for rendering standard emoji by code. Such emoji may sometimes be found in messages sent by bots or through webhooks. (Thanks [@CanePlayz](https://github.com/CanePlayz) and [@Lucas LaBuff](https://github.com/96-LB))
+- [HTML] Changed tooltips on standard emoji to show emoji code instead of their raw string representations. (Thanks [@CanePlayz](https://github.com/CanePlayz) and [@Lucas LaBuff](https://github.com/96-LB))
+- [HTML] Added tooltips on individual messages to show when those messages were sent.
+- [HTML] Updated colors and minor styling elements to match Discord's new style direction after rebranding.
+- [HTML] Updated Twemoji URLs to use SVG image variants for better rendering quality.
+- [HTML] Changed user avatar URLs to include predetermined size query parameter for better rendering quality.
+- Changed embed rendering logic to prefer Discord-proxied URLs for external content, in order to avoid unnecessary HTTP requests to third parties.
+- Fixed an issue where exporting with media sometimes resulted in a crash due to lack of permissions to change file attributes. These errors are now ignored, which means that the creation, write, and access dates of downloaded files may sometimes not match the dates provided by Discord's CDN.
+- [HTML] Fixed styling issues when rendering embed footers.
+- [HTML] Fixed an issue where links didn't render properly inside referenced messages.
+- [HTML] Fixed an issue where standalone emoji were incorrectly enlarged inside referenced messages.
+- [HTML] Fixed an issue where clicking on a referenced message revealed spoilers inside of it.
+- [GUI] Fixed an issue where the list of missing components, reported by the prerequisite check at application startup, included Windows updates that were not applicable to the user's system due to the fact that other superseding updates have already been installed. This issue only affected users running DiscordChatExporter on Windows 7.
+- [GUI] Fixed a few other minor issues related to the prerequisite installation window.
+
+### v2.27.1 (08-Jun-2021)
+
+- [GUI] Application will now detect if the required .NET Runtime or any of its prerequisites are missing and prompt the user to download and install them automatically. **Experimental feature, please test it out and report any issues you may find!**
+- [CLI] Fixed an issue where the application crashed when exporting a channel that had square brackets as part of its name or category name. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+
 ### v2.27 (24-Apr-2021)
 
 - Added partitioning by file size. You can now use values such as `10mb` to indicate a size-based cut off point, in addition to values like `10` to indicate a number of messages. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
@@ -73,10 +222,10 @@
 
 ### v2.21 (18-Jul-2020)
 
-- Added a new option that enables self-contained exports for all output formats. You can turn it on in the export setup dialog in GUI or using the `--media` option in CLI. When using this, the application will additionally download any media content directly referenced from the exported file instead of linking back to Discord CDN. The files which are downloaded include: guild icons, user avatars, attachments, embedded images, reaction emojis. Note that only files which are actually referenced by the export are downloaded, which means that, for example, user avatars will not be downloaded when using plain text export format. This option is not meant to enable complete offline viewing for HTML exports, but rather to make it easier to archive media content that may eventually get deleted from Discord servers. Also keep in mind that this option may make the export drastically slower and the total file size larger.
+- Added a new option that enables self-contained exports for all output formats. You can turn it on in the export setup dialog in GUI or using the `--media` option in CLI. When using this, the application will additionally download any media content directly referenced from the exported file instead of linking back to Discord CDN. The files which are downloaded include: guild icons, user avatars, attachments, embedded images, reaction emoji. Note that only files which are actually referenced by the export are downloaded, which means that, for example, user avatars will not be downloaded when using plain text export format. This option is not meant to enable complete offline viewing for HTML exports, but rather to make it easier to archive media content that may eventually get deleted from Discord servers. Also keep in mind that this option may make the export drastically slower and the total file size larger.
 - Changed "discordapp.com" to "discord.com" where applicable as Discord is migrating to a new domain. CDN will remain on "cdn.discordapp.com" for the foreseeable future.
 
-Note that all existing and current HTML exports will likely not render accurately because Discord enabled CORS for their font resources, which prevents them from loading locally. Please refer to [issue #322](https://github.com/Tyrrrz/DiscordChatExporter/issues/322) for discussion on this topic. 
+Note that all existing and current HTML exports will likely not render accurately because Discord enabled CORS for their font resources, which prevents them from loading locally. Please refer to [issue #322](https://github.com/Tyrrrz/DiscordChatExporter/issues/322) for discussion on this topic.
 
 ### v2.20 (27-Apr-2020)
 
@@ -112,7 +261,7 @@ Note that all existing and current HTML exports will likely not render accuratel
 
 - Fixed an issue where an empty file was produced when exporting a channel with no messages (for specified period). With the new behavior, no file will be created and instead a message will be shown to the user informing of the failure.
 - [HTML/TXT] Added message count to the bottom of the file. This number shows how many messages were exported as part of the current file. Prior to 2.16 this number was present along with the rest of the metadata at the top, then removed due to changes in the exporter, and now brought back at the end of the file instead.
-- [HTML] Fixed an issue where some emojis were not properly rendered.
+- [HTML] Fixed an issue where some emoji were not properly rendered.
 - [GUI] Added a setting that lets you configure whether to remember the last used token. Previously it was the default behavior, but now you can disable it if you don't want the token persisted on your system.
 
 ### v2.16 (08-Dec-2019)
@@ -125,7 +274,7 @@ Note that all existing and current HTML exports will likely not render accuratel
 - Fixed various issues that resulted in exceptions during export process.
 - [HTML/TXT] Removed message count from the metadata. Due to the fact that the messages are exported as they are streamed, total number of messages is not known ahead of time.
 - [HTML] Changed default color of the embed color pill to match the theme.
-- [HTML] Changed emoji parser to be less greedy. As a result it should match fewer character sequences that look like emojis but really aren't, but on the other hand it might miss some actual emojis. This means that some standard emojis (i.e. not custom server emojis) may not look like in Discord. This is a compromise I'm willing to take because detecting emojis in text is really hard to get right and not worth it at all.
+- [HTML] Changed emoji parser to be less greedy. As a result it should match fewer character sequences that look like emoji but really aren't, but on the other hand it might miss some actual emoji. This means that some standard emoji (i.e. not custom server emoji) may not look like in Discord. This is a compromise I'm willing to take because detecting emoji in text is really hard to get right and not worth it at all.
 - [HTML] Some other minor styling adjustments.
 - [CSV] Replaced semicolons (;) with (,) as separators.
 
@@ -166,8 +315,8 @@ Please note that CSV export is most likely not going to receive future updates a
 ### v2.12.1 (12-Apr-2019)
 
 - [GUI] Fixed an issue where the app crashed when trying to export multiple channels.
-- [HTML] Fixed an issue where some of the emojis were rendered via Twemoji while Discord renders them as plain text.
-- [HTML] Fixed an issue where emojis weren't jumbo if there were more than one of them.
+- [HTML] Fixed an issue where some of the emoji were rendered via Twemoji while Discord renders them as plain text.
+- [HTML] Fixed an issue where emoji weren't jumbo if there were more than one of them.
 
 ### v2.12 (11-Apr-2019)
 
@@ -189,15 +338,15 @@ Please note that CSV export is most likely not going to receive future updates a
 
 ### v2.10.1 (06-Mar-2019)
 
-- [HTML] Fixed an issue where multiple emojis on a single line would get rendered as one emoji.
+- [HTML] Fixed an issue where multiple emoji on a single line would get rendered as one emoji.
 - [HTML] Fixed an issue where an open square bracket character would incorrectly render as an emoji.
 - [HTML] Added alt text to emoji images so that they will be rendered using default font when Twemoji images are not available.
 
 ### v2.10 (03-Mar-2019)
 
 - [HTML] Reworked the entire markdown parsing engine which fixes numerous rendering inconsistencies (over 15 issues fixed).
-- [HTML] Added support for animated emojis.
-- [HTML] Standard emojis are now rendered using Twemoji, the same image set that Discord uses.
+- [HTML] Added support for animated emoji.
+- [HTML] Standard emoji are now rendered using Twemoji, the same image set that Discord uses.
 - [HTML] Fixed an issue where video attachments would render incorrectly.
 - [HTML] Minor fixes in styling.
 - [GUI] Aggregated export progress is now shown in the taskbar.
@@ -257,7 +406,7 @@ Please note that CSV export is most likely not going to receive future updates a
 - Added support for reactions (HTML only).
 - Selected date range is now shown in the export (HTML and PlainText).
 - Added placeholders for guild icons to display while the icons are loading.
-- Added support for jumbo emojis (custom emojis only).
+- Added support for jumbo emoji (custom emoji only).
 - Added basic retry policy for 429 error responses.
 - Added validation for from/to dates in the UI which prevents choosing invalid date ranges.
 - Added an error message when trying to export a deleted channel.
@@ -281,8 +430,8 @@ Please note that CSV export is most likely not going to receive future updates a
 
 - Improved message date filtering, it's now marginally faster.
 - Fixed underscores not recognized as italics in markdown.
-- Added support for custom emojis.
+- Added support for custom emoji.
 - Added support for user and role mentions.
 - Added support for channel mentions.
 - Fixed text in pre blocks not being wrapped correctly.
-- Added workaround for non-default message types.
+- Added workaround for non-default message types.

Contributing.md

@@ -1,56 +0,0 @@
-# Contributing
-
-DiscordChatExporter accepts contributions in the form of issues and pull requests.
-
-## Creating issues
-
-If you have a feature suggestion or want to report a bug, you are welcome to create an issue.
-
-Guidelines:
-
-- Avoid creating an issue if a similar one already exists. Look through existing open and closed issues first.
-- Keep your issue focused on one specific problem. If you have multiple suggestions or bug reports, please create separate issues for them.
-- Provide a descriptive title for your issue. Don't use generic titles like "A couple suggestions" or "Not working".
-- Provide more context in the body of the issue. If relevant, attach screenshots or screen recordings.
-- Remain civil and respectful when participating in discussions.
-
-## Creating pull requests
-
-If you want to contribute code to the project, you can do so by creating a pull request.
-
-Guidelines:
-
-- Make sure that there is an existing issue that describes the problem solved by your pull request. If there isn't one, please create it first.
-- Add a comment to the issue indicating that you want to submit a pull request for it. This can be a good opportunity to discuss possible solutions, finalize requirements, or ask questions.
-- Keep your pull request focused and as small as possible. If you want to contribute multiple unrelated changes, please create separate pull requests for them.
-- Follow the coding style and conventions already established by the project. When in doubt which style to use, ask in comments to your pull request.
-- If you want to start a discussion regarding a specific change you made, add a review comment to your own code. This can be used to highlight something important or to seek input from others.
-
-## Building the project locally
-
-Prerequisites:
-
-- [.NET 5.0 SDK](https://dotnet.microsoft.com/download/dotnet/5.0)
-- [.NET 3.1 SDK](https://dotnet.microsoft.com/download/dotnet/3.1) (temporarily as the app still targets .NET 3.1, but requires .NET 5.0 to build)
-- _(Optional)_ C#/.NET IDE, such as [JetBrains Rider](https://www.jetbrains.com/rider), [VS Code](https://code.visualstudio.com/docs/languages/csharp), or [Visual Studio](https://visualstudio.microsoft.com).
-
-To build the entire solution run the following command in the root of the repository:
-
-```sh
-> dotnet build
-```
-
-This will generate runtime artifacts for each project:
-
-```plaintext
-./DiscordChatExporter.Gui/bin/[Debug|Release]/[runtime]/*
-./DiscordChatExporter.Cli/bin/[Debug|Release]/[runtime]/*
-```
-
-You can also build and run a specific project directly.
-To do that, navigate to its directory and use `dotnet run`:
-
-```sh
-> cd DiscordChatExporter.Gui
-> dotnet run
-```

Directory.Build.props

@@ -1,13 +1,13 @@
 <Project>
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
-    <Version>2.27</Version>
+    <TargetFramework>net6.0</TargetFramework>
+    <Version>2.35.2</Version>
     <Company>Tyrrrz</Company>
-    <Copyright>Copyright (c) Alexey Golub</Copyright>
+    <Copyright>Copyright (c) Oleksii Holub</Copyright>
     <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>
     <WarningsAsErrors>nullable</WarningsAsErrors>
   </PropertyGroup>
 
-</Project>
+</Project>

DiscordChatExporter.Cli.Tests/DiscordChatExporter.Cli.Tests.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
+    <None Include="*.secret" CopyToOutputDirectory="PreserveNewest" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="AngleSharp" Version="0.17.1" />
+    <PackageReference Include="FluentAssertions" Version="6.7.0" />
+    <PackageReference Include="GitHubActionsTestLogger" Version="2.0.1" PrivateAssets="all" />
+    <PackageReference Include="JsonExtensions" Version="1.2.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.0" />
+    <PackageReference Include="System.Reactive" Version="5.0.0" />
+    <PackageReference Include="xunit" Version="2.4.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" PrivateAssets="all" />
+    <PackageReference Include="coverlet.collector" Version="3.1.2" PrivateAssets="all" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\DiscordChatExporter.Cli\DiscordChatExporter.Cli.csproj" />
+  </ItemGroup>
+
+</Project>

DiscordChatExporter.Cli.Tests/Fixtures/ExportWrapperFixture.cs

@@ -0,0 +1,117 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using AngleSharp.Html.Dom;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Cli.Tests.Infra;
+using DiscordChatExporter.Cli.Tests.Utils;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Exporting;
+using JsonExtensions;
+
+namespace DiscordChatExporter.Cli.Tests.Fixtures;
+
+public class ExportWrapperFixture : IDisposable
+{
+    private string DirPath { get; } = Path.Combine(
+        Path.GetDirectoryName(typeof(ExportWrapperFixture).Assembly.Location) ?? Directory.GetCurrentDirectory(),
+        "ExportCache",
+        Guid.NewGuid().ToString()
+    );
+
+    public ExportWrapperFixture() => DirectoryEx.Reset(DirPath);
+
+    private async ValueTask<string> ExportAsync(Snowflake channelId, ExportFormat format)
+    {
+        var fileName = channelId.ToString() + '.' + format.GetFileExtension();
+        var filePath = Path.Combine(DirPath, fileName);
+
+        // Perform export only if it hasn't been done before
+        if (!File.Exists(filePath))
+        {
+            await new ExportChannelsCommand
+            {
+                Token = Secrets.DiscordToken,
+                ChannelIds = new[] { channelId },
+                ExportFormat = format,
+                OutputPath = filePath
+            }.ExecuteAsync(new FakeConsole());
+        }
+
+        return await File.ReadAllTextAsync(filePath);
+    }
+
+    public async ValueTask<IHtmlDocument> ExportAsHtmlAsync(Snowflake channelId) => Html.Parse(
+        await ExportAsync(channelId, ExportFormat.HtmlDark)
+    );
+
+    public async ValueTask<JsonElement> ExportAsJsonAsync(Snowflake channelId) => Json.Parse(
+        await ExportAsync(channelId, ExportFormat.Json)
+    );
+
+    public async ValueTask<string> ExportAsPlainTextAsync(Snowflake channelId) =>
+        await ExportAsync(channelId, ExportFormat.PlainText);
+
+    public async ValueTask<string> ExportAsCsvAsync(Snowflake channelId) =>
+        await ExportAsync(channelId, ExportFormat.Csv);
+
+    public async ValueTask<IReadOnlyList<IElement>> GetMessagesAsHtmlAsync(Snowflake channelId) =>
+        (await ExportAsHtmlAsync(channelId))
+        .QuerySelectorAll("[data-message-id]")
+        .ToArray();
+
+    public async ValueTask<IReadOnlyList<JsonElement>> GetMessagesAsJsonAsync(Snowflake channelId) =>
+        (await ExportAsJsonAsync(channelId))
+        .GetProperty("messages")
+        .EnumerateArray()
+        .ToArray();
+
+    public async ValueTask<IElement> GetMessageAsHtmlAsync(Snowflake channelId, Snowflake messageId)
+    {
+        var message = (await GetMessagesAsHtmlAsync(channelId))
+            .SingleOrDefault(e =>
+                string.Equals(
+                    e.GetAttribute("data-message-id"),
+                    messageId.ToString(),
+                    StringComparison.OrdinalIgnoreCase
+                )
+            );
+
+        if (message is null)
+        {
+            throw new InvalidOperationException(
+                $"Message '{messageId}' does not exist in the export of channel '{channelId}'."
+            );
+        }
+
+        return message;
+    }
+
+    public async ValueTask<JsonElement> GetMessageAsJsonAsync(Snowflake channelId, Snowflake messageId)
+    {
+        var message = (await GetMessagesAsJsonAsync(channelId))
+            .SingleOrDefault(j =>
+                string.Equals(
+                    j.GetProperty("id").GetString(),
+                    messageId.ToString(),
+                    StringComparison.OrdinalIgnoreCase
+                )
+            );
+
+        if (message.ValueKind == JsonValueKind.Undefined)
+        {
+            throw new InvalidOperationException(
+                $"Message '{messageId}' does not exist in the export of channel '{channelId}'."
+            );
+        }
+
+        return message;
+    }
+
+    public void Dispose() => DirectoryEx.DeleteIfExists(DirPath);
+}

DiscordChatExporter.Cli.Tests/Fixtures/TempOutputFixture.cs

@@ -0,0 +1,22 @@
+using System;
+using System.IO;
+using DiscordChatExporter.Cli.Tests.Utils;
+
+namespace DiscordChatExporter.Cli.Tests.Fixtures;
+
+public class TempOutputFixture : IDisposable
+{
+    public string DirPath { get; } = Path.Combine(
+        Path.GetDirectoryName(typeof(TempOutputFixture).Assembly.Location) ?? Directory.GetCurrentDirectory(),
+        "Temp",
+        Guid.NewGuid().ToString()
+    );
+
+    public TempOutputFixture() => DirectoryEx.Reset(DirPath);
+
+    public string GetTempFilePath(string fileName) => Path.Combine(DirPath, fileName);
+
+    public string GetTempFilePath() => GetTempFilePath(Guid.NewGuid() + ".tmp");
+
+    public void Dispose() => DirectoryEx.DeleteIfExists(DirPath);
+}

DiscordChatExporter.Cli.Tests/Infra/Secrets.cs

@@ -0,0 +1,26 @@
+using System;
+using System.IO;
+
+namespace DiscordChatExporter.Cli.Tests.Infra;
+
+internal static class Secrets
+{
+    private static readonly Lazy<string> DiscordTokenLazy = new(() =>
+    {
+        var fromEnvironment = Environment.GetEnvironmentVariable("DISCORD_TOKEN");
+        if (!string.IsNullOrWhiteSpace(fromEnvironment))
+            return fromEnvironment;
+
+        var secretFilePath = Path.Combine(
+            Path.GetDirectoryName(typeof(Secrets).Assembly.Location) ?? Directory.GetCurrentDirectory(),
+            "DiscordToken.secret"
+        );
+
+        if (File.Exists(secretFilePath))
+            return File.ReadAllText(secretFilePath);
+
+        throw new InvalidOperationException("Discord token not provided for tests.");
+    });
+
+    public static string DiscordToken => DiscordTokenLazy.Value;
+}

DiscordChatExporter.Cli.Tests/Readme.md

@@ -0,0 +1,13 @@
+# DiscordChatExporter Tests
+
+This test suite runs against a real Discord server, specifically created to exercise different behaviors required by the test scenarios.
+In order to run these tests locally, you need to join the test server and configure your authentication token.
+
+1. [Join the test server](https://discord.gg/eRV8Vap5bm)
+2. Locate your Discord authentication token
+3. Specify your token using a file or an environment variable:
+    - **Using a file**: put your token in a new `DiscordToken.secret` file created in this directory
+    - **Using an environment variable**: set `DISCORD_TOKEN` variable to your token
+4. Run the tests: `dotnet test`
+
+> If you want to add a new test case, please let me know and I will give you the required permissions

DiscordChatExporter.Cli.Tests/Specs/CsvWriting/ContentSpecs.cs

@@ -0,0 +1,37 @@
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.CsvWriting;
+
+public class ContentSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public ContentSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Messages_are_exported_correctly()
+    {
+        // Act
+        var document = await _exportWrapper.ExportAsCsvAsync(ChannelIds.DateRangeTestCases);
+
+        // Assert
+        document.Should().ContainAll(
+            "Tyrrrz#5447",
+            "Hello world",
+            "Goodbye world",
+            "Foo bar",
+            "Hurdle Durdle",
+            "One",
+            "Two",
+            "Three",
+            "Yeet"
+        );
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/DateRangeSpecs.cs

@@ -0,0 +1,157 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.Infra;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Exporting;
+using FluentAssertions;
+using JsonExtensions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs;
+
+public class DateRangeSpecs : IClassFixture<TempOutputFixture>
+{
+    private readonly TempOutputFixture _tempOutput;
+
+    public DateRangeSpecs(TempOutputFixture tempOutput)
+    {
+        _tempOutput = tempOutput;
+    }
+
+    [Fact]
+    public async Task Messages_filtered_after_specific_date_only_include_messages_sent_after_that_date()
+    {
+        // Arrange
+        var after = new DateTimeOffset(2021, 07, 24, 0, 0, 0, TimeSpan.Zero);
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.DateRangeTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            After = Snowflake.FromDate(after)
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        var timestamps = Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("timestamp").GetDateTimeOffset())
+            .ToArray();
+
+        timestamps.All(t => t > after).Should().BeTrue();
+
+        timestamps.Should().BeEquivalentTo(new[]
+        {
+            new DateTimeOffset(2021, 07, 24, 13, 49, 13, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 24, 14, 52, 38, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 24, 14, 52, 39, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 24, 14, 52, 40, TimeSpan.Zero),
+            new DateTimeOffset(2021, 09, 08, 14, 26, 35, TimeSpan.Zero)
+        }, o =>
+        {
+            return o
+                .Using<DateTimeOffset>(ctx =>
+                    ctx.Subject.Should().BeCloseTo(ctx.Expectation, TimeSpan.FromSeconds(1))
+                )
+                .WhenTypeIs<DateTimeOffset>();
+        });
+    }
+
+    [Fact]
+    public async Task Messages_filtered_before_specific_date_only_include_messages_sent_before_that_date()
+    {
+        // Arrange
+        var before = new DateTimeOffset(2021, 07, 24, 0, 0, 0, TimeSpan.Zero);
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.DateRangeTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            Before = Snowflake.FromDate(before)
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        var timestamps = Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("timestamp").GetDateTimeOffset())
+            .ToArray();
+
+        timestamps.All(t => t < before).Should().BeTrue();
+
+        timestamps.Should().BeEquivalentTo(new[]
+        {
+            new DateTimeOffset(2021, 07, 19, 13, 34, 18, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 19, 15, 58, 48, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 19, 17, 23, 58, TimeSpan.Zero)
+        }, o =>
+        {
+            return o
+                .Using<DateTimeOffset>(ctx =>
+                    ctx.Subject.Should().BeCloseTo(ctx.Expectation, TimeSpan.FromSeconds(1))
+                )
+                .WhenTypeIs<DateTimeOffset>();
+        });
+    }
+
+    [Fact]
+    public async Task Messages_filtered_between_specific_dates_only_include_messages_sent_between_those_dates()
+    {
+        // Arrange
+        var after = new DateTimeOffset(2021, 07, 24, 0, 0, 0, TimeSpan.Zero);
+        var before = new DateTimeOffset(2021, 08, 01, 0, 0, 0, TimeSpan.Zero);
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.DateRangeTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            Before = Snowflake.FromDate(before),
+            After = Snowflake.FromDate(after)
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        var timestamps = Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("timestamp").GetDateTimeOffset())
+            .ToArray();
+
+        timestamps.All(t => t < before && t > after).Should().BeTrue();
+
+        timestamps.Should().BeEquivalentTo(new[]
+        {
+            new DateTimeOffset(2021, 07, 24, 13, 49, 13, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 24, 14, 52, 38, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 24, 14, 52, 39, TimeSpan.Zero),
+            new DateTimeOffset(2021, 07, 24, 14, 52, 40, TimeSpan.Zero)
+        }, o =>
+        {
+            return o
+                .Using<DateTimeOffset>(ctx =>
+                    ctx.Subject.Should().BeCloseTo(ctx.Expectation, TimeSpan.FromSeconds(1))
+                )
+                .WhenTypeIs<DateTimeOffset>();
+        });
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/FilterSpecs.cs

@@ -0,0 +1,155 @@
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.Infra;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Exporting;
+using DiscordChatExporter.Core.Exporting.Filtering;
+using FluentAssertions;
+using JsonExtensions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs;
+
+public class FilterSpecs : IClassFixture<TempOutputFixture>
+{
+    private readonly TempOutputFixture _tempOutput;
+
+    public FilterSpecs(TempOutputFixture tempOutput)
+    {
+        _tempOutput = tempOutput;
+    }
+
+    [Fact]
+    public async Task Messages_filtered_by_text_only_include_messages_that_contain_that_text()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.FilterTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            MessageFilter = MessageFilter.Parse("some text")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("content").GetString())
+            .Should()
+            .ContainSingle("Some random text");
+    }
+
+    [Fact]
+    public async Task Messages_filtered_by_author_only_include_messages_sent_by_that_author()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.FilterTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            MessageFilter = MessageFilter.Parse("from:Tyrrrz")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("author").GetProperty("name").GetString())
+            .Should()
+            .AllBe("Tyrrrz");
+    }
+
+    [Fact]
+    public async Task Messages_filtered_by_content_only_include_messages_that_have_that_content()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.FilterTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            MessageFilter = MessageFilter.Parse("has:image")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("content").GetString())
+            .Should()
+            .ContainSingle("This has image");
+    }
+
+    [Fact]
+    public async Task Messages_filtered_by_pin_only_include_messages_that_have_been_pinned()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.FilterTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            MessageFilter = MessageFilter.Parse("has:pin")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("content").GetString())
+            .Should()
+            .ContainSingle("This is pinned");
+    }
+
+    [Fact]
+    public async Task Messages_filtered_by_mention_only_include_messages_that_have_that_mention()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.FilterTestCases },
+            ExportFormat = ExportFormat.Json,
+            OutputPath = filePath,
+            MessageFilter = MessageFilter.Parse("mentions:Tyrrrz")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Json
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .GetProperty("messages")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("content").GetString())
+            .Should()
+            .ContainSingle("This has mention");
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/AttachmentSpecs.cs

@@ -0,0 +1,106 @@
+using System.Linq;
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class AttachmentSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public AttachmentSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Message_with_a_generic_attachment_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885587844989612074")
+        );
+
+        // Assert
+        message.Text().Should().ContainAll(
+            "Generic file attachment",
+            "Test.txt",
+            "11 bytes"
+        );
+
+        message
+            .QuerySelectorAll("a")
+            .Select(e => e.GetAttribute("href"))
+            .Should()
+            .Contain(
+                "https://cdn.discordapp.com/attachments/885587741654536192/885587844964417596/Test.txt"
+            );
+    }
+
+    [Fact]
+    public async Task Message_with_an_image_attachment_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885654862656843786")
+        );
+
+        // Assert
+        message.Text().Should().Contain("Image attachment");
+
+        message
+            .QuerySelectorAll("img")
+            .Select(e => e.GetAttribute("src"))
+            .Should()
+            .Contain(
+                "https://cdn.discordapp.com/attachments/885587741654536192/885654862430359613/bird-thumbnail.png"
+            );
+    }
+
+    [Fact]
+    public async Task Message_with_a_video_attachment_is_rendered_correctly()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/333
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885655761919836171")
+        );
+
+        // Assert
+        message.Text().Should().Contain("Video attachment");
+
+        var videoUrl = message.QuerySelector("video source")?.GetAttribute("src");
+        videoUrl.Should().Be(
+            "https://cdn.discordapp.com/attachments/885587741654536192/885655761512968233/file_example_MP4_640_3MG.mp4"
+        );
+    }
+
+    [Fact]
+    public async Task Message_with_an_audio_attachment_is_rendered_correctly()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/333
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885656175620808734")
+        );
+
+        // Assert
+        message.Text().Should().Contain("Audio attachment");
+
+        var audioUrl = message.QuerySelector("audio source")?.GetAttribute("src");
+        audioUrl.Should().Be(
+            "https://cdn.discordapp.com/attachments/885587741654536192/885656175348187146/file_example_MP3_1MG.mp3"
+        );
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/ContentSpecs.cs

@@ -0,0 +1,49 @@
+using System.Linq;
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class ContentSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public ContentSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Messages_are_exported_correctly()
+    {
+        // Act
+        var messages = await _exportWrapper.GetMessagesAsHtmlAsync(ChannelIds.DateRangeTestCases);
+
+        // Assert
+        messages.Select(e => e.GetAttribute("data-message-id")).Should().Equal(
+            "866674314627121232",
+            "866710679758045195",
+            "866732113319428096",
+            "868490009366396958",
+            "868505966528835604",
+            "868505969821364245",
+            "868505973294268457",
+            "885169254029213696"
+        );
+
+        messages.SelectMany(e => e.Text()).Should().ContainInOrder(
+            "Hello world",
+            "Goodbye world",
+            "Foo bar",
+            "Hurdle Durdle",
+            "One",
+            "Two",
+            "Three",
+            "Yeet"
+        );
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/EmbedSpecs.cs

@@ -0,0 +1,134 @@
+using System.Linq;
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class EmbedSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public EmbedSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Message_with_an_embed_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("866769910729146400")
+        );
+
+        // Assert
+        message.Text().Should().ContainAll(
+            "Embed author",
+            "Embed title",
+            "Embed description",
+            "Field 1", "Value 1",
+            "Field 2", "Value 2",
+            "Field 3", "Value 3",
+            "Embed footer"
+        );
+    }
+
+    [Fact]
+    public async Task Message_containing_an_image_link_is_rendered_with_an_image_embed()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/537
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("991768701126852638")
+        );
+
+        // Assert
+        message
+            .QuerySelectorAll("img")
+            .Select(e => e.GetAttribute("src"))
+            .Should()
+            .Contain("https://i.redd.it/f8w05ja8s4e61.png");
+    }
+
+    [Fact]
+    public async Task Message_containing_an_image_link_and_nothing_else_is_rendered_without_text_content()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/682
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("991768701126852638")
+        );
+
+        // Assert
+        var content = message.QuerySelector(".chatlog__content")?.Text();
+        content.Should().BeNullOrEmpty();
+    }
+
+    [Fact]
+    public async Task Message_containing_a_Spotify_track_link_is_rendered_with_a_track_embed()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/657
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("867886632203976775")
+        );
+
+        // Assert
+        var iframeUrl = message.QuerySelector("iframe")?.GetAttribute("src");
+        iframeUrl.Should().Be("https://open.spotify.com/embed/track/1LHZMWefF9502NPfArRfvP");
+    }
+
+    [Fact]
+    public async Task Message_containing_a_YouTube_video_link_is_rendered_with_a_video_embed()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/570
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("866472508588294165")
+        );
+
+        // Assert
+        var iframeUrl = message.QuerySelector("iframe")?.GetAttribute("src");
+        iframeUrl.Should().Be("https://www.youtube.com/embed/qOWW4OlgbvE");
+    }
+
+    [Fact]
+    public async Task Message_containing_a_Twitter_post_link_with_multiple_images_is_rendered_as_a_single_embed()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/695
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("991757444017557665")
+        );
+
+        // Assert
+        message
+            .QuerySelectorAll("img")
+            .Select(e => e.GetAttribute("src"))
+            .Should()
+            .ContainInOrder(
+                "https://images-ext-1.discordapp.net/external/-n--xW3EHH_3jlrheVkMXHCM7T86b5Ty4-MzXCT4m1Q/https/pbs.twimg.com/media/FVYIzYPWAAAMBqZ.png",
+                "https://images-ext-2.discordapp.net/external/z5nEmGeEldV-kswydGLhqUsFHbb5AWHtdvc9XT6N5rE/https/pbs.twimg.com/media/FVYJBWJWAAMNAx2.png",
+                "https://images-ext-2.discordapp.net/external/gnip03SawMB6uZLagN5sRDpA_1Ap1CcEhMbJfK1z6WQ/https/pbs.twimg.com/media/FVYJHiRX0AANZcz.png",
+                "https://images-ext-2.discordapp.net/external/jl1v6cCbLaGmiwmKU-ZkXnF4cFsJ39f9A3-oEdqPdZs/https/pbs.twimg.com/media/FVYJNZNXwAAPnVG.png"
+            );
+
+        message.QuerySelectorAll(".chatlog__embed").Should().ContainSingle();
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/GroupingSpecs.cs

@@ -0,0 +1,79 @@
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.Infra;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Cli.Tests.Utils;
+using DiscordChatExporter.Core.Exporting;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class GroupingSpecs : IClassFixture<TempOutputFixture>
+{
+    private readonly TempOutputFixture _tempOutput;
+
+    public GroupingSpecs(TempOutputFixture tempOutput)
+    {
+        _tempOutput = tempOutput;
+    }
+
+    [Fact]
+    public async Task Messages_are_grouped_correctly()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/152
+
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.GroupingTestCases },
+            ExportFormat = ExportFormat.HtmlDark,
+            OutputPath = filePath
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        var messageGroups = Html
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .QuerySelectorAll(".chatlog__message-group");
+
+        messageGroups.Should().HaveCount(2);
+
+        messageGroups[0]
+            .QuerySelectorAll(".chatlog__content")
+            .Select(e => e.Text())
+            .Should()
+            .ContainInOrder(
+                "First",
+                "Second",
+                "Third",
+                "Fourth",
+                "Fifth",
+                "Sixth",
+                "Seventh",
+                "Eighth",
+                "Ninth",
+                "Tenth"
+            );
+
+        messageGroups[1]
+            .QuerySelectorAll(".chatlog__content")
+            .Select(e => e.Text())
+            .Should()
+            .ContainInOrder(
+                "Eleventh",
+                "Twelveth",
+                "Thirteenth",
+                "Fourteenth",
+                "Fifteenth"
+            );
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/MentionSpecs.cs

@@ -0,0 +1,72 @@
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class MentionSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public MentionSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task User_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866458840245076028")
+        );
+
+        // Assert
+        message.Text().Should().Contain("User mention: @Tyrrrz");
+        message.InnerHtml.Should().Contain("Tyrrrz#5447");
+    }
+
+    [Fact]
+    public async Task Text_channel_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866459040480624680")
+        );
+
+        // Assert
+        message.Text().Should().Contain("Text channel mention: #mention-tests");
+    }
+
+    [Fact]
+    public async Task Voice_channel_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866459175462633503")
+        );
+
+        // Assert
+        message.Text().Should().Contain("Voice channel mention: 🔊chaos-vc");
+    }
+
+    [Fact]
+    public async Task Role_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866459254693429258")
+        );
+
+        // Assert
+        message.Text().Should().Contain("Role mention: @Role 1");
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/ReplySpecs.cs

@@ -0,0 +1,67 @@
+using System.Threading.Tasks;
+using AngleSharp.Dom;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class ReplySpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public ReplySpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Reply_to_a_normal_message_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.ReplyTestCases,
+            Snowflake.Parse("866460738239725598")
+        );
+
+        // Assert
+        message.Text().Should().Contain("reply to original");
+        message.QuerySelector(".chatlog__reference-link")?.Text().Should().Contain("original");
+    }
+
+    [Fact]
+    public async Task Reply_to_a_deleted_message_is_rendered_correctly()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/645
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.ReplyTestCases,
+            Snowflake.Parse("866460975388819486")
+        );
+
+        // Assert
+        message.Text().Should().Contain("reply to deleted");
+        message.QuerySelector(".chatlog__reference-link")?.Text().Should().Contain(
+            "Original message was deleted or could not be loaded."
+        );
+    }
+
+    [Fact]
+    public async Task Reply_to_an_empty_message_with_attachment_is_rendered_correctly()
+    {
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/634
+
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.ReplyTestCases,
+            Snowflake.Parse("866462470335627294")
+        );
+
+        // Assert
+        message.Text().Should().Contain("reply to attachment");
+        message.QuerySelector(".chatlog__reference-link")?.Text().Should().Contain("Click to see attachment");
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/HtmlWriting/StickerSpecs.cs

@@ -0,0 +1,46 @@
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.HtmlWriting;
+
+public class StickerSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public StickerSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Message_with_a_PNG_based_sticker_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.StickerTestCases,
+            Snowflake.Parse("939670623158943754")
+        );
+
+        // Assert
+        var stickerUrl = message.QuerySelector("[title='rock'] img")?.GetAttribute("src");
+        stickerUrl.Should().Be("https://discord.com/stickers/904215665597120572.png");
+    }
+
+    [Fact]
+    public async Task Message_with_a_Lottie_based_sticker_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsHtmlAsync(
+            ChannelIds.StickerTestCases,
+            Snowflake.Parse("939670526517997590")
+        );
+
+        // Assert
+        var stickerUrl = message.QuerySelector("[title='Yikes'] [data-source]")?.GetAttribute("data-source");
+        stickerUrl.Should().Be("https://discord.com/stickers/816087132447178774.json");
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/JsonWriting/AttachmentSpecs.cs

@@ -0,0 +1,103 @@
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.JsonWriting;
+
+public class AttachmentSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public AttachmentSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Message_with_a_generic_attachment_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885587844989612074")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Generic file attachment");
+
+        var attachments = message.GetProperty("attachments").EnumerateArray().ToArray();
+        attachments.Should().HaveCount(1);
+        attachments.Single().GetProperty("url").GetString().Should().Be(
+            "https://cdn.discordapp.com/attachments/885587741654536192/885587844964417596/Test.txt"
+        );
+        attachments.Single().GetProperty("fileName").GetString().Should().Be("Test.txt");
+        attachments.Single().GetProperty("fileSizeBytes").GetInt64().Should().Be(11);
+    }
+
+    [Fact]
+    public async Task Message_with_an_image_attachment_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885654862656843786")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Image attachment");
+
+        var attachments = message.GetProperty("attachments").EnumerateArray().ToArray();
+        attachments.Should().HaveCount(1);
+        attachments.Single().GetProperty("url").GetString().Should().Be(
+            "https://cdn.discordapp.com/attachments/885587741654536192/885654862430359613/bird-thumbnail.png"
+        );
+        attachments.Single().GetProperty("fileName").GetString().Should().Be("bird-thumbnail.png");
+        attachments.Single().GetProperty("fileSizeBytes").GetInt64().Should().Be(466335);
+    }
+
+    [Fact]
+    public async Task Message_with_a_video_attachment_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885655761919836171")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Video attachment");
+
+        var attachments = message.GetProperty("attachments").EnumerateArray().ToArray();
+        attachments.Should().HaveCount(1);
+        attachments.Single().GetProperty("url").GetString().Should().Be(
+            "https://cdn.discordapp.com/attachments/885587741654536192/885655761512968233/file_example_MP4_640_3MG.mp4"
+        );
+        attachments.Single().GetProperty("fileName").GetString().Should().Be("file_example_MP4_640_3MG.mp4");
+        attachments.Single().GetProperty("fileSizeBytes").GetInt64().Should().Be(3114374);
+    }
+
+    [Fact]
+    public async Task Message_with_an_audio_attachment_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.AttachmentTestCases,
+            Snowflake.Parse("885656175620808734")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Audio attachment");
+
+        var attachments = message.GetProperty("attachments").EnumerateArray().ToArray();
+        attachments.Should().HaveCount(1);
+        attachments.Single().GetProperty("url").GetString().Should().Be(
+            "https://cdn.discordapp.com/attachments/885587741654536192/885656175348187146/file_example_MP3_1MG.mp3"
+        );
+        attachments.Single().GetProperty("fileName").GetString().Should().Be("file_example_MP3_1MG.mp3");
+        attachments.Single().GetProperty("fileSizeBytes").GetInt64().Should().Be(1087849);
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/JsonWriting/ContentSpecs.cs

@@ -0,0 +1,48 @@
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.JsonWriting;
+
+public class ContentSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public ContentSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Messages_are_exported_correctly()
+    {
+        // Act
+        var messages = await _exportWrapper.GetMessagesAsJsonAsync(ChannelIds.DateRangeTestCases);
+
+        // Assert
+        messages.Select(j => j.GetProperty("id").GetString()).Should().Equal(
+            "866674314627121232",
+            "866710679758045195",
+            "866732113319428096",
+            "868490009366396958",
+            "868505966528835604",
+            "868505969821364245",
+            "868505973294268457",
+            "885169254029213696"
+        );
+
+        messages.Select(j => j.GetProperty("content").GetString()).Should().Equal(
+            "Hello world",
+            "Goodbye world",
+            "Foo bar",
+            "Hurdle Durdle",
+            "One",
+            "Two",
+            "Three",
+            "Yeet"
+        );
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/JsonWriting/EmbedSpecs.cs

@@ -0,0 +1,63 @@
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.JsonWriting;
+
+public class EmbedSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public EmbedSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Message_with_an_embed_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.EmbedTestCases,
+            Snowflake.Parse("866769910729146400")
+        );
+
+        // Assert
+        var embed = message.GetProperty("embeds").EnumerateArray().Single();
+        embed.GetProperty("title").GetString().Should().Be("Embed title");
+        embed.GetProperty("url").GetString().Should().Be("https://example.com");
+        embed.GetProperty("timestamp").GetString().Should().Be("2021-07-14T21:00:00+00:00");
+        embed.GetProperty("description").GetString().Should().Be("**Embed** _description_");
+        embed.GetProperty("color").GetString().Should().Be("#58B9FF");
+
+        var embedAuthor = embed.GetProperty("author");
+        embedAuthor.GetProperty("name").GetString().Should().Be("Embed author");
+        embedAuthor.GetProperty("url").GetString().Should().Be("https://example.com/author");
+        embedAuthor.GetProperty("iconUrl").GetString().Should().NotBeNullOrWhiteSpace();
+
+        var embedThumbnail = embed.GetProperty("thumbnail");
+        embedThumbnail.GetProperty("url").GetString().Should().NotBeNullOrWhiteSpace();
+        embedThumbnail.GetProperty("width").GetInt32().Should().Be(120);
+        embedThumbnail.GetProperty("height").GetInt32().Should().Be(120);
+
+        var embedFooter = embed.GetProperty("footer");
+        embedFooter.GetProperty("text").GetString().Should().Be("Embed footer");
+        embedFooter.GetProperty("iconUrl").GetString().Should().NotBeNullOrWhiteSpace();
+
+        var embedFields = embed.GetProperty("fields").EnumerateArray().ToArray();
+        embedFields.Should().HaveCount(3);
+        embedFields[0].GetProperty("name").GetString().Should().Be("Field 1");
+        embedFields[0].GetProperty("value").GetString().Should().Be("Value 1");
+        embedFields[0].GetProperty("isInline").GetBoolean().Should().BeTrue();
+        embedFields[1].GetProperty("name").GetString().Should().Be("Field 2");
+        embedFields[1].GetProperty("value").GetString().Should().Be("Value 2");
+        embedFields[1].GetProperty("isInline").GetBoolean().Should().BeTrue();
+        embedFields[2].GetProperty("name").GetString().Should().Be("Field 3");
+        embedFields[2].GetProperty("value").GetString().Should().Be("Value 3");
+        embedFields[2].GetProperty("isInline").GetBoolean().Should().BeTrue();
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/JsonWriting/MentionSpecs.cs

@@ -0,0 +1,78 @@
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.JsonWriting;
+
+public class MentionSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public MentionSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task User_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866458840245076028")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("User mention: @Tyrrrz");
+
+        message
+            .GetProperty("mentions")
+            .EnumerateArray()
+            .Select(j => j.GetProperty("id").GetString())
+            .Should()
+            .Contain("128178626683338752");
+    }
+
+    [Fact]
+    public async Task Text_channel_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866459040480624680")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Text channel mention: #mention-tests");
+    }
+
+    [Fact]
+    public async Task Voice_channel_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866459175462633503")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Voice channel mention: #chaos-vc [voice]");
+    }
+
+    [Fact]
+    public async Task Role_mention_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.MentionTestCases,
+            Snowflake.Parse("866459254693429258")
+        );
+
+        // Assert
+        message.GetProperty("content").GetString().Should().Be("Role mention: @Role 1");
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/JsonWriting/StickerSpecs.cs

@@ -0,0 +1,61 @@
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Discord;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.JsonWriting;
+
+public class StickerSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public StickerSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Message_with_a_PNG_based_sticker_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.StickerTestCases,
+            Snowflake.Parse("939670623158943754")
+        );
+
+        // Assert
+        var sticker = message
+            .GetProperty("stickers")
+            .EnumerateArray()
+            .Single();
+
+        sticker.GetProperty("id").GetString().Should().Be("904215665597120572");
+        sticker.GetProperty("name").GetString().Should().Be("rock");
+        sticker.GetProperty("format").GetString().Should().Be("PngAnimated");
+        sticker.GetProperty("sourceUrl").GetString().Should().Be("https://discord.com/stickers/904215665597120572.png");
+    }
+
+    [Fact]
+    public async Task Message_with_a_Lottie_based_sticker_is_rendered_correctly()
+    {
+        // Act
+        var message = await _exportWrapper.GetMessageAsJsonAsync(
+            ChannelIds.StickerTestCases,
+            Snowflake.Parse("939670526517997590")
+        );
+
+        // Assert
+        var sticker = message
+            .GetProperty("stickers")
+            .EnumerateArray()
+            .Single();
+
+        sticker.GetProperty("id").GetString().Should().Be("816087132447178774");
+        sticker.GetProperty("name").GetString().Should().Be("Yikes");
+        sticker.GetProperty("format").GetString().Should().Be("Lottie");
+        sticker.GetProperty("sourceUrl").GetString().Should().Be("https://discord.com/stickers/816087132447178774.json");
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/PartitioningSpecs.cs

@@ -0,0 +1,71 @@
+using System.IO;
+using System.Threading.Tasks;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.Infra;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Core.Exporting;
+using DiscordChatExporter.Core.Exporting.Partitioning;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs;
+
+public class PartitioningSpecs : IClassFixture<TempOutputFixture>
+{
+    private readonly TempOutputFixture _tempOutput;
+
+    public PartitioningSpecs(TempOutputFixture tempOutput)
+    {
+        _tempOutput = tempOutput;
+    }
+
+    [Fact]
+    public async Task Messages_partitioned_by_count_are_split_into_a_corresponding_number_of_files()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+        var fileNameWithoutExt = Path.GetFileNameWithoutExtension(filePath);
+        var dirPath = Path.GetDirectoryName(filePath) ?? Directory.GetCurrentDirectory();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.DateRangeTestCases },
+            ExportFormat = ExportFormat.HtmlDark,
+            OutputPath = filePath,
+            PartitionLimit = PartitionLimit.Parse("3")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Directory.EnumerateFiles(dirPath, fileNameWithoutExt + "*")
+            .Should()
+            .HaveCount(3);
+    }
+
+    [Fact]
+    public async Task Messages_partitioned_by_file_size_are_split_into_a_corresponding_number_of_files()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+        var fileNameWithoutExt = Path.GetFileNameWithoutExtension(filePath);
+        var dirPath = Path.GetDirectoryName(filePath) ?? Directory.GetCurrentDirectory();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.DateRangeTestCases },
+            ExportFormat = ExportFormat.HtmlDark,
+            OutputPath = filePath,
+            PartitionLimit = PartitionLimit.Parse("1kb")
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Directory.EnumerateFiles(dirPath, fileNameWithoutExt + "*")
+            .Should()
+            .HaveCount(8);
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/PlainTextWriting/ContentSpecs.cs

@@ -0,0 +1,37 @@
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.TestData;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs.PlainTextWriting;
+
+public class ContentSpecs : IClassFixture<ExportWrapperFixture>
+{
+    private readonly ExportWrapperFixture _exportWrapper;
+
+    public ContentSpecs(ExportWrapperFixture exportWrapper)
+    {
+        _exportWrapper = exportWrapper;
+    }
+
+    [Fact]
+    public async Task Messages_are_exported_correctly()
+    {
+        // Act
+        var document = await _exportWrapper.ExportAsPlainTextAsync(ChannelIds.DateRangeTestCases);
+
+        // Assert
+        document.Should().ContainAll(
+            "Tyrrrz#5447",
+            "Hello world",
+            "Goodbye world",
+            "Foo bar",
+            "Hurdle Durdle",
+            "One",
+            "Two",
+            "Three",
+            "Yeet"
+        );
+    }
+}

DiscordChatExporter.Cli.Tests/Specs/SelfContainedSpecs.cs

@@ -0,0 +1,52 @@
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Cli.Tests.Fixtures;
+using DiscordChatExporter.Cli.Tests.Infra;
+using DiscordChatExporter.Cli.Tests.TestData;
+using DiscordChatExporter.Cli.Tests.Utils;
+using DiscordChatExporter.Core.Exporting;
+using FluentAssertions;
+using Xunit;
+
+namespace DiscordChatExporter.Cli.Tests.Specs;
+
+public class SelfContainedSpecs : IClassFixture<TempOutputFixture>
+{
+    private readonly TempOutputFixture _tempOutput;
+
+    public SelfContainedSpecs(TempOutputFixture tempOutput)
+    {
+        _tempOutput = tempOutput;
+    }
+
+    [Fact]
+    public async Task Messages_in_self_contained_export_only_reference_local_file_resources()
+    {
+        // Arrange
+        var filePath = _tempOutput.GetTempFilePath();
+        var dirPath = Path.GetDirectoryName(filePath) ?? Directory.GetCurrentDirectory();
+
+        // Act
+        await new ExportChannelsCommand
+        {
+            Token = Secrets.DiscordToken,
+            ChannelIds = new[] { ChannelIds.SelfContainedTestCases },
+            ExportFormat = ExportFormat.HtmlDark,
+            OutputPath = filePath,
+            ShouldDownloadMedia = true
+        }.ExecuteAsync(new FakeConsole());
+
+        // Assert
+        Html
+            .Parse(await File.ReadAllTextAsync(filePath))
+            .QuerySelectorAll("body [src]")
+            .Select(e => e.GetAttribute("src")!)
+            .Select(f => Path.GetFullPath(f, dirPath))
+            .All(File.Exists)
+            .Should()
+            .BeTrue();
+    }
+}

DiscordChatExporter.Cli.Tests/TestData/ChannelIds.cs

@@ -0,0 +1,24 @@
+using DiscordChatExporter.Core.Discord;
+
+namespace DiscordChatExporter.Cli.Tests.TestData;
+
+public static class ChannelIds
+{
+    public static Snowflake AttachmentTestCases { get; } = Snowflake.Parse("885587741654536192");
+
+    public static Snowflake DateRangeTestCases { get; } = Snowflake.Parse("866674248747319326");
+
+    public static Snowflake EmbedTestCases { get; } = Snowflake.Parse("866472452459462687");
+
+    public static Snowflake GroupingTestCases { get; } = Snowflake.Parse("992092091545034842");
+
+    public static Snowflake FilterTestCases { get; } = Snowflake.Parse("866744075033641020");
+
+    public static Snowflake MentionTestCases { get; } = Snowflake.Parse("866458801389174794");
+
+    public static Snowflake ReplyTestCases { get; } = Snowflake.Parse("866459871934677052");
+
+    public static Snowflake SelfContainedTestCases { get; } = Snowflake.Parse("887441432678379560");
+
+    public static Snowflake StickerTestCases { get; } = Snowflake.Parse("939668868253769729");
+}

DiscordChatExporter.Cli.Tests/Utils/DirectoryEx.cs

@@ -0,0 +1,23 @@
+using System.IO;
+
+namespace DiscordChatExporter.Cli.Tests.Utils;
+
+internal static class DirectoryEx
+{
+    public static void DeleteIfExists(string dirPath, bool recursive = true)
+    {
+        try
+        {
+            Directory.Delete(dirPath, recursive);
+        }
+        catch (DirectoryNotFoundException)
+        {
+        }
+    }
+
+    public static void Reset(string dirPath)
+    {
+        DeleteIfExists(dirPath);
+        Directory.CreateDirectory(dirPath);
+    }
+}

DiscordChatExporter.Cli.Tests/Utils/Html.cs

@@ -0,0 +1,11 @@
+using AngleSharp.Html.Dom;
+using AngleSharp.Html.Parser;
+
+namespace DiscordChatExporter.Cli.Tests.Utils;
+
+internal static class Html
+{
+    private static readonly IHtmlParser Parser = new HtmlParser();
+
+    public static IHtmlDocument Parse(string source) => Parser.ParseDocument(source);
+}

DiscordChatExporter.Cli.Tests/xunit.runner.json

@@ -0,0 +1,5 @@
+{
+  "$schema": "https://xunit.net/schema/current/xunit.runner.schema.json",
+  "methodDisplayOptions": "all",
+  "methodDisplay": "method"
+}

DiscordChatExporter.Cli.dockerfile

@@ -0,0 +1,18 @@
+# Build
+FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
+
+COPY favicon.ico ./
+COPY NuGet.config ./
+COPY Directory.Build.props ./
+COPY DiscordChatExporter.Core ./DiscordChatExporter.Core
+COPY DiscordChatExporter.Cli ./DiscordChatExporter.Cli
+
+RUN dotnet publish DiscordChatExporter.Cli -c Release -o ./publish
+
+# Run
+FROM mcr.microsoft.com/dotnet/runtime:6.0 AS run
+
+COPY --from=build ./publish ./
+
+WORKDIR ./out
+ENTRYPOINT ["dotnet", "/DiscordChatExporter.Cli.dll"]

DiscordChatExporter.Cli/Commands/Base/ExportCommandBase.cs

@@ -12,134 +12,234 @@ using DiscordChatExporter.Core.Discord;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Exceptions;
 using DiscordChatExporter.Core.Exporting;
+using DiscordChatExporter.Core.Exporting.Filtering;
 using DiscordChatExporter.Core.Exporting.Partitioning;
-using DiscordChatExporter.Core.Utils.Extensions;
-using Tyrrrz.Extensions;
+using DiscordChatExporter.Core.Utils;
+using Gress;
 
-namespace DiscordChatExporter.Cli.Commands.Base
+namespace DiscordChatExporter.Cli.Commands.Base;
+
+public abstract class ExportCommandBase : TokenCommandBase
 {
-    public abstract class ExportCommandBase : TokenCommandBase
+    private readonly string _outputPath = Directory.GetCurrentDirectory();
+
+    [CommandOption(
+        "output",
+        'o',
+        Description = "Output file or directory path. Directory path should end in a slash."
+    )]
+    public string OutputPath
     {
-        [CommandOption("output", 'o', Description = "Output file or directory path.")]
-        public string OutputPath { get; init; } = Directory.GetCurrentDirectory();
+        get => _outputPath;
+        // Handle ~/ in paths on *nix systems
+        // https://github.com/Tyrrrz/DiscordChatExporter/pull/903
+        init => _outputPath = Path.GetFullPath(value);
+    }
 
-        [CommandOption("format", 'f', Description = "Export format.")]
-        public ExportFormat ExportFormat { get; init; } = ExportFormat.HtmlDark;
+    [CommandOption(
+        "format",
+        'f',
+        Description = "Export format."
+    )]
+    public ExportFormat ExportFormat { get; init; } = ExportFormat.HtmlDark;
 
-        [CommandOption("after", Description = "Only include messages sent after this date or message ID.")]
-        public Snowflake? After { get; init; }
+    [CommandOption(
+        "after",
+        Description = "Only include messages sent after this date or message ID."
+    )]
+    public Snowflake? After { get; init; }
 
-        [CommandOption("before", Description = "Only include messages sent before this date or message ID.")]
-        public Snowflake? Before { get; init; }
+    [CommandOption(
+        "before",
+        Description = "Only include messages sent before this date or message ID."
+    )]
+    public Snowflake? Before { get; init; }
 
-        [CommandOption("partition", 'p', Description = "Split output into partitions, each limited to this number of messages (e.g. 100) or file size (e.g. 10mb).")]
-        public PartitionLimit PartitionLimit { get; init; } = NullPartitionLimit.Instance;
+    [CommandOption(
+        "partition",
+        'p',
+        Description = "Split output into partitions, each limited to this number of messages (e.g. '100') or file size (e.g. '10mb')."
+    )]
+    public PartitionLimit PartitionLimit { get; init; } = PartitionLimit.Null;
 
-        [CommandOption("parallel", Description = "Limits how many channels can be exported in parallel.")]
-        public int ParallelLimit { get; init; } = 1;
+    [CommandOption(
+        "filter",
+        Description = "Only include messages that satisfy this filter (e.g. 'from:foo#1234' or 'has:image')."
+    )]
+    public MessageFilter MessageFilter { get; init; } = MessageFilter.Null;
 
-        [CommandOption("media", Description = "Download referenced media content.")]
-        public bool ShouldDownloadMedia { get; init; }
+    [CommandOption(
+        "parallel",
+        Description = "Limits how many channels can be exported in parallel."
+    )]
+    public int ParallelLimit { get; init; } = 1;
 
-        [CommandOption("reuse-media", Description = "Reuse already existing media content to skip redundant downloads.")]
-        public bool ShouldReuseMedia { get; init; }
+    [CommandOption(
+        "media",
+        Description = "Download referenced media content."
+    )]
+    public bool ShouldDownloadMedia { get; init; }
 
-        [CommandOption("dateformat", Description = "Format used when writing dates.")]
-        public string DateFormat { get; init; } = "dd-MMM-yy hh:mm tt";
+    [CommandOption(
+        "reuse-media",
+        Description = "Reuse already existing media content to skip redundant downloads."
+    )]
+    public bool ShouldReuseMedia { get; init; }
 
-        private ChannelExporter? _channelExporter;
-        protected ChannelExporter Exporter => _channelExporter ??= new ChannelExporter(Discord);
+    [CommandOption(
+        "dateformat",
+        Description = "Format used when writing dates."
+    )]
+    public string DateFormat { get; init; } = "dd-MMM-yy hh:mm tt";
 
-        protected async ValueTask ExportAsync(IConsole console, IReadOnlyList<Channel> channels)
+    private ChannelExporter? _channelExporter;
+    protected ChannelExporter Exporter => _channelExporter ??= new ChannelExporter(Discord);
+
+    protected async ValueTask ExecuteAsync(IConsole console, IReadOnlyList<Channel> channels)
+    {
+        // Reuse media option should only be used when the media option is set.
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/425
+        if (ShouldReuseMedia && !ShouldDownloadMedia)
         {
-            await console.Output.WriteLineAsync($"Exporting {channels.Count} channel(s)...");
+            throw new CommandException(
+                "Option --reuse-media cannot be used without --media."
+            );
+        }
 
-            var errors = new ConcurrentDictionary<Channel, string>();
+        // Make sure the user does not try to export all channels into a single file.
+        // Output path must either be a directory, or contain template tokens.
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/799
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/917
+        var isValidOutputPath =
+            // Anything is valid when exporting a single channel
+            channels.Count <= 1 ||
+            // When using template tokens, assume the user knows what they're doing
+            OutputPath.Contains('%') ||
+            // Otherwise, require an existing directory or an unambiguous directory path
+            Directory.Exists(OutputPath) || PathEx.IsDirectoryPath(OutputPath);
 
-            // Wrap everything in a progress ticker
-            await console.CreateProgressTicker().StartAsync(async progressContext =>
-            {
-                await channels.ParallelForEachAsync(async channel =>
+        if (!isValidOutputPath)
+        {
+            throw new CommandException(
+                "Attempted to export multiple channels, but the output path is neither a directory nor a template."
+            );
+        }
+
+        var cancellationToken = console.RegisterCancellationHandler();
+        var errors = new ConcurrentDictionary<Channel, string>();
+
+        // Export
+        await console.Output.WriteLineAsync($"Exporting {channels.Count} channel(s)...");
+        await console.CreateProgressTicker().StartAsync(async progressContext =>
+        {
+            await Parallel.ForEachAsync(
+                channels,
+                new ParallelOptions
+                {
+                    MaxDegreeOfParallelism = Math.Max(1, ParallelLimit),
+                    CancellationToken = cancellationToken
+                },
+                async (channel, innerCancellationToken) =>
                 {
-                    // Export
                     try
                     {
-                        await progressContext.StartTaskAsync($"{channel.Category} / {channel.Name}", async progress =>
-                        {
-                            var guild = await Discord.GetGuildAsync(channel.GuildId);
+                        await progressContext.StartTaskAsync($"{channel.Category.Name} / {channel.Name}",
+                            async progress =>
+                            {
+                                var guild = await Discord.GetGuildAsync(channel.GuildId, innerCancellationToken);
 
-                            var request = new ExportRequest(
-                                guild,
-                                channel,
-                                OutputPath,
-                                ExportFormat,
-                                After,
-                                Before,
-                                PartitionLimit,
-                                ShouldDownloadMedia,
-                                ShouldReuseMedia,
-                                DateFormat
-                            );
+                                var request = new ExportRequest(
+                                    guild,
+                                    channel,
+                                    OutputPath,
+                                    ExportFormat,
+                                    After,
+                                    Before,
+                                    PartitionLimit,
+                                    MessageFilter,
+                                    ShouldDownloadMedia,
+                                    ShouldReuseMedia,
+                                    DateFormat
+                                );
 
-                            await Exporter.ExportChannelAsync(request, progress);
-                        });
+                                await Exporter.ExportChannelAsync(
+                                    request,
+                                    progress.ToPercentageBased(),
+                                    innerCancellationToken
+                                );
+                            }
+                        );
                     }
-                    catch (DiscordChatExporterException ex) when (!ex.IsCritical)
+                    catch (DiscordChatExporterException ex) when (!ex.IsFatal)
                     {
                         errors[channel] = ex.Message;
                     }
-                }, ParallelLimit.ClampMin(1));
-            });
+                }
+            );
+        });
 
-            // Print result
-            using (console.WithForegroundColor(ConsoleColor.White))
+        // Print result
+        using (console.WithForegroundColor(ConsoleColor.White))
+        {
+            await console.Output.WriteLineAsync(
+                $"Successfully exported {channels.Count - errors.Count} channel(s)."
+            );
+        }
+
+        // Print errors
+        if (errors.Any())
+        {
+            await console.Output.WriteLineAsync();
+
+            using (console.WithForegroundColor(ConsoleColor.Red))
             {
                 await console.Output.WriteLineAsync(
-                    $"Successfully exported {channels.Count - errors.Count} channel(s)."
+                    $"Failed to export {errors.Count} channel(s):"
                 );
             }
 
-            // Print errors
-            if (errors.Any())
+            foreach (var (channel, error) in errors)
             {
-                await console.Output.WriteLineAsync();
+                await console.Output.WriteAsync($"{channel.Category.Name} / {channel.Name}: ");
 
                 using (console.WithForegroundColor(ConsoleColor.Red))
-                {
-                    await console.Output.WriteLineAsync(
-                        $"Failed to export {errors.Count} channel(s):"
-                    );
-                }
-
-                foreach (var (channel, error) in errors)
-                {
-                    await console.Output.WriteAsync($"{channel.Category} / {channel.Name}: ");
-
-                    using (console.WithForegroundColor(ConsoleColor.Red))
-                        await console.Output.WriteLineAsync(error);
-                }
-
-                await console.Output.WriteLineAsync();
+                    await console.Output.WriteLineAsync(error);
             }
 
-            // Fail the command if ALL channels failed to export.
-            // Having some of the channels fail to export is fine and expected.
-            if (errors.Count >= channels.Count)
-            {
-                throw new CommandException("Export failed.");
-            }
-
-            await console.Output.WriteLineAsync("Done.");
+            await console.Output.WriteLineAsync();
         }
 
-        public override ValueTask ExecuteAsync(IConsole console)
+        // Fail the command only if ALL channels failed to export.
+        // Having some of the channels fail to export is expected.
+        if (errors.Count >= channels.Count)
         {
-            if (ShouldReuseMedia && !ShouldDownloadMedia)
-            {
-                throw new CommandException("Option --reuse-media cannot be used without --media.");
-            }
-
-            return default;
+            throw new CommandException("Export failed.");
         }
     }
+
+    protected async ValueTask ExecuteAsync(IConsole console, IReadOnlyList<Snowflake> channelIds)
+    {
+        var cancellationToken = console.RegisterCancellationHandler();
+        var channels = new List<Channel>();
+
+        foreach (var channelId in channelIds)
+        {
+            var channel = await Discord.GetChannelAsync(channelId, cancellationToken);
+            channels.Add(channel);
+        }
+
+        await ExecuteAsync(console, channels);
+    }
+
+    public override ValueTask ExecuteAsync(IConsole console)
+    {
+        // War in Ukraine message
+        console.Output.WriteLine("========================================================================");
+        console.Output.WriteLine("||   Ukraine is at war! Support my country in its fight for freedom~  ||");
+        console.Output.WriteLine("||   Learn more on my website: https://tyrrrz.me                      ||");
+        console.Output.WriteLine("========================================================================");
+        console.Output.WriteLine("");
+
+        return default;
+    }
 }

DiscordChatExporter.Cli/Commands/Base/TokenCommandBase.cs

@@ -1,29 +1,34 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using CliFx;
 using CliFx.Attributes;
 using CliFx.Infrastructure;
 using DiscordChatExporter.Core.Discord;
 
-namespace DiscordChatExporter.Cli.Commands.Base
+namespace DiscordChatExporter.Cli.Commands.Base;
+
+public abstract class TokenCommandBase : ICommand
 {
-    public abstract class TokenCommandBase : ICommand
-    {
-        [CommandOption("token", 't', IsRequired = true, EnvironmentVariable = "DISCORD_TOKEN", Description = "Authentication token.")]
-        public string TokenValue { get; init; } = "";
+    [CommandOption(
+        "token",
+        't',
+        IsRequired = true,
+        EnvironmentVariable = "DISCORD_TOKEN",
+        Description = "Authentication token."
+    )]
+    public string Token { get; init; } = "";
 
-        [CommandOption("bot", 'b', EnvironmentVariable = "DISCORD_TOKEN_BOT", Description = "Authenticate as a bot.")]
-        public bool IsBotToken { get; init; }
+    [Obsolete("This option doesn't do anything. Kept for backwards compatibility.")]
+    [CommandOption(
+        "bot",
+        'b',
+        EnvironmentVariable = "DISCORD_TOKEN_BOT",
+        Description = "This option doesn't do anything. Kept for backwards compatibility."
+    )]
+    public bool IsBotToken { get; init; }
 
-        private AuthToken GetAuthToken() => new(
-            IsBotToken
-                ? AuthTokenType.Bot
-                : AuthTokenType.User,
-            TokenValue
-        );
+    private DiscordClient? _discordClient;
+    protected DiscordClient Discord => _discordClient ??= new DiscordClient(Token);
 
-        private DiscordClient? _discordClient;
-        protected DiscordClient Discord => _discordClient ??= new DiscordClient(GetAuthToken());
-
-        public abstract ValueTask ExecuteAsync(IConsole console);
-    }
+    public abstract ValueTask ExecuteAsync(IConsole console);
 }

DiscordChatExporter.Cli/Commands/ExportAllCommand.cs

@@ -5,38 +5,35 @@ using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
 using DiscordChatExporter.Core.Discord.Data;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("exportall", Description = "Export all accessible channels.")]
+public class ExportAllCommand : ExportCommandBase
 {
-    [Command("exportall", Description = "Export all accessible channels.")]
-    public class ExportAllCommand : ExportCommandBase
+    [CommandOption(
+        "include-dm",
+        Description = "Include direct message channels."
+    )]
+    public bool IncludeDirectMessages { get; init; } = true;
+
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        [CommandOption("include-dm", Description = "Include direct message channels.")]
-        public bool IncludeDirectMessages { get; init; } = true;
+        await base.ExecuteAsync(console);
 
-        public override async ValueTask ExecuteAsync(IConsole console)
+        var cancellationToken = console.RegisterCancellationHandler();
+        var channels = new List<Channel>();
+
+        await console.Output.WriteLineAsync("Fetching channels...");
+        await foreach (var guild in Discord.GetUserGuildsAsync(cancellationToken))
         {
-            await base.ExecuteAsync(console);
+            // Skip DMs if instructed to
+            if (!IncludeDirectMessages && guild.Id == Guild.DirectMessages.Id)
+                continue;
 
-            // Get channel metadata
-            await console.Output.WriteLineAsync("Fetching channels...");
-
-            var channels = new List<Channel>();
-
-            // Aggregate channels from all guilds
-            await foreach (var guild in Discord.GetUserGuildsAsync())
-            {
-                // Skip DMs if instructed to
-                if (!IncludeDirectMessages && guild.Id == Guild.DirectMessages.Id)
-                    continue;
-
-                await foreach (var channel in Discord.GetGuildChannelsAsync(guild.Id))
-                {
-                    channels.Add(channel);
-                }
-            }
-
-            // Export
-            await ExportAsync(console, channels);
+            await foreach (var channel in Discord.GetGuildChannelsAsync(guild.Id, cancellationToken))
+                channels.Add(channel);
         }
+
+        await base.ExecuteAsync(console, channels);
     }
 }

DiscordChatExporter.Cli/Commands/ExportChannelsCommand.cs

@@ -5,34 +5,24 @@ using CliFx.Attributes;
 using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
 using DiscordChatExporter.Core.Discord;
-using DiscordChatExporter.Core.Discord.Data;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("export", Description = "Export one or multiple channels.")]
+public class ExportChannelsCommand : ExportCommandBase
 {
-    [Command("export", Description = "Export one or multiple channels.")]
-    public class ExportChannelsCommand : ExportCommandBase
+    // TODO: change this to plural (breaking change)
+    [CommandOption(
+        "channel",
+        'c',
+        IsRequired = true,
+        Description = "Channel ID(s)."
+    )]
+    public IReadOnlyList<Snowflake> ChannelIds { get; init; } = Array.Empty<Snowflake>();
+
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        // TODO: change this to plural (breaking change)
-        [CommandOption("channel", 'c', IsRequired = true, Description = "Channel ID(s).")]
-        public IReadOnlyList<Snowflake> ChannelIds { get; init; } = Array.Empty<Snowflake>();
-
-        public override async ValueTask ExecuteAsync(IConsole console)
-        {
-            await base.ExecuteAsync(console);
-
-            // Get channel metadata
-            await console.Output.WriteLineAsync("Fetching channel(s)...");
-
-            var channels = new List<Channel>();
-
-            foreach (var channelId in ChannelIds)
-            {
-                var channel = await Discord.GetChannelAsync(channelId);
-                channels.Add(channel);
-            }
-
-            // Export
-            await ExportAsync(console, channels);
-        }
+        await base.ExecuteAsync(console);
+        await base.ExecuteAsync(console, ChannelIds);
     }
 }

DiscordChatExporter.Cli/Commands/ExportDirectMessagesCommand.cs

@@ -1,25 +1,28 @@
-using System.Threading.Tasks;
+using System.Linq;
+using System.Threading.Tasks;
 using CliFx.Attributes;
 using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("exportdm", Description = "Export all direct message channels.")]
+public class ExportDirectMessagesCommand : ExportCommandBase
 {
-    [Command("exportdm", Description = "Export all direct message channels.")]
-    public class ExportDirectMessagesCommand : ExportCommandBase
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        public override async ValueTask ExecuteAsync(IConsole console)
-        {
-            await base.ExecuteAsync(console);
+        await base.ExecuteAsync(console);
 
-            // Get channel metadata
-            await console.Output.WriteLineAsync("Fetching channels...");
-            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id);
+        var cancellationToken = console.RegisterCancellationHandler();
 
-            // Export
-            await ExportAsync(console, channels);
-        }
+        await console.Output.WriteLineAsync("Fetching channels...");
+
+        var channels = (await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id, cancellationToken))
+            .Where(c => c.Kind != ChannelKind.GuildCategory)
+            .ToArray();
+
+        await base.ExecuteAsync(console, channels);
     }
 }

DiscordChatExporter.Cli/Commands/ExportGuildCommand.cs

@@ -1,28 +1,37 @@
-using System.Threading.Tasks;
+using System.Linq;
+using System.Threading.Tasks;
 using CliFx.Attributes;
 using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
 using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("exportguild", Description = "Export all channels within specified guild.")]
+public class ExportGuildCommand : ExportCommandBase
 {
-    [Command("exportguild", Description = "Export all channels within specified guild.")]
-    public class ExportGuildCommand : ExportCommandBase
+    [CommandOption(
+        "guild",
+        'g',
+        IsRequired = true,
+        Description = "Guild ID."
+    )]
+    public Snowflake GuildId { get; init; }
+
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        [CommandOption("guild", 'g', IsRequired = true, Description = "Guild ID.")]
-        public Snowflake GuildId { get; init; }
+        await base.ExecuteAsync(console);
 
-        public override async ValueTask ExecuteAsync(IConsole console)
-        {
-            await base.ExecuteAsync(console);
+        var cancellationToken = console.RegisterCancellationHandler();
 
-            // Get channel metadata
-            await console.Output.WriteLineAsync("Fetching channels...");
-            var channels = await Discord.GetGuildChannelsAsync(GuildId);
+        await console.Output.WriteLineAsync("Fetching channels...");
 
-            // Export
-            await ExportAsync(console, channels);
-        }
+        var channels = (await Discord.GetGuildChannelsAsync(GuildId, cancellationToken))
+            .Where(c => c.Kind != ChannelKind.GuildCategory)
+            .ToArray();
+
+        await base.ExecuteAsync(console, channels);
     }
 }

DiscordChatExporter.Cli/Commands/GetChannelsCommand.cs

@@ -5,35 +5,46 @@ using CliFx.Attributes;
 using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
 using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("channels", Description = "Get the list of channels in a guild.")]
+public class GetChannelsCommand : TokenCommandBase
 {
-    [Command("channels", Description = "Get the list of channels in a guild.")]
-    public class GetChannelsCommand : TokenCommandBase
+    [CommandOption(
+        "guild",
+        'g',
+        IsRequired = true,
+        Description = "Guild ID."
+    )]
+    public Snowflake GuildId { get; init; }
+
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        [CommandOption("guild", 'g', IsRequired = true, Description = "Guild ID.")]
-        public Snowflake GuildId { get; init; }
+        var cancellationToken = console.RegisterCancellationHandler();
 
-        public override async ValueTask ExecuteAsync(IConsole console)
+        var channels = (await Discord.GetGuildChannelsAsync(GuildId, cancellationToken))
+            .Where(c => c.Kind != ChannelKind.GuildCategory)
+            .OrderBy(c => c.Category.Position)
+            .ThenBy(c => c.Name)
+            .ToArray();
+
+        foreach (var channel in channels)
         {
-            var channels = await Discord.GetGuildChannelsAsync(GuildId);
+            // Channel ID
+            await console.Output.WriteAsync(
+                channel.Id.ToString().PadRight(18, ' ')
+            );
 
-            foreach (var channel in channels.OrderBy(c => c.Category.Position).ThenBy(c => c.Name))
-            {
-                // Channel ID
-                await console.Output.WriteAsync(channel.Id.ToString());
+            // Separator
+            using (console.WithForegroundColor(ConsoleColor.DarkGray))
+                await console.Output.WriteAsync(" | ");
 
-                // Separator
-                using (console.WithForegroundColor(ConsoleColor.DarkGray))
-                    await console.Output.WriteAsync(" | ");
-
-                // Channel category / name
-                using (console.WithForegroundColor(ConsoleColor.White))
-                    await console.Output.WriteAsync($"{channel.Category} / {channel.Name}");
-
-                await console.Output.WriteLineAsync();
-            }
+            // Channel category / name
+            using (console.WithForegroundColor(ConsoleColor.White))
+                await console.Output.WriteLineAsync($"{channel.Category.Name} / {channel.Name}");
         }
     }
 }

DiscordChatExporter.Cli/Commands/GetDirectMessageChannelsCommand.cs

@@ -7,30 +7,35 @@ using DiscordChatExporter.Cli.Commands.Base;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("dm", Description = "Get the list of direct message channels.")]
+public class GetDirectMessageChannelsCommand : TokenCommandBase
 {
-    [Command("dm", Description = "Get the list of direct message channels.")]
-    public class GetDirectMessageChannelsCommand : TokenCommandBase
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        public override async ValueTask ExecuteAsync(IConsole console)
+        var cancellationToken = console.RegisterCancellationHandler();
+
+        var channels = (await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id, cancellationToken))
+            .Where(c => c.Kind != ChannelKind.GuildCategory)
+            .OrderByDescending(c => c.LastMessageId)
+            .ThenBy(c => c.Name)
+            .ToArray();
+
+        foreach (var channel in channels)
         {
-            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id);
+            // Channel ID
+            await console.Output.WriteAsync(
+                channel.Id.ToString().PadRight(18, ' ')
+            );
 
-            foreach (var channel in channels.OrderBy(c => c.Name))
-            {
-                // Channel ID
-                await console.Output.WriteAsync(channel.Id.ToString());
+            // Separator
+            using (console.WithForegroundColor(ConsoleColor.DarkGray))
+                await console.Output.WriteAsync(" | ");
 
-                // Separator
-                using (console.WithForegroundColor(ConsoleColor.DarkGray))
-                    await console.Output.WriteAsync(" | ");
-
-                // Channel category / name
-                using (console.WithForegroundColor(ConsoleColor.White))
-                    await console.Output.WriteAsync($"{channel.Category} / {channel.Name}");
-
-                await console.Output.WriteLineAsync();
-            }
+            // Channel category / name
+            using (console.WithForegroundColor(ConsoleColor.White))
+                await console.Output.WriteLineAsync($"{channel.Category.Name} / {channel.Name}");
         }
     }
 }

DiscordChatExporter.Cli/Commands/GetGuildsCommand.cs

@@ -4,32 +4,37 @@ using System.Threading.Tasks;
 using CliFx.Attributes;
 using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
+using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("guilds", Description = "Get the list of accessible guilds.")]
+public class GetGuildsCommand : TokenCommandBase
 {
-    [Command("guilds", Description = "Get the list of accessible guilds.")]
-    public class GetGuildsCommand : TokenCommandBase
+    public override async ValueTask ExecuteAsync(IConsole console)
     {
-        public override async ValueTask ExecuteAsync(IConsole console)
+        var cancellationToken = console.RegisterCancellationHandler();
+
+        var guilds = (await Discord.GetUserGuildsAsync(cancellationToken))
+            // Show direct messages first
+            .OrderByDescending(g => g.Id == Guild.DirectMessages.Id)
+            .ThenBy(g => g.Name);
+
+        foreach (var guild in guilds)
         {
-            var guilds = await Discord.GetUserGuildsAsync();
+            // Guild ID
+            await console.Output.WriteAsync(
+                guild.Id.ToString().PadRight(18, ' ')
+            );
 
-            foreach (var guild in guilds.OrderBy(g => g.Name))
-            {
-                // Guild ID
-                await console.Output.WriteAsync(guild.Id.ToString());
+            // Separator
+            using (console.WithForegroundColor(ConsoleColor.DarkGray))
+                await console.Output.WriteAsync(" | ");
 
-                // Separator
-                using (console.WithForegroundColor(ConsoleColor.DarkGray))
-                    await console.Output.WriteAsync(" | ");
-
-                // Guild name
-                using (console.WithForegroundColor(ConsoleColor.White))
-                    await console.Output.WriteAsync(guild.Name);
-
-                await console.Output.WriteLineAsync();
-            }
+            // Guild name
+            using (console.WithForegroundColor(ConsoleColor.White))
+                await console.Output.WriteLineAsync(guild.Name);
         }
     }
 }

DiscordChatExporter.Cli/Commands/GuideCommand.cs

@@ -1,65 +1,72 @@
-using System;
+using System;
 using System.Threading.Tasks;
 using CliFx;
 using CliFx.Attributes;
 using CliFx.Infrastructure;
 
-namespace DiscordChatExporter.Cli.Commands
+namespace DiscordChatExporter.Cli.Commands;
+
+[Command("guide", Description = "Explains how to obtain token, guild or channel ID.")]
+public class GuideCommand : ICommand
 {
-    [Command("guide", Description = "Explains how to obtain token, guild or channel ID.")]
-    public class GuideCommand : ICommand
+    public ValueTask ExecuteAsync(IConsole console)
     {
-        public ValueTask ExecuteAsync(IConsole console)
-        {
-            using (console.WithForegroundColor(ConsoleColor.White))
-                console.Output.WriteLine("To get user token:");
+        // User token
+        using (console.WithForegroundColor(ConsoleColor.White))
+            console.Output.WriteLine("To get user token:");
 
-            console.Output.WriteLine(" 1. Open Discord");
-            console.Output.WriteLine(" 2. Press Ctrl+Shift+I to show developer tools");
-            console.Output.WriteLine(" 3. Navigate to the Application tab");
-            console.Output.WriteLine(" 4. Select \"Local Storage\" > \"https://discord.com\" on the left");
-            console.Output.WriteLine(" 5. Press Ctrl+R to reload");
-            console.Output.WriteLine(" 6. Find \"token\" at the bottom and copy the value");
-            console.Output.WriteLine(" *  Automating user accounts is technically against TOS, use at your own risk.");
-            console.Output.WriteLine();
+        console.Output.WriteLine(" *  Automating user accounts is technically against TOS — USE AT YOUR OWN RISK!");
+        console.Output.WriteLine(" 1. Open Discord in your web browser and login");
+        console.Output.WriteLine(" 2. Open any server or direct message channel");
+        console.Output.WriteLine(" 3. Press Ctrl+Shift+I to show developer tools");
+        console.Output.WriteLine(" 4. Navigate to the Network tab");
+        console.Output.WriteLine(" 5. Press Ctrl+R to reload");
+        console.Output.WriteLine(" 6. Search for a request containing \"messages?limit=50\" or similar");
+        console.Output.WriteLine(" 7. Select the Headers tab on the right");
+        console.Output.WriteLine(" 8. Scroll down to the Request Headers section");
+        console.Output.WriteLine(" 9. Copy the value of the \"authorization\" header");
+        console.Output.WriteLine();
 
-            using (console.WithForegroundColor(ConsoleColor.White))
-                console.Output.WriteLine("To get bot token:");
+        // Bot token
+        using (console.WithForegroundColor(ConsoleColor.White))
+            console.Output.WriteLine("To get bot token:");
 
-            console.Output.WriteLine(" 1. Go to Discord developer portal");
-            console.Output.WriteLine(" 2. Open your application's settings");
-            console.Output.WriteLine(" 3. Navigate to the Bot section on the left");
-            console.Output.WriteLine(" 4. Under Token click Copy");
-            console.Output.WriteLine();
+        console.Output.WriteLine(" 1. Go to Discord developer portal");
+        console.Output.WriteLine(" 2. Open your application's settings");
+        console.Output.WriteLine(" 3. Navigate to the Bot section on the left");
+        console.Output.WriteLine(" 4. Under Token click Copy");
+        console.Output.WriteLine(" *  Your bot needs to have Message Content Intent enabled to read messages");
+        console.Output.WriteLine();
 
-            using (console.WithForegroundColor(ConsoleColor.White))
-                console.Output.WriteLine("To get guild ID or guild channel ID:");
+        // Guild or channel ID
+        using (console.WithForegroundColor(ConsoleColor.White))
+            console.Output.WriteLine("To get guild ID or guild channel ID:");
 
-            console.Output.WriteLine(" 1. Open Discord");
-            console.Output.WriteLine(" 2. Open Settings");
-            console.Output.WriteLine(" 3. Go to Appearance section");
-            console.Output.WriteLine(" 4. Enable Developer Mode");
-            console.Output.WriteLine(" 5. Right click on the desired guild or channel and click Copy ID");
-            console.Output.WriteLine();
+        console.Output.WriteLine(" 1. Open Discord");
+        console.Output.WriteLine(" 2. Open Settings");
+        console.Output.WriteLine(" 3. Go to Advanced section");
+        console.Output.WriteLine(" 4. Enable Developer Mode");
+        console.Output.WriteLine(" 5. Right click on the desired guild or channel and click Copy ID");
+        console.Output.WriteLine();
 
-            using (console.WithForegroundColor(ConsoleColor.White))
-                console.Output.WriteLine("To get direct message channel ID:");
+        // Direct message channel ID
+        using (console.WithForegroundColor(ConsoleColor.White))
+            console.Output.WriteLine("To get direct message channel ID:");
 
-            console.Output.WriteLine(" 1. Open Discord");
-            console.Output.WriteLine(" 2. Open the desired direct message channel");
-            console.Output.WriteLine(" 3. Press Ctrl+Shift+I to show developer tools");
-            console.Output.WriteLine(" 4. Navigate to the Console tab");
-            console.Output.WriteLine(" 5. Type \"window.location.href\" and press Enter");
-            console.Output.WriteLine(" 6. Copy the first long sequence of numbers inside the URL");
-            console.Output.WriteLine();
+        console.Output.WriteLine(" 1. Open Discord");
+        console.Output.WriteLine(" 2. Open the desired direct message channel");
+        console.Output.WriteLine(" 3. Press Ctrl+Shift+I to show developer tools");
+        console.Output.WriteLine(" 4. Navigate to the Console tab");
+        console.Output.WriteLine(" 5. Type \"window.location.href\" and press Enter");
+        console.Output.WriteLine(" 6. Copy the first long sequence of numbers inside the URL");
+        console.Output.WriteLine();
 
-            using (console.WithForegroundColor(ConsoleColor.White))
-                console.Output.WriteLine("For more information, check out the wiki:");
+        // Wiki link
+        using (console.WithForegroundColor(ConsoleColor.White))
+            console.Output.WriteLine("If you have questions or issues, please refer to the wiki:");
+        using (console.WithForegroundColor(ConsoleColor.DarkCyan))
+            console.Output.WriteLine("https://github.com/Tyrrrz/DiscordChatExporter/wiki");
 
-            using (console.WithForegroundColor(ConsoleColor.DarkCyan))
-                console.Output.WriteLine("https://github.com/Tyrrrz/DiscordChatExporter/wiki");
-
-            return default;
-        }
+        return default;
     }
 }

DiscordChatExporter.Cli/DiscordChatExporter.Cli.csproj

@@ -6,10 +6,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CliFx" Version="2.0.4" />
-    <PackageReference Include="Spectre.Console" Version="0.39.0" />
-    <PackageReference Include="Gress" Version="1.2.0" />
-    <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
+    <PackageReference Include="CliFx" Version="2.3.0" />
+    <PackageReference Include="Spectre.Console" Version="0.44.0" />
+    <PackageReference Include="Gress" Version="2.0.1" />
+    <PackageReference Include="DotnetRuntimeBootstrapper" Version="2.3.1" PrivateAssets="all" />
   </ItemGroup>
 
   <ItemGroup>

DiscordChatExporter.Cli/Program.cs

@@ -1,14 +1,6 @@
-using System.Threading.Tasks;
-using CliFx;
+using CliFx;
 
-namespace DiscordChatExporter.Cli
-{
-    public static class Program
-    {
-        public static async Task<int> Main(string[] args) =>
-            await new CliApplicationBuilder()
-                .AddCommandsFromThisAssembly()
-                .Build()
-                .RunAsync(args);
-    }
-}
+return await new CliApplicationBuilder()
+    .AddCommandsFromThisAssembly()
+    .Build()
+    .RunAsync(args);

DiscordChatExporter.Cli/Utils/Extensions/ConsoleExtensions.cs

@@ -3,46 +3,48 @@ using System.Threading.Tasks;
 using CliFx.Infrastructure;
 using Spectre.Console;
 
-namespace DiscordChatExporter.Cli.Utils.Extensions
+namespace DiscordChatExporter.Cli.Utils.Extensions;
+
+internal static class ConsoleExtensions
 {
-    internal static class ConsoleExtensions
-    {
-        public static IAnsiConsole CreateAnsiConsole(this IConsole console) => AnsiConsole.Create(
-            new AnsiConsoleSettings
-            {
-                Ansi = AnsiSupport.Detect,
-                ColorSystem = ColorSystemSupport.Detect,
-                Out = new AnsiConsoleOutput(console.Output)
-            }
+    public static IAnsiConsole CreateAnsiConsole(this IConsole console) =>
+        AnsiConsole.Create(new AnsiConsoleSettings
+        {
+            Ansi = AnsiSupport.Detect,
+            ColorSystem = ColorSystemSupport.Detect,
+            Out = new AnsiConsoleOutput(console.Output)
+        });
+
+    public static Progress CreateProgressTicker(this IConsole console) => console
+        .CreateAnsiConsole()
+        .Progress()
+        .AutoClear(false)
+        .AutoRefresh(true)
+        .HideCompleted(false)
+        .Columns(
+            new TaskDescriptionColumn {Alignment = Justify.Left},
+            new ProgressBarColumn(),
+            new PercentageColumn()
         );
 
-        public static Progress CreateProgressTicker(this IConsole console) => console
-            .CreateAnsiConsole()
-            .Progress()
-            .AutoClear(false)
-            .AutoRefresh(true)
-            .HideCompleted(false)
-            .Columns(
-                new TaskDescriptionColumn {Alignment = Justify.Left},
-                new ProgressBarColumn(),
-                new PercentageColumn()
-            );
+    public static async ValueTask StartTaskAsync(
+        this ProgressContext progressContext,
+        string description,
+        Func<ProgressTask, ValueTask> performOperationAsync)
+    {
+        var progressTask = progressContext.AddTask(
+            // Don't recognize random square brackets as style tags
+            Markup.Escape(description),
+            new ProgressTaskSettings {MaxValue = 1}
+        );
 
-        public static async ValueTask StartTaskAsync(
-            this ProgressContext progressContext,
-            string description,
-            Func<ProgressTask, ValueTask> performOperationAsync)
+        try
         {
-            var progressTask = progressContext.AddTask(description, new ProgressTaskSettings {MaxValue = 1});
-
-            try
-            {
-                await performOperationAsync(progressTask);
-            }
-            finally
-            {
-                progressTask.StopTask();
-            }
+            await performOperationAsync(progressTask);
+        }
+        finally
+        {
+            progressTask.StopTask();
         }
     }
 }

DiscordChatExporter.Cli/Utils/Pollyfills.cs

@@ -1,9 +0,0 @@
-// ReSharper disable CheckNamespace
-// TODO: remove after moving to .NET 5
-
-namespace System.Runtime.CompilerServices
-{
-    internal static class IsExternalInit
-    {
-    }
-}

DiscordChatExporter.Core/Discord/AuthToken.cs

@@ -1,27 +0,0 @@
-using System.Net.Http.Headers;
-
-namespace DiscordChatExporter.Core.Discord
-{
-    public enum AuthTokenType { User, Bot }
-
-    public class AuthToken
-    {
-        public AuthTokenType Type { get; }
-
-        public string Value { get; }
-
-        public AuthToken(AuthTokenType type, string value)
-        {
-            Type = type;
-            Value = value;
-        }
-
-        public AuthenticationHeaderValue GetAuthenticationHeader() => Type switch
-        {
-            AuthTokenType.Bot => new AuthenticationHeaderValue("Bot", Value),
-            _ => new AuthenticationHeaderValue(Value)
-        };
-
-        public override string ToString() => Value;
-    }
-}

DiscordChatExporter.Core/Discord/Data/Attachment.cs

@@ -1,77 +1,46 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Text.Json;
 using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Utils;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#attachment-object
+public partial record Attachment(
+    Snowflake Id,
+    string Url,
+    string FileName,
+    string? Description,
+    int? Width,
+    int? Height,
+    FileSize FileSize) : IHasId
 {
-    // https://discord.com/developers/docs/resources/channel#attachment-object
-    public partial class Attachment : IHasId
+    public string FileExtension => Path.GetExtension(FileName);
+
+    public bool IsImage => FileFormat.IsImage(FileExtension);
+
+    public bool IsVideo => FileFormat.IsVideo(FileExtension);
+
+    public bool IsAudio => FileFormat.IsAudio(FileExtension);
+
+    public bool IsSpoiler => FileName.StartsWith("SPOILER_", StringComparison.Ordinal);
+}
+
+public partial record Attachment
+{
+    public static Attachment Parse(JsonElement json)
     {
-        public Snowflake Id { get; }
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var url = json.GetProperty("url").GetNonWhiteSpaceString();
+        var fileName = json.GetProperty("filename").GetNonNullString();
+        var description = json.GetPropertyOrNull("description")?.GetNonWhiteSpaceStringOrNull();
+        var width = json.GetPropertyOrNull("width")?.GetInt32OrNull();
+        var height = json.GetPropertyOrNull("height")?.GetInt32OrNull();
+        var fileSize = json.GetProperty("size").GetInt64().Pipe(FileSize.FromBytes);
 
-        public string Url { get; }
-
-        public string FileName { get; }
-
-        public int? Width { get; }
-
-        public int? Height { get; }
-
-        public bool IsImage => ImageFileExtensions.Contains(Path.GetExtension(FileName));
-
-        public bool IsVideo => VideoFileExtensions.Contains(Path.GetExtension(FileName));
-
-        public bool IsAudio => AudioFileExtensions.Contains(Path.GetExtension(FileName));
-
-        public bool IsSpoiler =>
-            (IsImage || IsVideo || IsAudio) && FileName.StartsWith("SPOILER_", StringComparison.Ordinal);
-
-        public FileSize FileSize { get; }
-
-        public Attachment(
-            Snowflake id,
-            string url,
-            string fileName,
-            int? width,
-            int? height,
-            FileSize fileSize)
-        {
-            Id = id;
-            Url = url;
-            FileName = fileName;
-            Width = width;
-            Height = height;
-            FileSize = fileSize;
-        }
-
-        public override string ToString() => FileName;
-    }
-
-    public partial class Attachment
-    {
-        private static readonly HashSet<string> ImageFileExtensions = new(StringComparer.OrdinalIgnoreCase)
-            {".jpg", ".jpeg", ".png", ".gif", ".bmp", ".webp"};
-
-        private static readonly HashSet<string> VideoFileExtensions = new(StringComparer.OrdinalIgnoreCase)
-            {".mp4", ".webm"};
-
-        private static readonly HashSet<string> AudioFileExtensions = new(StringComparer.OrdinalIgnoreCase)
-            {".mp3", ".wav", ".ogg", ".flac", ".m4a"};
-
-        public static Attachment Parse(JsonElement json)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            var url = json.GetProperty("url").GetString();
-            var width = json.GetPropertyOrNull("width")?.GetInt32();
-            var height = json.GetPropertyOrNull("height")?.GetInt32();
-            var fileName = json.GetProperty("filename").GetString();
-            var fileSize = json.GetProperty("size").GetInt64().Pipe(FileSize.FromBytes);
-
-            return new Attachment(id, url, fileName, width, height, fileSize);
-        }
+        return new Attachment(id, url, fileName, description, width, height, fileSize);
     }
 }

DiscordChatExporter.Core/Discord/Data/Channel.cs

@@ -3,109 +3,78 @@ using System.Text.Json;
 using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
-using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#channel-object
+public partial record Channel(
+    Snowflake Id,
+    ChannelKind Kind,
+    Snowflake GuildId,
+    ChannelCategory Category,
+    string Name,
+    int? Position,
+    string? Topic,
+    Snowflake? LastMessageId) : IHasId
 {
-    // https://discord.com/developers/docs/resources/channel#channel-object-channel-types
-    // Order of enum fields needs to match the order in the docs.
-    public enum ChannelType
-    {
-        GuildTextChat,
-        DirectTextChat,
-        GuildVoiceChat,
-        DirectGroupTextChat,
-        GuildCategory,
-        GuildNews,
-        GuildStore
-    }
+    public bool SupportsVoice => Kind is ChannelKind.GuildVoiceChat or ChannelKind.GuildStageVoice;
+}
 
-    // https://discord.com/developers/docs/resources/channel#channel-object
-    public partial class Channel : IHasId, IHasPosition
-    {
-        public Snowflake Id { get; }
-
-        public ChannelType Type { get; }
-
-        public bool IsTextChannel =>
-            Type == ChannelType.GuildTextChat ||
-            Type == ChannelType.DirectTextChat ||
-            Type == ChannelType.DirectGroupTextChat ||
-            Type == ChannelType.GuildNews ||
-            Type == ChannelType.GuildStore;
-
-        public Snowflake GuildId { get; }
-
-        public ChannelCategory Category { get; }
-
-        public string Name { get; }
-
-        public int? Position { get; }
-
-        public string? Topic { get; }
-
-        public Channel(
-            Snowflake id,
-            ChannelType type,
-            Snowflake guildId,
-            ChannelCategory? category,
-            string name,
-            int? position,
-            string? topic)
+public partial record Channel
+{
+    private static ChannelCategory GetFallbackCategory(ChannelKind channelKind) => new(
+        Snowflake.Zero,
+        channelKind switch
         {
-            Id = id;
-            Type = type;
-            GuildId = guildId;
-            Category = category ?? GetFallbackCategory(type);
-            Name = name;
-            Position = position;
-            Topic = topic;
-        }
+            ChannelKind.GuildTextChat => "Text",
+            ChannelKind.DirectTextChat => "Private",
+            ChannelKind.DirectGroupTextChat => "Group",
+            ChannelKind.GuildNews => "News",
+            _ => "Default"
+        },
+        null
+    );
 
-        public override string ToString() => Name;
-
-    }
-
-    public partial class Channel
+    public static Channel Parse(JsonElement json, ChannelCategory? category = null, int? positionHint = null)
     {
-        private static ChannelCategory GetFallbackCategory(ChannelType channelType) => new(
-            Snowflake.Zero,
-            channelType switch
-            {
-                ChannelType.GuildTextChat => "Text",
-                ChannelType.DirectTextChat => "Private",
-                ChannelType.DirectGroupTextChat => "Group",
-                ChannelType.GuildNews => "News",
-                ChannelType.GuildStore => "Store",
-                _ => "Default"
-            },
-            0
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var kind = (ChannelKind)json.GetProperty("type").GetInt32();
+        var guildId = json.GetPropertyOrNull("guild_id")?.GetNonWhiteSpaceStringOrNull()?.Pipe(Snowflake.Parse);
+
+        var name =
+            // Guild channel
+            json.GetPropertyOrNull("name")?.GetNonWhiteSpaceStringOrNull() ??
+
+            // DM channel
+            json.GetPropertyOrNull("recipients")?
+                .EnumerateArrayOrNull()?
+                .Select(User.Parse)
+                .Select(u => u.Name)
+                .Pipe(s => string.Join(", ", s)) ??
+
+            // Fallback
+            id.ToString();
+
+        var position =
+            positionHint ??
+            json.GetPropertyOrNull("position")?.GetInt32OrNull();
+
+        var topic = json.GetPropertyOrNull("topic")?.GetStringOrNull();
+
+        var lastMessageId = json
+            .GetPropertyOrNull("last_message_id")?
+            .GetNonWhiteSpaceStringOrNull()?
+            .Pipe(Snowflake.Parse);
+
+        return new Channel(
+            id,
+            kind,
+            guildId ?? Guild.DirectMessages.Id,
+            category ?? GetFallbackCategory(kind),
+            name,
+            position,
+            topic,
+            lastMessageId
         );
-
-        public static Channel Parse(JsonElement json, ChannelCategory? category = null, int? position = null)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            var guildId = json.GetPropertyOrNull("guild_id")?.GetString().Pipe(Snowflake.Parse);
-            var topic = json.GetPropertyOrNull("topic")?.GetString();
-
-            var type = (ChannelType) json.GetProperty("type").GetInt32();
-
-            var name =
-                json.GetPropertyOrNull("name")?.GetString() ??
-                json.GetPropertyOrNull("recipients")?.EnumerateArray().Select(User.Parse).Select(u => u.Name).JoinToString(", ") ??
-                id.ToString();
-
-            position ??= json.GetPropertyOrNull("position")?.GetInt32();
-
-            return new Channel(
-                id,
-                type,
-                guildId ?? Guild.DirectMessages.Id,
-                category ?? GetFallbackCategory(type),
-                name,
-                position,
-                topic
-            );
-        }
     }
 }

DiscordChatExporter.Core/Discord/Data/ChannelCategory.cs

@@ -1,49 +1,26 @@
-using System.Linq;
-using System.Text.Json;
+using System.Text.Json;
 using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
-using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+public record ChannelCategory(Snowflake Id, string Name, int? Position) : IHasId
 {
-    public partial class ChannelCategory : IHasId, IHasPosition
+    public static ChannelCategory Unknown { get; } = new(Snowflake.Zero, "<unknown category>", 0);
+
+    public static ChannelCategory Parse(JsonElement json, int? positionHint = null)
     {
-        public Snowflake Id { get; }
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
 
-        public string Name { get; }
+        var name =
+            json.GetPropertyOrNull("name")?.GetNonWhiteSpaceStringOrNull() ??
+            id.ToString();
 
-        public int? Position { get; }
-
-        public ChannelCategory(Snowflake id, string name, int? position)
-        {
-            Id = id;
-            Name = name;
-            Position = position;
-        }
-
-        public override string ToString() => Name;
+        var position =
+            positionHint ??
+            json.GetPropertyOrNull("position")?.GetInt32OrNull();
 
+        return new ChannelCategory(id, name, position);
     }
-
-    public partial class ChannelCategory
-    {
-        public static ChannelCategory Parse(JsonElement json, int? position = null)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            position ??= json.GetPropertyOrNull("position")?.GetInt32();
-
-            var name = json.GetPropertyOrNull("name")?.GetString() ??
-                json.GetPropertyOrNull("recipients")?.EnumerateArray().Select(User.Parse).Select(u => u.Name).JoinToString(", ") ??
-                id.ToString();
-
-            return new ChannelCategory(
-                id,
-                name,
-                position
-            );
-        }
-
-        public static ChannelCategory Empty { get; } = new(Snowflake.Zero, "<unknown category>", 0);
-    }
-}
+}

DiscordChatExporter.Core/Discord/Data/ChannelKind.cs

@@ -0,0 +1,19 @@
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#channel-object-channel-types
+// Order of enum fields needs to match the order in the docs.
+public enum ChannelKind
+{
+    GuildTextChat = 0,
+    DirectTextChat = 1,
+    GuildVoiceChat = 2,
+    DirectGroupTextChat = 3,
+    GuildCategory = 4,
+    GuildNews = 5,
+    GuildNewsThread = 10,
+    GuildPublicThread = 11,
+    GuildPrivateThread = 12,
+    GuildStageVoice = 13,
+    GuildDirectory = 14,
+    GuildForum = 15
+}

DiscordChatExporter.Core/Discord/Data/Common/FileSize.cs

@@ -1,51 +1,48 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 
-namespace DiscordChatExporter.Core.Discord.Data.Common
+namespace DiscordChatExporter.Core.Discord.Data.Common;
+
+// Loosely based on https://github.com/omar/ByteSize (MIT license)
+public readonly partial record struct FileSize(long TotalBytes)
 {
-    // Loosely based on https://github.com/omar/ByteSize (MIT license)
-    public readonly partial struct FileSize
+    public double TotalKiloBytes => TotalBytes / 1024.0;
+    public double TotalMegaBytes => TotalKiloBytes / 1024.0;
+    public double TotalGigaBytes => TotalMegaBytes / 1024.0;
+
+    private double GetLargestWholeNumberValue()
     {
-        public long TotalBytes { get; }
+        if (Math.Abs(TotalGigaBytes) >= 1)
+            return TotalGigaBytes;
 
-        public double TotalKiloBytes => TotalBytes / 1024.0;
-        public double TotalMegaBytes => TotalKiloBytes / 1024.0;
-        public double TotalGigaBytes => TotalMegaBytes / 1024.0;
+        if (Math.Abs(TotalMegaBytes) >= 1)
+            return TotalMegaBytes;
 
-        public FileSize(long bytes) => TotalBytes = bytes;
+        if (Math.Abs(TotalKiloBytes) >= 1)
+            return TotalKiloBytes;
 
-        private double GetLargestWholeNumberValue()
-        {
-            if (Math.Abs(TotalGigaBytes) >= 1)
-                return TotalGigaBytes;
-
-            if (Math.Abs(TotalMegaBytes) >= 1)
-                return TotalMegaBytes;
-
-            if (Math.Abs(TotalKiloBytes) >= 1)
-                return TotalKiloBytes;
-
-            return TotalBytes;
-        }
-
-        private string GetLargestWholeNumberSymbol()
-        {
-            if (Math.Abs(TotalGigaBytes) >= 1)
-                return "GB";
-
-            if (Math.Abs(TotalMegaBytes) >= 1)
-                return "MB";
-
-            if (Math.Abs(TotalKiloBytes) >= 1)
-                return "KB";
-
-            return "bytes";
-        }
-
-        public override string ToString() => $"{GetLargestWholeNumberValue():0.##} {GetLargestWholeNumberSymbol()}";
+        return TotalBytes;
     }
 
-    public partial struct FileSize
+    private string GetLargestWholeNumberSymbol()
     {
-        public static FileSize FromBytes(long bytes) => new(bytes);
+        if (Math.Abs(TotalGigaBytes) >= 1)
+            return "GB";
+
+        if (Math.Abs(TotalMegaBytes) >= 1)
+            return "MB";
+
+        if (Math.Abs(TotalKiloBytes) >= 1)
+            return "KB";
+
+        return "bytes";
     }
+
+    [ExcludeFromCodeCoverage]
+    public override string ToString() => $"{GetLargestWholeNumberValue():0.##} {GetLargestWholeNumberSymbol()}";
+}
+
+public partial record struct FileSize
+{
+    public static FileSize FromBytes(long bytes) => new(bytes);
 }

DiscordChatExporter.Core/Discord/Data/Common/IHasId.cs

@@ -1,7 +1,6 @@
-namespace DiscordChatExporter.Core.Discord.Data.Common
+namespace DiscordChatExporter.Core.Discord.Data.Common;
+
+public interface IHasId
 {
-    public interface IHasId
-    {
-        Snowflake Id { get; }
-    }
+    Snowflake Id { get; }
 }

DiscordChatExporter.Core/Discord/Data/Common/IHasPosition.cs

@@ -1,7 +0,0 @@
-namespace DiscordChatExporter.Core.Discord.Data.Common
-{
-    public interface IHasPosition
-    {
-        int? Position { get; }
-    }
-}

DiscordChatExporter.Core/Discord/Data/Common/IdBasedEqualityComparer.cs

@@ -1,16 +1,12 @@
 using System.Collections.Generic;
 
-namespace DiscordChatExporter.Core.Discord.Data.Common
+namespace DiscordChatExporter.Core.Discord.Data.Common;
+
+public class IdBasedEqualityComparer : IEqualityComparer<IHasId>
 {
-    public partial class IdBasedEqualityComparer : IEqualityComparer<IHasId>
-    {
-        public bool Equals(IHasId? x, IHasId? y) => x?.Id == y?.Id;
+    public static IdBasedEqualityComparer Instance { get; } = new();
 
-        public int GetHashCode(IHasId obj) => obj.Id.GetHashCode();
-    }
+    public bool Equals(IHasId? x, IHasId? y) => x?.Id == y?.Id;
 
-    public partial class IdBasedEqualityComparer
-    {
-        public static IdBasedEqualityComparer Instance { get; } = new();
-    }
+    public int GetHashCode(IHasId obj) => obj.Id.GetHashCode();
 }

DiscordChatExporter.Core/Discord/Data/Embed.cs

@@ -1,94 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Drawing;
-using System.Linq;
-using System.Text.Json;
-using DiscordChatExporter.Core.Utils.Extensions;
-using JsonExtensions.Reading;
-
-namespace DiscordChatExporter.Core.Discord.Data
-{
-    // https://discord.com/developers/docs/resources/channel#embed-object
-    public partial class Embed
-    {
-        public string? Title { get; }
-
-        public string? Url { get; }
-
-        public DateTimeOffset? Timestamp { get; }
-
-        public Color? Color { get; }
-
-        public EmbedAuthor? Author { get; }
-
-        public string? Description { get; }
-
-        public IReadOnlyList<EmbedField> Fields { get; }
-
-        public EmbedImage? Thumbnail { get; }
-
-        public EmbedImage? Image { get; }
-
-        public EmbedFooter? Footer { get; }
-
-        public Embed(
-            string? title,
-            string? url,
-            DateTimeOffset? timestamp,
-            Color? color,
-            EmbedAuthor? author,
-            string? description,
-            IReadOnlyList<EmbedField> fields,
-            EmbedImage? thumbnail,
-            EmbedImage? image,
-            EmbedFooter? footer)
-        {
-            Title = title;
-            Url = url;
-            Timestamp = timestamp;
-            Color = color;
-            Author = author;
-            Description = description;
-            Fields = fields;
-            Thumbnail = thumbnail;
-            Image = image;
-            Footer = footer;
-        }
-
-        public override string ToString() => Title ?? "<untitled embed>";
-    }
-
-    public partial class Embed
-    {
-        public static Embed Parse(JsonElement json)
-        {
-            var title = json.GetPropertyOrNull("title")?.GetString();
-            var description = json.GetPropertyOrNull("description")?.GetString();
-            var url = json.GetPropertyOrNull("url")?.GetString();
-            var timestamp = json.GetPropertyOrNull("timestamp")?.GetDateTimeOffset();
-            var color = json.GetPropertyOrNull("color")?.GetInt32().Pipe(System.Drawing.Color.FromArgb).ResetAlpha();
-
-            var author = json.GetPropertyOrNull("author")?.Pipe(EmbedAuthor.Parse);
-            var thumbnail = json.GetPropertyOrNull("thumbnail")?.Pipe(EmbedImage.Parse);
-            var image = json.GetPropertyOrNull("image")?.Pipe(EmbedImage.Parse);
-            var footer = json.GetPropertyOrNull("footer")?.Pipe(EmbedFooter.Parse);
-
-            var fields =
-                json.GetPropertyOrNull("fields")?.EnumerateArray().Select(EmbedField.Parse).ToArray() ??
-                Array.Empty<EmbedField>();
-
-            return new Embed(
-                title,
-                url,
-                timestamp,
-                color,
-                author,
-                description,
-                fields,
-                thumbnail,
-                image,
-                footer
-            );
-        }
-    }
-}

DiscordChatExporter.Core/Discord/Data/EmbedAuthor.cs

@@ -1,36 +0,0 @@
-using System.Text.Json;
-using JsonExtensions.Reading;
-
-namespace DiscordChatExporter.Core.Discord.Data
-{
-    // https://discord.com/developers/docs/resources/channel#embed-object-embed-author-structure
-    public partial class EmbedAuthor
-    {
-        public string? Name { get; }
-
-        public string? Url { get; }
-
-        public string? IconUrl { get; }
-
-        public EmbedAuthor(string? name, string? url, string? iconUrl)
-        {
-            Name = name;
-            Url = url;
-            IconUrl = iconUrl;
-        }
-
-        public override string ToString() => Name ?? "<unnamed author>";
-    }
-
-    public partial class EmbedAuthor
-    {
-        public static EmbedAuthor Parse(JsonElement json)
-        {
-            var name = json.GetPropertyOrNull("name")?.GetString();
-            var url = json.GetPropertyOrNull("url")?.GetString();
-            var iconUrl = json.GetPropertyOrNull("icon_url")?.GetString();
-
-            return new EmbedAuthor(name, url, iconUrl);
-        }
-    }
-}

DiscordChatExporter.Core/Discord/Data/EmbedField.cs

@@ -1,36 +0,0 @@
-using System.Text.Json;
-using JsonExtensions.Reading;
-
-namespace DiscordChatExporter.Core.Discord.Data
-{
-    // https://discord.com/developers/docs/resources/channel#embed-object-embed-field-structure
-    public partial class EmbedField
-    {
-        public string Name { get; }
-
-        public string Value { get; }
-
-        public bool IsInline { get; }
-
-        public EmbedField(string name, string value, bool isInline)
-        {
-            Name = name;
-            Value = value;
-            IsInline = isInline;
-        }
-
-        public override string ToString() => $"{Name} | {Value}";
-    }
-
-    public partial class EmbedField
-    {
-        public static EmbedField Parse(JsonElement json)
-        {
-            var name = json.GetProperty("name").GetString();
-            var value = json.GetProperty("value").GetString();
-            var isInline = json.GetPropertyOrNull("inline")?.GetBoolean() ?? false;
-
-            return new EmbedField(name, value, isInline);
-        }
-    }
-}

DiscordChatExporter.Core/Discord/Data/EmbedFooter.cs

@@ -1,32 +0,0 @@
-using System.Text.Json;
-using JsonExtensions.Reading;
-
-namespace DiscordChatExporter.Core.Discord.Data
-{
-    // https://discord.com/developers/docs/resources/channel#embed-object-embed-footer-structure
-    public partial class EmbedFooter
-    {
-        public string Text { get; }
-
-        public string? IconUrl { get; }
-
-        public EmbedFooter(string text, string? iconUrl)
-        {
-            Text = text;
-            IconUrl = iconUrl;
-        }
-
-        public override string ToString() => Text;
-    }
-
-    public partial class EmbedFooter
-    {
-        public static EmbedFooter Parse(JsonElement json)
-        {
-            var text = json.GetProperty("text").GetString();
-            var iconUrl = json.GetPropertyOrNull("icon_url")?.GetString();
-
-            return new EmbedFooter(text, iconUrl);
-        }
-    }
-}

DiscordChatExporter.Core/Discord/Data/EmbedImage.cs

@@ -1,34 +0,0 @@
-using System.Text.Json;
-using JsonExtensions.Reading;
-
-namespace DiscordChatExporter.Core.Discord.Data
-{
-    // https://discord.com/developers/docs/resources/channel#embed-object-embed-image-structure
-    public partial class EmbedImage
-    {
-        public string? Url { get; }
-
-        public int? Width { get; }
-
-        public int? Height { get; }
-
-        public EmbedImage(string? url, int? width, int? height)
-        {
-            Url = url;
-            Height = height;
-            Width = width;
-        }
-    }
-
-    public partial class EmbedImage
-    {
-        public static EmbedImage Parse(JsonElement json)
-        {
-            var url = json.GetPropertyOrNull("url")?.GetString();
-            var width = json.GetPropertyOrNull("width")?.GetInt32();
-            var height = json.GetPropertyOrNull("height")?.GetInt32();
-
-            return new EmbedImage(url, width, height);
-        }
-    }
-}

DiscordChatExporter.Core/Discord/Data/Embeds/Embed.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+using System.Text.Json;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+// https://discord.com/developers/docs/resources/channel#embed-object
+public partial record Embed(
+    string? Title,
+    string? Url,
+    DateTimeOffset? Timestamp,
+    Color? Color,
+    EmbedAuthor? Author,
+    string? Description,
+    IReadOnlyList<EmbedField> Fields,
+    EmbedImage? Thumbnail,
+    IReadOnlyList<EmbedImage> Images,
+    EmbedFooter? Footer)
+{
+    public PlainImageEmbedProjection? TryGetPlainImage() =>
+        PlainImageEmbedProjection.TryResolve(this);
+
+    public SpotifyTrackEmbedProjection? TryGetSpotifyTrack() =>
+        SpotifyTrackEmbedProjection.TryResolve(this);
+
+    public YouTubeVideoEmbedProjection? TryGetYouTubeVideo() =>
+        YouTubeVideoEmbedProjection.TryResolve(this);
+}
+
+public partial record Embed
+{
+    public static Embed Parse(JsonElement json)
+    {
+        var title = json.GetPropertyOrNull("title")?.GetStringOrNull();
+        var url = json.GetPropertyOrNull("url")?.GetNonWhiteSpaceStringOrNull();
+        var timestamp = json.GetPropertyOrNull("timestamp")?.GetDateTimeOffset();
+        var color = json.GetPropertyOrNull("color")?.GetInt32OrNull()?.Pipe(System.Drawing.Color.FromArgb).ResetAlpha();
+        var author = json.GetPropertyOrNull("author")?.Pipe(EmbedAuthor.Parse);
+        var description = json.GetPropertyOrNull("description")?.GetStringOrNull();
+
+        var fields =
+            json.GetPropertyOrNull("fields")?.EnumerateArrayOrNull()?.Select(EmbedField.Parse).ToArray() ??
+            Array.Empty<EmbedField>();
+
+        var thumbnail = json.GetPropertyOrNull("thumbnail")?.Pipe(EmbedImage.Parse);
+
+        // Under the Discord API model, embeds can only have at most one image.
+        // Because of that, embeds that are rendered with multiple images on the client
+        // (e.g. tweet embeds), are exposed from the API as multiple separate embeds.
+        // Our embed model is consistent with the user-facing side of Discord, so images
+        // are stored as an array. The API will only ever return one image, but we deal
+        // with this by merging related embeds at the end of the message parsing process.
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/695
+        var images =
+            json.GetPropertyOrNull("image")?.Pipe(EmbedImage.Parse).Enumerate().ToArray() ??
+            Array.Empty<EmbedImage>();
+
+        var footer = json.GetPropertyOrNull("footer")?.Pipe(EmbedFooter.Parse);
+
+        return new Embed(
+            title,
+            url,
+            timestamp,
+            color,
+            author,
+            description,
+            fields,
+            thumbnail,
+            images,
+            footer
+        );
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/EmbedAuthor.cs

@@ -0,0 +1,22 @@
+using System.Text.Json;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+// https://discord.com/developers/docs/resources/channel#embed-object-embed-author-structure
+public record EmbedAuthor(
+    string? Name,
+    string? Url,
+    string? IconUrl,
+    string? IconProxyUrl)
+{
+    public static EmbedAuthor Parse(JsonElement json)
+    {
+        var name = json.GetPropertyOrNull("name")?.GetStringOrNull();
+        var url = json.GetPropertyOrNull("url")?.GetNonWhiteSpaceStringOrNull();
+        var iconUrl = json.GetPropertyOrNull("icon_url")?.GetNonWhiteSpaceStringOrNull();
+        var iconProxyUrl = json.GetPropertyOrNull("proxy_icon_url")?.GetNonWhiteSpaceStringOrNull();
+
+        return new EmbedAuthor(name, url, iconUrl, iconProxyUrl);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/EmbedField.cs

@@ -0,0 +1,20 @@
+using System.Text.Json;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+// https://discord.com/developers/docs/resources/channel#embed-object-embed-field-structure
+public record EmbedField(
+    string Name,
+    string Value,
+    bool IsInline)
+{
+    public static EmbedField Parse(JsonElement json)
+    {
+        var name = json.GetProperty("name").GetNonNullString();
+        var value = json.GetProperty("value").GetNonNullString();
+        var isInline = json.GetPropertyOrNull("inline")?.GetBooleanOrNull() ?? false;
+
+        return new EmbedField(name, value, isInline);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/EmbedFooter.cs

@@ -0,0 +1,20 @@
+using System.Text.Json;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+// https://discord.com/developers/docs/resources/channel#embed-object-embed-footer-structure
+public record EmbedFooter(
+    string Text,
+    string? IconUrl,
+    string? IconProxyUrl)
+{
+    public static EmbedFooter Parse(JsonElement json)
+    {
+        var text = json.GetProperty("text").GetNonNullString();
+        var iconUrl = json.GetPropertyOrNull("icon_url")?.GetNonWhiteSpaceStringOrNull();
+        var iconProxyUrl = json.GetPropertyOrNull("proxy_icon_url")?.GetNonWhiteSpaceStringOrNull();
+
+        return new EmbedFooter(text, iconUrl, iconProxyUrl);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/EmbedImage.cs

@@ -0,0 +1,22 @@
+using System.Text.Json;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+// https://discord.com/developers/docs/resources/channel#embed-object-embed-image-structure
+public record EmbedImage(
+    string? Url,
+    string? ProxyUrl,
+    int? Width,
+    int? Height)
+{
+    public static EmbedImage Parse(JsonElement json)
+    {
+        var url = json.GetPropertyOrNull("url")?.GetNonWhiteSpaceStringOrNull();
+        var proxyUrl = json.GetPropertyOrNull("proxy_url")?.GetNonWhiteSpaceStringOrNull();
+        var width = json.GetPropertyOrNull("width")?.GetInt32OrNull();
+        var height = json.GetPropertyOrNull("height")?.GetInt32OrNull();
+
+        return new EmbedImage(url, proxyUrl, width, height);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/PlainImageEmbedProjection.cs

@@ -0,0 +1,33 @@
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using DiscordChatExporter.Core.Utils;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+public record PlainImageEmbedProjection(string Url)
+{
+    public static PlainImageEmbedProjection? TryResolve(Embed embed)
+    {
+        if (string.IsNullOrWhiteSpace(embed.Url))
+            return null;
+
+        // Has to be an embed without any data (except URL and image)
+        if (!string.IsNullOrWhiteSpace(embed.Title) ||
+            embed.Timestamp is not null ||
+            embed.Author is not null ||
+            !string.IsNullOrWhiteSpace(embed.Description) ||
+            embed.Fields.Any() ||
+            embed.Footer is not null)
+        {
+            return null;
+        }
+
+        // Has to be an image file
+        var fileName = Regex.Match(embed.Url, @".+/([^?]*)").Groups[1].Value;
+        if (string.IsNullOrWhiteSpace(fileName) || !FileFormat.IsImage(Path.GetExtension(fileName)))
+            return null;
+
+        return new PlainImageEmbedProjection(embed.Url);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/SpotifyTrackEmbedProjection.cs

@@ -0,0 +1,33 @@
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+public partial record SpotifyTrackEmbedProjection(string TrackId)
+{
+    public string Url => $"https://open.spotify.com/embed/track/{TrackId}";
+}
+
+public partial record SpotifyTrackEmbedProjection
+{
+    private static string? TryParseTrackId(string embedUrl)
+    {
+        // https://open.spotify.com/track/1LHZMWefF9502NPfArRfvP?si=3efac6ce9be04f0a
+        var trackId = Regex.Match(embedUrl, @"spotify\.com/track/(.*?)(?:\?|&|/|$)").Groups[1].Value;
+        if (!string.IsNullOrWhiteSpace(trackId))
+            return trackId;
+
+        return null;
+    }
+
+    public static SpotifyTrackEmbedProjection? TryResolve(Embed embed)
+    {
+        if (string.IsNullOrWhiteSpace(embed.Url))
+            return null;
+
+        var trackId = TryParseTrackId(embed.Url);
+        if (string.IsNullOrWhiteSpace(trackId))
+            return null;
+
+        return new SpotifyTrackEmbedProjection(trackId);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embeds/YouTubeVideoEmbedProjection.cs

@@ -0,0 +1,54 @@
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Discord.Data.Embeds;
+
+public partial record YouTubeVideoEmbedProjection(string VideoId)
+{
+    public string Url => $"https://www.youtube.com/embed/{VideoId}";
+}
+
+public partial record YouTubeVideoEmbedProjection
+{
+    // Adapted from YoutubeExplode
+    // https://github.com/Tyrrrz/YoutubeExplode/blob/bc700b631bd105d0be208a88116347034bdca88b/YoutubeExplode/Videos/VideoId.cs#L40-L62
+    private static string? TryParseVideoId(string embedUrl)
+    {
+        // Regular URL
+        // https://www.youtube.com/watch?v=yIVRs6YSbOM
+        var regularMatch = Regex.Match(embedUrl, @"youtube\..+?/watch.*?v=(.*?)(?:&|/|$)").Groups[1].Value;
+        if (!string.IsNullOrWhiteSpace(regularMatch))
+            return regularMatch;
+
+        // Short URL
+        // https://youtu.be/yIVRs6YSbOM
+        var shortMatch = Regex.Match(embedUrl, @"youtu\.be/(.*?)(?:\?|&|/|$)").Groups[1].Value;
+        if (!string.IsNullOrWhiteSpace(shortMatch))
+            return shortMatch;
+
+        // Embed URL
+        // https://www.youtube.com/embed/yIVRs6YSbOM
+        var embedMatch = Regex.Match(embedUrl, @"youtube\..+?/embed/(.*?)(?:\?|&|/|$)").Groups[1].Value;
+        if (!string.IsNullOrWhiteSpace(embedMatch))
+            return embedMatch;
+
+        // Shorts URL
+        // https://www.youtube.com/shorts/sKL1vjP0tIo
+        var shortsMatch = Regex.Match(embedUrl, @"youtube\..+?/shorts/(.*?)(?:\?|&|/|$)").Groups[1].Value;
+        if (!string.IsNullOrWhiteSpace(shortsMatch))
+            return shortsMatch;
+
+        return null;
+    }
+
+    public static YouTubeVideoEmbedProjection? TryResolve(Embed embed)
+    {
+        if (string.IsNullOrWhiteSpace(embed.Url))
+            return null;
+
+        var videoId = TryParseVideoId(embed.Url);
+        if (string.IsNullOrWhiteSpace(videoId))
+            return null;
+
+        return new YouTubeVideoEmbedProjection(videoId);
+    }
+}

DiscordChatExporter.Core/Discord/Data/Emoji.cs

@@ -1,79 +1,79 @@
-using System.Collections.Generic;
+using System;
 using System.Linq;
-using System.Text;
 using System.Text.Json;
+using DiscordChatExporter.Core.Utils;
+using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
-using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/emoji#emoji-object
+public partial record Emoji(
+    // Only present on custom emoji
+    Snowflake? Id,
+    // Name of a custom emoji (e.g. LUL) or actual representation of a standard emoji (e.g. 🙂)
+    string Name,
+    bool IsAnimated,
+    string ImageUrl)
 {
-    // https://discord.com/developers/docs/resources/emoji#emoji-object
-    public partial class Emoji
+    // Name of a custom emoji (e.g. LUL) or name of a standard emoji (e.g. slight_smile)
+    public string Code => Id is not null
+        ? Name
+        : EmojiIndex.TryGetCode(Name) ?? Name;
+}
+
+public partial record Emoji
+{
+    private static string GetTwemojiId(string name)
     {
-        public string? Id { get; }
+        var runes = name.GetRunes().ToArray();
 
-        public string Name { get; }
+        // Variant selector rune is skipped in Twemoji names, except when the emoji also contains a zero-width joiner.
+        // VS = 0xfe0f; ZWJ = 0x200d.
+        var filteredRunes = runes.Any(r => r.Value == 0x200d)
+            ? runes
+            : runes.Where(r => r.Value != 0xfe0f);
 
-        public bool IsAnimated { get; }
-
-        public string ImageUrl { get; }
-
-        public Emoji(string? id, string name, bool isAnimated)
-        {
-            Id = id;
-            Name = name;
-            IsAnimated = isAnimated;
-
-            ImageUrl = GetImageUrl(id, name, isAnimated);
-        }
-
-        public override string ToString() => Name;
+        return string.Join(
+            "-",
+            filteredRunes.Select(r => r.Value.ToString("x"))
+        );
     }
 
-    public partial class Emoji
+    private static string GetImageUrl(Snowflake id, bool isAnimated) => isAnimated
+        ? $"https://cdn.discordapp.com/emojis/{id}.gif"
+        : $"https://cdn.discordapp.com/emojis/{id}.png";
+
+    private static string GetImageUrl(string name) =>
+        $"https://twemoji.maxcdn.com/v/latest/svg/{GetTwemojiId(name)}.svg";
+
+    public static string GetImageUrl(Snowflake? id, string? name, bool isAnimated)
     {
-        private static IEnumerable<Rune> GetRunes(string emoji)
-        {
-            var lastIndex = 0;
-            while (lastIndex < emoji.Length && Rune.TryGetRuneAt(emoji, lastIndex, out var rune))
-            {
-                // Skip variant selector rune
-                if (rune.Value != 0xfe0f)
-                    yield return rune;
+        // Custom emoji
+        if (id is not null)
+            return GetImageUrl(id.Value, isAnimated);
 
-                lastIndex += rune.Utf16SequenceLength;
-            }
-        }
+        // Standard emoji
+        if (!string.IsNullOrWhiteSpace(name))
+            return GetImageUrl(name);
 
-        private static string GetTwemojiName(IEnumerable<Rune> runes) =>
-            runes.Select(r => r.Value.ToString("x")).JoinToString("-");
+        // Either ID or name should be set
+        throw new ApplicationException("Emoji has neither ID nor name set.");
+    }
 
-        public static string GetImageUrl(string? id, string name, bool isAnimated)
-        {
-            // Custom emoji
-            if (!string.IsNullOrWhiteSpace(id))
-            {
-                // Animated
-                if (isAnimated)
-                    return $"https://cdn.discordapp.com/emojis/{id}.gif";
+    public static Emoji Parse(JsonElement json)
+    {
+        var id = json.GetPropertyOrNull("id")?.GetNonWhiteSpaceStringOrNull()?.Pipe(Snowflake.Parse);
+        var name = json.GetPropertyOrNull("name")?.GetNonWhiteSpaceStringOrNull();
+        var isAnimated = json.GetPropertyOrNull("animated")?.GetBooleanOrNull() ?? false;
+        var imageUrl = GetImageUrl(id, name, isAnimated);
 
-                // Non-animated
-                return $"https://cdn.discordapp.com/emojis/{id}.png";
-            }
-
-            // Standard emoji
-            var emojiRunes = GetRunes(name).ToArray();
-            var twemojiName = GetTwemojiName(emojiRunes);
-            return $"https://twemoji.maxcdn.com/2/72x72/{twemojiName}.png";
-        }
-
-        public static Emoji Parse(JsonElement json)
-        {
-            var id = json.GetPropertyOrNull("id")?.GetString();
-            var name = json.GetProperty("name").GetString();
-            var isAnimated = json.GetPropertyOrNull("animated")?.GetBoolean() ?? false;
-
-            return new Emoji(id, name, isAnimated);
-        }
+        return new Emoji(
+            id,
+            // Name may be missing if it's an emoji inside a reaction
+            name ?? "<unknown emoji>",
+            isAnimated,
+            imageUrl
+        );
     }
 }

DiscordChatExporter.Core/Discord/Data/Guild.cs

@@ -1,53 +1,42 @@
-using System.Text.Json;
+using System;
+using System.Text.Json;
 using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/guild#guild-object
+public record Guild(Snowflake Id, string Name, string IconUrl) : IHasId
 {
-    // https://discord.com/developers/docs/resources/guild#guild-object
-    public partial class Guild : IHasId
+    public static Guild DirectMessages { get; } = new(
+        Snowflake.Zero,
+        "Direct Messages",
+        GetDefaultIconUrl()
+    );
+
+    private static string GetDefaultIconUrl() =>
+        "https://cdn.discordapp.com/embed/avatars/0.png";
+
+    private static string GetIconUrl(Snowflake id, string iconHash)
     {
-        public Snowflake Id { get; }
+        var extension = iconHash.StartsWith("a_", StringComparison.Ordinal)
+            ? "gif"
+            : "png";
 
-        public string Name { get; }
-
-        public string IconUrl { get; }
-
-        public Guild(Snowflake id, string name, string iconUrl)
-        {
-            Id = id;
-            Name = name;
-            IconUrl = iconUrl;
-        }
-
-        public override string ToString() => Name;
+        return $"https://cdn.discordapp.com/icons/{id}/{iconHash}.{extension}";
     }
 
-    public partial class Guild
+    public static Guild Parse(JsonElement json)
     {
-        public static Guild DirectMessages { get; } = new(
-            Snowflake.Zero,
-            "Direct Messages",
-            GetDefaultIconUrl()
-        );
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var name = json.GetProperty("name").GetNonNullString();
 
-        private static string GetDefaultIconUrl() =>
-            "https://cdn.discordapp.com/embed/avatars/0.png";
+        var iconHash = json.GetPropertyOrNull("icon")?.GetNonWhiteSpaceStringOrNull();
+        var iconUrl = !string.IsNullOrWhiteSpace(iconHash)
+            ? GetIconUrl(id, iconHash)
+            : GetDefaultIconUrl();
 
-        private static string GetIconUrl(Snowflake id, string iconHash) =>
-            $"https://cdn.discordapp.com/icons/{id}/{iconHash}.png";
-
-        public static Guild Parse(JsonElement json)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            var name = json.GetProperty("name").GetString();
-            var iconHash = json.GetProperty("icon").GetString();
-
-            var iconUrl = !string.IsNullOrWhiteSpace(iconHash)
-                ? GetIconUrl(id, iconHash)
-                : GetDefaultIconUrl();
-
-            return new Guild(id, name, iconUrl);
-        }
+        return new Guild(id, name, iconUrl);
     }
 }

DiscordChatExporter.Core/Discord/Data/Member.cs

@@ -6,51 +6,41 @@ using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/guild#guild-member-object
+public partial record Member(
+    User User,
+    string Nick,
+    IReadOnlyList<Snowflake> RoleIds) : IHasId
 {
-    // https://discord.com/developers/docs/resources/guild#guild-member-object
-    public partial class Member : IHasId
+    public Snowflake Id => User.Id;
+}
+
+public partial record Member
+{
+    public static Member CreateForUser(User user) => new(
+        user,
+        user.Name,
+        Array.Empty<Snowflake>()
+    );
+
+    public static Member Parse(JsonElement json)
     {
-        public Snowflake Id => User.Id;
+        var user = json.GetProperty("user").Pipe(User.Parse);
+        var nick = json.GetPropertyOrNull("nick")?.GetNonWhiteSpaceStringOrNull();
 
-        public User User { get; }
+        var roleIds = json
+            .GetPropertyOrNull("roles")?
+            .EnumerateArray()
+            .Select(j => j.GetNonWhiteSpaceString())
+            .Select(Snowflake.Parse)
+            .ToArray() ?? Array.Empty<Snowflake>();
 
-        public string Nick { get; }
-
-        public IReadOnlyList<Snowflake> RoleIds { get; }
-
-        public Member(User user, string? nick, IReadOnlyList<Snowflake> roleIds)
-        {
-            User = user;
-            Nick = nick ?? user.Name;
-            RoleIds = roleIds;
-        }
-
-        public override string ToString() => Nick;
-    }
-
-    public partial class Member
-    {
-        public static Member CreateForUser(User user) => new(
+        return new Member(
             user,
-            null,
-            Array.Empty<Snowflake>()
+            nick ?? user.Name,
+            roleIds
         );
-
-        public static Member Parse(JsonElement json)
-        {
-            var user = json.GetProperty("user").Pipe(User.Parse);
-            var nick = json.GetPropertyOrNull("nick")?.GetString();
-
-            var roleIds =
-                json.GetPropertyOrNull("roles")?.EnumerateArray().Select(j => j.GetString().Pipe(Snowflake.Parse)).ToArray() ??
-                Array.Empty<Snowflake>();
-
-            return new Member(
-                user,
-                nick,
-                roleIds
-            );
-        }
     }
 }

DiscordChatExporter.Core/Discord/Data/Message.cs

@@ -3,150 +3,154 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json;
 using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Discord.Data.Embeds;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#message-object
+public record Message(
+    Snowflake Id,
+    MessageKind Kind,
+    User Author,
+    DateTimeOffset Timestamp,
+    DateTimeOffset? EditedTimestamp,
+    DateTimeOffset? CallEndedTimestamp,
+    bool IsPinned,
+    string Content,
+    IReadOnlyList<Attachment> Attachments,
+    IReadOnlyList<Embed> Embeds,
+    IReadOnlyList<Sticker> Stickers,
+    IReadOnlyList<Reaction> Reactions,
+    IReadOnlyList<User> MentionedUsers,
+    MessageReference? Reference,
+    Message? ReferencedMessage) : IHasId
 {
-    // https://discord.com/developers/docs/resources/channel#message-object-message-types
-    public enum MessageType
+    private static IReadOnlyList<Embed> NormalizeEmbeds(IReadOnlyList<Embed> embeds)
     {
-        Default = 0,
-        RecipientAdd = 1,
-        RecipientRemove = 2,
-        Call = 3,
-        ChannelNameChange = 4,
-        ChannelIconChange = 5,
-        ChannelPinnedMessage = 6,
-        GuildMemberJoin = 7,
-        Reply = 19
-    }
+        if (embeds.Count <= 1)
+            return embeds;
 
-    // https://discord.com/developers/docs/resources/channel#message-object
-    public partial class Message : IHasId
-    {
-        public Snowflake Id { get; }
+        // Discord API doesn't support embeds with multiple images, even though the Discord client does.
+        // To work around this, it seems that the API returns multiple consecutive embeds with different images,
+        // which are then merged together on the client. We need to replicate the same behavior ourselves.
+        // Currently, only known case where this workaround is required is Twitter embeds.
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/695
 
-        public MessageType Type { get; }
+        var normalizedEmbeds = new List<Embed>();
 
-        public User Author { get; }
-
-        public DateTimeOffset Timestamp { get; }
-
-        public DateTimeOffset? EditedTimestamp { get; }
-
-        public DateTimeOffset? CallEndedTimestamp { get; }
-
-        public bool IsPinned { get; }
-
-        public string Content { get; }
-
-        public IReadOnlyList<Attachment> Attachments { get; }
-
-        public IReadOnlyList<Embed> Embeds { get; }
-
-        public IReadOnlyList<Reaction> Reactions { get; }
-
-        public IReadOnlyList<User> MentionedUsers { get; }
-
-        public MessageReference? Reference { get; }
-
-        public Message? ReferencedMessage { get; }
-
-        public Message(
-            Snowflake id,
-            MessageType type,
-            User author,
-            DateTimeOffset timestamp,
-            DateTimeOffset? editedTimestamp,
-            DateTimeOffset? callEndedTimestamp,
-            bool isPinned,
-            string content,
-            IReadOnlyList<Attachment> attachments,
-            IReadOnlyList<Embed> embeds,
-            IReadOnlyList<Reaction> reactions,
-            IReadOnlyList<User> mentionedUsers,
-            MessageReference? messageReference,
-            Message? referencedMessage)
+        for (var i = 0; i < embeds.Count; i++)
         {
-            Id = id;
-            Type = type;
-            Author = author;
-            Timestamp = timestamp;
-            EditedTimestamp = editedTimestamp;
-            CallEndedTimestamp = callEndedTimestamp;
-            IsPinned = isPinned;
-            Content = content;
-            Attachments = attachments;
-            Embeds = embeds;
-            Reactions = reactions;
-            MentionedUsers = mentionedUsers;
-            Reference = messageReference;
-            ReferencedMessage = referencedMessage;
-        }
+            var embed = embeds[i];
 
-        public override string ToString() => Content;
-    }
-
-    public partial class Message
-    {
-        public static Message Parse(JsonElement json)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            var author = json.GetProperty("author").Pipe(User.Parse);
-            var timestamp = json.GetProperty("timestamp").GetDateTimeOffset();
-            var editedTimestamp = json.GetPropertyOrNull("edited_timestamp")?.GetDateTimeOffset();
-            var callEndedTimestamp = json.GetPropertyOrNull("call")?.GetPropertyOrNull("ended_timestamp")?.GetDateTimeOffset();
-            var type = (MessageType) json.GetProperty("type").GetInt32();
-            var isPinned = json.GetPropertyOrNull("pinned")?.GetBoolean() ?? false;
-            var messageReference = json.GetPropertyOrNull("message_reference")?.Pipe(MessageReference.Parse);
-            var referencedMessage = json.GetPropertyOrNull("referenced_message")?.Pipe(Message.Parse);
-
-            var content = type switch
+            if (embed.Url?.Contains("://twitter.com/") == true)
             {
-                MessageType.RecipientAdd => "Added a recipient.",
-                MessageType.RecipientRemove => "Removed a recipient.",
-                MessageType.Call =>
-                    $"Started a call that lasted {callEndedTimestamp?.Pipe(t => t - timestamp).Pipe(t => (int) t.TotalMinutes) ?? 0} minutes.",
-                MessageType.ChannelNameChange => "Changed the channel name.",
-                MessageType.ChannelIconChange => "Changed the channel icon.",
-                MessageType.ChannelPinnedMessage => "Pinned a message.",
-                MessageType.GuildMemberJoin => "Joined the server.",
-                _ => json.GetPropertyOrNull("content")?.GetString() ?? ""
-            };
+                // Find embeds with the same URL that only contain a single image and nothing else
+                var trailingEmbeds = embeds
+                    .Skip(i + 1)
+                    .TakeWhile(e =>
+                        e.Url == embed.Url &&
+                        e.Timestamp is null &&
+                        e.Author is null &&
+                        e.Color is null &&
+                        string.IsNullOrWhiteSpace(e.Description) &&
+                        !e.Fields.Any() &&
+                        e.Images.Count == 1 &&
+                        e.Footer is null
+                    )
+                    .ToArray();
 
-            var attachments =
-                json.GetPropertyOrNull("attachments")?.EnumerateArray().Select(Attachment.Parse).ToArray() ??
-                Array.Empty<Attachment>();
+                if (trailingEmbeds.Any())
+                {
+                    // Concatenate all images into one embed
+                    var images = embed.Images.Concat(trailingEmbeds.SelectMany(e => e.Images)).ToArray();
+                    normalizedEmbeds.Add(embed with { Images = images });
 
-            var embeds =
-                json.GetPropertyOrNull("embeds")?.EnumerateArray().Select(Embed.Parse).ToArray() ??
-                Array.Empty<Embed>();
-
-            var reactions =
-                json.GetPropertyOrNull("reactions")?.EnumerateArray().Select(Reaction.Parse).ToArray() ??
-                Array.Empty<Reaction>();
-
-            var mentionedUsers =
-                json.GetPropertyOrNull("mentions")?.EnumerateArray().Select(User.Parse).ToArray() ??
-                Array.Empty<User>();
-
-            return new Message(
-                id,
-                type,
-                author,
-                timestamp,
-                editedTimestamp,
-                callEndedTimestamp,
-                isPinned,
-                content,
-                attachments,
-                embeds,
-                reactions,
-                mentionedUsers,
-                messageReference,
-                referencedMessage
-            );
+                    i += trailingEmbeds.Length;
+                }
+                else
+                {
+                    normalizedEmbeds.Add(embed);
+                }
+            }
+            else
+            {
+                normalizedEmbeds.Add(embed);
+            }
         }
+
+        return normalizedEmbeds;
+    }
+
+    public static Message Parse(JsonElement json)
+    {
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var kind = (MessageKind)json.GetProperty("type").GetInt32();
+        var author = json.GetProperty("author").Pipe(User.Parse);
+
+        var timestamp = json.GetProperty("timestamp").GetDateTimeOffset();
+        var editedTimestamp = json.GetPropertyOrNull("edited_timestamp")?.GetDateTimeOffset();
+        var callEndedTimestamp = json
+            .GetPropertyOrNull("call")?
+            .GetPropertyOrNull("ended_timestamp")?
+            .GetDateTimeOffset();
+
+        var isPinned = json.GetPropertyOrNull("pinned")?.GetBooleanOrNull() ?? false;
+
+        var content = kind switch
+        {
+            MessageKind.RecipientAdd => "Added a recipient.",
+            MessageKind.RecipientRemove => "Removed a recipient.",
+            MessageKind.Call =>
+                $"Started a call that lasted {callEndedTimestamp?.Pipe(t => t - timestamp).Pipe(t => (int)t.TotalMinutes) ?? 0} minutes.",
+            MessageKind.ChannelNameChange => "Changed the channel name.",
+            MessageKind.ChannelIconChange => "Changed the channel icon.",
+            MessageKind.ChannelPinnedMessage => "Pinned a message.",
+            MessageKind.GuildMemberJoin => "Joined the server.",
+            _ => json.GetPropertyOrNull("content")?.GetStringOrNull() ?? ""
+        };
+
+        var attachments =
+            json.GetPropertyOrNull("attachments")?.EnumerateArrayOrNull()?.Select(Attachment.Parse).ToArray() ??
+            Array.Empty<Attachment>();
+
+        var embeds = NormalizeEmbeds(
+            json.GetPropertyOrNull("embeds")?.EnumerateArrayOrNull()?.Select(Embed.Parse).ToArray() ??
+            Array.Empty<Embed>()
+        );
+
+        var stickers =
+            json.GetPropertyOrNull("sticker_items")?.EnumerateArrayOrNull()?.Select(Sticker.Parse).ToArray() ??
+            Array.Empty<Sticker>();
+
+        var reactions =
+            json.GetPropertyOrNull("reactions")?.EnumerateArrayOrNull()?.Select(Reaction.Parse).ToArray() ??
+            Array.Empty<Reaction>();
+
+        var mentionedUsers =
+            json.GetPropertyOrNull("mentions")?.EnumerateArrayOrNull()?.Select(User.Parse).ToArray() ??
+            Array.Empty<User>();
+
+        var messageReference = json.GetPropertyOrNull("message_reference")?.Pipe(MessageReference.Parse);
+        var referencedMessage = json.GetPropertyOrNull("referenced_message")?.Pipe(Parse);
+
+        return new Message(
+            id,
+            kind,
+            author,
+            timestamp,
+            editedTimestamp,
+            callEndedTimestamp,
+            isPinned,
+            content,
+            attachments,
+            embeds,
+            stickers,
+            reactions,
+            mentionedUsers,
+            messageReference,
+            referencedMessage
+        );
     }
 }

DiscordChatExporter.Core/Discord/Data/MessageKind.cs

@@ -0,0 +1,15 @@
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#message-object-message-types
+public enum MessageKind
+{
+    Default = 0,
+    RecipientAdd = 1,
+    RecipientRemove = 2,
+    Call = 3,
+    ChannelNameChange = 4,
+    ChannelIconChange = 5,
+    ChannelPinnedMessage = 6,
+    GuildMemberJoin = 7,
+    Reply = 19
+}

DiscordChatExporter.Core/Discord/Data/MessageReference.cs

@@ -2,36 +2,28 @@ using System.Text.Json;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#message-object-message-reference-structure
+public record MessageReference(Snowflake? MessageId, Snowflake? ChannelId, Snowflake? GuildId)
 {
-    // https://discord.com/developers/docs/resources/channel#message-object-message-reference-structure
-    public partial class MessageReference
+    public static MessageReference Parse(JsonElement json)
     {
-        public Snowflake? MessageId { get; }
+        var messageId = json
+            .GetPropertyOrNull("message_id")?
+            .GetNonWhiteSpaceStringOrNull()?
+            .Pipe(Snowflake.Parse);
 
-        public Snowflake? ChannelId { get; }
+        var channelId = json
+            .GetPropertyOrNull("channel_id")?
+            .GetNonWhiteSpaceStringOrNull()?
+            .Pipe(Snowflake.Parse);
 
-        public Snowflake? GuildId { get; }
+        var guildId = json
+            .GetPropertyOrNull("guild_id")?
+            .GetNonWhiteSpaceStringOrNull()?
+            .Pipe(Snowflake.Parse);
 
-        public MessageReference(Snowflake? messageId, Snowflake? channelId, Snowflake? guildId)
-        {
-            MessageId = messageId;
-            ChannelId = channelId;
-            GuildId = guildId;
-        }
-
-        public override string ToString() => MessageId?.ToString() ?? "<unknown reference>";
-    }
-
-    public partial class MessageReference
-    {
-        public static MessageReference Parse(JsonElement json)
-        {
-            var messageId = json.GetPropertyOrNull("message_id")?.GetString().Pipe(Snowflake.Parse);
-            var channelId = json.GetPropertyOrNull("channel_id")?.GetString().Pipe(Snowflake.Parse);
-            var guildId = json.GetPropertyOrNull("guild_id")?.GetString().Pipe(Snowflake.Parse);
-
-            return new MessageReference(messageId, channelId, guildId);
-        }
+        return new MessageReference(messageId, channelId, guildId);
     }
 }

DiscordChatExporter.Core/Discord/Data/Reaction.cs

@@ -1,32 +1,16 @@
 using System.Text.Json;
 using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/channel#reaction-object
+public record Reaction(Emoji Emoji, int Count)
 {
-    // https://discord.com/developers/docs/resources/channel#reaction-object
-    public partial class Reaction
+    public static Reaction Parse(JsonElement json)
     {
-        public Emoji Emoji { get; }
+        var emoji = json.GetProperty("emoji").Pipe(Emoji.Parse);
+        var count = json.GetProperty("count").GetInt32();
 
-        public int Count { get; }
-
-        public Reaction(Emoji emoji, int count)
-        {
-            Emoji = emoji;
-            Count = count;
-        }
-
-        public override string ToString() => $"{Emoji} ({Count})";
-    }
-
-    public partial class Reaction
-    {
-        public static Reaction Parse(JsonElement json)
-        {
-            var count = json.GetProperty("count").GetInt32();
-            var emoji = json.GetProperty("emoji").Pipe(Emoji.Parse);
-
-            return new Reaction(emoji, count);
-        }
+        return new Reaction(emoji, count);
     }
 }

DiscordChatExporter.Core/Discord/Data/Role.cs

@@ -4,49 +4,24 @@ using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/topics/permissions#role-object
+public record Role(Snowflake Id, string Name, int Position, Color? Color) : IHasId
 {
-    // https://discord.com/developers/docs/topics/permissions#role-object
-    public partial class Role : IHasId
+    public static Role Parse(JsonElement json)
     {
-        public Snowflake Id { get; }
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var name = json.GetProperty("name").GetNonNullString();
+        var position = json.GetProperty("position").GetInt32();
 
-        public string Name { get; }
+        var color = json
+            .GetPropertyOrNull("color")?
+            .GetInt32()
+            .Pipe(System.Drawing.Color.FromArgb)
+            .ResetAlpha()
+            .NullIf(c => c.ToRgb() <= 0);
 
-        public int Position { get; }
-
-        public Color? Color { get; }
-
-        public Role(
-            Snowflake id,
-            string name,
-            int position,
-            Color? color)
-        {
-            Id = id;
-            Name = name;
-            Position = position;
-            Color = color;
-        }
-
-        public override string ToString() => Name;
-    }
-
-    public partial class Role
-    {
-        public static Role Parse(JsonElement json)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            var name = json.GetProperty("name").GetString();
-            var position = json.GetProperty("position").GetInt32();
-
-            var color = json.GetPropertyOrNull("color")?
-                .GetInt32()
-                .Pipe(System.Drawing.Color.FromArgb)
-                .ResetAlpha()
-                .NullIf(c => c.ToRgb() <= 0);
-
-            return new Role(id, name, position, color);
-        }
+        return new Role(id, name, position, color);
     }
 }

DiscordChatExporter.Core/Discord/Data/Sticker.cs

@@ -0,0 +1,25 @@
+using System.Text.Json;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/sticker#sticker-resource
+public record Sticker(Snowflake Id, string Name, StickerFormat Format, string SourceUrl)
+{
+    private static string GetSourceUrl(Snowflake id, StickerFormat format)
+    {
+        var extension = format == StickerFormat.Lottie ? "json" : "png";
+        return $"https://discord.com/stickers/{id}.{extension}";
+    }
+
+    public static Sticker Parse(JsonElement json)
+    {
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var name = json.GetProperty("name").GetNonNullString();
+        var format = (StickerFormat)json.GetProperty("format_type").GetInt32();
+        var sourceUrl = GetSourceUrl(id, format);
+
+        return new Sticker(id, name, format, sourceUrl);
+    }
+}

DiscordChatExporter.Core/Discord/Data/StickerFormat.cs

@@ -0,0 +1,8 @@
+namespace DiscordChatExporter.Core.Discord.Data;
+
+public enum StickerFormat
+{
+    Png = 1,
+    PngAnimated = 2,
+    Lottie = 3
+}

DiscordChatExporter.Core/Discord/Data/User.cs

@@ -4,70 +4,47 @@ using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Utils.Extensions;
 using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Core.Discord.Data
+namespace DiscordChatExporter.Core.Discord.Data;
+
+// https://discord.com/developers/docs/resources/user#user-object
+public partial record User(
+    Snowflake Id,
+    bool IsBot,
+    int Discriminator,
+    string Name,
+    string AvatarUrl) : IHasId
 {
-    // https://discord.com/developers/docs/resources/user#user-object
-    public partial class User : IHasId
+    public string DiscriminatorFormatted => $"{Discriminator:0000}";
+
+    public string FullName => $"{Name}#{DiscriminatorFormatted}";
+}
+
+public partial record User
+{
+    private static string GetDefaultAvatarUrl(int discriminator) =>
+        $"https://cdn.discordapp.com/embed/avatars/{discriminator % 5}.png";
+
+    private static string GetAvatarUrl(Snowflake id, string avatarHash)
     {
-        public Snowflake Id { get; }
+        var extension = avatarHash.StartsWith("a_", StringComparison.Ordinal)
+            ? "gif"
+            : "png";
 
-        public bool IsBot { get; }
-
-        public int Discriminator { get; }
-
-        public string DiscriminatorFormatted => $"{Discriminator:0000}";
-
-        public string Name { get; }
-
-        public string FullName => $"{Name}#{DiscriminatorFormatted}";
-
-        public string AvatarUrl { get; }
-
-        public User(
-            Snowflake id,
-            bool isBot,
-            int discriminator,
-            string name,
-            string avatarUrl)
-        {
-            Id = id;
-            IsBot = isBot;
-            Discriminator = discriminator;
-            Name = name;
-            AvatarUrl = avatarUrl;
-        }
-
-        public override string ToString() => FullName;
+        return $"https://cdn.discordapp.com/avatars/{id}/{avatarHash}.{extension}?size=512";
     }
 
-    public partial class User
+    public static User Parse(JsonElement json)
     {
-        private static string GetDefaultAvatarUrl(int discriminator) =>
-            $"https://cdn.discordapp.com/embed/avatars/{discriminator % 5}.png";
+        var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
+        var isBot = json.GetPropertyOrNull("bot")?.GetBooleanOrNull() ?? false;
+        var discriminator = json.GetProperty("discriminator").GetNonWhiteSpaceString().Pipe(int.Parse);
+        var name = json.GetProperty("username").GetNonNullString();
 
-        private static string GetAvatarUrl(Snowflake id, string avatarHash)
-        {
-            // Animated
-            if (avatarHash.StartsWith("a_", StringComparison.Ordinal))
-                return $"https://cdn.discordapp.com/avatars/{id}/{avatarHash}.gif";
+        var avatarHash = json.GetPropertyOrNull("avatar")?.GetNonWhiteSpaceStringOrNull();
+        var avatarUrl = !string.IsNullOrWhiteSpace(avatarHash)
+            ? GetAvatarUrl(id, avatarHash)
+            : GetDefaultAvatarUrl(discriminator);
 
-            // Non-animated
-            return $"https://cdn.discordapp.com/avatars/{id}/{avatarHash}.png";
-        }
-
-        public static User Parse(JsonElement json)
-        {
-            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
-            var discriminator = json.GetProperty("discriminator").GetString().Pipe(int.Parse);
-            var name = json.GetProperty("username").GetString();
-            var avatarHash = json.GetProperty("avatar").GetString();
-            var isBot = json.GetPropertyOrNull("bot")?.GetBoolean() ?? false;
-
-            var avatarUrl = !string.IsNullOrWhiteSpace(avatarHash)
-                ? GetAvatarUrl(id, avatarHash)
-                : GetDefaultAvatarUrl(discriminator);
-
-            return new User(id, isBot, discriminator, name, avatarUrl);
-        }
+        return new User(id, isBot, discriminator, name, avatarUrl);
     }
 }

DiscordChatExporter.Core/Discord/DiscordClient.cs

@@ -3,285 +3,342 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
+using System.Runtime.CompilerServices;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Exceptions;
 using DiscordChatExporter.Core.Utils;
 using DiscordChatExporter.Core.Utils.Extensions;
+using Gress;
 using JsonExtensions.Http;
 using JsonExtensions.Reading;
-using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Core.Discord
+namespace DiscordChatExporter.Core.Discord;
+
+public class DiscordClient
 {
-    public class DiscordClient
+    private readonly string _token;
+    private readonly Uri _baseUri = new("https://discord.com/api/v9/", UriKind.Absolute);
+
+    private TokenKind _tokenKind = TokenKind.Unknown;
+
+    public DiscordClient(string token) => _token = token;
+
+    private async ValueTask<HttpResponseMessage> GetResponseAsync(
+        string url,
+        bool isBot,
+        CancellationToken cancellationToken = default)
     {
-        private readonly HttpClient _httpClient;
-        private readonly AuthToken _token;
+        using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
 
-        private readonly Uri _baseUri = new("https://discord.com/api/v8/", UriKind.Absolute);
+        // Don't validate because token can have invalid characters
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/828
+        request.Headers.TryAddWithoutValidation(
+            "Authorization",
+            isBot ? $"Bot {_token}" : _token
+        );
 
-        public DiscordClient(HttpClient httpClient, AuthToken token)
+        return await Http.Client.SendAsync(
+            request,
+            HttpCompletionOption.ResponseHeadersRead,
+            cancellationToken
+        );
+    }
+
+    private async ValueTask<HttpResponseMessage> GetResponseAsync(
+        string url,
+        CancellationToken cancellationToken = default)
+    {
+        return await Http.ResponseResiliencePolicy.ExecuteAsync(async innerCancellationToken =>
         {
-            _httpClient = httpClient;
-            _token = token;
-        }
+            if (_tokenKind == TokenKind.User)
+                return await GetResponseAsync(url, false, innerCancellationToken);
 
-        public DiscordClient(AuthToken token)
-            : this(Http.Client, token) {}
+            if (_tokenKind == TokenKind.Bot)
+                return await GetResponseAsync(url, true, innerCancellationToken);
 
-        private async ValueTask<HttpResponseMessage> GetResponseAsync(string url) =>
-            await Http.ResponsePolicy.ExecuteAsync(async () =>
+            // Try to authenticate as user
+            var userResponse = await GetResponseAsync(url, false, innerCancellationToken);
+            if (userResponse.StatusCode != HttpStatusCode.Unauthorized)
             {
-                using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
-                request.Headers.Authorization = _token.GetAuthenticationHeader();
-
-                return await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
-            });
-
-        private async ValueTask<JsonElement> GetJsonResponseAsync(string url)
-        {
-            using var response = await GetResponseAsync(url);
-
-            if (!response.IsSuccessStatusCode)
-            {
-                throw response.StatusCode switch
-                {
-                    HttpStatusCode.Unauthorized => DiscordChatExporterException.Unauthorized(),
-                    HttpStatusCode.Forbidden => DiscordChatExporterException.Forbidden(),
-                    HttpStatusCode.NotFound => DiscordChatExporterException.NotFound(),
-                    _ => DiscordChatExporterException.FailedHttpRequest(response)
-                };
+                _tokenKind = TokenKind.User;
+                return userResponse;
             }
 
-            return await response.Content.ReadAsJsonAsync();
-        }
+            userResponse.Dispose();
 
-        private async ValueTask<JsonElement?> TryGetJsonResponseAsync(string url)
-        {
-            using var response = await GetResponseAsync(url);
-
-            return response.IsSuccessStatusCode
-                ? await response.Content.ReadAsJsonAsync()
-                : (JsonElement?) null;
-        }
-
-        public async IAsyncEnumerable<Guild> GetUserGuildsAsync()
-        {
-            yield return Guild.DirectMessages;
-
-            var currentAfter = Snowflake.Zero;
-
-            while (true)
+            // Otherwise, try to authenticate as bot
+            var botResponse = await GetResponseAsync(url, true, innerCancellationToken);
+            if (botResponse.StatusCode != HttpStatusCode.Unauthorized)
             {
-                var url = new UrlBuilder()
-                    .SetPath("users/@me/guilds")
-                    .SetQueryParameter("limit", "100")
-                    .SetQueryParameter("after", currentAfter.ToString())
-                    .Build();
-
-                var response = await GetJsonResponseAsync(url);
-
-                var isEmpty = true;
-                foreach (var guild in response.EnumerateArray().Select(Guild.Parse))
-                {
-                    yield return guild;
-
-                    currentAfter = guild.Id;
-                    isEmpty = false;
-                }
-
-                if (isEmpty)
-                    yield break;
-            }
-        }
-
-        public async ValueTask<Guild> GetGuildAsync(Snowflake guildId)
-        {
-            if (guildId == Guild.DirectMessages.Id)
-                return Guild.DirectMessages;
-
-            var response = await GetJsonResponseAsync($"guilds/{guildId}");
-            return Guild.Parse(response);
-        }
-
-        public async IAsyncEnumerable<Channel> GetGuildChannelsAsync(Snowflake guildId)
-        {
-            if (guildId == Guild.DirectMessages.Id)
-            {
-                var response = await GetJsonResponseAsync("users/@me/channels");
-                foreach (var channelJson in response.EnumerateArray())
-                    yield return Channel.Parse(channelJson);
-            }
-            else
-            {
-                var response = await GetJsonResponseAsync($"guilds/{guildId}/channels");
-
-                var orderedResponse = response
-                    .EnumerateArray()
-                    .OrderBy(j => j.GetProperty("position").GetInt32())
-                    .ThenBy(j => ulong.Parse(j.GetProperty("id").GetString()))
-                    .ToArray();
-
-                var categories = orderedResponse
-                    .Where(j => j.GetProperty("type").GetInt32() == (int)ChannelType.GuildCategory)
-                    .Select((j, index) => ChannelCategory.Parse(j, index + 1))
-                    .ToDictionary(j => j.Id.ToString());
-
-                var position = 0;
-
-                foreach (var channelJson in orderedResponse)
-                {
-                    var parentId = channelJson.GetPropertyOrNull("parent_id")?.GetString();
-                    var category = !string.IsNullOrWhiteSpace(parentId)
-                        ? categories.GetValueOrDefault(parentId)
-                        : null;
-
-                    var channel = Channel.Parse(channelJson, category, position);
-
-                    // Skip non-text channels
-                    if (!channel.IsTextChannel)
-                        continue;
-
-                    position++;
-
-                    yield return channel;
-                }
-            }
-        }
-
-        public async IAsyncEnumerable<Role> GetGuildRolesAsync(Snowflake guildId)
-        {
-            if (guildId == Guild.DirectMessages.Id)
-                yield break;
-
-            var response = await GetJsonResponseAsync($"guilds/{guildId}/roles");
-
-            foreach (var roleJson in response.EnumerateArray())
-                yield return Role.Parse(roleJson);
-        }
-
-        public async ValueTask<Member?> TryGetGuildMemberAsync(Snowflake guildId, User user)
-        {
-            if (guildId == Guild.DirectMessages.Id)
-                return Member.CreateForUser(user);
-
-            var response = await TryGetJsonResponseAsync($"guilds/{guildId}/members/{user.Id}");
-            return response?.Pipe(Member.Parse);
-        }
-
-        public async ValueTask<ChannelCategory> GetChannelCategoryAsync(Snowflake channelId)
-        {
-            try
-            {
-                var response = await GetJsonResponseAsync($"channels/{channelId}");
-                return ChannelCategory.Parse(response);
-            }
-            /***
-             * In some cases, the Discord API returns an empty body when requesting some channel category info.
-             * Instead, we use an empty channel category as a fallback.
-             */
-            catch (DiscordChatExporterException)
-            {
-                return ChannelCategory.Empty;
+                _tokenKind = TokenKind.Bot;
+                return botResponse;
             }
 
-        }
+            // The token is probably invalid altogether.
+            // Return the last response anyway, upstream should handle the error.
+            return botResponse;
+        }, cancellationToken);
+    }
 
-        public async ValueTask<Channel> GetChannelAsync(Snowflake channelId)
+    private async ValueTask<JsonElement> GetJsonResponseAsync(
+        string url,
+        CancellationToken cancellationToken = default)
+    {
+        using var response = await GetResponseAsync(url, cancellationToken);
+
+        if (!response.IsSuccessStatusCode)
         {
-            var response = await GetJsonResponseAsync($"channels/{channelId}");
-
-            var parentId = response.GetPropertyOrNull("parent_id")?.GetString().Pipe(Snowflake.Parse);
-
-            var category = parentId is not null
-                ? await GetChannelCategoryAsync(parentId.Value)
-                : null;
-
-            return Channel.Parse(response, category);
+            throw response.StatusCode switch
+            {
+                HttpStatusCode.Unauthorized => DiscordChatExporterException.Unauthorized(),
+                HttpStatusCode.Forbidden => DiscordChatExporterException.Forbidden(),
+                HttpStatusCode.NotFound => DiscordChatExporterException.NotFound(url),
+                _ => DiscordChatExporterException.FailedHttpRequest(response)
+            };
         }
 
-        private async ValueTask<Message?> TryGetLastMessageAsync(Snowflake channelId, Snowflake? before = null)
+        return await response.Content.ReadAsJsonAsync(cancellationToken);
+    }
+
+    private async ValueTask<JsonElement?> TryGetJsonResponseAsync(
+        string url,
+        CancellationToken cancellationToken = default)
+    {
+        using var response = await GetResponseAsync(url, cancellationToken);
+
+        return response.IsSuccessStatusCode
+            ? await response.Content.ReadAsJsonAsync(cancellationToken)
+            : null;
+    }
+
+    public async IAsyncEnumerable<Guild> GetUserGuildsAsync(
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        yield return Guild.DirectMessages;
+
+        var currentAfter = Snowflake.Zero;
+
+        while (true)
         {
             var url = new UrlBuilder()
-                .SetPath($"channels/{channelId}/messages")
-                .SetQueryParameter("limit", "1")
-                .SetQueryParameter("before", before?.ToString())
+                .SetPath("users/@me/guilds")
+                .SetQueryParameter("limit", "100")
+                .SetQueryParameter("after", currentAfter.ToString())
                 .Build();
 
-            var response = await GetJsonResponseAsync(url);
-            return response.EnumerateArray().Select(Message.Parse).LastOrDefault();
-        }
+            var response = await GetJsonResponseAsync(url, cancellationToken);
 
-        public async IAsyncEnumerable<Message> GetMessagesAsync(
-            Snowflake channelId,
-            Snowflake? after = null,
-            Snowflake? before = null,
-            IProgress<double>? progress = null)
-        {
-            // Get the last message in the specified range.
-            // This snapshots the boundaries, which means that messages posted after the exported started
-            // will not appear in the output.
-            // Additionally, it provides the date of the last message, which is used to calculate progress.
-            var lastMessage = await TryGetLastMessageAsync(channelId, before);
-            if (lastMessage is null || lastMessage.Timestamp < after?.ToDate())
-                yield break;
-
-            // Keep track of first message in range in order to calculate progress
-            var firstMessage = default(Message);
-            var currentAfter = after ?? Snowflake.Zero;
-
-            while (true)
+            var isEmpty = true;
+            foreach (var guild in response.EnumerateArray().Select(Guild.Parse))
             {
-                var url = new UrlBuilder()
-                    .SetPath($"channels/{channelId}/messages")
-                    .SetQueryParameter("limit", "100")
-                    .SetQueryParameter("after", currentAfter.ToString())
-                    .Build();
+                yield return guild;
 
-                var response = await GetJsonResponseAsync(url);
+                currentAfter = guild.Id;
+                isEmpty = false;
+            }
 
-                var messages = response
-                    .EnumerateArray()
-                    .Select(Message.Parse)
-                    .Reverse() // reverse because messages appear newest first
-                    .ToArray();
+            if (isEmpty)
+                yield break;
+        }
+    }
 
-                // Break if there are no messages (can happen if messages are deleted during execution)
-                if (!messages.Any())
-                    yield break;
+    public async ValueTask<Guild> GetGuildAsync(
+        Snowflake guildId,
+        CancellationToken cancellationToken = default)
+    {
+        if (guildId == Guild.DirectMessages.Id)
+            return Guild.DirectMessages;
 
-                foreach (var message in messages)
-                {
-                    firstMessage ??= message;
+        var response = await GetJsonResponseAsync($"guilds/{guildId}", cancellationToken);
+        return Guild.Parse(response);
+    }
 
-                    // Ensure messages are in range (take into account that last message could have been deleted)
-                    if (message.Timestamp > lastMessage.Timestamp)
-                        yield break;
+    public async IAsyncEnumerable<Channel> GetGuildChannelsAsync(
+        Snowflake guildId,
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        if (guildId == Guild.DirectMessages.Id)
+        {
+            var response = await GetJsonResponseAsync("users/@me/channels", cancellationToken);
+            foreach (var channelJson in response.EnumerateArray())
+                yield return Channel.Parse(channelJson);
+        }
+        else
+        {
+            var response = await GetJsonResponseAsync($"guilds/{guildId}/channels", cancellationToken);
 
-                    // Report progress based on the duration of exported messages divided by total
-                    if (progress is not null)
-                    {
-                        var exportedDuration = (message.Timestamp - firstMessage.Timestamp).Duration();
-                        var totalDuration = (lastMessage.Timestamp - firstMessage.Timestamp).Duration();
+            var responseOrdered = response
+                .EnumerateArray()
+                .OrderBy(j => j.GetProperty("position").GetInt32())
+                .ThenBy(j => j.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse))
+                .ToArray();
 
-                        if (totalDuration > TimeSpan.Zero)
-                        {
-                            progress.Report(exportedDuration / totalDuration);
-                        }
-                        // Avoid division by zero if all messages have the exact same timestamp
-                        // (which can happen easily if there's only one message in the channel)
-                        else
-                        {
-                            progress.Report(1);
-                        }
-                    }
+            var categories = responseOrdered
+                .Where(j => j.GetProperty("type").GetInt32() == (int) ChannelKind.GuildCategory)
+                .Select((j, index) => ChannelCategory.Parse(j, index + 1))
+                .ToDictionary(j => j.Id.ToString(), StringComparer.Ordinal);
 
-                    yield return message;
-                    currentAfter = message.Id;
-                }
+            // Discord positions are not deterministic, so we need to normalize them
+            // because the user may refer to the channel position via file name template.
+            var position = 0;
+
+            foreach (var channelJson in responseOrdered)
+            {
+                var parentId = channelJson.GetPropertyOrNull("parent_id")?.GetNonWhiteSpaceStringOrNull();
+
+                var category = !string.IsNullOrWhiteSpace(parentId)
+                    ? categories.GetValueOrDefault(parentId)
+                    : null;
+
+                var channel = Channel.Parse(channelJson, category, position);
+
+                position++;
+
+                yield return channel;
             }
         }
     }
-}
+
+    public async IAsyncEnumerable<Role> GetGuildRolesAsync(
+        Snowflake guildId,
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        if (guildId == Guild.DirectMessages.Id)
+            yield break;
+
+        var response = await GetJsonResponseAsync($"guilds/{guildId}/roles", cancellationToken);
+
+        foreach (var roleJson in response.EnumerateArray())
+            yield return Role.Parse(roleJson);
+    }
+
+    public async ValueTask<Member> GetGuildMemberAsync(
+        Snowflake guildId,
+        User user,
+        CancellationToken cancellationToken = default)
+    {
+        if (guildId == Guild.DirectMessages.Id)
+            return Member.CreateForUser(user);
+
+        var response = await TryGetJsonResponseAsync($"guilds/{guildId}/members/{user.Id}", cancellationToken);
+        return response?.Pipe(Member.Parse) ?? Member.CreateForUser(user);
+    }
+
+    public async ValueTask<ChannelCategory> GetChannelCategoryAsync(
+        Snowflake channelId,
+        CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var response = await GetJsonResponseAsync($"channels/{channelId}", cancellationToken);
+            return ChannelCategory.Parse(response);
+        }
+        // In some cases, the Discord API returns an empty body when requesting channel category.
+        // Instead, we use an empty channel category as a fallback.
+        catch (DiscordChatExporterException)
+        {
+            return ChannelCategory.Unknown;
+        }
+    }
+
+    public async ValueTask<Channel> GetChannelAsync(
+        Snowflake channelId,
+        CancellationToken cancellationToken = default)
+    {
+        var response = await GetJsonResponseAsync($"channels/{channelId}", cancellationToken);
+
+        var parentId = response.GetPropertyOrNull("parent_id")?.GetNonWhiteSpaceStringOrNull()?.Pipe(Snowflake.Parse);
+
+        var category = parentId is not null
+            ? await GetChannelCategoryAsync(parentId.Value, cancellationToken)
+            : null;
+
+        return Channel.Parse(response, category);
+    }
+
+    private async ValueTask<Message?> TryGetLastMessageAsync(
+        Snowflake channelId,
+        Snowflake? before = null,
+        CancellationToken cancellationToken = default)
+    {
+        var url = new UrlBuilder()
+            .SetPath($"channels/{channelId}/messages")
+            .SetQueryParameter("limit", "1")
+            .SetQueryParameter("before", before?.ToString())
+            .Build();
+
+        var response = await GetJsonResponseAsync(url, cancellationToken);
+        return response.EnumerateArray().Select(Message.Parse).LastOrDefault();
+    }
+
+    public async IAsyncEnumerable<Message> GetMessagesAsync(
+        Snowflake channelId,
+        Snowflake? after = null,
+        Snowflake? before = null,
+        IProgress<Percentage>? progress = null,
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        // Get the last message in the specified range.
+        // This snapshots the boundaries, which means that messages posted after the export started
+        // will not appear in the output.
+        // Additionally, it provides the date of the last message, which is used to calculate progress.
+        var lastMessage = await TryGetLastMessageAsync(channelId, before, cancellationToken);
+        if (lastMessage is null || lastMessage.Timestamp < after?.ToDate())
+            yield break;
+
+        // Keep track of first message in range in order to calculate progress
+        var firstMessage = default(Message);
+        var currentAfter = after ?? Snowflake.Zero;
+
+        while (true)
+        {
+            var url = new UrlBuilder()
+                .SetPath($"channels/{channelId}/messages")
+                .SetQueryParameter("limit", "100")
+                .SetQueryParameter("after", currentAfter.ToString())
+                .Build();
+
+            var response = await GetJsonResponseAsync(url, cancellationToken);
+
+            var messages = response
+                .EnumerateArray()
+                .Select(Message.Parse)
+                .Reverse() // reverse because messages appear newest first
+                .ToArray();
+
+            // Break if there are no messages (can happen if messages are deleted during execution)
+            if (!messages.Any())
+                yield break;
+
+            foreach (var message in messages)
+            {
+                firstMessage ??= message;
+
+                // Ensure messages are in range (take into account that last message could have been deleted)
+                if (message.Timestamp > lastMessage.Timestamp)
+                    yield break;
+
+                // Report progress based on the duration of exported messages divided by total
+                if (progress is not null)
+                {
+                    var exportedDuration = (message.Timestamp - firstMessage.Timestamp).Duration();
+                    var totalDuration = (lastMessage.Timestamp - firstMessage.Timestamp).Duration();
+
+                    progress.Report(Percentage.FromFraction(
+                        // Avoid division by zero if all messages have the exact same timestamp
+                        // (which may be the case if there's only one message in the channel)
+                        totalDuration > TimeSpan.Zero
+                            ? exportedDuration / totalDuration
+                            : 1
+                    ));
+                }
+
+                yield return message;
+                currentAfter = message.Id;
+            }
+        }
+    }
+}

DiscordChatExporter.Core/Discord/Snowflake.cs

@@ -1,68 +1,63 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Text.RegularExpressions;
 
-namespace DiscordChatExporter.Core.Discord
+namespace DiscordChatExporter.Core.Discord;
+
+public readonly partial record struct Snowflake(ulong Value)
 {
-    public readonly partial struct Snowflake
+    public DateTimeOffset ToDate() => DateTimeOffset.FromUnixTimeMilliseconds(
+        (long)((Value >> 22) + 1420070400000UL)
+    ).ToLocalTime();
+
+    [ExcludeFromCodeCoverage]
+    public override string ToString() => Value.ToString(CultureInfo.InvariantCulture);
+}
+
+public partial record struct Snowflake
+{
+    public static Snowflake Zero { get; } = new(0);
+
+    public static Snowflake FromDate(DateTimeOffset date) => new(
+        ((ulong)date.ToUnixTimeMilliseconds() - 1420070400000UL) << 22
+    );
+
+    public static Snowflake? TryParse(string? str, IFormatProvider? formatProvider = null)
     {
-        public ulong Value { get; }
+        if (string.IsNullOrWhiteSpace(str))
+            return null;
 
-        public Snowflake(ulong value) => Value = value;
-
-        public DateTimeOffset ToDate() =>
-            DateTimeOffset.FromUnixTimeMilliseconds((long) ((Value >> 22) + 1420070400000UL)).ToLocalTime();
-
-        public override string ToString() => Value.ToString(CultureInfo.InvariantCulture);
-    }
-
-    public partial struct Snowflake
-    {
-        public static Snowflake Zero { get; } = new(0);
-
-        public static Snowflake FromDate(DateTimeOffset date)
+        // As number
+        if (Regex.IsMatch(str, @"^\d+$") && ulong.TryParse(str, NumberStyles.Number, formatProvider, out var value))
         {
-            var value = ((ulong) date.ToUnixTimeMilliseconds() - 1420070400000UL) << 22;
             return new Snowflake(value);
         }
 
-        public static Snowflake? TryParse(string? str, IFormatProvider? formatProvider = null)
+        // As date
+        if (DateTimeOffset.TryParse(str, formatProvider, DateTimeStyles.None, out var date))
         {
-            if (string.IsNullOrWhiteSpace(str))
-                return null;
-
-            // As number
-            if (Regex.IsMatch(str, @"^\d+$") &&
-                ulong.TryParse(str, NumberStyles.Number, formatProvider, out var value))
-            {
-                return new Snowflake(value);
-            }
-
-            // As date
-            if (DateTimeOffset.TryParse(str, formatProvider, DateTimeStyles.None, out var date))
-            {
-                return FromDate(date);
-            }
-
-            return null;
+            return FromDate(date);
         }
 
-        public static Snowflake Parse(string str, IFormatProvider? formatProvider) =>
-            TryParse(str, formatProvider) ?? throw new FormatException($"Invalid snowflake '{str}'.");
-
-        public static Snowflake Parse(string str) => Parse(str, null);
+        return null;
     }
 
-    public partial struct Snowflake : IEquatable<Snowflake>
+    public static Snowflake Parse(string str, IFormatProvider? formatProvider) =>
+        TryParse(str, formatProvider) ?? throw new FormatException($"Invalid snowflake '{str}'.");
+
+    public static Snowflake Parse(string str) => Parse(str, null);
+}
+
+public partial record struct Snowflake : IComparable<Snowflake>, IComparable
+{
+    public int CompareTo(Snowflake other) => Value.CompareTo(other.Value);
+
+    public int CompareTo(object? obj)
     {
-        public bool Equals(Snowflake other) => Value == other.Value;
+        if (obj is not Snowflake other)
+            throw new ArgumentException($"Object must be of type {nameof(Snowflake)}.");
 
-        public override bool Equals(object? obj) => obj is Snowflake other && Equals(other);
-
-        public override int GetHashCode() => Value.GetHashCode();
-
-        public static bool operator ==(Snowflake left, Snowflake right) => left.Equals(right);
-
-        public static bool operator !=(Snowflake left, Snowflake right) => !(left == right);
+        return Value.CompareTo(other.Value);
     }
 }

DiscordChatExporter.Core/Discord/TokenKind.cs

@@ -0,0 +1,8 @@
+namespace DiscordChatExporter.Core.Discord;
+
+public enum TokenKind
+{
+    Unknown,
+    User,
+    Bot
+}

DiscordChatExporter.Core/DiscordChatExporter.Core.csproj

@@ -5,19 +5,16 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="JsonExtensions" Version="1.0.1" />
-    <PackageReference Include="MiniRazor.CodeGen" Version="2.1.2" />
-    <PackageReference Include="Polly" Version="7.2.2" />
-    <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
+    <PackageReference Include="Gress" Version="2.0.1" />
+    <PackageReference Include="JsonExtensions" Version="1.2.0" />
+    <PackageReference Include="MiniRazor.CodeGen" Version="2.2.1" />
+    <PackageReference Include="Polly" Version="7.2.3" />
+    <PackageReference Include="Superpower" Version="3.0.0" />
+    <PackageReference Include="WebMarkupMin.Core" Version="2.12.0" />
   </ItemGroup>
 
   <ItemGroup>
-    <EmbeddedResource Include="Exporting\Writers\Html\Core.css" />
-    <EmbeddedResource Include="Exporting\Writers\Html\Dark.css" />
-    <EmbeddedResource Include="Exporting\Writers\Html\Light.css" />
-    <AdditionalFiles Include="Exporting\Writers\Html\PreambleTemplate.cshtml" IsRazorTemplate="true" />
-    <AdditionalFiles Include="Exporting\Writers\Html\PostambleTemplate.cshtml" IsRazorTemplate="true" />
-    <AdditionalFiles Include="Exporting\Writers\Html\MessageGroupTemplate.cshtml" IsRazorTemplate="true" />
+    <AdditionalFiles Include="Exporting\Writers\Html\*.cshtml" IsRazorTemplate="true" />
   </ItemGroup>
 
 </Project>

DiscordChatExporter.Core/Exceptions/DiscordChatExporterException.cs

@@ -1,24 +1,24 @@
 using System;
 using System.Net.Http;
 
-namespace DiscordChatExporter.Core.Exceptions
+namespace DiscordChatExporter.Core.Exceptions;
+
+public partial class DiscordChatExporterException : Exception
 {
-    public partial class DiscordChatExporterException : Exception
-    {
-        public bool IsCritical { get; }
+    public bool IsFatal { get; }
 
-        public DiscordChatExporterException(string message, bool isCritical = false)
-            : base(message)
-        {
-            IsCritical = isCritical;
-        }
+    public DiscordChatExporterException(string message, bool isFatal = false)
+        : base(message)
+    {
+        IsFatal = isFatal;
     }
+}
 
-    public partial class DiscordChatExporterException
+public partial class DiscordChatExporterException
+{
+    internal static DiscordChatExporterException FailedHttpRequest(HttpResponseMessage response)
     {
-        internal static DiscordChatExporterException FailedHttpRequest(HttpResponseMessage response)
-        {
-            var message = $@"
+        var message = $@"
 Failed to perform an HTTP request.
 
 [Request]
@@ -27,19 +27,18 @@ Failed to perform an HTTP request.
 [Response]
 {response}";
 
-            return new DiscordChatExporterException(message.Trim(), true);
-        }
-
-        internal static DiscordChatExporterException Unauthorized() =>
-            new("Authentication token is invalid.");
-
-        internal static DiscordChatExporterException Forbidden() =>
-            new("Access is forbidden.");
-
-        internal static DiscordChatExporterException NotFound() =>
-            new("Requested resource does not exist.");
-
-        internal static DiscordChatExporterException ChannelIsEmpty() =>
-            new("No messages found for the specified period.");
+        return new DiscordChatExporterException(message.Trim(), true);
     }
+
+    internal static DiscordChatExporterException Unauthorized() =>
+        new("Authentication token is invalid.", true);
+
+    internal static DiscordChatExporterException Forbidden() =>
+        new("Access is forbidden.");
+
+    internal static DiscordChatExporterException NotFound(string resourceId) =>
+        new($"Requested resource ({resourceId}) does not exist.");
+
+    internal static DiscordChatExporterException ChannelIsEmpty() =>
+        new("No messages found for the specified period.");
 }

DiscordChatExporter.Core/Exporting/ChannelExporter.cs

@@ -1,65 +1,81 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Discord.Data.Common;
 using DiscordChatExporter.Core.Exceptions;
 using DiscordChatExporter.Core.Utils.Extensions;
+using Gress;
 
-namespace DiscordChatExporter.Core.Exporting
+namespace DiscordChatExporter.Core.Exporting;
+
+public class ChannelExporter
 {
-    public class ChannelExporter
+    private readonly DiscordClient _discord;
+
+    public ChannelExporter(DiscordClient discord) => _discord = discord;
+
+    public async ValueTask ExportChannelAsync(
+        ExportRequest request,
+        IProgress<Percentage>? progress = null,
+        CancellationToken cancellationToken = default)
     {
-        private readonly DiscordClient _discord;
+        // Build context
+        var contextMembers = new HashSet<Member>(IdBasedEqualityComparer.Instance);
+        var contextChannels = await _discord.GetGuildChannelsAsync(request.Guild.Id, cancellationToken);
+        var contextRoles = await _discord.GetGuildRolesAsync(request.Guild.Id, cancellationToken);
 
-        public ChannelExporter(DiscordClient discord) => _discord = discord;
+        var context = new ExportContext(
+            request,
+            contextMembers,
+            contextChannels,
+            contextRoles
+        );
 
-        public ChannelExporter(AuthToken token) : this(new DiscordClient(token)) {}
+        // Export messages
+        await using var messageExporter = new MessageExporter(context);
 
-        public async ValueTask ExportChannelAsync(ExportRequest request, IProgress<double>? progress = null)
+        var exportedAnything = false;
+        var encounteredUsers = new HashSet<User>(IdBasedEqualityComparer.Instance);
+
+        await foreach (var message in _discord.GetMessagesAsync(
+                           request.Channel.Id,
+                           request.After,
+                           request.Before,
+                           progress,
+                           cancellationToken))
         {
-            // Build context
-            var contextMembers = new HashSet<Member>(IdBasedEqualityComparer.Instance);
-            var contextChannels = await _discord.GetGuildChannelsAsync(request.Guild.Id);
-            var contextRoles = await _discord.GetGuildRolesAsync(request.Guild.Id);
+            cancellationToken.ThrowIfCancellationRequested();
 
-            var context = new ExportContext(
-                request,
-                contextMembers,
-                contextChannels,
-                contextRoles
-            );
+            // Skips any messages that fail to pass the supplied filter
+            if (!request.MessageFilter.IsMatch(message))
+                continue;
 
-            // Export messages
-            await using var messageExporter = new MessageExporter(context);
-
-            var exportedAnything = false;
-            var encounteredUsers = new HashSet<User>(IdBasedEqualityComparer.Instance);
-            await foreach (var message in _discord.GetMessagesAsync(request.Channel.Id, request.After, request.Before, progress))
+            // Resolve members for referenced users
+            foreach (var referencedUser in message.MentionedUsers.Prepend(message.Author))
             {
-                // Resolve members for referenced users
-                foreach (var referencedUser in message.MentionedUsers.Prepend(message.Author))
-                {
-                    if (!encounteredUsers.Add(referencedUser))
-                        continue;
+                if (!encounteredUsers.Add(referencedUser))
+                    continue;
 
-                    var member =
-                        await _discord.TryGetGuildMemberAsync(request.Guild.Id, referencedUser) ??
-                        Member.CreateForUser(referencedUser);
+                var member = await _discord.GetGuildMemberAsync(
+                    request.Guild.Id,
+                    referencedUser,
+                    cancellationToken
+                );
 
-                    contextMembers.Add(member);
-                }
-
-                // Export message
-                await messageExporter.ExportMessageAsync(message);
-                exportedAnything = true;
+                contextMembers.Add(member);
             }
 
-            // Throw if no messages were exported
-            if (!exportedAnything)
-                throw DiscordChatExporterException.ChannelIsEmpty();
+            // Export message
+            await messageExporter.ExportMessageAsync(message, cancellationToken);
+            exportedAnything = true;
         }
+
+        // Throw if no messages were exported
+        if (!exportedAnything)
+            throw DiscordChatExporterException.ChannelIsEmpty();
     }
 }

DiscordChatExporter.Core/Exporting/ExportContext.cs

@@ -4,101 +4,102 @@ using System.Drawing;
 using System.IO;
 using System.Linq;
 using System.Net.Http;
+using System.Threading;
 using System.Threading.Tasks;
 using DiscordChatExporter.Core.Discord;
 using DiscordChatExporter.Core.Discord.Data;
 using DiscordChatExporter.Core.Utils.Extensions;
-using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Core.Exporting
+namespace DiscordChatExporter.Core.Exporting;
+
+internal class ExportContext
 {
-    internal class ExportContext
+    private readonly MediaDownloader _mediaDownloader;
+
+    public ExportRequest Request { get; }
+
+    public IReadOnlyCollection<Member> Members { get; }
+
+    public IReadOnlyCollection<Channel> Channels { get; }
+
+    public IReadOnlyCollection<Role> Roles { get; }
+
+    public ExportContext(
+        ExportRequest request,
+        IReadOnlyCollection<Member> members,
+        IReadOnlyCollection<Channel> channels,
+        IReadOnlyCollection<Role> roles)
     {
-        private readonly MediaDownloader _mediaDownloader;
+        Request = request;
+        Members = members;
+        Channels = channels;
+        Roles = roles;
 
-        public ExportRequest Request { get; }
+        _mediaDownloader = new MediaDownloader(request.OutputMediaDirPath, request.ShouldReuseMedia);
+    }
 
-        public IReadOnlyCollection<Member> Members { get; }
+    public string FormatDate(DateTimeOffset date) => Request.DateFormat switch
+    {
+        "unix" => date.ToUnixTimeSeconds().ToString(),
+        "unixms" => date.ToUnixTimeMilliseconds().ToString(),
+        var dateFormat => date.ToLocalString(dateFormat)
+    };
 
-        public IReadOnlyCollection<Channel> Channels { get; }
+    public Member? TryGetMember(Snowflake id) => Members.FirstOrDefault(m => m.Id == id);
 
-        public IReadOnlyCollection<Role> Roles { get; }
+    public Channel? TryGetChannel(Snowflake id) => Channels.FirstOrDefault(c => c.Id == id);
 
-        public ExportContext(
-            ExportRequest request,
-            IReadOnlyCollection<Member> members,
-            IReadOnlyCollection<Channel> channels,
-            IReadOnlyCollection<Role> roles)
+    public Role? TryGetRole(Snowflake id) => Roles.FirstOrDefault(r => r.Id == id);
+
+    public Color? TryGetUserColor(Snowflake id)
+    {
+        var member = TryGetMember(id);
+        var roles = member?.RoleIds.Join(Roles, i => i, r => r.Id, (_, role) => role);
+
+        return roles?
+            .Where(r => r.Color is not null)
+            .OrderByDescending(r => r.Position)
+            .Select(r => r.Color)
+            .FirstOrDefault();
+    }
+
+    public async ValueTask<string> ResolveMediaUrlAsync(string url, CancellationToken cancellationToken = default)
+    {
+        if (!Request.ShouldDownloadMedia)
+            return url;
+
+        try
         {
-            Request = request;
-            Members = members;
-            Channels = channels;
-            Roles = roles;
+            var filePath = await _mediaDownloader.DownloadAsync(url, cancellationToken);
 
-            _mediaDownloader = new MediaDownloader(request.OutputMediaDirPath, request.ShouldReuseMedia);
-        }
+            // We want relative path so that the output files can be copied around without breaking.
+            // Base directory path may be null if the file is stored at the root or relative to working directory.
+            var relativeFilePath = !string.IsNullOrWhiteSpace(Request.OutputBaseDirPath)
+                ? Path.GetRelativePath(Request.OutputBaseDirPath, filePath)
+                : filePath;
 
-        public string FormatDate(DateTimeOffset date) => Request.DateFormat switch
-        {
-            "unix" => date.ToUnixTimeSeconds().ToString(),
-            "unixms" => date.ToUnixTimeMilliseconds().ToString(),
-            var dateFormat => date.ToLocalString(dateFormat)
-        };
-
-        public Member? TryGetMember(Snowflake id) => Members.FirstOrDefault(m => m.Id == id);
-
-        public Channel? TryGetChannel(Snowflake id) => Channels.FirstOrDefault(c => c.Id == id);
-
-        public Role? TryGetRole(Snowflake id) => Roles.FirstOrDefault(r => r.Id == id);
-
-        public Color? TryGetUserColor(Snowflake id)
-        {
-            var member = TryGetMember(id);
-            var roles = member?.RoleIds.Join(Roles, i => i, r => r.Id, (_, role) => role);
-
-            return roles?
-                .Where(r => r.Color is not null)
-                .OrderByDescending(r => r.Position)
-                .Select(r => r.Color)
-                .FirstOrDefault();
-        }
-
-        public async ValueTask<string> ResolveMediaUrlAsync(string url)
-        {
-            if (!Request.ShouldDownloadMedia)
-                return url;
-
-            try
+            // HACK: for HTML, we need to format the URL properly
+            if (Request.Format is ExportFormat.HtmlDark or ExportFormat.HtmlLight)
             {
-                var filePath = await _mediaDownloader.DownloadAsync(url);
-
-                // We want relative path so that the output files can be copied around without breaking.
-                // Base directory path may be null if the file is stored at the root or relative to working directory.
-                var relativeFilePath = !string.IsNullOrWhiteSpace(Request.OutputBaseDirPath)
-                    ? Path.GetRelativePath(Request.OutputBaseDirPath, filePath)
-                    : filePath;
-
-                // HACK: for HTML, we need to format the URL properly
-                if (Request.Format == ExportFormat.HtmlDark || Request.Format == ExportFormat.HtmlLight)
-                {
-                    // Need to escape each path segment while keeping the directory separators intact
-                    return relativeFilePath
+                // Need to escape each path segment while keeping the directory separators intact
+                return string.Join(
+                    Path.AltDirectorySeparatorChar,
+                    relativeFilePath
                         .Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
                         .Select(Uri.EscapeDataString)
-                        .JoinToString(Path.AltDirectorySeparatorChar.ToString());
-                }
+                );
+            }
 
-                return relativeFilePath;
-            }
-            // Try to catch only exceptions related to failed HTTP requests
-            // https://github.com/Tyrrrz/DiscordChatExporter/issues/332
-            // https://github.com/Tyrrrz/DiscordChatExporter/issues/372
-            catch (Exception ex) when (ex is HttpRequestException || ex is OperationCanceledException)
-            {
-                // TODO: add logging so we can be more liberal with catching exceptions
-                // We don't want this to crash the exporting process in case of failure
-                return url;
-            }
+            return relativeFilePath;
+        }
+        // Try to catch only exceptions related to failed HTTP requests
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/332
+        // https://github.com/Tyrrrz/DiscordChatExporter/issues/372
+        catch (Exception ex) when (ex is HttpRequestException or OperationCanceledException)
+        {
+            // TODO: add logging so we can be more liberal with catching exceptions
+            // We don't want this to crash the exporting process in case of failure
+            return url;
         }
     }
 }

DiscordChatExporter.Core/Exporting/ExportFormat.cs

@@ -1,36 +1,35 @@
 using System;
 
-namespace DiscordChatExporter.Core.Exporting
+namespace DiscordChatExporter.Core.Exporting;
+
+public enum ExportFormat
 {
-    public enum ExportFormat
-    {
-        PlainText,
-        HtmlDark,
-        HtmlLight,
-        Csv,
-        Json
-    }
+    PlainText,
+    HtmlDark,
+    HtmlLight,
+    Csv,
+    Json
+}
 
-    public static class ExportFormatExtensions
+public static class ExportFormatExtensions
+{
+    public static string GetFileExtension(this ExportFormat format) => format switch
     {
-        public static string GetFileExtension(this ExportFormat format) => format switch
-        {
-            ExportFormat.PlainText => "txt",
-            ExportFormat.HtmlDark => "html",
-            ExportFormat.HtmlLight => "html",
-            ExportFormat.Csv => "csv",
-            ExportFormat.Json => "json",
-            _ => throw new ArgumentOutOfRangeException(nameof(format))
-        };
+        ExportFormat.PlainText => "txt",
+        ExportFormat.HtmlDark => "html",
+        ExportFormat.HtmlLight => "html",
+        ExportFormat.Csv => "csv",
+        ExportFormat.Json => "json",
+        _ => throw new ArgumentOutOfRangeException(nameof(format))
+    };
 
-        public static string GetDisplayName(this ExportFormat format) => format switch
-        {
-            ExportFormat.PlainText => "TXT",
-            ExportFormat.HtmlDark => "HTML (Dark)",
-            ExportFormat.HtmlLight => "HTML (Light)",
-            ExportFormat.Csv => "CSV",
-            ExportFormat.Json => "JSON",
-            _ => throw new ArgumentOutOfRangeException(nameof(format))
-        };
-    }
+    public static string GetDisplayName(this ExportFormat format) => format switch
+    {
+        ExportFormat.PlainText => "TXT",
+        ExportFormat.HtmlDark => "HTML (Dark)",
+        ExportFormat.HtmlLight => "HTML (Light)",
+        ExportFormat.Csv => "CSV",
+        ExportFormat.Json => "JSON",
+        _ => throw new ArgumentOutOfRangeException(nameof(format))
+    };
 }