Update version

Fixes #551

.gitattributes

@@ -1,63 +0,0 @@
-###############################################################################
-# Set default behavior to automatically normalize line endings.
-###############################################################################
-* text=auto
-
-###############################################################################
-# Set default behavior for command prompt diff.
-#
-# This is need for earlier builds of msysgit that does not have it on by
-# default for csharp files.
-# Note: This is only used by command line
-###############################################################################
-#*.cs     diff=csharp
-
-###############################################################################
-# Set the merge driver for project and solution files
-#
-# Merging from the command prompt will add diff markers to the files if there
-# are conflicts (Merging from VS is not affected by the settings below, in VS
-# the diff markers are never inserted). Diff markers may cause the following 
-# file extensions to fail to load in VS. An alternative would be to treat
-# these files as binary and thus will always conflict and require user
-# intervention with every merge. To do so, just uncomment the entries below
-###############################################################################
-#*.sln       merge=binary
-#*.csproj    merge=binary
-#*.vbproj    merge=binary
-#*.vcxproj   merge=binary
-#*.vcproj    merge=binary
-#*.dbproj    merge=binary
-#*.fsproj    merge=binary
-#*.lsproj    merge=binary
-#*.wixproj   merge=binary
-#*.modelproj merge=binary
-#*.sqlproj   merge=binary
-#*.wwaproj   merge=binary
-
-###############################################################################
-# behavior for image files
-#
-# image files are treated as binary by default.
-###############################################################################
-#*.jpg   binary
-#*.png   binary
-#*.gif   binary
-
-###############################################################################
-# diff behavior for common document formats
-# 
-# Convert binary document formats to text before diffing them. This feature
-# is only available from the command line. Turn it on by uncommenting the 
-# entries below.
-###############################################################################
-#*.doc   diff=astextplain
-#*.DOC   diff=astextplain
-#*.docx  diff=astextplain
-#*.DOCX  diff=astextplain
-#*.dot   diff=astextplain
-#*.DOT   diff=astextplain
-#*.pdf   diff=astextplain
-#*.PDF   diff=astextplain
-#*.rtf   diff=astextplain
-#*.RTF   diff=astextplain

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -0,0 +1,42 @@
+name: "\U0001F41E 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.
+
+- type: input
+  attributes:
+    label: Version
+    description: "Which version(s) of DiscordChatExporter does this bug affect?"
+  validations:
+    required: true
+
+- type: dropdown
+  attributes:
+    label: Flavor
+    description: "Which flavor(s) of DiscordChatExporter does this bug affect?"
+    multiple: true
+    options:
+    - GUI (Graphical User Interface)
+    - CLI (Command Line Interface)
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Details
+    description: "Clear and thorough explanation of the bug. If relevant, include screenshots or screen recordings."
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Steps to reproduce
+    description: "Minimum steps required to reproduce the bug."
+  validations:
+    required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: "\U0001F4D6 Read the wiki"
+    url: https://github.com/Tyrrrz/DiscordChatExporter/wiki
+    about: Find answers to most common questions.
+  - name: "\U0001F5E8 Ask a question"
+    url: https://github.com/Tyrrrz/DiscordChatExporter/discussions/new
+    about: Please ask and answer questions here.

.github/ISSUE_TEMPLATE/feature-request.yml

@@ -0,0 +1,26 @@
+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

@@ -3,64 +3,69 @@ name: CD
 on:
   push:
     tags:
-    - '*'
+      - "*"
 
 jobs:
   build:
     runs-on: windows-latest
 
     steps:
-    - name: Checkout
-      uses: actions/checkout@v2
+      - name: Checkout
+        uses: actions/checkout@v2.3.3
 
-    - name: Install .NET Core
-      uses: actions/setup-dotnet@v1.4.0
-      with:
-        dotnet-version: 3.1.100
+      - name: Install .NET (v3.1)
+        uses: actions/setup-dotnet@v1.7.2
+        with:
+          dotnet-version: 3.1.x
 
-    - name: Build & publish (CLI)
-      run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
+      - name: Install .NET (v5.0)
+        uses: actions/setup-dotnet@v1.7.2
+        with:
+          dotnet-version: 5.0.x
 
-    - name: Build & publish (GUI)
-      run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
+      - name: Build & publish (CLI)
+        run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/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: Build & publish (GUI)
+        run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
 
-    - name: Pack (GUI)
-      run: Compress-Archive -Path DiscordChatExporter.Gui/bin/Publish/* -DestinationPath DiscordChatExporter.Gui/bin/Publish/Archive.zip -Force
-      shell: pwsh
+      - name: Pack (CLI)
+        run: Compress-Archive -Path DiscordChatExporter.Cli/bin/Publish/* -DestinationPath DiscordChatExporter.Cli/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: Pack (GUI)
+        run: Compress-Archive -Path DiscordChatExporter.Gui/bin/Publish/* -DestinationPath DiscordChatExporter.Gui/bin/Publish/Archive.zip -Force
+        shell: pwsh
 
-    - 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: 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 (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
+      - 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

@@ -7,28 +7,33 @@ jobs:
     runs-on: windows-latest
 
     steps:
-    - name: Checkout
-      uses: actions/checkout@v2
+      - name: Checkout
+        uses: actions/checkout@v2.3.3
 
-    - name: Install .NET Core
-      uses: actions/setup-dotnet@v1.4.0
-      with:
-        dotnet-version: 3.1.100
+      - name: Install .NET (v3.1)
+        uses: actions/setup-dotnet@v1.7.2
+        with:
+          dotnet-version: 3.1.x
 
-    - name: Build & publish (CLI)
-      run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
+      - name: Install .NET (v5.0)
+        uses: actions/setup-dotnet@v1.7.2
+        with:
+          dotnet-version: 5.0.x
 
-    - name: Build & publish (GUI)
-      run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
+      - name: Build & publish (CLI)
+        run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
 
-    - name: Upload build artifacts (CLI)
-      uses: actions/upload-artifact@v1
-      with:
-        name: DiscordChatExporter.CLI
-        path: DiscordChatExporter.Cli/bin/Publish/
+      - name: Build & publish (GUI)
+        run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
 
-    - name: Upload build artifact (GUI)
-      uses: actions/upload-artifact@v1
-      with:
-        name: DiscordChatExporter
-        path: DiscordChatExporter.Gui/bin/Publish/
+      - 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/

.gitignore

@@ -1,261 +1,22 @@
-## Ignore Visual Studio temporary files, build results, and
-## files generated by popular Visual Studio add-ons.
-
 # User-specific files
 *.suo
 *.user
 *.userosscache
 *.sln.docstates
-
-# User-specific files (MonoDevelop/Xamarin Studio)
-*.userprefs
+.idea/
+.vs/
 
 # Build results
 [Dd]ebug/
 [Dd]ebugPublic/
 [Rr]elease/
 [Rr]eleases/
-x64/
-x86/
+[Xx]64/
+[Xx]86/
+[Bb]uild/
 bld/
 [Bb]in/
 [Oo]bj/
-[Ll]og/
 
-# Visual Studio 2015 cache/options directory
-.vs/
-# Uncomment if you have tasks that create the project's static files in wwwroot
-#wwwroot/
-
-# MSTest test Results
-[Tt]est[Rr]esult*/
-[Bb]uild[Ll]og.*
-
-# NUNIT
-*.VisualState.xml
-TestResult.xml
-
-# Build Results of an ATL Project
-[Dd]ebugPS/
-[Rr]eleasePS/
-dlldata.c
-
-# DNX
-project.lock.json
-project.fragment.lock.json
-artifacts/
-
-*_i.c
-*_p.c
-*_i.h
-*.ilk
-*.meta
-*.obj
-*.pch
-*.pdb
-*.pgc
-*.pgd
-*.rsp
-*.sbr
-*.tlb
-*.tli
-*.tlh
-*.tmp
-*.tmp_proj
-*.log
-*.vspscc
-*.vssscc
-.builds
-*.pidb
-*.svclog
-*.scc
-
-# Chutzpah Test files
-_Chutzpah*
-
-# Visual C++ cache files
-ipch/
-*.aps
-*.ncb
-*.opendb
-*.opensdf
-*.sdf
-*.cachefile
-*.VC.db
-*.VC.VC.opendb
-
-# Visual Studio profiler
-*.psess
-*.vsp
-*.vspx
-*.sap
-
-# TFS 2012 Local Workspace
-$tf/
-
-# Guidance Automation Toolkit
-*.gpState
-
-# ReSharper is a .NET coding add-in
-_ReSharper*/
-*.[Rr]e[Ss]harper
-*.DotSettings.user
-
-# JustCode is a .NET coding add-in
-.JustCode
-
-# TeamCity is a build add-in
-_TeamCity*
-
-# DotCover is a Code Coverage Tool
-*.dotCover
-
-# NCrunch
-_NCrunch_*
-.*crunch*.local.xml
-nCrunchTemp_*
-
-# MightyMoose
-*.mm.*
-AutoTest.Net/
-
-# Web workbench (sass)
-.sass-cache/
-
-# Installshield output folder
-[Ee]xpress/
-
-# DocProject is a documentation generator add-in
-DocProject/buildhelp/
-DocProject/Help/*.HxT
-DocProject/Help/*.HxC
-DocProject/Help/*.hhc
-DocProject/Help/*.hhk
-DocProject/Help/*.hhp
-DocProject/Help/Html2
-DocProject/Help/html
-
-# Click-Once directory
-publish/
-
-# Publish Web Output
-*.[Pp]ublish.xml
-*.azurePubxml
-# TODO: Comment the next line if you want to checkin your web deploy settings
-# but database connection strings (with potential passwords) will be unencrypted
-#*.pubxml
-*.publishproj
-
-# Microsoft Azure Web App publish settings. Comment the next line if you want to
-# checkin your Azure Web App publish settings, but sensitive information contained
-# in these scripts will be unencrypted
-PublishScripts/
-
-# NuGet Packages
-*.nupkg
-# The packages folder can be ignored because of Package Restore
-**/packages/*
-# except build/, which is used as an MSBuild target.
-!**/packages/build/
-# Uncomment if necessary however generally it will be regenerated when needed
-#!**/packages/repositories.config
-# NuGet v3's project.json files produces more ignoreable files
-*.nuget.props
-*.nuget.targets
-
-# Microsoft Azure Build Output
-csx/
-*.build.csdef
-
-# Microsoft Azure Emulator
-ecf/
-rcf/
-
-# Windows Store app package directories and files
-AppPackages/
-BundleArtifacts/
-Package.StoreAssociation.xml
-_pkginfo.txt
-
-# Visual Studio cache files
-# files ending in .cache can be ignored
-*.[Cc]ache
-# but keep track of directories ending in .cache
-!*.[Cc]ache/
-
-# Others
-ClientBin/
-~$*
-*~
-*.dbmdl
-*.dbproj.schemaview
-*.jfm
-*.pfx
-*.publishsettings
-node_modules/
-orleans.codegen.cs
-
-# Since there are multiple workflows, uncomment next line to ignore bower_components
-# (https://github.com/github/gitignore/pull/1529#issuecomment-104372622)
-#bower_components/
-
-# RIA/Silverlight projects
-Generated_Code/
-
-# Backup & report files from converting an old project file
-# to a newer Visual Studio version. Backup files are not needed,
-# because we have git ;-)
-_UpgradeReport_Files/
-Backup*/
-UpgradeLog*.XML
-UpgradeLog*.htm
-
-# SQL Server files
-*.mdf
-*.ldf
-
-# Business Intelligence projects
-*.rdl.data
-*.bim.layout
-*.bim_*.settings
-
-# Microsoft Fakes
-FakesAssemblies/
-
-# GhostDoc plugin setting file
-*.GhostDoc.xml
-
-# Node.js Tools for Visual Studio
-.ntvs_analysis.dat
-
-# Visual Studio 6 build log
-*.plg
-
-# Visual Studio 6 workspace options file
-*.opt
-
-# Visual Studio LightSwitch build output
-**/*.HTMLClient/GeneratedArtifacts
-**/*.DesktopClient/GeneratedArtifacts
-**/*.DesktopClient/ModelManifest.xml
-**/*.Server/GeneratedArtifacts
-**/*.Server/ModelManifest.xml
-_Pvt_Extensions
-
-# Paket dependency manager
-.paket/paket.exe
-paket-files/
-
-# FAKE - F# Make
-.fake/
-
-# JetBrains Rider
-.idea/
-*.sln.iml
-
-# CodeRush
-.cr/
-
-# Python Tools for Visual Studio (PTVS)
-__pycache__/
-*.pyc
+# Coverage
+*.opencover.xml

Changelog.md

@@ -1,3 +1,83 @@
+### 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))
+- [CLI] Improved formatting and progress reporting.
+- [CLI] Changed `export` command so that it can accept multiple channel IDs passed to `-c|--channel` option. This makes it possible to export multiple channels at once while benefiting from parallelization.
+- [JSON] Added `color` field to message author. This is a hex string that represents user's color, inherited from their roles. (Thanks [@rtm516](https://github.com/rtm516))
+- [JSON] Added `categoryId` field to the root. This represents the ID of the category channel that the currently exported channel belongs to. (Thanks [@rtm516](https://github.com/rtm516))
+- [JSON] Fixed an issue where user discriminator was written without leading zeroes. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- [JSON] Fixed an issue where the application sometimes crashed with an error saying `']' invalid without a matching open`, which was just a validation message that masked the actual error behind the failure. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- Fixed an issue where progress was not reported correctly if the channel didn't have any messages in the specified time range.
+
+### v2.26.1 (06-Feb-2021)
+
+- [CLI] Added support for file name templates, which allow you to dynamically generate output file names based on channel and guild metadata. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- Fixed an issue where the application sometimes crashed with `Invalid snowflake` message when exporting chat logs that contained invalid or outdated mentions. (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+
+### v2.26 (29-Dec-2020)
+
+- [HTML] Added support for replies. (Thanks [@Sanqui](https://github.com/Sanqui))
+- [HTML] Improved styling of non-media attachments (regular files, i.e. not video, audio, or image). (Thanks [@Lucas LaBuff](https://github.com/96-LB))
+- [HTML] Improved initial export performance.
+- [JSON] Relaxed escaping rules for unicode characters. (Thanks [@Sanqui](https://github.com/Sanqui))
+- [JSON] Added support for replies. (Thanks [@Sanqui](https://github.com/Sanqui))
+- [CLI] Added channel names to errors shown on failures when exporting multiple channels. (Thanks [@Sanqui](https://github.com/Sanqui))
+- [CLI] Added support for passing message IDs (snowflakes) to `--after` and `--before` options. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- Files downloaded by the "download referenced media" option now have their dates set according to the `Last-Modified` header provided by Discord CDN. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- Fixed an issue where the application sometimes crashed with `NullReferenceException` when retrying a failed HTTP request.
+- Migrated to Discord API v8.
+
+### v2.25 (23-Nov-2020)
+
+- [JSON] Added `mentions` property to the output. This contains users referenced inside the message text, but doesn't include mentions in embeds. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- [HTML] Added better previews for attached video and audio. They are now rendered using a browser native player element. The actual file path can still be retrieved by right clicking and selecting "Copy file path". (Thanks [@sas41](https://github.com/sas41))
+- [CLI] Fixed an issue where using `--media` option without providing a rooted path via `--output` option triggered an error.
+- [CLI] Fixed an issue where using `--reuse-media` option without also providing `--media` option was accepted, but didn't actually do anything. Now this produces an error instead. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+
+### v2.24 (24-Oct-2020)
+
+- [CLI] Updated to [CliFx v1.5](https://github.com/Tyrrrz/CliFx), which brings some UX improvements.
+- [GUI] Added dark mode, which can be enabled in settings. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- [GUI] Improved the UX in a few minor places.
+- [JSON] Added `embed.color` property to the output. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- Added additional date formats: `unix` to write dates as a unix timestamp and `unixms` for the milliseconds version. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- Added retry policy for downloading media content. This is mostly a workaround for transient failures that sometimes may occur when downloading assets referenced from embeds. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+- Added an option to reuse already downloaded media to avoid redundant network requests. It can be enabled in settings in GUI, or by passing `--reuse-media` in CLI. To facilitate this feature, the file name strategy has been changed as well -- now instead of relying on the original file name and adding `(n)` to the end in case of duplicates, a URL hash is injected in every file name. This also means that when the "reuse media" option is disabled, existing files inside the media directory may be overwritten. (Thanks [@Andrew Kolos](https://github.com/andrewkolos))
+
+### v2.23 (14-Sep-2020)
+
+- [CLI] Added a command to export all channels across all servers. Use `exportall` to do it. (Thanks [@wyattscarpenter](https://github.com/wyattscarpenter))
+- [HTML] Fixed an issue where Whitney fonts were not being loaded properly, causing the browser to fall back to Helvetica.
+- Fixed an issue where self-contained export crashed occasionally. This usually happened when the server hosting the file did not serve the stream properly. Such files are now ignored after the first failed attempt.
+
+### v2.22 (12-Aug-2020)
+
+- [GUI] Improved the channel list by adding collapsible category groups. (Thanks [@CarJem Generations](https://github.com/CarJem))
+- [GUI] Improved exporting options by adding a set of controls that can be used to limit the date range of the export down to minutes. Previously it was only possible to configure the date range without the time component. (Thanks [@CarJem Generations](https://github.com/CarJem))
+- [HTML] Fixed an issue where the export didn't reflect changes in nicknames between messages sent by bots. This affected chat logs that contained interactions with the Tupperbox bot. (Thanks [@CarJem Generations](https://github.com/CarJem))
+- [CLI] Fixed an issue where the application crashed if there were two environment variables defined that had the same name but in different case.
+
+### v2.21.2 (30-Jul-2020)
+
+- [GUI] When copy-pasting token, any surrounding spaces are now discarded, in addition to double quotes.
+- [HTML] Changed underlying templating engine to provide higher performance and better error messages. New templating engine adds a small cold start, but any export after the first should be faster.
+- Changed naming schema for downloaded media so that it follows `<original filename> (nn)` format rather than `<original filename>-salt`.
+- [HTML] Fixed an issue where downloaded media was sometimes inaccessible due to reserved characters appearing in the URL.
+- Fixed an issue where the application crashed when trying to download media with a file name that exceeds system's maximum allowed length.
+- Fixed an issue where the application crashed when trying to download media with illegal characters in the file name.
+
+### v2.21.1 (19-Jul-2020)
+
+- Fixed an issue where the export crashed if an embedded image has been deleted. Such media files are now ignored.
+- Changed the naming convention for downloaded media files so that the original file names are used when possible.
+
+### 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.
+- 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. 
+
 ### v2.20 (27-Apr-2020)
 
 - [CLI] Added environment variables as fallback for `--token` and `--bot` options. They are `DISCORD_TOKEN` and `DISCORD_TOKEN_BOT` respectively.

Contributing.md

@@ -0,0 +1,56 @@
+# 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

@@ -2,11 +2,12 @@
 
   <PropertyGroup>
     <TargetFramework>netcoreapp3.1</TargetFramework>
-    <Version>2.20</Version>
+    <Version>2.27</Version>
     <Company>Tyrrrz</Company>
     <Copyright>Copyright (c) Alexey Golub</Copyright>
-    <LangVersion>latest</LangVersion>
+    <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
   </PropertyGroup>
 
-</Project>
+</Project>

DiscordChatExporter.Cli/Commands/Base/ExportCommandBase.cs

@@ -1,59 +1,145 @@
 using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Threading.Tasks;
-using CliFx;
 using CliFx.Attributes;
-using CliFx.Utilities;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Exporting;
+using CliFx.Exceptions;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Utils.Extensions;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exceptions;
+using DiscordChatExporter.Core.Exporting;
+using DiscordChatExporter.Core.Exporting.Partitioning;
+using DiscordChatExporter.Core.Utils.Extensions;
+using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands.Base
 {
     public abstract class ExportCommandBase : TokenCommandBase
     {
-        [CommandOption("format", 'f', Description = "Output file format.")]
-        public ExportFormat ExportFormat { get; set; } = ExportFormat.HtmlDark;
-
         [CommandOption("output", 'o', Description = "Output file or directory path.")]
-        public string OutputPath { get; set; } = Directory.GetCurrentDirectory();
+        public string OutputPath { get; init; } = Directory.GetCurrentDirectory();
 
-        [CommandOption("after", Description = "Limit to messages sent after this date.")]
-        public DateTimeOffset? After { get; set; }
+        [CommandOption("format", 'f', Description = "Export format.")]
+        public ExportFormat ExportFormat { get; init; } = ExportFormat.HtmlDark;
 
-        [CommandOption("before", Description = "Limit to messages sent before this date.")]
-        public DateTimeOffset? Before { get; set; }
+        [CommandOption("after", Description = "Only include messages sent after this date or message ID.")]
+        public Snowflake? After { get; init; }
 
-        [CommandOption("partition", 'p', Description = "Split output into partitions limited to this number of messages.")]
-        public int? PartitionLimit { get; set; }
+        [CommandOption("before", Description = "Only include messages sent before this date or message ID.")]
+        public Snowflake? Before { get; init; }
 
-        [CommandOption("dateformat", Description = "Date format used in output.")]
-        public string DateFormat { get; set; } = "dd-MMM-yy hh:mm tt";
+        [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;
 
-        protected ChannelExporter GetChannelExporter() => new ChannelExporter(GetDiscordClient());
+        [CommandOption("parallel", Description = "Limits how many channels can be exported in parallel.")]
+        public int ParallelLimit { get; init; } = 1;
 
-        protected async ValueTask ExportAsync(IConsole console, Guild guild, Channel channel)
+        [CommandOption("media", Description = "Download referenced media content.")]
+        public bool ShouldDownloadMedia { get; init; }
+
+        [CommandOption("reuse-media", Description = "Reuse already existing media content to skip redundant downloads.")]
+        public bool ShouldReuseMedia { get; init; }
+
+        [CommandOption("dateformat", Description = "Format used when writing dates.")]
+        public string DateFormat { get; init; } = "dd-MMM-yy hh:mm tt";
+
+        private ChannelExporter? _channelExporter;
+        protected ChannelExporter Exporter => _channelExporter ??= new ChannelExporter(Discord);
+
+        protected async ValueTask ExportAsync(IConsole console, IReadOnlyList<Channel> channels)
         {
-            console.Output.Write($"Exporting channel '{channel.Category} / {channel.Name}'... ");
-            var progress = console.CreateProgressTicker();
+            await console.Output.WriteLineAsync($"Exporting {channels.Count} channel(s)...");
 
-            await GetChannelExporter().ExportAsync(guild, channel,
-                OutputPath, ExportFormat, DateFormat, PartitionLimit,
-                After, Before, progress);
+            var errors = new ConcurrentDictionary<Channel, string>();
 
-            console.Output.WriteLine();
-            console.Output.WriteLine("Done.");
+            // Wrap everything in a progress ticker
+            await console.CreateProgressTicker().StartAsync(async progressContext =>
+            {
+                await channels.ParallelForEachAsync(async channel =>
+                {
+                    // Export
+                    try
+                    {
+                        await progressContext.StartTaskAsync($"{channel.Category} / {channel.Name}", async progress =>
+                        {
+                            var guild = await Discord.GetGuildAsync(channel.GuildId);
+
+                            var request = new ExportRequest(
+                                guild,
+                                channel,
+                                OutputPath,
+                                ExportFormat,
+                                After,
+                                Before,
+                                PartitionLimit,
+                                ShouldDownloadMedia,
+                                ShouldReuseMedia,
+                                DateFormat
+                            );
+
+                            await Exporter.ExportChannelAsync(request, progress);
+                        });
+                    }
+                    catch (DiscordChatExporterException ex) when (!ex.IsCritical)
+                    {
+                        errors[channel] = ex.Message;
+                    }
+                }, ParallelLimit.ClampMin(1));
+            });
+
+            // 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(
+                        $"Failed to export {errors.Count} channel(s):"
+                    );
+                }
+
+                foreach (var (channel, error) in errors)
+                {
+                    await console.Output.WriteAsync($"{channel.Category} / {channel.Name}: ");
+
+                    using (console.WithForegroundColor(ConsoleColor.Red))
+                        await console.Output.WriteLineAsync(error);
+                }
+
+                await console.Output.WriteLineAsync();
+            }
+
+            // 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.");
         }
 
-        protected async ValueTask ExportAsync(IConsole console, Channel channel)
+        public override ValueTask ExecuteAsync(IConsole console)
         {
-            var guild = await GetDiscordClient().GetGuildAsync(channel.GuildId);
-            await ExportAsync(console, guild, channel);
-        }
+            if (ShouldReuseMedia && !ShouldDownloadMedia)
+            {
+                throw new CommandException("Option --reuse-media cannot be used without --media.");
+            }
 
-        protected async ValueTask ExportAsync(IConsole console, string channelId)
-        {
-            var channel = await GetDiscordClient().GetChannelAsync(channelId);
-            await ExportAsync(console, channel);
+            return default;
         }
     }
 }

DiscordChatExporter.Cli/Commands/Base/ExportMultipleCommandBase.cs

@@ -1,66 +0,0 @@
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using CliFx;
-using CliFx.Attributes;
-using CliFx.Utilities;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Exceptions;
-using DiscordChatExporter.Domain.Utilities;
-using Gress;
-using Tyrrrz.Extensions;
-
-namespace DiscordChatExporter.Cli.Commands.Base
-{
-    public abstract class ExportMultipleCommandBase : ExportCommandBase
-    {
-        [CommandOption("parallel", Description = "Export this number of separate channels in parallel.")]
-        public int ParallelLimit { get; set; } = 1;
-
-        protected async ValueTask ExportMultipleAsync(IConsole console, IReadOnlyList<Channel> channels)
-        {
-            // This uses a separate route from ExportCommandBase because the progress ticker is not thread-safe
-            // Ugly code ahead. Will need to refactor.
-
-            console.Output.Write($"Exporting {channels.Count} channels... ");
-            var progress = console.CreateProgressTicker();
-
-            var operations = progress.Wrap().CreateOperations(channels.Count);
-
-            var errors = new List<string>();
-
-            var successfulExportCount = 0;
-            await channels.Zip(operations).ParallelForEachAsync(async tuple =>
-            {
-                var (channel, operation) = tuple;
-
-                try
-                {
-                    var guild = await GetDiscordClient().GetGuildAsync(channel.GuildId);
-
-                    await GetChannelExporter().ExportAsync(guild, channel,
-                        OutputPath, ExportFormat, DateFormat, PartitionLimit,
-                        After, Before, operation);
-
-                    Interlocked.Increment(ref successfulExportCount);
-                }
-                catch (DiscordChatExporterException ex) when (!ex.IsCritical)
-                {
-                    errors.Add(ex.Message);
-                }
-                finally
-                {
-                    operation.Dispose();
-                }
-            }, ParallelLimit.ClampMin(1));
-
-            console.Output.WriteLine();
-
-            foreach (var error in errors)
-                console.Error.WriteLine(error);
-
-            console.Output.WriteLine($"Successfully exported {successfulExportCount} channel(s).");
-        }
-    }
-}

DiscordChatExporter.Cli/Commands/Base/TokenCommandBase.cs

@@ -1,23 +1,28 @@
 using System.Threading.Tasks;
 using CliFx;
 using CliFx.Attributes;
-using DiscordChatExporter.Domain.Discord;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Core.Discord;
 
 namespace DiscordChatExporter.Cli.Commands.Base
 {
     public abstract class TokenCommandBase : ICommand
     {
-        [CommandOption("token", 't', IsRequired = true, EnvironmentVariableName = "DISCORD_TOKEN",
-            Description = "Authorization token.")]
-        public string TokenValue { get; set; } = "";
+        [CommandOption("token", 't', IsRequired = true, EnvironmentVariable = "DISCORD_TOKEN", Description = "Authentication token.")]
+        public string TokenValue { get; init; } = "";
 
-        [CommandOption("bot", 'b', EnvironmentVariableName = "DISCORD_TOKEN_BOT",
-            Description = "Whether this authorization token belongs to a bot.")]
-        public bool IsBotToken { get; set; }
+        [CommandOption("bot", 'b', EnvironmentVariable = "DISCORD_TOKEN_BOT", Description = "Authenticate as a bot.")]
+        public bool IsBotToken { get; init; }
 
-        protected AuthToken GetAuthToken() => new AuthToken(IsBotToken ? AuthTokenType.Bot : AuthTokenType.User, TokenValue);
+        private AuthToken GetAuthToken() => new(
+            IsBotToken
+                ? AuthTokenType.Bot
+                : AuthTokenType.User,
+            TokenValue
+        );
 
-        protected DiscordClient GetDiscordClient() => new DiscordClient(GetAuthToken());
+        private DiscordClient? _discordClient;
+        protected DiscordClient Discord => _discordClient ??= new DiscordClient(GetAuthToken());
 
         public abstract ValueTask ExecuteAsync(IConsole console);
     }

DiscordChatExporter.Cli/Commands/ExportAllCommand.cs

@@ -0,0 +1,42 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands.Base;
+using DiscordChatExporter.Core.Discord.Data;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [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)
+        {
+            await base.ExecuteAsync(console);
+
+            // 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);
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/ExportChannelCommand.cs

@@ -1,16 +0,0 @@
-using System.Threading.Tasks;
-using CliFx;
-using CliFx.Attributes;
-using DiscordChatExporter.Cli.Commands.Base;
-
-namespace DiscordChatExporter.Cli.Commands
-{
-    [Command("export", Description = "Export a channel.")]
-    public class ExportChannelCommand : ExportCommandBase
-    {
-        [CommandOption("channel", 'c', IsRequired = true, Description = "Channel ID.")]
-        public string ChannelId { get; set; } = "";
-
-        public override async ValueTask ExecuteAsync(IConsole console) => await ExportAsync(console, ChannelId);
-    }
-}

DiscordChatExporter.Cli/Commands/ExportChannelsCommand.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Infrastructure;
+using DiscordChatExporter.Cli.Commands.Base;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Discord.Data;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [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)
+        {
+            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);
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/ExportDirectMessagesCommand.cs

@@ -1,19 +1,25 @@
 using System.Threading.Tasks;
-using CliFx;
 using CliFx.Attributes;
+using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Utilities;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Utils.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands
 {
     [Command("exportdm", Description = "Export all direct message channels.")]
-    public class ExportDirectMessagesCommand : ExportMultipleCommandBase
+    public class ExportDirectMessagesCommand : ExportCommandBase
     {
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var dmChannels = await GetDiscordClient().GetGuildChannelsAsync(Guild.DirectMessages.Id);
-            await ExportMultipleAsync(console, dmChannels);
+            await base.ExecuteAsync(console);
+
+            // Get channel metadata
+            await console.Output.WriteLineAsync("Fetching channels...");
+            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id);
+
+            // Export
+            await ExportAsync(console, channels);
         }
     }
 }

DiscordChatExporter.Cli/Commands/ExportGuildCommand.cs

@@ -1,21 +1,28 @@
 using System.Threading.Tasks;
-using CliFx;
 using CliFx.Attributes;
+using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
-using DiscordChatExporter.Domain.Utilities;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Utils.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands
 {
     [Command("exportguild", Description = "Export all channels within specified guild.")]
-    public class ExportGuildCommand : ExportMultipleCommandBase
+    public class ExportGuildCommand : ExportCommandBase
     {
         [CommandOption("guild", 'g', IsRequired = true, Description = "Guild ID.")]
-        public string GuildId { get; set; } = "";
+        public Snowflake GuildId { get; init; }
 
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var guildChannels = await GetDiscordClient().GetGuildChannelsAsync(GuildId);
-            await ExportMultipleAsync(console, guildChannels);
+            await base.ExecuteAsync(console);
+
+            // Get channel metadata
+            await console.Output.WriteLineAsync("Fetching channels...");
+            var channels = await Discord.GetGuildChannelsAsync(GuildId);
+
+            // Export
+            await ExportAsync(console, channels);
         }
     }
 }

DiscordChatExporter.Cli/Commands/GetChannelsCommand.cs

@@ -1,24 +1,39 @@
-using System.Linq;
+using System;
+using System.Linq;
 using System.Threading.Tasks;
-using CliFx;
 using CliFx.Attributes;
+using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
-using DiscordChatExporter.Domain.Utilities;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Utils.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands
 {
-    [Command("channels", Description = "Get the list of channels in specified guild.")]
+    [Command("channels", Description = "Get the list of channels in a guild.")]
     public class GetChannelsCommand : TokenCommandBase
     {
         [CommandOption("guild", 'g', IsRequired = true, Description = "Guild ID.")]
-        public string GuildId { get; set; } = "";
+        public Snowflake GuildId { get; init; }
 
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var guildChannels = await GetDiscordClient().GetGuildChannelsAsync(GuildId);
+            var channels = await Discord.GetGuildChannelsAsync(GuildId);
 
-            foreach (var channel in guildChannels.OrderBy(c => c.Category).ThenBy(c => c.Name))
-                console.Output.WriteLine($"{channel.Id} | {channel.Category} / {channel.Name}");
+            foreach (var channel in channels.OrderBy(c => c.Category.Position).ThenBy(c => c.Name))
+            {
+                // Channel ID
+                await console.Output.WriteAsync(channel.Id.ToString());
+
+                // Separator
+                using (console.WithForegroundColor(ConsoleColor.DarkGray))
+                    await console.Output.WriteAsync(" | ");
+
+                // Channel category / name
+                using (console.WithForegroundColor(ConsoleColor.White))
+                    await console.Output.WriteAsync($"{channel.Category} / {channel.Name}");
+
+                await console.Output.WriteLineAsync();
+            }
         }
     }
 }

DiscordChatExporter.Cli/Commands/GetDirectMessageChannelsCommand.cs

@@ -1,10 +1,11 @@
-using System.Linq;
+using System;
+using System.Linq;
 using System.Threading.Tasks;
-using CliFx;
 using CliFx.Attributes;
+using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Utilities;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Utils.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands
 {
@@ -13,10 +14,23 @@ namespace DiscordChatExporter.Cli.Commands
     {
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var dmChannels = await GetDiscordClient().GetGuildChannelsAsync(Guild.DirectMessages.Id);
+            var channels = await Discord.GetGuildChannelsAsync(Guild.DirectMessages.Id);
 
-            foreach (var channel in dmChannels.OrderBy(c => c.Category).ThenBy(c => c.Name))
-                console.Output.WriteLine($"{channel.Id} | {channel.Category} / {channel.Name}");
+            foreach (var channel in channels.OrderBy(c => c.Name))
+            {
+                // Channel ID
+                await console.Output.WriteAsync(channel.Id.ToString());
+
+                // Separator
+                using (console.WithForegroundColor(ConsoleColor.DarkGray))
+                    await console.Output.WriteAsync(" | ");
+
+                // Channel category / name
+                using (console.WithForegroundColor(ConsoleColor.White))
+                    await console.Output.WriteAsync($"{channel.Category} / {channel.Name}");
+
+                await console.Output.WriteLineAsync();
+            }
         }
     }
 }

DiscordChatExporter.Cli/Commands/GetGuildsCommand.cs

@@ -1,9 +1,10 @@
-using System.Linq;
+using System;
+using System.Linq;
 using System.Threading.Tasks;
-using CliFx;
 using CliFx.Attributes;
+using CliFx.Infrastructure;
 using DiscordChatExporter.Cli.Commands.Base;
-using DiscordChatExporter.Domain.Utilities;
+using DiscordChatExporter.Core.Utils.Extensions;
 
 namespace DiscordChatExporter.Cli.Commands
 {
@@ -12,10 +13,23 @@ namespace DiscordChatExporter.Cli.Commands
     {
         public override async ValueTask ExecuteAsync(IConsole console)
         {
-            var guilds = await GetDiscordClient().GetUserGuildsAsync();
+            var guilds = await Discord.GetUserGuildsAsync();
 
             foreach (var guild in guilds.OrderBy(g => g.Name))
-                console.Output.WriteLine($"{guild.Id} | {guild.Name}");
+            {
+                // Guild ID
+                await console.Output.WriteAsync(guild.Id.ToString());
+
+                // 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();
+            }
         }
     }
 }

DiscordChatExporter.Cli/Commands/GuideCommand.cs

@@ -2,6 +2,7 @@
 using System.Threading.Tasks;
 using CliFx;
 using CliFx.Attributes;
+using CliFx.Infrastructure;
 
 namespace DiscordChatExporter.Cli.Commands
 {
@@ -10,24 +11,30 @@ namespace DiscordChatExporter.Cli.Commands
     {
         public ValueTask ExecuteAsync(IConsole console)
         {
-            console.WithForegroundColor(ConsoleColor.White, () => console.Output.WriteLine("To get 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://discordapp.com\" on the left");
+            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.WithForegroundColor(ConsoleColor.White, () => console.Output.WriteLine("To get 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.WithForegroundColor(ConsoleColor.White, () => console.Output.WriteLine("To get guild ID or guild 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");
@@ -35,7 +42,9 @@ namespace DiscordChatExporter.Cli.Commands
             console.Output.WriteLine(" 5. Right click on the desired guild or channel and click Copy ID");
             console.Output.WriteLine();
 
-            console.WithForegroundColor(ConsoleColor.White, () => console.Output.WriteLine("To get 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");
@@ -44,8 +53,11 @@ namespace DiscordChatExporter.Cli.Commands
             console.Output.WriteLine(" 6. Copy the first long sequence of numbers inside the URL");
             console.Output.WriteLine();
 
-            console.Output.WriteLine("For more information, check out the wiki:");
-            console.Output.WriteLine("https://github.com/Tyrrrz/DiscordChatExporter/wiki");
+            using (console.WithForegroundColor(ConsoleColor.White))
+                console.Output.WriteLine("For more information, check out the wiki:");
+
+            using (console.WithForegroundColor(ConsoleColor.DarkCyan))
+                console.Output.WriteLine("https://github.com/Tyrrrz/DiscordChatExporter/wiki");
 
             return default;
         }

DiscordChatExporter.Cli/DiscordChatExporter.Cli.csproj

@@ -1,5 +1,4 @@
 <Project Sdk="Microsoft.NET.Sdk">
-  <Import Project="../DiscordChatExporter.props" />
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
@@ -7,13 +6,14 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CliFx" Version="1.1.0" />
+    <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" />
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\DiscordChatExporter.Domain\DiscordChatExporter.Domain.csproj" />
+    <ProjectReference Include="..\DiscordChatExporter.Core\DiscordChatExporter.Core.csproj" />
   </ItemGroup>
 
 </Project>

DiscordChatExporter.Cli/Utils/Extensions/ConsoleExtensions.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Threading.Tasks;
+using CliFx.Infrastructure;
+using Spectre.Console;
+
+namespace DiscordChatExporter.Cli.Utils.Extensions
+{
+    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 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(description, new ProgressTaskSettings {MaxValue = 1});
+
+            try
+            {
+                await performOperationAsync(progressTask);
+            }
+            finally
+            {
+                progressTask.StopTask();
+            }
+        }
+    }
+}

DiscordChatExporter.Cli/Utils/Pollyfills.cs

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

DiscordChatExporter.Core/Discord/AuthToken.cs

@@ -1,6 +1,6 @@
 using System.Net.Http.Headers;
 
-namespace DiscordChatExporter.Domain.Discord
+namespace DiscordChatExporter.Core.Discord
 {
     public enum AuthTokenType { User, Bot }
 
@@ -16,9 +16,11 @@ namespace DiscordChatExporter.Domain.Discord
             Value = value;
         }
 
-        public AuthenticationHeaderValue GetAuthorizationHeader() => Type == AuthTokenType.User
-            ? new AuthenticationHeaderValue(Value)
-            : new AuthenticationHeaderValue("Bot", 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

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text.Json;
+using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data
+{
+    // https://discord.com/developers/docs/resources/channel#attachment-object
+    public partial class Attachment : IHasId
+    {
+        public Snowflake Id { get; }
+
+        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);
+        }
+    }
+}

DiscordChatExporter.Core/Discord/Data/Channel.cs

@@ -0,0 +1,111 @@
+using System.Linq;
+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
+{
+    // 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
+    }
+
+    // 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)
+        {
+            Id = id;
+            Type = type;
+            GuildId = guildId;
+            Category = category ?? GetFallbackCategory(type);
+            Name = name;
+            Position = position;
+            Topic = topic;
+        }
+
+        public override string ToString() => Name;
+
+    }
+
+    public partial class Channel
+    {
+        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
+        );
+
+        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

@@ -0,0 +1,49 @@
+using System.Linq;
+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
+{
+    public partial class ChannelCategory : IHasId, IHasPosition
+    {
+        public Snowflake Id { get; }
+
+        public string Name { get; }
+
+        public int? Position { get; }
+
+        public ChannelCategory(Snowflake id, string name, int? position)
+        {
+            Id = id;
+            Name = name;
+            Position = position;
+        }
+
+        public override string ToString() => Name;
+
+    }
+
+    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/Common/FileSize.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace DiscordChatExporter.Domain.Discord.Models.Common
+namespace DiscordChatExporter.Core.Discord.Data.Common
 {
     // Loosely based on https://github.com/omar/ByteSize (MIT license)
     public readonly partial struct FileSize
@@ -10,19 +10,11 @@ namespace DiscordChatExporter.Domain.Discord.Models.Common
         public double TotalKiloBytes => TotalBytes / 1024.0;
         public double TotalMegaBytes => TotalKiloBytes / 1024.0;
         public double TotalGigaBytes => TotalMegaBytes / 1024.0;
-        public double TotalTeraBytes => TotalGigaBytes / 1024.0;
-        public double TotalPetaBytes => TotalTeraBytes / 1024.0;
 
         public FileSize(long bytes) => TotalBytes = bytes;
 
         private double GetLargestWholeNumberValue()
         {
-            if (Math.Abs(TotalPetaBytes) >= 1)
-                return TotalPetaBytes;
-
-            if (Math.Abs(TotalTeraBytes) >= 1)
-                return TotalTeraBytes;
-
             if (Math.Abs(TotalGigaBytes) >= 1)
                 return TotalGigaBytes;
 
@@ -37,12 +29,6 @@ namespace DiscordChatExporter.Domain.Discord.Models.Common
 
         private string GetLargestWholeNumberSymbol()
         {
-            if (Math.Abs(TotalPetaBytes) >= 1)
-                return "PB";
-
-            if (Math.Abs(TotalTeraBytes) >= 1)
-                return "TB";
-
             if (Math.Abs(TotalGigaBytes) >= 1)
                 return "GB";
 
@@ -52,7 +38,7 @@ namespace DiscordChatExporter.Domain.Discord.Models.Common
             if (Math.Abs(TotalKiloBytes) >= 1)
                 return "KB";
 
-            return "B";
+            return "bytes";
         }
 
         public override string ToString() => $"{GetLargestWholeNumberValue():0.##} {GetLargestWholeNumberSymbol()}";
@@ -60,6 +46,6 @@ namespace DiscordChatExporter.Domain.Discord.Models.Common
 
     public partial struct FileSize
     {
-        public static FileSize FromBytes(long bytes) => new FileSize(bytes);
+        public static FileSize FromBytes(long bytes) => new(bytes);
     }
 }

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

@@ -0,0 +1,7 @@
+namespace DiscordChatExporter.Core.Discord.Data.Common
+{
+    public interface IHasId
+    {
+        Snowflake Id { get; }
+    }
+}

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

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

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

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Discord.Data.Common
+{
+    public partial class IdBasedEqualityComparer : IEqualityComparer<IHasId>
+    {
+        public bool Equals(IHasId? x, IHasId? y) => x?.Id == y?.Id;
+
+        public int GetHashCode(IHasId obj) => obj.Id.GetHashCode();
+    }
+
+    public partial class IdBasedEqualityComparer
+    {
+        public static IdBasedEqualityComparer Instance { get; } = new();
+    }
+}

DiscordChatExporter.Core/Discord/Data/Embed.cs

@@ -3,11 +3,12 @@ using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object
+    // https://discord.com/developers/docs/resources/channel#embed-object
     public partial class Embed
     {
         public string? Title { get; }

DiscordChatExporter.Core/Discord/Data/EmbedAuthor.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-author-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-author-structure
     public partial class EmbedAuthor
     {
         public string? Name { get; }

DiscordChatExporter.Core/Discord/Data/EmbedField.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-field-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-field-structure
     public partial class EmbedField
     {
         public string Name { get; }

DiscordChatExporter.Core/Discord/Data/EmbedFooter.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-footer-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-footer-structure
     public partial class EmbedFooter
     {
         public string Text { get; }

DiscordChatExporter.Core/Discord/Data/EmbedImage.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-image-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-image-structure
     public partial class EmbedImage
     {
         public string? Url { get; }

DiscordChatExporter.Core/Discord/Data/Emoji.cs

@@ -2,12 +2,12 @@
 using System.Linq;
 using System.Text;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using JsonExtensions.Reading;
 using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/emoji#emoji-object
+    // https://discord.com/developers/docs/resources/emoji#emoji-object
     public partial class Emoji
     {
         public string? Id { get; }

DiscordChatExporter.Core/Discord/Data/Guild.cs

@@ -0,0 +1,53 @@
+using System.Text.Json;
+using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Utils.Extensions;
+
+namespace DiscordChatExporter.Core.Discord.Data
+{
+    // https://discord.com/developers/docs/resources/guild#guild-object
+    public partial class Guild : IHasId
+    {
+        public Snowflake Id { get; }
+
+        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;
+    }
+
+    public partial class Guild
+    {
+        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) =>
+            $"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);
+        }
+    }
+}

DiscordChatExporter.Core/Discord/Data/Member.cs

@@ -2,23 +2,24 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/guild#guild-member-object
+    // https://discord.com/developers/docs/resources/guild#guild-member-object
     public partial class Member : IHasId
     {
-        public string Id => User.Id;
+        public Snowflake Id => User.Id;
 
         public User User { get; }
 
         public string Nick { get; }
 
-        public IReadOnlyList<string> RoleIds { get; }
+        public IReadOnlyList<Snowflake> RoleIds { get; }
 
-        public Member(User user, string? nick, IReadOnlyList<string> roleIds)
+        public Member(User user, string? nick, IReadOnlyList<Snowflake> roleIds)
         {
             User = user;
             Nick = nick ?? user.Name;
@@ -30,8 +31,11 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
     public partial class Member
     {
-        public static Member CreateForUser(User user) =>
-            new Member(user, null, Array.Empty<string>());
+        public static Member CreateForUser(User user) => new(
+            user,
+            null,
+            Array.Empty<Snowflake>()
+        );
 
         public static Member Parse(JsonElement json)
         {
@@ -39,8 +43,8 @@ namespace DiscordChatExporter.Domain.Discord.Models
             var nick = json.GetPropertyOrNull("nick")?.GetString();
 
             var roleIds =
-                json.GetPropertyOrNull("roles")?.EnumerateArray().Select(j => j.GetString()).ToArray() ??
-                Array.Empty<string>();
+                json.GetPropertyOrNull("roles")?.EnumerateArray().Select(j => j.GetString().Pipe(Snowflake.Parse)).ToArray() ??
+                Array.Empty<Snowflake>();
 
             return new Member(
                 user,

DiscordChatExporter.Core/Discord/Data/Message.cs

@@ -2,28 +2,30 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#message-object-message-types
+    // https://discord.com/developers/docs/resources/channel#message-object-message-types
     public enum MessageType
     {
-        Default,
-        RecipientAdd,
-        RecipientRemove,
-        Call,
-        ChannelNameChange,
-        ChannelIconChange,
-        ChannelPinnedMessage,
-        GuildMemberJoin
+        Default = 0,
+        RecipientAdd = 1,
+        RecipientRemove = 2,
+        Call = 3,
+        ChannelNameChange = 4,
+        ChannelIconChange = 5,
+        ChannelPinnedMessage = 6,
+        GuildMemberJoin = 7,
+        Reply = 19
     }
 
-    // https://discordapp.com/developers/docs/resources/channel#message-object
+    // https://discord.com/developers/docs/resources/channel#message-object
     public partial class Message : IHasId
     {
-        public string Id { get; }
+        public Snowflake Id { get; }
 
         public MessageType Type { get; }
 
@@ -33,6 +35,8 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
         public DateTimeOffset? EditedTimestamp { get; }
 
+        public DateTimeOffset? CallEndedTimestamp { get; }
+
         public bool IsPinned { get; }
 
         public string Content { get; }
@@ -45,54 +49,65 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
         public IReadOnlyList<User> MentionedUsers { get; }
 
+        public MessageReference? Reference { get; }
+
+        public Message? ReferencedMessage { get; }
+
         public Message(
-            string id,
+            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)
+            IReadOnlyList<User> mentionedUsers,
+            MessageReference? messageReference,
+            Message? referencedMessage)
         {
             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;
         }
 
-        public override string ToString() =>
-            Content ?? (Embeds.Any()
-                ? "<embed>"
-                : "<no content>");
+        public override string ToString() => Content;
     }
 
     public partial class Message
     {
         public static Message Parse(JsonElement json)
         {
-            var id = json.GetProperty("id").GetString();
+            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
             {
                 MessageType.RecipientAdd => "Added a recipient.",
                 MessageType.RecipientRemove => "Removed a recipient.",
-                MessageType.Call => "Started a call.",
+                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.",
@@ -122,12 +137,15 @@ namespace DiscordChatExporter.Domain.Discord.Models
                 author,
                 timestamp,
                 editedTimestamp,
+                callEndedTimestamp,
                 isPinned,
                 content,
                 attachments,
                 embeds,
                 reactions,
-                mentionedUsers
+                mentionedUsers,
+                messageReference,
+                referencedMessage
             );
         }
     }

DiscordChatExporter.Core/Discord/Data/MessageReference.cs

@@ -0,0 +1,37 @@
+using System.Text.Json;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
+
+namespace DiscordChatExporter.Core.Discord.Data
+{
+    // https://discord.com/developers/docs/resources/channel#message-object-message-reference-structure
+    public partial class MessageReference
+    {
+        public Snowflake? MessageId { get; }
+
+        public Snowflake? ChannelId { get; }
+
+        public Snowflake? GuildId { get; }
+
+        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);
+        }
+    }
+}

DiscordChatExporter.Core/Discord/Data/Reaction.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/resources/channel#reaction-object
+    // https://discord.com/developers/docs/resources/channel#reaction-object
     public partial class Reaction
     {
         public Emoji Emoji { get; }

DiscordChatExporter.Core/Discord/Data/Role.cs

@@ -1,13 +1,15 @@
 using System.Drawing;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Core.Discord.Data.Common;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Reading;
 
-namespace DiscordChatExporter.Domain.Discord.Models
+namespace DiscordChatExporter.Core.Discord.Data
 {
-    // https://discordapp.com/developers/docs/topics/permissions#role-object
-    public partial class Role
+    // https://discord.com/developers/docs/topics/permissions#role-object
+    public partial class Role : IHasId
     {
-        public string Id { get; }
+        public Snowflake Id { get; }
 
         public string Name { get; }
 
@@ -15,7 +17,11 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
         public Color? Color { get; }
 
-        public Role(string id, string name, int position, Color? color)
+        public Role(
+            Snowflake id,
+            string name,
+            int position,
+            Color? color)
         {
             Id = id;
             Name = name;
@@ -30,7 +36,7 @@ namespace DiscordChatExporter.Domain.Discord.Models
     {
         public static Role Parse(JsonElement json)
         {
-            var id = json.GetProperty("id").GetString();
+            var id = json.GetProperty("id").GetString().Pipe(Snowflake.Parse);
             var name = json.GetProperty("name").GetString();
             var position = json.GetProperty("position").GetInt32();
 

DiscordChatExporter.Core/Discord/Data/User.cs

@@ -0,0 +1,73 @@
+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
+{
+    // https://discord.com/developers/docs/resources/user#user-object
+    public partial class User : IHasId
+    {
+        public Snowflake Id { get; }
+
+        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;
+    }
+
+    public partial class User
+    {
+        private static string GetDefaultAvatarUrl(int discriminator) =>
+            $"https://cdn.discordapp.com/embed/avatars/{discriminator % 5}.png";
+
+        private static string GetAvatarUrl(Snowflake id, string avatarHash)
+        {
+            // Animated
+            if (avatarHash.StartsWith("a_", StringComparison.Ordinal))
+                return $"https://cdn.discordapp.com/avatars/{id}/{avatarHash}.gif";
+
+            // 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);
+        }
+    }
+}

DiscordChatExporter.Core/Discord/DiscordClient.cs

@@ -5,62 +5,42 @@ using System.Net;
 using System.Net.Http;
 using System.Text.Json;
 using System.Threading.Tasks;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Exceptions;
-using DiscordChatExporter.Domain.Internal;
-using Polly;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exceptions;
+using DiscordChatExporter.Core.Utils;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Http;
+using JsonExtensions.Reading;
+using Tyrrrz.Extensions;
 
-namespace DiscordChatExporter.Domain.Discord
+namespace DiscordChatExporter.Core.Discord
 {
-    public partial class DiscordClient
+    public class DiscordClient
     {
-        private readonly AuthToken _token;
         private readonly HttpClient _httpClient;
-        private readonly IAsyncPolicy<HttpResponseMessage> _httpRequestPolicy;
+        private readonly AuthToken _token;
 
-        private readonly Uri _baseUri = new Uri("https://discordapp.com/api/v6/", UriKind.Absolute);
+        private readonly Uri _baseUri = new("https://discord.com/api/v8/", UriKind.Absolute);
 
-        public DiscordClient(AuthToken token, HttpClient httpClient)
+        public DiscordClient(HttpClient httpClient, AuthToken token)
         {
-            _token = token;
             _httpClient = httpClient;
-
-            // Discord seems to always respond with 429 on the first request with unreasonable wait time (10+ minutes).
-            // For that reason the policy will start respecting their retry-after header only after Nth failed response.
-            _httpRequestPolicy = Policy
-                .HandleResult<HttpResponseMessage>(m => m.StatusCode == HttpStatusCode.TooManyRequests)
-                .OrResult(m => m.StatusCode >= HttpStatusCode.InternalServerError)
-                .WaitAndRetryAsync(6,
-                    (i, result, ctx) =>
-                    {
-                        if (i <= 3)
-                            return TimeSpan.FromSeconds(2 * i);
-
-                        if (i <= 5)
-                            return TimeSpan.FromSeconds(5 * i);
-
-                        return result.Result.Headers.RetryAfter.Delta ?? TimeSpan.FromSeconds(10 * i);
-                    },
-                    (response, timespan, retryCount, context) => Task.CompletedTask);
+            _token = token;
         }
 
         public DiscordClient(AuthToken token)
-            : this(token, LazyHttpClient.Value)
-        {
-        }
+            : this(Http.Client, token) {}
 
-        private async Task<HttpResponseMessage> GetResponseAsync(string url)
-        {
-            return await _httpRequestPolicy.ExecuteAsync(async () =>
+        private async ValueTask<HttpResponseMessage> GetResponseAsync(string url) =>
+            await Http.ResponsePolicy.ExecuteAsync(async () =>
             {
                 using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
-                request.Headers.Authorization = _token.GetAuthorizationHeader();
+                request.Headers.Authorization = _token.GetAuthenticationHeader();
 
                 return await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
             });
-        }
 
-        private async Task<JsonElement> GetJsonResponseAsync(string url)
+        private async ValueTask<JsonElement> GetJsonResponseAsync(string url)
         {
             using var response = await GetResponseAsync(url);
 
@@ -78,7 +58,7 @@ namespace DiscordChatExporter.Domain.Discord
             return await response.Content.ReadAsJsonAsync();
         }
 
-        private async Task<JsonElement?> TryGetJsonResponseAsync(string url)
+        private async ValueTask<JsonElement?> TryGetJsonResponseAsync(string url)
         {
             using var response = await GetResponseAsync(url);
 
@@ -91,24 +71,24 @@ namespace DiscordChatExporter.Domain.Discord
         {
             yield return Guild.DirectMessages;
 
-            var afterId = "";
+            var currentAfter = Snowflake.Zero;
+
             while (true)
             {
                 var url = new UrlBuilder()
                     .SetPath("users/@me/guilds")
                     .SetQueryParameter("limit", "100")
-                    .SetQueryParameterIfNotNullOrWhiteSpace("after", afterId)
+                    .SetQueryParameter("after", currentAfter.ToString())
                     .Build();
 
                 var response = await GetJsonResponseAsync(url);
 
                 var isEmpty = true;
-                foreach (var guildJson in response.EnumerateArray())
+                foreach (var guild in response.EnumerateArray().Select(Guild.Parse))
                 {
-                    var guild = Guild.Parse(guildJson);
                     yield return guild;
 
-                    afterId = guild.Id;
+                    currentAfter = guild.Id;
                     isEmpty = false;
                 }
 
@@ -117,7 +97,7 @@ namespace DiscordChatExporter.Domain.Discord
             }
         }
 
-        public async Task<Guild> GetGuildAsync(string guildId)
+        public async ValueTask<Guild> GetGuildAsync(Snowflake guildId)
         {
             if (guildId == Guild.DirectMessages.Id)
                 return Guild.DirectMessages;
@@ -126,7 +106,7 @@ namespace DiscordChatExporter.Domain.Discord
             return Guild.Parse(response);
         }
 
-        public async IAsyncEnumerable<Channel> GetGuildChannelsAsync(string guildId)
+        public async IAsyncEnumerable<Channel> GetGuildChannelsAsync(Snowflake guildId)
         {
             if (guildId == Guild.DirectMessages.Id)
             {
@@ -138,32 +118,40 @@ namespace DiscordChatExporter.Domain.Discord
             {
                 var response = await GetJsonResponseAsync($"guilds/{guildId}/channels");
 
-                var categories = response
+                var orderedResponse = response
                     .EnumerateArray()
-                    .ToDictionary(
-                        j => j.GetProperty("id").GetString(),
-                        j => j.GetProperty("name").GetString()
-                    );
+                    .OrderBy(j => j.GetProperty("position").GetInt32())
+                    .ThenBy(j => ulong.Parse(j.GetProperty("id").GetString()))
+                    .ToArray();
 
-                foreach (var channelJson in response.EnumerateArray())
+                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);
+                    var channel = Channel.Parse(channelJson, category, position);
 
                     // Skip non-text channels
                     if (!channel.IsTextChannel)
                         continue;
 
+                    position++;
+
                     yield return channel;
                 }
             }
         }
 
-        public async IAsyncEnumerable<Role> GetGuildRolesAsync(string guildId)
+        public async IAsyncEnumerable<Role> GetGuildRolesAsync(Snowflake guildId)
         {
             if (guildId == Guild.DirectMessages.Id)
                 yield break;
@@ -174,7 +162,7 @@ namespace DiscordChatExporter.Domain.Discord
                 yield return Role.Parse(roleJson);
         }
 
-        public async Task<Member?> TryGetGuildMemberAsync(string guildId, User user)
+        public async ValueTask<Member?> TryGetGuildMemberAsync(Snowflake guildId, User user)
         {
             if (guildId == Guild.DirectMessages.Id)
                 return Member.CreateForUser(user);
@@ -183,30 +171,43 @@ namespace DiscordChatExporter.Domain.Discord
             return response?.Pipe(Member.Parse);
         }
 
-        private async Task<string> GetChannelCategoryAsync(string channelParentId)
+        public async ValueTask<ChannelCategory> GetChannelCategoryAsync(Snowflake channelId)
         {
-            var response = await GetJsonResponseAsync($"channels/{channelParentId}");
-            return response.GetProperty("name").GetString();
+            try
+            {
+                var response = await GetJsonResponseAsync($"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;
+            }
+
         }
 
-        public async Task<Channel> GetChannelAsync(string channelId)
+        public async ValueTask<Channel> GetChannelAsync(Snowflake channelId)
         {
             var response = await GetJsonResponseAsync($"channels/{channelId}");
 
-            var parentId = response.GetPropertyOrNull("parent_id")?.GetString();
-            var category = !string.IsNullOrWhiteSpace(parentId)
-                ? await GetChannelCategoryAsync(parentId)
+            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);
         }
 
-        private async Task<Message?> TryGetLastMessageAsync(string channelId, DateTimeOffset? before = null)
+        private async ValueTask<Message?> TryGetLastMessageAsync(Snowflake channelId, Snowflake? before = null)
         {
             var url = new UrlBuilder()
                 .SetPath($"channels/{channelId}/messages")
                 .SetQueryParameter("limit", "1")
-                .SetQueryParameterIfNotNullOrWhiteSpace("before", before?.ToSnowflake())
+                .SetQueryParameter("before", before?.ToString())
                 .Build();
 
             var response = await GetJsonResponseAsync(url);
@@ -214,25 +215,29 @@ namespace DiscordChatExporter.Domain.Discord
         }
 
         public async IAsyncEnumerable<Message> GetMessagesAsync(
-            string channelId,
-            DateTimeOffset? after = null,
-            DateTimeOffset? before = null,
+            Snowflake channelId,
+            Snowflake? after = null,
+            Snowflake? before = null,
             IProgress<double>? progress = null)
         {
-            // Get the last message in the specified range
+            // 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 == null || lastMessage.Timestamp < after)
+            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 afterId = after?.ToSnowflake() ?? "0";
+            var currentAfter = after ?? Snowflake.Zero;
 
             while (true)
             {
                 var url = new UrlBuilder()
                     .SetPath($"channels/{channelId}/messages")
                     .SetQueryParameter("limit", "100")
-                    .SetQueryParameter("after", afterId)
+                    .SetQueryParameter("after", currentAfter.ToString())
                     .Build();
 
                 var response = await GetJsonResponseAsync(url);
@@ -255,31 +260,28 @@ namespace DiscordChatExporter.Domain.Discord
                     if (message.Timestamp > lastMessage.Timestamp)
                         yield break;
 
-                    // Report progress based on the duration of parsed messages divided by total
-                    progress?.Report(
-                        (message.Timestamp - firstMessage.Timestamp) /
-                        (lastMessage.Timestamp - firstMessage.Timestamp)
-                    );
+                    // 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();
+
+                        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);
+                        }
+                    }
 
                     yield return message;
-                    afterId = message.Id;
+                    currentAfter = message.Id;
                 }
             }
         }
     }
-
-    public partial class DiscordClient
-    {
-        private static readonly Lazy<HttpClient> LazyHttpClient = new Lazy<HttpClient>(() =>
-        {
-            var handler = new HttpClientHandler();
-
-            if (handler.SupportsAutomaticDecompression)
-                handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
-
-            handler.UseCookies = false;
-
-            return new HttpClient(handler, true);
-        });
-    }
-}
+}

DiscordChatExporter.Core/Discord/Snowflake.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Globalization;
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Discord
+{
+    public readonly partial struct Snowflake
+    {
+        public ulong Value { get; }
+
+        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)
+        {
+            var value = ((ulong) date.ToUnixTimeMilliseconds() - 1420070400000UL) << 22;
+            return new Snowflake(value);
+        }
+
+        public static Snowflake? TryParse(string? str, IFormatProvider? formatProvider = null)
+        {
+            if (string.IsNullOrWhiteSpace(str))
+                return null;
+
+            // As number
+            if (Regex.IsMatch(str, @"^\d+$") &&
+                ulong.TryParse(str, NumberStyles.Number, formatProvider, out var value))
+            {
+                return new Snowflake(value);
+            }
+
+            // As date
+            if (DateTimeOffset.TryParse(str, formatProvider, DateTimeStyles.None, out var date))
+            {
+                return FromDate(date);
+            }
+
+            return null;
+        }
+
+        public static Snowflake Parse(string str, IFormatProvider? formatProvider) =>
+            TryParse(str, formatProvider) ?? throw new FormatException($"Invalid snowflake '{str}'.");
+
+        public static Snowflake Parse(string str) => Parse(str, null);
+    }
+
+    public partial struct Snowflake : IEquatable<Snowflake>
+    {
+        public bool Equals(Snowflake other) => Value == other.Value;
+
+        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);
+    }
+}

DiscordChatExporter.Core/DiscordChatExporter.Core.csproj

@@ -0,0 +1,23 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+  </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" />
+  </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" />
+  </ItemGroup>
+
+</Project>

DiscordChatExporter.Core/Exceptions/DiscordChatExporterException.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Net.Http;
+
+namespace DiscordChatExporter.Core.Exceptions
+{
+    public partial class DiscordChatExporterException : Exception
+    {
+        public bool IsCritical { get; }
+
+        public DiscordChatExporterException(string message, bool isCritical = false)
+            : base(message)
+        {
+            IsCritical = isCritical;
+        }
+    }
+
+    public partial class DiscordChatExporterException
+    {
+        internal static DiscordChatExporterException FailedHttpRequest(HttpResponseMessage response)
+        {
+            var message = $@"
+Failed to perform an HTTP request.
+
+[Request]
+{response.RequestMessage}
+
+[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.");
+    }
+}

DiscordChatExporter.Core/Exporting/ChannelExporter.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+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;
+
+namespace DiscordChatExporter.Core.Exporting
+{
+    public class ChannelExporter
+    {
+        private readonly DiscordClient _discord;
+
+        public ChannelExporter(DiscordClient discord) => _discord = discord;
+
+        public ChannelExporter(AuthToken token) : this(new DiscordClient(token)) {}
+
+        public async ValueTask ExportChannelAsync(ExportRequest request, IProgress<double>? progress = null)
+        {
+            // 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);
+
+            var context = new ExportContext(
+                request,
+                contextMembers,
+                contextChannels,
+                contextRoles
+            );
+
+            // 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))
+                {
+                    if (!encounteredUsers.Add(referencedUser))
+                        continue;
+
+                    var member =
+                        await _discord.TryGetGuildMemberAsync(request.Guild.Id, referencedUser) ??
+                        Member.CreateForUser(referencedUser);
+
+                    contextMembers.Add(member);
+                }
+
+                // Export message
+                await messageExporter.ExportMessageAsync(message);
+                exportedAnything = true;
+            }
+
+            // Throw if no messages were exported
+            if (!exportedAnything)
+                throw DiscordChatExporterException.ChannelIsEmpty();
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/ExportContext.cs

@@ -0,0 +1,104 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+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
+{
+    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)
+        {
+            Request = request;
+            Members = members;
+            Channels = channels;
+            Roles = roles;
+
+            _mediaDownloader = new MediaDownloader(request.OutputMediaDirPath, request.ShouldReuseMedia);
+        }
+
+        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
+            {
+                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
+                        .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;
+            }
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/ExportFormat.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace DiscordChatExporter.Domain.Exporting
+namespace DiscordChatExporter.Core.Exporting
 {
     public enum ExportFormat
     {

DiscordChatExporter.Core/Exporting/ExportRequest.cs

@@ -0,0 +1,163 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exporting.Partitioning;
+using DiscordChatExporter.Core.Utils;
+
+namespace DiscordChatExporter.Core.Exporting
+{
+    public partial class ExportRequest
+    {
+        public Guild Guild { get; }
+
+        public Channel Channel { get; }
+
+        public string OutputPath { get; }
+
+        public string OutputBaseFilePath { get; }
+
+        public string OutputBaseDirPath { get; }
+
+        public string OutputMediaDirPath { get; }
+
+        public ExportFormat Format { get; }
+
+        public Snowflake? After { get; }
+
+        public Snowflake? Before { get; }
+
+        public PartitionLimit PartitionLimit { get; }
+
+        public bool ShouldDownloadMedia { get; }
+
+        public bool ShouldReuseMedia { get; }
+
+        public string DateFormat { get; }
+
+        public ExportRequest(
+            Guild guild,
+            Channel channel,
+            string outputPath,
+            ExportFormat format,
+            Snowflake? after,
+            Snowflake? before,
+            PartitionLimit partitionLimit,
+            bool shouldDownloadMedia,
+            bool shouldReuseMedia,
+            string dateFormat)
+        {
+            Guild = guild;
+            Channel = channel;
+            OutputPath = outputPath;
+            Format = format;
+            After = after;
+            Before = before;
+            PartitionLimit = partitionLimit;
+            ShouldDownloadMedia = shouldDownloadMedia;
+            ShouldReuseMedia = shouldReuseMedia;
+            DateFormat = dateFormat;
+
+            OutputBaseFilePath = GetOutputBaseFilePath(
+                guild,
+                channel,
+                outputPath,
+                format,
+                after,
+                before
+            );
+
+            OutputBaseDirPath = Path.GetDirectoryName(OutputBaseFilePath) ?? OutputPath;
+            OutputMediaDirPath = $"{OutputBaseFilePath}_Files{Path.DirectorySeparatorChar}";
+        }
+    }
+
+    public partial class ExportRequest
+    {
+        private static string GetOutputBaseFilePath(
+            Guild guild,
+            Channel channel,
+            string outputPath,
+            ExportFormat format,
+            Snowflake? after = null,
+            Snowflake? before = null)
+        {
+
+            // Formats path
+            outputPath = Regex.Replace(outputPath, "%.", m =>
+                PathEx.EscapePath(m.Value switch
+                {
+                    "%g" => guild.Id.ToString(),
+                    "%G" => guild.Name,
+                    "%t" => channel.Category.Id.ToString(),
+                    "%T" => channel.Category.Name,
+                    "%c" => channel.Id.ToString(),
+                    "%C" => channel.Name,
+                    "%p" => channel.Position?.ToString() ?? "0",
+                    "%P" => channel.Category.Position?.ToString() ?? "0",
+                    "%a" => (after ?? Snowflake.Zero).ToDate().ToString("yyyy-MM-dd"),
+                    "%b" => (before?.ToDate() ?? DateTime.Now).ToString("yyyy-MM-dd"),
+                    "%%" => "%",
+                    _ => m.Value
+                })
+            );
+
+            // Output is a directory
+            if (Directory.Exists(outputPath) || string.IsNullOrWhiteSpace(Path.GetExtension(outputPath)))
+            {
+                var fileName = GetDefaultOutputFileName(guild, channel, format, after, before);
+                return Path.Combine(outputPath, fileName);
+            }
+
+            // Output is a file
+            return outputPath;
+        }
+
+        public static string GetDefaultOutputFileName(
+            Guild guild,
+            Channel channel,
+            ExportFormat format,
+            Snowflake? after = null,
+            Snowflake? before = null)
+        {
+            var buffer = new StringBuilder();
+
+            // Guild and channel names
+            buffer.Append($"{guild.Name} - {channel.Category.Name} - {channel.Name} [{channel.Id}]");
+
+            // Date range
+            if (after is not null || before is not null)
+            {
+                buffer.Append(" (");
+
+                // Both 'after' and 'before' are set
+                if (after is not null && before is not null)
+                {
+                    buffer.Append($"{after?.ToDate():yyyy-MM-dd} to {before?.ToDate():yyyy-MM-dd}");
+                }
+                // Only 'after' is set
+                else if (after is not null)
+                {
+                    buffer.Append($"after {after?.ToDate():yyyy-MM-dd}");
+                }
+                // Only 'before' is set
+                else
+                {
+                    buffer.Append($"before {before?.ToDate():yyyy-MM-dd}");
+                }
+
+                buffer.Append(")");
+            }
+
+            // File extension
+            buffer.Append($".{format.GetFileExtension()}");
+
+            // Replace invalid chars
+            PathEx.EscapePath(buffer);
+
+            return buffer.ToString();
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/MediaDownloader.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Net.Http;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Utils;
+using DiscordChatExporter.Core.Utils.Extensions;
+
+namespace DiscordChatExporter.Core.Exporting
+{
+    internal partial class MediaDownloader
+    {
+        private readonly HttpClient _httpClient;
+        private readonly string _workingDirPath;
+        private readonly bool _reuseMedia;
+
+        // URL -> Local file path
+        private readonly Dictionary<string, string> _pathCache = new(StringComparer.Ordinal);
+
+        public MediaDownloader(HttpClient httpClient, string workingDirPath, bool reuseMedia)
+        {
+            _httpClient = httpClient;
+            _workingDirPath = workingDirPath;
+            _reuseMedia = reuseMedia;
+        }
+
+        public MediaDownloader(string workingDirPath, bool reuseMedia)
+            : this(Http.Client, workingDirPath, reuseMedia) {}
+
+        public async ValueTask<string> DownloadAsync(string url)
+        {
+            if (_pathCache.TryGetValue(url, out var cachedFilePath))
+                return cachedFilePath;
+
+            var fileName = GetFileNameFromUrl(url);
+            var filePath = Path.Combine(_workingDirPath, fileName);
+
+            // Reuse existing files if we're allowed to
+            if (_reuseMedia && File.Exists(filePath))
+                return _pathCache[url] = filePath;
+
+            Directory.CreateDirectory(_workingDirPath);
+
+            // This catches IOExceptions which is dangerous as we're working also with files
+            await Http.ExceptionPolicy.ExecuteAsync(async () =>
+            {
+                // Download the file
+                using var response = await _httpClient.GetAsync(url);
+                await using (var output = File.Create(filePath))
+                {
+                    await response.Content.CopyToAsync(output);
+                }
+
+                // Try to set the file date according to the last-modified header
+                var lastModified = response.Content.Headers.TryGetValue("Last-Modified")?.Pipe(s =>
+                    DateTimeOffset.TryParse(s, CultureInfo.InvariantCulture, DateTimeStyles.None, out var date)
+                        ? date
+                        : (DateTimeOffset?) null
+                );
+
+                if (lastModified is not null)
+                {
+                    File.SetCreationTimeUtc(filePath, lastModified.Value.UtcDateTime);
+                    File.SetLastWriteTimeUtc(filePath, lastModified.Value.UtcDateTime);
+                    File.SetLastAccessTimeUtc(filePath, lastModified.Value.UtcDateTime);
+                }
+            });
+
+            return _pathCache[url] = filePath;
+        }
+    }
+
+    internal partial class MediaDownloader
+    {
+        private static string GetUrlHash(string url)
+        {
+            using var hash = SHA256.Create();
+
+            var data = hash.ComputeHash(Encoding.UTF8.GetBytes(url));
+            return data.ToHex().Truncate(5); // 5 chars ought to be enough for anybody
+        }
+
+        private static string GetFileNameFromUrl(string url)
+        {
+            var urlHash = GetUrlHash(url);
+
+            // Try to extract file name from URL
+            var fileName = Regex.Match(url, @".+/([^?]*)").Groups[1].Value;
+
+            // If it's not there, just use the URL hash as the file name
+            if (string.IsNullOrWhiteSpace(fileName))
+                return urlHash;
+
+            // Otherwise, use the original file name but inject the hash in the middle
+            var fileNameWithoutExtension = Path.GetFileNameWithoutExtension(fileName);
+            var fileExtension = Path.GetExtension(fileName);
+
+            return PathEx.EscapePath(fileNameWithoutExtension.Truncate(42) + '-' + urlHash + fileExtension);
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/MessageExporter.cs

@@ -1,35 +1,26 @@
 using System;
 using System.IO;
 using System.Threading.Tasks;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Exporting.Writers;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exporting.Writers;
 
-namespace DiscordChatExporter.Domain.Exporting
+namespace DiscordChatExporter.Core.Exporting
 {
     internal partial class MessageExporter : IAsyncDisposable
     {
-        private readonly ExportOptions _options;
         private readonly ExportContext _context;
 
-        private long _renderedMessageCount;
         private int _partitionIndex;
         private MessageWriter? _writer;
 
-        public MessageExporter(ExportOptions options, ExportContext context)
+        public MessageExporter(ExportContext context)
         {
-            _options = options;
             _context = context;
         }
 
-        private bool IsPartitionLimitReached() =>
-            _renderedMessageCount > 0 &&
-            _options.PartitionLimit != null &&
-            _options.PartitionLimit != 0 &&
-            _renderedMessageCount % _options.PartitionLimit == 0;
-
-        private async Task ResetWriterAsync()
+        private async ValueTask ResetWriterAsync()
         {
-            if (_writer != null)
+            if (_writer is not null)
             {
                 await _writer.WritePostambleAsync();
                 await _writer.DisposeAsync();
@@ -37,36 +28,36 @@ namespace DiscordChatExporter.Domain.Exporting
             }
         }
 
-        private async Task<MessageWriter> GetWriterAsync()
+        private async ValueTask<MessageWriter> GetWriterAsync()
         {
             // Ensure partition limit has not been exceeded
-            if (IsPartitionLimitReached())
+            if (_writer is not null &&
+                _context.Request.PartitionLimit.IsReached(_writer.MessagesWritten, _writer.BytesWritten))
             {
                 await ResetWriterAsync();
                 _partitionIndex++;
             }
 
             // Writer is still valid - return
-            if (_writer != null)
+            if (_writer is not null)
                 return _writer;
 
-            var filePath = GetPartitionFilePath(_options.BaseFilePath, _partitionIndex);
+            var filePath = GetPartitionFilePath(_context.Request.OutputBaseFilePath, _partitionIndex);
 
-            var dirPath = Path.GetDirectoryName(_options.BaseFilePath);
+            var dirPath = Path.GetDirectoryName(_context.Request.OutputBaseFilePath);
             if (!string.IsNullOrWhiteSpace(dirPath))
                 Directory.CreateDirectory(dirPath);
 
-            var writer = CreateMessageWriter(filePath, _options.Format, _context);
+            var writer = CreateMessageWriter(filePath, _context.Request.Format, _context);
             await writer.WritePreambleAsync();
 
             return _writer = writer;
         }
 
-        public async Task ExportMessageAsync(Message message)
+        public async ValueTask ExportMessageAsync(Message message)
         {
             var writer = await GetWriterAsync();
             await writer.WriteMessageAsync(message);
-            _renderedMessageCount++;
         }
 
         public async ValueTask DisposeAsync() => await ResetWriterAsync();
@@ -84,16 +75,17 @@ namespace DiscordChatExporter.Domain.Exporting
             var fileNameWithoutExt = Path.GetFileNameWithoutExtension(baseFilePath);
             var fileExt = Path.GetExtension(baseFilePath);
             var fileName = $"{fileNameWithoutExt} [part {partitionIndex + 1}]{fileExt}";
-
-            // Generate new path
             var dirPath = Path.GetDirectoryName(baseFilePath);
-            if (!string.IsNullOrWhiteSpace(dirPath))
-                return Path.Combine(dirPath, fileName);
 
-            return fileName;
+            return !string.IsNullOrWhiteSpace(dirPath)
+                ? Path.Combine(dirPath, fileName)
+                : fileName;
         }
 
-        private static MessageWriter CreateMessageWriter(string filePath, ExportFormat format, ExportContext context)
+        private static MessageWriter CreateMessageWriter(
+            string filePath,
+            ExportFormat format,
+            ExportContext context)
         {
             // Stream will be disposed by the underlying writer
             var stream = File.Create(filePath);

DiscordChatExporter.Core/Exporting/Partitioning/FileSizePartitionLimit.cs

@@ -0,0 +1,12 @@
+namespace DiscordChatExporter.Core.Exporting.Partitioning
+{
+    public class FileSizePartitionLimit : PartitionLimit
+    {
+        private readonly long _limit;
+
+        public FileSizePartitionLimit(long limit) => _limit = limit;
+
+        public override bool IsReached(long messagesWritten, long bytesWritten) =>
+            bytesWritten >= _limit;
+    }
+}

DiscordChatExporter.Core/Exporting/Partitioning/MessageCountPartitionLimit.cs

@@ -0,0 +1,12 @@
+namespace DiscordChatExporter.Core.Exporting.Partitioning
+{
+    public class MessageCountPartitionLimit : PartitionLimit
+    {
+        private readonly long _limit;
+
+        public MessageCountPartitionLimit(long limit) => _limit = limit;
+
+        public override bool IsReached(long messagesWritten, long bytesWritten) =>
+            messagesWritten >= _limit;
+    }
+}

DiscordChatExporter.Core/Exporting/Partitioning/NullPartitionLimit.cs

@@ -0,0 +1,9 @@
+namespace DiscordChatExporter.Core.Exporting.Partitioning
+{
+    public class NullPartitionLimit : PartitionLimit
+    {
+        public static NullPartitionLimit Instance { get; } = new();
+
+        public override bool IsReached(long messagesWritten, long bytesWritten) => false;
+    }
+}

DiscordChatExporter.Core/Exporting/Partitioning/PartitionLimit.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Globalization;
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Exporting.Partitioning
+{
+    public abstract partial class PartitionLimit
+    {
+        public abstract bool IsReached(long messagesWritten, long bytesWritten);
+    }
+
+    public partial class PartitionLimit
+    {
+        private static long? TryParseFileSizeBytes(string value, IFormatProvider? formatProvider = null)
+        {
+            var match = Regex.Match(value, @"^\s*(\d+[\.,]?\d*)\s*(\w)?b\s*$", RegexOptions.IgnoreCase);
+
+            // Number part
+            if (!double.TryParse(
+                match.Groups[1].Value,
+                NumberStyles.Float,
+                formatProvider,
+                out var number))
+            {
+                return null;
+            }
+
+            // Magnitude part
+            var magnitude = match.Groups[2].Value.ToUpperInvariant() switch
+            {
+                "G" => 1_000_000_000,
+                "M" => 1_000_000,
+                "K" => 1_000,
+                "" => 1,
+                _ => -1
+            };
+
+            if (magnitude < 0)
+            {
+                return null;
+            }
+
+            return (long) (number * magnitude);
+        }
+
+        public static PartitionLimit? TryParse(string value, IFormatProvider? formatProvider = null)
+        {
+            var fileSizeLimit = TryParseFileSizeBytes(value, formatProvider);
+            if (fileSizeLimit is not null)
+                return new FileSizePartitionLimit(fileSizeLimit.Value);
+
+            if (int.TryParse(value, NumberStyles.Integer, formatProvider, out var messageCountLimit))
+                return new MessageCountPartitionLimit(messageCountLimit);
+
+            return null;
+        }
+
+        public static PartitionLimit Parse(string value, IFormatProvider? formatProvider = null) =>
+            TryParse(value, formatProvider) ?? throw new FormatException($"Invalid partition limit '{value}'.");
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/CsvMessageWriter.cs

@@ -0,0 +1,105 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors;
+using DiscordChatExporter.Core.Utils.Extensions;
+
+namespace DiscordChatExporter.Core.Exporting.Writers
+{
+    internal partial class CsvMessageWriter : MessageWriter
+    {
+        private readonly TextWriter _writer;
+
+        public CsvMessageWriter(Stream stream, ExportContext context)
+            : base(stream, context)
+        {
+            _writer = new StreamWriter(stream);
+        }
+
+        private string FormatMarkdown(string? markdown) =>
+            PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
+
+        public override async ValueTask WritePreambleAsync() =>
+            await _writer.WriteLineAsync("AuthorID,Author,Date,Content,Attachments,Reactions");
+
+        private async ValueTask WriteAttachmentsAsync(IReadOnlyList<Attachment> attachments)
+        {
+            var buffer = new StringBuilder();
+
+            foreach (var attachment in attachments)
+            {
+                buffer
+                    .AppendIfNotEmpty(',')
+                    .Append(await Context.ResolveMediaUrlAsync(attachment.Url));
+            }
+
+            await _writer.WriteAsync(CsvEncode(buffer.ToString()));
+        }
+
+        private async ValueTask WriteReactionsAsync(IReadOnlyList<Reaction> reactions)
+        {
+            var buffer = new StringBuilder();
+
+            foreach (var reaction in reactions)
+            {
+                buffer
+                    .AppendIfNotEmpty(',')
+                    .Append(reaction.Emoji.Name)
+                    .Append(' ')
+                    .Append('(')
+                    .Append(reaction.Count)
+                    .Append(')');
+            }
+
+            await _writer.WriteAsync(CsvEncode(buffer.ToString()));
+        }
+
+        public override async ValueTask WriteMessageAsync(Message message)
+        {
+            await base.WriteMessageAsync(message);
+
+            // Author ID
+            await _writer.WriteAsync(CsvEncode(message.Author.Id.ToString()));
+            await _writer.WriteAsync(',');
+
+            // Author name
+            await _writer.WriteAsync(CsvEncode(message.Author.FullName));
+            await _writer.WriteAsync(',');
+
+            // Message timestamp
+            await _writer.WriteAsync(CsvEncode(Context.FormatDate(message.Timestamp)));
+            await _writer.WriteAsync(',');
+
+            // Message content
+            await _writer.WriteAsync(CsvEncode(FormatMarkdown(message.Content)));
+            await _writer.WriteAsync(',');
+
+            // Attachments
+            await WriteAttachmentsAsync(message.Attachments);
+            await _writer.WriteAsync(',');
+
+            // Reactions
+            await WriteReactionsAsync(message.Reactions);
+
+            // Finish row
+            await _writer.WriteLineAsync();
+        }
+
+        public override async ValueTask DisposeAsync()
+        {
+            await _writer.DisposeAsync();
+            await base.DisposeAsync();
+        }
+    }
+
+    internal partial class CsvMessageWriter
+    {
+        private static string CsvEncode(string value)
+        {
+            value = value.Replace("\"", "\"\"");
+            return $"\"{value}\"";
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/Html/Core.css

@@ -2,31 +2,31 @@
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/6c6374bad0b0b6d204d8d6dc4a18d820.woff);
+    src: url(https://cdn.jsdelivr.net/gh/Tyrrrz/DiscordFonts@master/whitney-300.woff);
     font-weight: 300;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/e8acd7d9bf6207f99350ca9f9e23b168.woff);
+    src: url(https://cdn.jsdelivr.net/gh/Tyrrrz/DiscordFonts@master/whitney-400.woff);
     font-weight: 400;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/3bdef1251a424500c1b3a78dea9b7e57.woff);
+    src: url(https://cdn.jsdelivr.net/gh/Tyrrrz/DiscordFonts@master/whitney-500.woff);
     font-weight: 500;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/be0060dafb7a0e31d2a1ca17c0708636.woff);
+    src: url(https://cdn.jsdelivr.net/gh/Tyrrrz/DiscordFonts@master/whitney-600.woff);
     font-weight: 600;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/8e12fb4f14d9c4592eb8ec9f22337b04.woff);
+    src: url(https://cdn.jsdelivr.net/gh/Tyrrrz/DiscordFonts@master/whitney-700.woff);
     font-weight: 700;
 }
 
@@ -49,13 +49,18 @@ img {
 
 .markdown {
     max-width: 100%;
-    white-space: pre-wrap;
     line-height: 1.3;
     overflow-wrap: break-word;
 }
 
+.preserve-whitespace {
+    white-space: pre-wrap;
+}
+
 .spoiler {
-    width: fit-content;
+    /* width: fit-content; */
+    display: inline-block;
+    /* This is more consistent across browsers, the old attribute worked well under Chrome but not FireFox. */
 }
 
 .spoiler--hidden {
@@ -84,7 +89,7 @@ img {
     box-shadow: 0 0 1px 1px rgba(0, 0, 0, 0.1);
 }
 
-.spoiler--hidden .spoiler-image img {
+.spoiler--hidden .spoiler-image * {
     filter: blur(44px);
 }
 
@@ -97,7 +102,7 @@ img {
     top: 50%;
     transform: translate(-50%, -50%);
     font-weight: 600;
-    padding: 0.5em 0.7em;
+    padding: 100%;
     border-radius: 20px;
     letter-spacing: 0.05em;
     font-size: 0.9em;
@@ -202,6 +207,58 @@ img {
     grid-template-columns: auto 1fr;
 }
 
+.chatlog__reference-symbol {
+    grid-column: 1;
+    border-style: solid;
+    border-width: 2px 0 0 2px;
+    border-radius: 8px 0 0 0;
+    margin-left: 16px;
+    margin-top: 8px;
+}
+
+.chatlog__reference {
+    display: flex;
+    grid-column: 2;
+    margin-left: 1.2em;
+    margin-bottom: 0.25em;
+    font-size: 0.875em;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    align-items: center;
+}
+
+.chatlog__reference-avatar {
+    border-radius: 50%;
+    height: 16px;
+    width: 16px;
+    margin-right: 0.25em;
+}
+
+.chatlog__reference-name {
+    margin-right: 0.25em;
+    font-weight: 600;
+}
+
+.chatlog__reference-link {
+    flex-grow: 1;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+
+.chatlog__reference-link:hover {
+    text-decoration: none;
+}
+
+.chatlog__reference-content > * {
+    display: inline;
+}
+
+.chatlog__reference-edited-timestamp {
+    margin-left: 0.25em;
+    font-size: 0.8em;
+}
+
 .chatlog__author-avatar-container {
     grid-column: 1;
     width: 40px;
@@ -257,6 +314,53 @@ img {
     border-radius: 3px;
 }
 
+.chatlog__attachment-container {
+    height: 40px;
+    width: 100%;
+    max-width: 520px;
+    padding: 10px;
+    border: 1px solid;
+    border-radius: 3px;
+    overflow: hidden;
+}
+
+.chatlog__attachment-icon {
+    float: left;
+    height: 100%;
+    margin-right: 10px;
+}
+
+.chatlog__attachment-icon > .a {
+    fill: #f4f5fb;
+    d: path("M50,935a25,25,0,0,1-25-25V50A25,25,0,0,1,50,25H519.6L695,201.32V910a25,25,0,0,1-25,25Z");
+}
+
+.chatlog__attachment-icon > .b {
+    fill: #7789c4;
+    d: path("M509.21,50,670,211.63V910H50V50H509.21M530,0H50A50,50,0,0,0,0,50V910a50,50,0,0,0,50,50H670a50,50,0,0,0,50-50h0V191Z");
+}
+
+.chatlog__attachment-icon > .c {
+    fill: #f4f5fb;
+    d: path("M530,215a25,25,0,0,1-25-25V50a25,25,0,0,1,16.23-23.41L693.41,198.77A25,25,0,0,1,670,215Z");
+}
+
+.chatlog__attachment-icon > .d {
+    fill: #7789c4;
+    d: path("M530,70.71,649.29,190H530V70.71M530,0a50,50,0,0,0-50,50V190a50,50,0,0,0,50,50H670a50,50,0,0,0,50-50Z");
+}
+
+.chatlog__attachment-filesize {
+    color: #72767d;
+    font-size: 12px;
+}
+
+.chatlog__attachment-filename {
+    overflow: hidden;
+    white-space: nowrap;
+    text-overflow: ellipsis;
+}
+
 .chatlog__embed {
     display: flex;
     margin-top: 0.3em;

DiscordChatExporter.Core/Exporting/Writers/Html/Dark.css

@@ -46,6 +46,26 @@ a {
     border-color: rgba(255, 255, 255, 0.1);
 }
 
+.chatlog__reference-symbol {
+    border-color: #4f545c;
+}
+
+.chatlog__reference {
+    color: #b5b6b8;
+}
+
+.chatlog__reference-link {
+    color: #b5b6b8;
+}
+
+.chatlog__reference-link:hover {
+    color: #ffffff;
+}
+
+.chatlog__reference-edited-timestamp {
+    color: rgba(255, 255, 255, 0.2);
+}
+
 .chatlog__author-name {
     color: #ffffff;
 }
@@ -62,6 +82,11 @@ a {
     background-color: rgba(249, 168, 37, 0.05);
 }
 
+.chatlog__attachment-container {
+    background-color: #2f3136;
+    border-color: #292b2f;
+}
+
 .chatlog__edited-timestamp {
     color: rgba(255, 255, 255, 0.2);
 }

DiscordChatExporter.Core/Exporting/Writers/Html/Light.css

@@ -47,6 +47,26 @@ a {
     border-color: #eceeef;
 }
 
+.chatlog__reference-symbol {
+    border-color: #c7ccd1;
+}
+
+.chatlog__reference {
+    color: #5f5f60;
+}
+
+.chatlog__reference-link {
+    color: #5f5f60;
+}
+
+.chatlog__reference-link:hover {
+    color: #2f3136;
+}
+
+.chatlog__reference-edited-timestamp {
+    color: #747f8d;
+}
+
 .chatlog__author-name {
     font-weight: 600;
     color: #2f3136;
@@ -64,6 +84,11 @@ a {
     background-color: rgba(249, 168, 37, 0.05);
 }
 
+.chatlog__attachment-container {
+    background-color: #f2f3f5;
+    border-color: #ebedef;
+}
+
 .chatlog__edited-timestamp {
     color: #747f8d;
 }

DiscordChatExporter.Core/Exporting/Writers/Html/MessageGroup.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using DiscordChatExporter.Core.Discord.Data;
+
+namespace DiscordChatExporter.Core.Exporting.Writers.Html
+{
+    // Used for grouping contiguous messages in HTML export
+    internal partial class MessageGroup
+    {
+        public User Author { get; }
+
+        public DateTimeOffset Timestamp { get; }
+
+        public IReadOnlyList<Message> Messages { get; }
+
+        public MessageReference? Reference { get; }
+
+        public Message? ReferencedMessage {get; }
+
+        public MessageGroup(
+            User author,
+            DateTimeOffset timestamp,
+            MessageReference? reference,
+            Message? referencedMessage,
+            IReadOnlyList<Message> messages)
+        {
+            Author = author;
+            Timestamp = timestamp;
+            Reference = reference;
+            ReferencedMessage = referencedMessage;
+            Messages = messages;
+        }
+    }
+
+    internal partial class MessageGroup
+    {
+        public static bool CanJoin(Message message1, Message message2) =>
+            message1.Author.Id == message2.Author.Id &&
+            string.Equals(message1.Author.FullName, message2.Author.FullName, StringComparison.Ordinal) &&
+            (message2.Timestamp - message1.Timestamp).Duration().TotalMinutes <= 7 &&
+            message2.Reference is null;
+
+        public static MessageGroup Join(IReadOnlyList<Message> messages)
+        {
+            var first = messages.First();
+
+            return new MessageGroup(
+                first.Author,
+                first.Timestamp,
+                first.Reference,
+                first.ReferencedMessage,
+                messages
+            );
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/Html/MessageGroupTemplate.cshtml

@@ -0,0 +1,316 @@
+@using System
+@using System.Linq
+@using System.Threading.Tasks
+@namespace DiscordChatExporter.Core.Exporting.Writers.Html
+@inherits MiniRazor.TemplateBase<DiscordChatExporter.Core.Exporting.Writers.Html.MessageGroupTemplateContext>
+
+@{
+    string FormatDate(DateTimeOffset date) => Model.ExportContext.FormatDate(date);
+
+    string FormatMarkdown(string markdown) => Model.FormatMarkdown(markdown);
+
+    string FormatEmbedMarkdown(string markdown) => Model.FormatMarkdown(markdown, false);
+
+    ValueTask<string> ResolveUrlAsync(string url) => Model.ExportContext.ResolveMediaUrlAsync(url);
+
+    var userMember = Model.ExportContext.TryGetMember(Model.MessageGroup.Author.Id);
+
+    var userColor = Model.ExportContext.TryGetUserColor(Model.MessageGroup.Author.Id);
+
+    var userColorStyle = userColor is not null
+        ? $"color: rgb({userColor?.R},{userColor?.G},{userColor?.B})"
+        : null;
+
+    var userNick = Model.MessageGroup.Author.IsBot
+        ? Model.MessageGroup.Author.Name
+        : userMember?.Nick ?? Model.MessageGroup.Author.Name;
+
+    var referencedUserMember = Model.MessageGroup.ReferencedMessage is not null
+        ? Model.ExportContext.TryGetMember(Model.MessageGroup.ReferencedMessage.Author.Id)
+        : null;
+
+    var referencedUserColor = Model.MessageGroup.ReferencedMessage is not null
+        ? Model.ExportContext.TryGetUserColor(Model.MessageGroup.ReferencedMessage.Author.Id)
+        : null;
+
+    var referencedUserColorStyle = referencedUserColor is not null
+        ? $"color: rgb({referencedUserColor?.R},{referencedUserColor?.G},{referencedUserColor?.B})"
+        : null;
+
+    var referencedUserNick = Model.MessageGroup.ReferencedMessage is not null
+        ? Model.MessageGroup.ReferencedMessage.Author.IsBot
+            ? Model.MessageGroup.ReferencedMessage.Author.Name
+            : referencedUserMember?.Nick ?? Model.MessageGroup.ReferencedMessage.Author.Name
+        : null;
+}
+
+<div class="chatlog__message-group">
+    @if (Model.MessageGroup.Reference is not null)
+    {
+        <div class="chatlog__reference-symbol">
+        </div>
+        <div class="chatlog__reference">
+            @if (Model.MessageGroup.ReferencedMessage is not null)
+            {
+                <img class="chatlog__reference-avatar" src="@await ResolveUrlAsync(Model.MessageGroup.ReferencedMessage.Author.AvatarUrl)" alt="Avatar">
+                <span class="chatlog__reference-name" title="@Model.MessageGroup.ReferencedMessage.Author.FullName" style="@referencedUserColorStyle">@referencedUserNick</span>
+                <a class="chatlog__reference-link" href="#" onclick="scrollToMessage(event, '@Model.MessageGroup.ReferencedMessage.Id')">
+                    <span class="chatlog__reference-content">
+                        @if (!string.IsNullOrWhiteSpace(Model.MessageGroup.ReferencedMessage.Content))
+                        {
+                            @Raw(FormatMarkdown(Model.MessageGroup.ReferencedMessage.Content))
+                        }
+                        else
+                        {
+                            <em>Click to see original message</em>
+                        }
+                    </span>
+
+                    @if (Model.MessageGroup.ReferencedMessage.EditedTimestamp is not null)
+                    {
+                        <span class="chatlog__reference-edited-timestamp" title="@FormatDate(Model.MessageGroup.ReferencedMessage.EditedTimestamp.Value)">(edited)</span>
+                    }
+                </a>
+            }
+            else
+            {
+                <span class="chatlog__reference-unknown">
+                    Original message was deleted.
+                </span>
+            }
+        </div>
+    }
+    <div class="chatlog__author-avatar-container">
+        <img class="chatlog__author-avatar" src="@await ResolveUrlAsync(Model.MessageGroup.Author.AvatarUrl)" alt="Avatar">
+    </div>
+    <div class="chatlog__messages">
+        <span class="chatlog__author-name" title="@Model.MessageGroup.Author.FullName" data-user-id="@Model.MessageGroup.Author.Id" style="@userColorStyle">@userNick</span>
+
+        @if (Model.MessageGroup.Author.IsBot)
+        {
+            <span class="chatlog__bot-tag">BOT</span>
+        }
+
+        <span class="chatlog__timestamp">@FormatDate(Model.MessageGroup.Timestamp)</span>
+
+        @foreach (var message in Model.MessageGroup.Messages)
+        {
+            var isPinnedStyle = message.IsPinned ? "chatlog__message--pinned" : null;
+
+            <div class="chatlog__message @isPinnedStyle" data-message-id="@message.Id" id="message-@message.Id">
+                @if (!string.IsNullOrWhiteSpace(message.Content) || message.EditedTimestamp is not null)
+                {
+                    <div class="chatlog__content">
+                        <div class="markdown">
+                            <span class="preserve-whitespace">@Raw(FormatMarkdown(message.Content))</span>
+
+                            @if (message.EditedTimestamp is not null)
+                            {
+                                <span class="chatlog__edited-timestamp" title="@FormatDate(message.EditedTimestamp.Value)">(edited)</span>
+                            }
+                        </div>
+                    </div>
+                }
+
+                @foreach (var attachment in message.Attachments)
+                {
+                    <div class="chatlog__attachment">
+                        <div class="@(attachment.IsSpoiler ? "spoiler spoiler--hidden" : "")" onclick="@(attachment.IsSpoiler ? "showSpoiler(event, this)" : "")">
+                            <div class="@(attachment.IsSpoiler ? "spoiler-image" : "")">
+                                @if (attachment.IsImage)
+                                {
+                                    <a href="@await ResolveUrlAsync(attachment.Url)">
+                                        <img class="chatlog__attachment-thumbnail" src="@await ResolveUrlAsync(attachment.Url)" alt="Image attachment" title="@($"Image: {attachment.FileName} ({attachment.FileSize})")">
+                                    </a>
+                                }
+                                else if (attachment.IsVideo)
+                                {
+                                    <video controls class="chatlog__attachment-thumbnail">
+                                        <source src="@await ResolveUrlAsync(attachment.Url)" alt="Video attachment" title="@($"Video: {attachment.FileName} ({attachment.FileSize})")">
+                                    </video>
+                                }
+                                else if (attachment.IsAudio)
+                                {
+                                    <audio controls class="chatlog__attachment-thumbnail">
+                                        <source src="@await ResolveUrlAsync(attachment.Url)" alt="Audio attachment" title="@($"Audio: {attachment.FileName} ({attachment.FileSize})")">
+                                    </audio>
+                                }
+                                else
+                                {
+                                    <div class="chatlog__attachment-container">
+                                        <svg class="chatlog__attachment-icon" viewBox="0 0 720 960">
+                                            <path class="a"/>
+                                            <path class="b"/>
+                                            <path class="c"/>
+                                            <path class="d"/>
+                                        </svg>
+                                        <div class="chatlog__attachment-filename">
+                                            <a href="@await ResolveUrlAsync(attachment.Url)">
+                                                @attachment.FileName
+                                            </a>
+                                        </div>
+                                        <div class="chatlog__attachment-filesize">
+                                            @attachment.FileSize
+                                        </div>
+                                    </div>
+                                }
+                            </div>
+                        </div>
+                    </div>
+                }
+
+                @foreach (var embed in message.Embeds)
+                {
+                    <div class="chatlog__embed">
+                        @if (embed.Color is not null)
+                        {
+                            var embedColorStyle = $"background-color: rgba({embed.Color?.R},{embed.Color?.G},{embed.Color?.B},{embed.Color?.A})";
+                            <div class="chatlog__embed-color-pill" style="@embedColorStyle"></div>
+                        }
+                        else
+                        {
+                            <div class="chatlog__embed-color-pill chatlog__embed-color-pill--default"></div>
+                        }
+
+                        <div class="chatlog__embed-content-container">
+                            <div class="chatlog__embed-content">
+                                <div class="chatlog__embed-text">
+                                    @if (embed.Author is not null)
+                                    {
+                                        <div class="chatlog__embed-author">
+                                            @if (!string.IsNullOrWhiteSpace(embed.Author.IconUrl))
+                                            {
+                                                <img class="chatlog__embed-author-icon" src="@await ResolveUrlAsync(embed.Author.IconUrl)" alt="Author icon">
+                                            }
+
+                                            @if (!string.IsNullOrWhiteSpace(embed.Author.Name))
+                                            {
+                                                <span class="chatlog__embed-author-name">
+                                                    @if (!string.IsNullOrWhiteSpace(embed.Author.Url))
+                                                    {
+                                                        <a class="chatlog__embed-author-name-link" href="@embed.Author.Url">@embed.Author.Name</a>
+                                                    }
+                                                    else
+                                                    {
+                                                        @embed.Author.Name
+                                                    }
+                                                </span>
+                                            }
+                                        </div>
+                                    }
+
+                                    @if (!string.IsNullOrWhiteSpace(embed.Title))
+                                    {
+                                        <div class="chatlog__embed-title">
+                                            @if (!string.IsNullOrWhiteSpace(embed.Url))
+                                            {
+                                                <a class="chatlog__embed-title-link" href="@embed.Url">
+                                                    <div class="markdown preserve-whitespace">@Raw(FormatEmbedMarkdown(embed.Title))</div>
+                                                </a>
+                                            }
+                                            else
+                                            {
+                                                <div class="markdown preserve-whitespace">@Raw(FormatEmbedMarkdown(embed.Title))</div>
+                                            }
+                                        </div>
+                                    }
+
+                                    @if (!string.IsNullOrWhiteSpace(embed.Description))
+                                    {
+                                        <div class="chatlog__embed-description">
+                                            <div class="markdown preserve-whitespace">@Raw(FormatEmbedMarkdown(embed.Description))</div>
+                                        </div>
+                                    }
+
+                                    @if (embed.Fields.Any())
+                                    {
+                                        <div class="chatlog__embed-fields">
+                                            @foreach (var field in embed.Fields)
+                                            {
+                                                var isInlineStyle = field.IsInline ? "chatlog__embed-field--inline" : null;
+
+                                                <div class="chatlog__embed-field @isInlineStyle">
+                                                    @if (!string.IsNullOrWhiteSpace(field.Name))
+                                                    {
+                                                        <div class="chatlog__embed-field-name">
+                                                            <div class="markdown preserve-whitespace">@Raw(FormatEmbedMarkdown(field.Name))</div>
+                                                        </div>
+                                                    }
+
+                                                    @if (!string.IsNullOrWhiteSpace(field.Value))
+                                                    {
+                                                        <div class="chatlog__embed-field-value">
+                                                            <div class="markdown preserve-whitespace">@Raw(FormatEmbedMarkdown(field.Value))</div>
+                                                        </div>
+                                                    }
+                                                </div>
+                                            }
+                                        </div>
+                                    }
+                                </div>
+
+                                @if (embed.Thumbnail is not null)
+                                {
+                                    <div class="chatlog__embed-thumbnail-container">
+                                        <a class="chatlog__embed-thumbnail-link" href="@await ResolveUrlAsync(embed.Thumbnail.Url)">
+                                            <img class="chatlog__embed-thumbnail" src="@await ResolveUrlAsync(embed.Thumbnail.Url)" alt="Thumbnail">
+                                        </a>
+                                    </div>
+                                }
+                            </div>
+
+                            @if (embed.Image is not null)
+                            {
+                                <div class="chatlog__embed-image-container">
+                                    <a class="chatlog__embed-image-link" href="@await ResolveUrlAsync(embed.Image.Url)">
+                                        <img class="chatlog__embed-image" src="@await ResolveUrlAsync(embed.Image.Url)" alt="Image">
+                                    </a>
+                                </div>
+                            }
+
+                            @if (embed.Footer is not null || embed.Timestamp is not null)
+                            {
+                                <div class="chatlog__embed-footer">
+                                    @if (!string.IsNullOrWhiteSpace(embed.Footer?.IconUrl))
+                                    {
+                                        <img class="chatlog__embed-footer-icon" src="@await ResolveUrlAsync(embed.Footer.IconUrl)" alt="Footer icon">
+                                    }
+
+                                    <span class="chatlog__embed-footer-text">
+                                        @if (!string.IsNullOrWhiteSpace(embed.Footer?.Text))
+                                        {
+                                            @embed.Footer.Text
+                                        }
+
+                                        @if (!string.IsNullOrWhiteSpace(embed.Footer?.Text) && embed.Timestamp is not null)
+                                        {
+                                            @(" • ")
+                                        }
+
+                                        @if (embed.Timestamp is not null)
+                                        {
+                                            @FormatDate(embed.Timestamp.Value)
+                                        }
+                                    </span>
+                                </div>
+                            }
+                        </div>
+                    </div>
+                }
+
+                @if (message.Reactions.Any())
+                {
+                    <div class="chatlog__reactions">
+                        @foreach (var reaction in message.Reactions)
+                        {
+                            <div class="chatlog__reaction">
+                                <img class="emoji emoji--small" alt="@reaction.Emoji.Name" title="@reaction.Emoji.Name" src="@await ResolveUrlAsync(reaction.Emoji.ImageUrl)">
+                                <span class="chatlog__reaction-count">@reaction.Count</span>
+                            </div>
+                        }
+                    </div>
+                }
+            </div>
+        }
+    </div>
+</div>

DiscordChatExporter.Core/Exporting/Writers/Html/MessageGroupTemplateContext.cs

@@ -0,0 +1,20 @@
+using DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors;
+
+namespace DiscordChatExporter.Core.Exporting.Writers.Html
+{
+    internal class MessageGroupTemplateContext
+    {
+        public ExportContext ExportContext { get; }
+
+        public MessageGroup MessageGroup { get; }
+
+        public MessageGroupTemplateContext(ExportContext exportContext, MessageGroup messageGroup)
+        {
+            ExportContext = exportContext;
+            MessageGroup = messageGroup;
+        }
+
+        public string FormatMarkdown(string? markdown, bool isJumboAllowed = true) =>
+            HtmlMarkdownVisitor.Format(ExportContext, markdown ?? "", isJumboAllowed);
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/Html/PostambleTemplate.cshtml

@@ -0,0 +1,12 @@
+@namespace DiscordChatExporter.Core.Exporting.Writers.Html
+@inherits MiniRazor.TemplateBase<DiscordChatExporter.Core.Exporting.Writers.Html.PostambleTemplateContext>
+
+</div>
+
+<div class="postamble">
+    <div class="postamble__entry">Exported @Model.MessagesWritten.ToString("N0") message(s)</div>
+</div>
+
+</body>
+
+</html>

DiscordChatExporter.Core/Exporting/Writers/Html/PostambleTemplateContext.cs

@@ -0,0 +1,15 @@
+namespace DiscordChatExporter.Core.Exporting.Writers.Html
+{
+    internal class PostambleTemplateContext
+    {
+        public ExportContext ExportContext { get; }
+
+        public long MessagesWritten { get; }
+
+        public PostambleTemplateContext(ExportContext exportContext, long messagesWritten)
+        {
+            ExportContext = exportContext;
+            MessagesWritten = messagesWritten;
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/Html/PreambleTemplate.cshtml

@@ -0,0 +1,101 @@
+@using System
+@using System.Threading.Tasks
+@using Tyrrrz.Extensions
+@namespace DiscordChatExporter.Core.Exporting.Writers.Html
+@inherits MiniRazor.TemplateBase<DiscordChatExporter.Core.Exporting.Writers.Html.PreambleTemplateContext>
+
+@{
+    string FormatDate(DateTimeOffset date) => Model.ExportContext.FormatDate(date);
+
+    ValueTask<string> ResolveUrlAsync(string url) => Model.ExportContext.ResolveMediaUrlAsync(url);
+
+    string GetStyleSheet(string name) => Model.GetType().Assembly.GetManifestResourceString($"DiscordChatExporter.Core.Exporting.Writers.Html.{name}.css");
+}
+
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <title>@Model.ExportContext.Request.Guild.Name - @Model.ExportContext.Request.Channel.Name</title>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width">
+
+    <style>
+        @Raw(GetStyleSheet("Core"))
+    </style>
+    <style>
+        @Raw(GetStyleSheet(Model.ThemeName))
+    </style>
+
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/styles/solarized-@(Model.ThemeName.ToLowerInvariant()).min.css">
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/highlight.min.js"></script>
+    <script>
+        document.addEventListener('DOMContentLoaded', () => {
+            document.querySelectorAll('.pre--multiline').forEach(block => hljs.highlightBlock(block));
+        });
+    </script>
+
+    <script>
+        function scrollToMessage(event, id) {
+            var element = document.getElementById('message-' + id);
+
+            if (element) {
+                event.preventDefault();
+
+                element.classList.add('chatlog__message--highlighted');
+
+                window.scrollTo({
+                    top: element.getBoundingClientRect().top - document.body.getBoundingClientRect().top - (window.innerHeight / 2),
+                    behavior: 'smooth'
+                });
+
+                window.setTimeout(function() {
+                    element.classList.remove('chatlog__message--highlighted');
+                }, 2000);
+            }
+        }
+
+        function showSpoiler(event, element) {
+            if (element && element.classList.contains('spoiler--hidden')) {
+                event.preventDefault();
+                element.classList.remove('spoiler--hidden');
+            }
+        }
+    </script>
+</head>
+<body>
+
+<div class="preamble">
+    <div class="preamble__guild-icon-container">
+        <img class="preamble__guild-icon" src="@await ResolveUrlAsync(Model.ExportContext.Request.Guild.IconUrl)" alt="Guild icon">
+    </div>
+    <div class="preamble__entries-container">
+        <div class="preamble__entry">@Model.ExportContext.Request.Guild.Name</div>
+        <div class="preamble__entry">@Model.ExportContext.Request.Channel.Category / @Model.ExportContext.Request.Channel.Name</div>
+
+        @if (!string.IsNullOrWhiteSpace(Model.ExportContext.Request.Channel.Topic))
+        {
+            <div class="preamble__entry preamble__entry--small">@Model.ExportContext.Request.Channel.Topic</div>
+        }
+
+        @if (Model.ExportContext.Request.After is not null || Model.ExportContext.Request.Before is not null)
+        {
+            <div class="preamble__entry preamble__entry--small">
+            @if (Model.ExportContext.Request.After is not null && Model.ExportContext.Request.Before is not null)
+            {
+                @($"Between {FormatDate(Model.ExportContext.Request.After.Value.ToDate())} and {FormatDate(Model.ExportContext.Request.Before.Value.ToDate())}")
+            }
+            else if (Model.ExportContext.Request.After is not null)
+            {
+                @($"After {FormatDate(Model.ExportContext.Request.After.Value.ToDate())}")
+            }
+            else if (Model.ExportContext.Request.Before is not null)
+            {
+                @($"Before {FormatDate(Model.ExportContext.Request.Before.Value.ToDate())}")
+            }
+            </div>
+        }
+    </div>
+</div>
+
+<div class="chatlog">

DiscordChatExporter.Core/Exporting/Writers/Html/PreambleTemplateContext.cs

@@ -0,0 +1,15 @@
+namespace DiscordChatExporter.Core.Exporting.Writers.Html
+{
+    internal class PreambleTemplateContext
+    {
+        public ExportContext ExportContext { get; }
+
+        public string ThemeName { get; }
+
+        public PreambleTemplateContext(ExportContext exportContext, string themeName)
+        {
+            ExportContext = exportContext;
+            ThemeName = themeName;
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/HtmlMessageWriter.cs

@@ -0,0 +1,80 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exporting.Writers.Html;
+
+namespace DiscordChatExporter.Core.Exporting.Writers
+{
+    internal class HtmlMessageWriter : MessageWriter
+    {
+        private readonly TextWriter _writer;
+        private readonly string _themeName;
+
+        private readonly List<Message> _messageGroupBuffer = new();
+
+        public HtmlMessageWriter(Stream stream, ExportContext context, string themeName)
+            : base(stream, context)
+        {
+            _writer = new StreamWriter(stream);
+            _themeName = themeName;
+        }
+
+        public override async ValueTask WritePreambleAsync()
+        {
+            var templateContext = new PreambleTemplateContext(Context, _themeName);
+
+            await _writer.WriteLineAsync(
+                await PreambleTemplate.RenderAsync(templateContext)
+            );
+        }
+
+        private async ValueTask WriteMessageGroupAsync(MessageGroup messageGroup)
+        {
+            var templateContext = new MessageGroupTemplateContext(Context, messageGroup);
+
+            await _writer.WriteLineAsync(
+                await MessageGroupTemplate.RenderAsync(templateContext)
+            );
+        }
+
+        public override async ValueTask WriteMessageAsync(Message message)
+        {
+            await base.WriteMessageAsync(message);
+
+            // If message group is empty or the given message can be grouped, buffer the given message
+            if (!_messageGroupBuffer.Any() || MessageGroup.CanJoin(_messageGroupBuffer.Last(), message))
+            {
+                _messageGroupBuffer.Add(message);
+            }
+            // Otherwise, flush the group and render messages
+            else
+            {
+                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer));
+
+                _messageGroupBuffer.Clear();
+                _messageGroupBuffer.Add(message);
+            }
+        }
+
+        public override async ValueTask WritePostambleAsync()
+        {
+            // Flush current message group
+            if (_messageGroupBuffer.Any())
+                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer));
+
+            var templateContext = new PostambleTemplateContext(Context, MessagesWritten);
+
+            await _writer.WriteLineAsync(
+                await PostambleTemplate.RenderAsync(templateContext)
+            );
+        }
+
+        public override async ValueTask DisposeAsync()
+        {
+            await _writer.DisposeAsync();
+            await base.DisposeAsync();
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/JsonMessageWriter.cs

@@ -0,0 +1,303 @@
+using System.IO;
+using System.Text.Encodings.Web;
+using System.Text.Json;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors;
+using DiscordChatExporter.Core.Utils.Extensions;
+using JsonExtensions.Writing;
+
+namespace DiscordChatExporter.Core.Exporting.Writers
+{
+    internal class JsonMessageWriter : MessageWriter
+    {
+        private readonly Utf8JsonWriter _writer;
+
+        public JsonMessageWriter(Stream stream, ExportContext context)
+            : base(stream, context)
+        {
+            _writer = new Utf8JsonWriter(stream, new JsonWriterOptions
+            {
+                Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+                Indented = true,
+                SkipValidation = true
+            });
+        }
+
+        private string FormatMarkdown(string? markdown) =>
+            PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
+
+        private async ValueTask WriteAttachmentAsync(Attachment attachment)
+        {
+            _writer.WriteStartObject();
+
+            _writer.WriteString("id", attachment.Id.ToString());
+            _writer.WriteString("url", await Context.ResolveMediaUrlAsync(attachment.Url));
+            _writer.WriteString("fileName", attachment.FileName);
+            _writer.WriteNumber("fileSizeBytes", attachment.FileSize.TotalBytes);
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteEmbedAuthorAsync(EmbedAuthor embedAuthor)
+        {
+            _writer.WriteStartObject("author");
+
+            _writer.WriteString("name", embedAuthor.Name);
+            _writer.WriteString("url", embedAuthor.Url);
+
+            if (!string.IsNullOrWhiteSpace(embedAuthor.IconUrl))
+                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedAuthor.IconUrl));
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteEmbedThumbnailAsync(EmbedImage embedThumbnail)
+        {
+            _writer.WriteStartObject("thumbnail");
+
+            if (!string.IsNullOrWhiteSpace(embedThumbnail.Url))
+                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedThumbnail.Url));
+
+            _writer.WriteNumber("width", embedThumbnail.Width);
+            _writer.WriteNumber("height", embedThumbnail.Height);
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteEmbedImageAsync(EmbedImage embedImage)
+        {
+            _writer.WriteStartObject("image");
+
+            if (!string.IsNullOrWhiteSpace(embedImage.Url))
+                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedImage.Url));
+
+            _writer.WriteNumber("width", embedImage.Width);
+            _writer.WriteNumber("height", embedImage.Height);
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteEmbedFooterAsync(EmbedFooter embedFooter)
+        {
+            _writer.WriteStartObject("footer");
+
+            _writer.WriteString("text", embedFooter.Text);
+
+            if (!string.IsNullOrWhiteSpace(embedFooter.IconUrl))
+                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedFooter.IconUrl));
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteEmbedFieldAsync(EmbedField embedField)
+        {
+            _writer.WriteStartObject();
+
+            _writer.WriteString("name", FormatMarkdown(embedField.Name));
+            _writer.WriteString("value", FormatMarkdown(embedField.Value));
+            _writer.WriteBoolean("isInline", embedField.IsInline);
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteEmbedAsync(Embed embed)
+        {
+            _writer.WriteStartObject();
+
+            _writer.WriteString("title", FormatMarkdown(embed.Title));
+            _writer.WriteString("url", embed.Url);
+            _writer.WriteString("timestamp", embed.Timestamp);
+            _writer.WriteString("description", FormatMarkdown(embed.Description));
+
+            if (embed.Color is not null)
+                _writer.WriteString("color", embed.Color.Value.ToHex());
+
+            if (embed.Author is not null)
+                await WriteEmbedAuthorAsync(embed.Author);
+
+            if (embed.Thumbnail is not null)
+                await WriteEmbedThumbnailAsync(embed.Thumbnail);
+
+            if (embed.Image is not null)
+                await WriteEmbedImageAsync(embed.Image);
+
+            if (embed.Footer is not null)
+                await WriteEmbedFooterAsync(embed.Footer);
+
+            // Fields
+            _writer.WriteStartArray("fields");
+
+            foreach (var field in embed.Fields)
+                await WriteEmbedFieldAsync(field);
+
+            _writer.WriteEndArray();
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteReactionAsync(Reaction reaction)
+        {
+            _writer.WriteStartObject();
+
+            // Emoji
+            _writer.WriteStartObject("emoji");
+            _writer.WriteString("id", reaction.Emoji.Id);
+            _writer.WriteString("name", reaction.Emoji.Name);
+            _writer.WriteBoolean("isAnimated", reaction.Emoji.IsAnimated);
+            _writer.WriteString("imageUrl", await Context.ResolveMediaUrlAsync(reaction.Emoji.ImageUrl));
+            _writer.WriteEndObject();
+
+            _writer.WriteNumber("count", reaction.Count);
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        private async ValueTask WriteMentionAsync(User mentionedUser)
+        {
+            _writer.WriteStartObject();
+
+            _writer.WriteString("id", mentionedUser.Id.ToString());
+            _writer.WriteString("name", mentionedUser.Name);
+            _writer.WriteString("discriminator", mentionedUser.DiscriminatorFormatted);
+            _writer.WriteString("nickname", Context.TryGetMember(mentionedUser.Id)?.Nick ?? mentionedUser.Name);
+            _writer.WriteBoolean("isBot", mentionedUser.IsBot);
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        public override async ValueTask WritePreambleAsync()
+        {
+            // Root object (start)
+            _writer.WriteStartObject();
+
+            // Guild
+            _writer.WriteStartObject("guild");
+            _writer.WriteString("id", Context.Request.Guild.Id.ToString());
+            _writer.WriteString("name", Context.Request.Guild.Name);
+            _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(Context.Request.Guild.IconUrl));
+            _writer.WriteEndObject();
+
+            // Channel
+            _writer.WriteStartObject("channel");
+            _writer.WriteString("id", Context.Request.Channel.Id.ToString());
+            _writer.WriteString("type", Context.Request.Channel.Type.ToString());
+            _writer.WriteString("categoryId", Context.Request.Channel.Category.Id.ToString());
+            _writer.WriteString("category", Context.Request.Channel.Category.Name);
+            _writer.WriteString("name", Context.Request.Channel.Name);
+            _writer.WriteString("topic", Context.Request.Channel.Topic);
+            _writer.WriteEndObject();
+
+            // Date range
+            _writer.WriteStartObject("dateRange");
+            _writer.WriteString("after", Context.Request.After?.ToDate());
+            _writer.WriteString("before", Context.Request.Before?.ToDate());
+            _writer.WriteEndObject();
+
+            // Message array (start)
+            _writer.WriteStartArray("messages");
+            await _writer.FlushAsync();
+        }
+
+        public override async ValueTask WriteMessageAsync(Message message)
+        {
+            await base.WriteMessageAsync(message);
+
+            _writer.WriteStartObject();
+
+            // Metadata
+            _writer.WriteString("id", message.Id.ToString());
+            _writer.WriteString("type", message.Type.ToString());
+            _writer.WriteString("timestamp", message.Timestamp);
+            _writer.WriteString("timestampEdited", message.EditedTimestamp);
+            _writer.WriteString("callEndedTimestamp", message.CallEndedTimestamp);
+            _writer.WriteBoolean("isPinned", message.IsPinned);
+
+            // Content
+            _writer.WriteString("content", FormatMarkdown(message.Content));
+
+            // Author
+            _writer.WriteStartObject("author");
+            _writer.WriteString("id", message.Author.Id.ToString());
+            _writer.WriteString("name", message.Author.Name);
+            _writer.WriteString("discriminator", message.Author.DiscriminatorFormatted);
+            _writer.WriteString("nickname", Context.TryGetMember(message.Author.Id)?.Nick ?? message.Author.Name);
+            _writer.WriteString("color", Context.TryGetUserColor(message.Author.Id)?.ToHex());
+            _writer.WriteBoolean("isBot", message.Author.IsBot);
+            _writer.WriteString("avatarUrl", await Context.ResolveMediaUrlAsync(message.Author.AvatarUrl));
+            _writer.WriteEndObject();
+
+            // Attachments
+            _writer.WriteStartArray("attachments");
+
+            foreach (var attachment in message.Attachments)
+                await WriteAttachmentAsync(attachment);
+
+            _writer.WriteEndArray();
+
+            // Embeds
+            _writer.WriteStartArray("embeds");
+
+            foreach (var embed in message.Embeds)
+                await WriteEmbedAsync(embed);
+
+            _writer.WriteEndArray();
+
+            // Reactions
+            _writer.WriteStartArray("reactions");
+
+            foreach (var reaction in message.Reactions)
+                await WriteReactionAsync(reaction);
+
+            _writer.WriteEndArray();
+
+            // Mentions
+            _writer.WriteStartArray("mentions");
+
+            foreach (var mention in message.MentionedUsers)
+                await WriteMentionAsync(mention);
+
+            _writer.WriteEndArray();
+
+            // Message reference
+            if (message.Reference is not null)
+            {
+                _writer.WriteStartObject("reference");
+                _writer.WriteString("messageId", message.Reference.MessageId?.ToString());
+                _writer.WriteString("channelId", message.Reference.ChannelId?.ToString());
+                _writer.WriteString("guildId", message.Reference.GuildId?.ToString());
+                _writer.WriteEndObject();
+            }
+
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        public override async ValueTask WritePostambleAsync()
+        {
+            // Message array (end)
+            _writer.WriteEndArray();
+
+            _writer.WriteNumber("messageCount", MessagesWritten);
+
+            // Root object (end)
+            _writer.WriteEndObject();
+            await _writer.FlushAsync();
+        }
+
+        public override async ValueTask DisposeAsync()
+        {
+            await _writer.DisposeAsync();
+            await base.DisposeAsync();
+        }
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/MarkdownVisitors/HtmlMarkdownVisitor.cs

@@ -3,12 +3,13 @@ using System.Linq;
 using System.Net;
 using System.Text;
 using System.Text.RegularExpressions;
-using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Internal;
-using DiscordChatExporter.Domain.Markdown;
-using DiscordChatExporter.Domain.Markdown.Ast;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Markdown;
+using DiscordChatExporter.Core.Markdown.Ast;
+using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
+namespace DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors
 {
     internal partial class HtmlMarkdownVisitor : MarkdownVisitor
     {
@@ -23,13 +24,13 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             _isJumbo = isJumbo;
         }
 
-        public override MarkdownNode VisitText(TextNode text)
+        protected override MarkdownNode VisitText(TextNode text)
         {
             _buffer.Append(HtmlEncode(text.Text));
             return base.VisitText(text);
         }
 
-        public override MarkdownNode VisitFormatted(FormattedNode formatted)
+        protected override MarkdownNode VisitFormatted(FormattedNode formatted)
         {
             var (tagOpen, tagClose) = formatted.Formatting switch
             {
@@ -50,7 +51,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return result;
         }
 
-        public override MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock)
+        protected override MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock)
         {
             _buffer
                 .Append("<span class=\"pre pre--inline\">")
@@ -60,7 +61,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitInlineCodeBlock(inlineCodeBlock);
         }
 
-        public override MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock)
+        protected override MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock)
         {
             var highlightCssClass = !string.IsNullOrWhiteSpace(multiLineCodeBlock.Language)
                 ? $"language-{multiLineCodeBlock.Language}"
@@ -74,8 +75,9 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitMultiLineCodeBlock(multiLineCodeBlock);
         }
 
-        public override MarkdownNode VisitMention(MentionNode mention)
+        protected override MarkdownNode VisitMention(MentionNode mention)
         {
+            var mentionId = Snowflake.TryParse(mention.Id);
             if (mention.Type == MentionType.Meta)
             {
                 _buffer
@@ -85,7 +87,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.User)
             {
-                var member = _context.TryGetMentionedMember(mention.Id);
+                var member = mentionId?.Pipe(_context.TryGetMember);
                 var fullName = member?.User.FullName ?? "Unknown";
                 var nick = member?.Nick ?? "Unknown";
 
@@ -96,7 +98,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.Channel)
             {
-                var channel = _context.TryGetMentionedChannel(mention.Id);
+                var channel = mentionId?.Pipe(_context.TryGetChannel);
                 var name = channel?.Name ?? "deleted-channel";
 
                 _buffer
@@ -106,11 +108,11 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.Role)
             {
-                var role = _context.TryGetMentionedRole(mention.Id);
+                var role = mentionId?.Pipe(_context.TryGetRole);
                 var name = role?.Name ?? "deleted-role";
                 var color = role?.Color;
 
-                var style = color != null
+                var style = color is not null
                     ? $"color: rgb({color?.R}, {color?.G}, {color?.B}); background-color: rgba({color?.R}, {color?.G}, {color?.B}, 0.1);"
                     : "";
 
@@ -123,7 +125,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitMention(mention);
         }
 
-        public override MarkdownNode VisitEmoji(EmojiNode emoji)
+        protected override MarkdownNode VisitEmoji(EmojiNode emoji)
         {
             var emojiImageUrl = Emoji.GetImageUrl(emoji.Id, emoji.Name, emoji.IsAnimated);
             var jumboClass = _isJumbo ? "emoji--large" : "";
@@ -134,10 +136,10 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitEmoji(emoji);
         }
 
-        public override MarkdownNode VisitLink(LinkNode link)
+        protected override MarkdownNode VisitLink(LinkNode link)
         {
             // Extract message ID if the link points to a Discord message
-            var linkedMessageId = Regex.Match(link.Url, "^https?://discordapp.com/channels/.*?/(\\d+)/?$").Groups[1].Value;
+            var linkedMessageId = Regex.Match(link.Url, "^https?://(?:discord|discordapp).com/channels/.*?/(\\d+)/?$").Groups[1].Value;
 
             if (!string.IsNullOrWhiteSpace(linkedMessageId))
             {

DiscordChatExporter.Core/Exporting/Writers/MarkdownVisitors/PlainTextMarkdownVisitor.cs

@@ -1,8 +1,10 @@
 using System.Text;
-using DiscordChatExporter.Domain.Markdown;
-using DiscordChatExporter.Domain.Markdown.Ast;
+using DiscordChatExporter.Core.Discord;
+using DiscordChatExporter.Core.Markdown;
+using DiscordChatExporter.Core.Markdown.Ast;
+using DiscordChatExporter.Core.Utils.Extensions;
 
-namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
+namespace DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors
 {
     internal partial class PlainTextMarkdownVisitor : MarkdownVisitor
     {
@@ -15,35 +17,36 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             _buffer = buffer;
         }
 
-        public override MarkdownNode VisitText(TextNode text)
+        protected override MarkdownNode VisitText(TextNode text)
         {
             _buffer.Append(text.Text);
             return base.VisitText(text);
         }
 
-        public override MarkdownNode VisitMention(MentionNode mention)
+        protected override MarkdownNode VisitMention(MentionNode mention)
         {
+            var mentionId = Snowflake.TryParse(mention.Id);
             if (mention.Type == MentionType.Meta)
             {
                 _buffer.Append($"@{mention.Id}");
             }
             else if (mention.Type == MentionType.User)
             {
-                var member = _context.TryGetMentionedMember(mention.Id);
+                var member = mentionId?.Pipe(_context.TryGetMember);
                 var name = member?.User.Name ?? "Unknown";
 
                 _buffer.Append($"@{name}");
             }
             else if (mention.Type == MentionType.Channel)
             {
-                var channel = _context.TryGetMentionedChannel(mention.Id);
+                var channel = mentionId?.Pipe(_context.TryGetChannel);
                 var name = channel?.Name ?? "deleted-channel";
 
                 _buffer.Append($"#{name}");
             }
             else if (mention.Type == MentionType.Role)
             {
-                var role = _context.TryGetMentionedRole(mention.Id);
+                var role = mentionId?.Pipe(_context.TryGetRole);
                 var name = role?.Name ?? "deleted-role";
 
                 _buffer.Append($"@{name}");
@@ -52,7 +55,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitMention(mention);
         }
 
-        public override MarkdownNode VisitEmoji(EmojiNode emoji)
+        protected override MarkdownNode VisitEmoji(EmojiNode emoji)
         {
             _buffer.Append(
                 emoji.IsCustomEmoji

DiscordChatExporter.Core/Exporting/Writers/MessageWriter.cs

@@ -0,0 +1,36 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Discord.Data;
+
+namespace DiscordChatExporter.Core.Exporting.Writers
+{
+    internal abstract class MessageWriter : IAsyncDisposable
+    {
+        protected Stream Stream { get; }
+
+        protected ExportContext Context { get; }
+
+        public long MessagesWritten { get; private set; }
+
+        public long BytesWritten => Stream.Length;
+
+        protected MessageWriter(Stream stream, ExportContext context)
+        {
+            Stream = stream;
+            Context = context;
+        }
+
+        public virtual ValueTask WritePreambleAsync() => default;
+
+        public virtual ValueTask WriteMessageAsync(Message message)
+        {
+            MessagesWritten++;
+            return default;
+        }
+
+        public virtual ValueTask WritePostambleAsync() => default;
+
+        public virtual async ValueTask DisposeAsync() => await Stream.DisposeAsync();
+    }
+}

DiscordChatExporter.Core/Exporting/Writers/PlainTextMessageWriter.cs

@@ -0,0 +1,163 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Discord.Data;
+using DiscordChatExporter.Core.Exporting.Writers.MarkdownVisitors;
+using Tyrrrz.Extensions;
+
+namespace DiscordChatExporter.Core.Exporting.Writers
+{
+    internal class PlainTextMessageWriter : MessageWriter
+    {
+        private readonly TextWriter _writer;
+
+        public PlainTextMessageWriter(Stream stream, ExportContext context)
+            : base(stream, context)
+        {
+            _writer = new StreamWriter(stream);
+        }
+
+        private string FormatMarkdown(string? markdown) =>
+            PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
+
+        private async ValueTask WriteMessageHeaderAsync(Message message)
+        {
+            // Timestamp & author
+            await _writer.WriteAsync($"[{Context.FormatDate(message.Timestamp)}]");
+            await _writer.WriteAsync($" {message.Author.FullName}");
+
+            // Whether the message is pinned
+            if (message.IsPinned)
+                await _writer.WriteAsync(" (pinned)");
+
+            await _writer.WriteLineAsync();
+        }
+
+        private async ValueTask WriteAttachmentsAsync(IReadOnlyList<Attachment> attachments)
+        {
+            if (!attachments.Any())
+                return;
+
+            await _writer.WriteLineAsync("{Attachments}");
+
+            foreach (var attachment in attachments)
+                await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(attachment.Url));
+
+            await _writer.WriteLineAsync();
+        }
+
+        private async ValueTask WriteEmbedsAsync(IReadOnlyList<Embed> embeds)
+        {
+            foreach (var embed in embeds)
+            {
+                await _writer.WriteLineAsync("{Embed}");
+
+                if (!string.IsNullOrWhiteSpace(embed.Author?.Name))
+                    await _writer.WriteLineAsync(embed.Author.Name);
+
+                if (!string.IsNullOrWhiteSpace(embed.Url))
+                    await _writer.WriteLineAsync(embed.Url);
+
+                if (!string.IsNullOrWhiteSpace(embed.Title))
+                    await _writer.WriteLineAsync(FormatMarkdown(embed.Title));
+
+                if (!string.IsNullOrWhiteSpace(embed.Description))
+                    await _writer.WriteLineAsync(FormatMarkdown(embed.Description));
+
+                foreach (var field in embed.Fields)
+                {
+                    if (!string.IsNullOrWhiteSpace(field.Name))
+                        await _writer.WriteLineAsync(FormatMarkdown(field.Name));
+
+                    if (!string.IsNullOrWhiteSpace(field.Value))
+                        await _writer.WriteLineAsync(FormatMarkdown(field.Value));
+                }
+
+                if (!string.IsNullOrWhiteSpace(embed.Thumbnail?.Url))
+                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Thumbnail.Url));
+
+                if (!string.IsNullOrWhiteSpace(embed.Image?.Url))
+                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Image.Url));
+
+                if (!string.IsNullOrWhiteSpace(embed.Footer?.Text))
+                    await _writer.WriteLineAsync(embed.Footer.Text);
+
+                await _writer.WriteLineAsync();
+            }
+        }
+
+        private async ValueTask WriteReactionsAsync(IReadOnlyList<Reaction> reactions)
+        {
+            if (!reactions.Any())
+                return;
+
+            await _writer.WriteLineAsync("{Reactions}");
+
+            foreach (var reaction in reactions)
+            {
+                await _writer.WriteAsync(reaction.Emoji.Name);
+
+                if (reaction.Count > 1)
+                    await _writer.WriteAsync($" ({reaction.Count})");
+
+                await _writer.WriteAsync(' ');
+            }
+
+            await _writer.WriteLineAsync();
+        }
+
+        public override async ValueTask WritePreambleAsync()
+        {
+            await _writer.WriteLineAsync('='.Repeat(62));
+            await _writer.WriteLineAsync($"Guild: {Context.Request.Guild.Name}");
+            await _writer.WriteLineAsync($"Channel: {Context.Request.Channel.Category.Name} / {Context.Request.Channel.Name}");
+
+            if (!string.IsNullOrWhiteSpace(Context.Request.Channel.Topic))
+                await _writer.WriteLineAsync($"Topic: {Context.Request.Channel.Topic}");
+
+            if (Context.Request.After is not null)
+                await _writer.WriteLineAsync($"After: {Context.FormatDate(Context.Request.After.Value.ToDate())}");
+
+            if (Context.Request.Before is not null)
+                await _writer.WriteLineAsync($"Before: {Context.FormatDate(Context.Request.Before.Value.ToDate())}");
+
+            await _writer.WriteLineAsync('='.Repeat(62));
+            await _writer.WriteLineAsync();
+        }
+
+        public override async ValueTask WriteMessageAsync(Message message)
+        {
+            await base.WriteMessageAsync(message);
+
+            // Header
+            await WriteMessageHeaderAsync(message);
+
+            // Content
+            if (!string.IsNullOrWhiteSpace(message.Content))
+                await _writer.WriteLineAsync(FormatMarkdown(message.Content));
+
+            await _writer.WriteLineAsync();
+
+            // Attachments, embeds, reactions
+            await WriteAttachmentsAsync(message.Attachments);
+            await WriteEmbedsAsync(message.Embeds);
+            await WriteReactionsAsync(message.Reactions);
+
+            await _writer.WriteLineAsync();
+        }
+
+        public override async ValueTask WritePostambleAsync()
+        {
+            await _writer.WriteLineAsync('='.Repeat(62));
+            await _writer.WriteLineAsync($"Exported {MessagesWritten:N0} message(s)");
+            await _writer.WriteLineAsync('='.Repeat(62));
+        }
+
+        public override async ValueTask DisposeAsync()
+        {
+            await _writer.DisposeAsync();
+            await base.DisposeAsync();
+        }
+    }
+}

DiscordChatExporter.Core/Markdown/Ast/EmojiNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal class EmojiNode : MarkdownNode
     {

DiscordChatExporter.Core/Markdown/Ast/FormattedNode.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal enum TextFormatting
     {

DiscordChatExporter.Core/Markdown/Ast/InlineCodeBlockNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal class InlineCodeBlockNode : MarkdownNode
     {

DiscordChatExporter.Core/Markdown/Ast/LinkNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal class LinkNode : MarkdownNode
     {

DiscordChatExporter.Core/Markdown/Ast/MarkdownNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal abstract class MarkdownNode
     {

DiscordChatExporter.Core/Markdown/Ast/MentionNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal enum MentionType
     {

DiscordChatExporter.Core/Markdown/Ast/MultiLineCodeBlockNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal class MultiLineCodeBlockNode : MarkdownNode
     {

DiscordChatExporter.Core/Markdown/Ast/TextNode.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Ast
+namespace DiscordChatExporter.Core.Markdown.Ast
 {
     internal class TextNode : MarkdownNode
     {

DiscordChatExporter.Core/Markdown/MarkdownParser.cs

@@ -1,82 +1,100 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
-using DiscordChatExporter.Domain.Markdown.Ast;
-using DiscordChatExporter.Domain.Markdown.Matching;
+using DiscordChatExporter.Core.Markdown.Ast;
+using DiscordChatExporter.Core.Markdown.Matching;
 
-namespace DiscordChatExporter.Domain.Markdown
+namespace DiscordChatExporter.Core.Markdown
 {
     // The following parsing logic is meant to replicate Discord's markdown grammar as close as possible
     internal static partial class MarkdownParser
     {
-        private const RegexOptions DefaultRegexOptions = RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.Multiline;
+        private const RegexOptions DefaultRegexOptions =
+            RegexOptions.Compiled |
+            RegexOptions.CultureInvariant |
+            RegexOptions.Multiline;
 
         /* Formatting */
 
         // Capture any character until the earliest double asterisk not followed by an asterisk
         private static readonly IMatcher<MarkdownNode> BoldFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\*\\*(.+?)\\*\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Bold, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Bold, Parse(p.Slice(m.Groups[1])))
+        );
 
         // Capture any character until the earliest single asterisk not preceded or followed by an asterisk
         // Opening asterisk must not be followed by whitespace
         // Closing asterisk must not be preceded by whitespace
         private static readonly IMatcher<MarkdownNode> ItalicFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\*(?!\\s)(.+?)(?<!\\s|\\*)\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1])))
+        );
 
         // Capture any character until the earliest triple asterisk not followed by an asterisk
         private static readonly IMatcher<MarkdownNode> ItalicBoldFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\*(\\*\\*.+?\\*\\*)\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]), BoldFormattedNodeMatcher)));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]), BoldFormattedNodeMatcher))
+        );
 
         // Capture any character except underscore until an underscore
         // Closing underscore must not be followed by a word character
         private static readonly IMatcher<MarkdownNode> ItalicAltFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("_([^_]+)_(?!\\w)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1])))
+        );
 
         // Capture any character until the earliest double underscore not followed by an underscore
         private static readonly IMatcher<MarkdownNode> UnderlineFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("__(.+?)__(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Underline, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Underline, Parse(p.Slice(m.Groups[1])))
+        );
 
         // Capture any character until the earliest triple underscore not followed by an underscore
-        private static readonly IMatcher<MarkdownNode> ItalicUnderlineFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
-            new Regex("_(__.+?__)_(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]), UnderlineFormattedNodeMatcher)));
+        private static readonly IMatcher<MarkdownNode> ItalicUnderlineFormattedNodeMatcher =
+            new RegexMatcher<MarkdownNode>(
+                new Regex("_(__.+?__)_(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
+                (p, m) => new FormattedNode(TextFormatting.Italic,
+                    Parse(p.Slice(m.Groups[1]), UnderlineFormattedNodeMatcher))
+            );
 
         // Capture any character until the earliest double tilde
-        private static readonly IMatcher<MarkdownNode> StrikethroughFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
-            new Regex("~~(.+?)~~", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Strikethrough, Parse(p.Slice(m.Groups[1]))));
+        private static readonly IMatcher<MarkdownNode> StrikethroughFormattedNodeMatcher =
+            new RegexMatcher<MarkdownNode>(
+                new Regex("~~(.+?)~~", DefaultRegexOptions | RegexOptions.Singleline),
+                (p, m) => new FormattedNode(TextFormatting.Strikethrough, Parse(p.Slice(m.Groups[1])))
+            );
 
         // Capture any character until the earliest double pipe
         private static readonly IMatcher<MarkdownNode> SpoilerFormattedNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\|\\|(.+?)\\|\\|", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Spoiler, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Spoiler, Parse(p.Slice(m.Groups[1])))
+        );
 
         // Capture any character until the end of the line
         // Opening 'greater than' character must be followed by whitespace
         private static readonly IMatcher<MarkdownNode> SingleLineQuoteNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("^>\\s(.+\n?)", DefaultRegexOptions),
-            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1])))
+        );
 
         // Repeatedly capture any character until the end of the line
         // This one is tricky as it ends up producing multiple separate captures which need to be joined
-        private static readonly IMatcher<MarkdownNode> RepeatedSingleLineQuoteNodeMatcher = new RegexMatcher<MarkdownNode>(
-            new Regex("(?:^>\\s(.+\n?)){2,}", DefaultRegexOptions),
-            (p, m) =>
-            {
-                var content = string.Concat(m.Groups[1].Captures.Select(c => c.Value));
-                return new FormattedNode(TextFormatting.Quote, Parse(content));
-            });
+        private static readonly IMatcher<MarkdownNode> RepeatedSingleLineQuoteNodeMatcher =
+            new RegexMatcher<MarkdownNode>(
+                new Regex("(?:^>\\s(.+\n?)){2,}", DefaultRegexOptions),
+                (_, m) =>
+                {
+                    var content = string.Concat(m.Groups[1].Captures.Select(c => c.Value));
+                    return new FormattedNode(TextFormatting.Quote, Parse(content));
+                }
+            );
 
         // Capture any character until the end of the input
         // Opening 'greater than' characters must be followed by whitespace
         private static readonly IMatcher<MarkdownNode> MultiLineQuoteNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("^>>>\\s(.+)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1])))
+        );
 
         /* Code blocks */
 
@@ -85,41 +103,48 @@ namespace DiscordChatExporter.Domain.Markdown
         // There can be either one or two backticks, but equal number on both sides
         private static readonly IMatcher<MarkdownNode> InlineCodeBlockNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("(`{1,2})([^`]+)\\1", DefaultRegexOptions | RegexOptions.Singleline),
-            m => new InlineCodeBlockNode(m.Groups[2].Value.Trim('\r', '\n')));
+            m => new InlineCodeBlockNode(m.Groups[2].Value.Trim('\r', '\n'))
+        );
 
         // Capture language identifier and then any character until the earliest triple backtick
         // Language identifier is one word immediately after opening backticks, followed immediately by newline
         // Blank lines at the beginning and end of content are trimmed
         private static readonly IMatcher<MarkdownNode> MultiLineCodeBlockNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("```(?:(\\w*)\\n)?(.+?)```", DefaultRegexOptions | RegexOptions.Singleline),
-            m => new MultiLineCodeBlockNode(m.Groups[1].Value, m.Groups[2].Value.Trim('\r', '\n')));
+            m => new MultiLineCodeBlockNode(m.Groups[1].Value, m.Groups[2].Value.Trim('\r', '\n'))
+        );
 
         /* Mentions */
 
         // Capture @everyone
         private static readonly IMatcher<MarkdownNode> EveryoneMentionNodeMatcher = new StringMatcher<MarkdownNode>(
             "@everyone",
-            p => new MentionNode("everyone", MentionType.Meta));
+            _ => new MentionNode("everyone", MentionType.Meta)
+        );
 
         // Capture @here
         private static readonly IMatcher<MarkdownNode> HereMentionNodeMatcher = new StringMatcher<MarkdownNode>(
             "@here",
-            p => new MentionNode("here", MentionType.Meta));
+            _ => new MentionNode("here", MentionType.Meta)
+        );
 
         // Capture <@123456> or <@!123456>
         private static readonly IMatcher<MarkdownNode> UserMentionNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("<@!?(\\d+)>", DefaultRegexOptions),
-            m => new MentionNode(m.Groups[1].Value, MentionType.User));
+            m => new MentionNode(m.Groups[1].Value, MentionType.User)
+        );
 
         // Capture <#123456>
         private static readonly IMatcher<MarkdownNode> ChannelMentionNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("<#(\\d+)>", DefaultRegexOptions),
-            m => new MentionNode(m.Groups[1].Value, MentionType.Channel));
+            m => new MentionNode(m.Groups[1].Value, MentionType.Channel)
+        );
 
         // Capture <@&123456>
         private static readonly IMatcher<MarkdownNode> RoleMentionNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("<@&(\\d+)>", DefaultRegexOptions),
-            m => new MentionNode(m.Groups[1].Value, MentionType.Role));
+            m => new MentionNode(m.Groups[1].Value, MentionType.Role)
+        );
 
         /* Emojis */
 
@@ -129,30 +154,36 @@ namespace DiscordChatExporter.Domain.Markdown
         // ... or digit followed by enclosing mark
         // (this does not match all emojis in Discord but it's reasonably accurate enough)
         private static readonly IMatcher<MarkdownNode> StandardEmojiNodeMatcher = new RegexMatcher<MarkdownNode>(
-            new Regex("((?:[\\uD83C][\\uDDE6-\\uDDFF]){2}|[\\u2600-\\u26FF]|\\p{Cs}{2}|\\d\\p{Me})", DefaultRegexOptions),
-            m => new EmojiNode(m.Groups[1].Value));
+            new Regex("((?:[\\uD83C][\\uDDE6-\\uDDFF]){2}|[\\u2600-\\u26FF]|\\p{Cs}{2}|\\d\\p{Me})",
+                DefaultRegexOptions),
+            m => new EmojiNode(m.Groups[1].Value)
+        );
 
         // Capture <:lul:123456> or <a:lul:123456>
         private static readonly IMatcher<MarkdownNode> CustomEmojiNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("<(a)?:(.+?):(\\d+?)>", DefaultRegexOptions),
-            m => new EmojiNode(m.Groups[3].Value, m.Groups[2].Value, !string.IsNullOrWhiteSpace(m.Groups[1].Value)));
+            m => new EmojiNode(m.Groups[3].Value, m.Groups[2].Value, !string.IsNullOrWhiteSpace(m.Groups[1].Value))
+        );
 
         /* Links */
 
         // Capture [title](link)
         private static readonly IMatcher<MarkdownNode> TitledLinkNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\[(.+?)\\]\\((.+?)\\)", DefaultRegexOptions),
-            m => new LinkNode(m.Groups[2].Value, m.Groups[1].Value));
+            m => new LinkNode(m.Groups[2].Value, m.Groups[1].Value)
+        );
 
         // Capture any non-whitespace character after http:// or https:// until the last punctuation character or whitespace
         private static readonly IMatcher<MarkdownNode> AutoLinkNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("(https?://\\S*[^\\.,:;\"\'\\s])", DefaultRegexOptions),
-            m => new LinkNode(m.Groups[1].Value));
+            m => new LinkNode(m.Groups[1].Value)
+        );
 
         // Same as auto link but also surrounded by angular brackets
         private static readonly IMatcher<MarkdownNode> HiddenLinkNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("<(https?://\\S*[^\\.,:;\"\'\\s])>", DefaultRegexOptions),
-            m => new LinkNode(m.Groups[1].Value));
+            m => new LinkNode(m.Groups[1].Value)
+        );
 
         /* Text */
 
@@ -160,25 +191,29 @@ namespace DiscordChatExporter.Domain.Markdown
         // This escapes it from matching for formatting
         private static readonly IMatcher<MarkdownNode> ShrugTextNodeMatcher = new StringMatcher<MarkdownNode>(
             @"¯\_(ツ)_/¯",
-            p => new TextNode(p.ToString()));
+            p => new TextNode(p.ToString())
+        );
 
         // Capture some specific emojis that don't get rendered
         // This escapes it from matching for emoji
         private static readonly IMatcher<MarkdownNode> IgnoredEmojiTextNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("(\\u26A7|\\u2640|\\u2642|\\u2695|\\u267E|\\u00A9|\\u00AE|\\u2122)", DefaultRegexOptions),
-            m => new TextNode(m.Groups[1].Value));
+            m => new TextNode(m.Groups[1].Value)
+        );
 
         // Capture any "symbol/other" character or surrogate pair preceded by a backslash
         // This escapes it from matching for emoji
         private static readonly IMatcher<MarkdownNode> EscapedSymbolTextNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\\\(\\p{So}|\\p{Cs}{2})", DefaultRegexOptions),
-            m => new TextNode(m.Groups[1].Value));
+            m => new TextNode(m.Groups[1].Value)
+        );
 
         // Capture any non-whitespace, non latin alphanumeric character preceded by a backslash
         // This escapes it from matching for formatting or other tokens
         private static readonly IMatcher<MarkdownNode> EscapedCharacterTextNodeMatcher = new RegexMatcher<MarkdownNode>(
             new Regex("\\\\([^a-zA-Z0-9\\s])", DefaultRegexOptions),
-            m => new TextNode(m.Groups[1].Value));
+            m => new TextNode(m.Groups[1].Value)
+        );
 
         // Combine all matchers into one
         // Matchers that have similar patterns are ordered from most specific to least specific

DiscordChatExporter.Core/Markdown/MarkdownVisitor.cs

@@ -1,28 +1,28 @@
 using System;
 using System.Collections.Generic;
-using DiscordChatExporter.Domain.Markdown.Ast;
+using DiscordChatExporter.Core.Markdown.Ast;
 
-namespace DiscordChatExporter.Domain.Markdown
+namespace DiscordChatExporter.Core.Markdown
 {
     internal abstract class MarkdownVisitor
     {
-        public virtual MarkdownNode VisitText(TextNode text) => text;
+        protected virtual MarkdownNode VisitText(TextNode text) => text;
 
-        public virtual MarkdownNode VisitFormatted(FormattedNode formatted)
+        protected virtual MarkdownNode VisitFormatted(FormattedNode formatted)
         {
             Visit(formatted.Children);
             return formatted;
         }
 
-        public virtual MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock) => inlineCodeBlock;
+        protected virtual MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock) => inlineCodeBlock;
 
-        public virtual MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock) => multiLineCodeBlock;
+        protected virtual MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock) => multiLineCodeBlock;
 
-        public virtual MarkdownNode VisitLink(LinkNode link) => link;
+        protected virtual MarkdownNode VisitLink(LinkNode link) => link;
 
-        public virtual MarkdownNode VisitEmoji(EmojiNode emoji) => emoji;
+        protected virtual MarkdownNode VisitEmoji(EmojiNode emoji) => emoji;
 
-        public virtual MarkdownNode VisitMention(MentionNode mention) => mention;
+        protected virtual MarkdownNode VisitMention(MentionNode mention) => mention;
 
         public MarkdownNode Visit(MarkdownNode node) => node switch
         {

DiscordChatExporter.Core/Markdown/Matching/AggregateMatcher.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 
-namespace DiscordChatExporter.Domain.Markdown.Matching
+namespace DiscordChatExporter.Core.Markdown.Matching
 {
     internal class AggregateMatcher<T> : IMatcher<T>
     {
@@ -27,11 +27,11 @@ namespace DiscordChatExporter.Domain.Markdown.Matching
                 var match = matcher.TryMatch(stringPart);
 
                 // If there's no match - continue
-                if (match == null)
+                if (match is null)
                     continue;
 
                 // If this match is earlier than previous earliest - replace
-                if (earliestMatch == null || match.StringPart.StartIndex < earliestMatch.StringPart.StartIndex)
+                if (earliestMatch is null || match.StringPart.StartIndex < earliestMatch.StringPart.StartIndex)
                     earliestMatch = match;
 
                 // If the earliest match starts at the very beginning - break,

DiscordChatExporter.Core/Markdown/Matching/IMatcher.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace DiscordChatExporter.Domain.Markdown.Matching
+namespace DiscordChatExporter.Core.Markdown.Matching
 {
     internal interface IMatcher<T>
     {
@@ -21,7 +21,7 @@ namespace DiscordChatExporter.Domain.Markdown.Matching
                 var match = matcher.TryMatch(stringPart.Slice(currentIndex, stringPart.EndIndex - currentIndex));
 
                 // If there's no match - break
-                if (match == null)
+                if (match is null)
                     break;
 
                 // If this match doesn't start immediately at current index - transform and yield fallback first

DiscordChatExporter.Core/Markdown/Matching/ParsedMatch.cs

@@ -1,4 +1,4 @@
-namespace DiscordChatExporter.Domain.Markdown.Matching
+namespace DiscordChatExporter.Core.Markdown.Matching
 {
     internal class ParsedMatch<T>
     {

DiscordChatExporter.Core/Markdown/Matching/RegexMatcher.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Text.RegularExpressions;
 
-namespace DiscordChatExporter.Domain.Markdown.Matching
+namespace DiscordChatExporter.Core.Markdown.Matching
 {
     internal class RegexMatcher<T> : IMatcher<T>
     {

DiscordChatExporter.Core/Markdown/Matching/StringMatcher.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace DiscordChatExporter.Domain.Markdown.Matching
+namespace DiscordChatExporter.Core.Markdown.Matching
 {
     internal class StringMatcher<T> : IMatcher<T>
     {

DiscordChatExporter.Core/Markdown/Matching/StringPart.cs

@@ -1,6 +1,6 @@
 using System.Text.RegularExpressions;
 
-namespace DiscordChatExporter.Domain.Markdown.Matching
+namespace DiscordChatExporter.Core.Markdown.Matching
 {
     internal readonly struct StringPart
     {
@@ -25,7 +25,7 @@ namespace DiscordChatExporter.Domain.Markdown.Matching
         {
         }
 
-        public StringPart Slice(int newStartIndex, int newLength) => new StringPart(Target, newStartIndex, newLength);
+        public StringPart Slice(int newStartIndex, int newLength) => new(Target, newStartIndex, newLength);
 
         public StringPart Slice(int newStartIndex) => Slice(newStartIndex, EndIndex - newStartIndex);
 

DiscordChatExporter.Core/Utils/Extensions/AsyncExtensions.cs

@@ -5,11 +5,12 @@ using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace DiscordChatExporter.Domain.Utilities
+namespace DiscordChatExporter.Core.Utils.Extensions
 {
     public static class AsyncExtensions
     {
-        private static async ValueTask<IReadOnlyList<T>> AggregateAsync<T>(this IAsyncEnumerable<T> asyncEnumerable)
+        private static async ValueTask<IReadOnlyList<T>> AggregateAsync<T>(
+            this IAsyncEnumerable<T> asyncEnumerable)
         {
             var list = new List<T>();
 
@@ -19,10 +20,14 @@ namespace DiscordChatExporter.Domain.Utilities
             return list;
         }
 
-        public static ValueTaskAwaiter<IReadOnlyList<T>> GetAwaiter<T>(this IAsyncEnumerable<T> asyncEnumerable) =>
+        public static ValueTaskAwaiter<IReadOnlyList<T>> GetAwaiter<T>(
+            this IAsyncEnumerable<T> asyncEnumerable) =>
             asyncEnumerable.AggregateAsync().GetAwaiter();
 
-        public static async Task ParallelForEachAsync<T>(this IEnumerable<T> source, Func<T, Task> handleAsync, int degreeOfParallelism)
+        public static async ValueTask ParallelForEachAsync<T>(
+            this IEnumerable<T> source,
+            Func<T, ValueTask> handleAsync,
+            int degreeOfParallelism)
         {
             using var semaphore = new SemaphoreSlim(degreeOfParallelism);
 

DiscordChatExporter.Core/Utils/Extensions/BinaryExtensions.cs

@@ -0,0 +1,19 @@
+using System.Text;
+
+namespace DiscordChatExporter.Core.Utils.Extensions
+{
+    public static class BinaryExtensions
+    {
+        public static string ToHex(this byte[] data)
+        {
+            var buffer = new StringBuilder();
+
+            foreach (var t in data)
+            {
+                buffer.Append(t.ToString("X2"));
+            }
+
+            return buffer.ToString();
+        }
+    }
+}

DiscordChatExporter.Core/Utils/Extensions/ColorExtensions.cs

@@ -1,13 +1,15 @@
 using System.Drawing;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Core.Utils.Extensions
 {
-    internal static class ColorExtensions
+    public static class ColorExtensions
     {
         public static Color WithAlpha(this Color color, int alpha) => Color.FromArgb(alpha, color);
 
         public static Color ResetAlpha(this Color color) => color.WithAlpha(255);
 
         public static int ToRgb(this Color color) => color.ToArgb() & 0xffffff;
+
+        public static string ToHex(this Color color) => $"#{color.R:X2}{color.G:X2}{color.B:X2}";
     }
 }

DiscordChatExporter.Core/Utils/Extensions/DateExtensions.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Globalization;
+
+namespace DiscordChatExporter.Core.Utils.Extensions
+{
+    public static class DateExtensions
+    {
+        public static string ToLocalString(this DateTimeOffset dateTime, string format) =>
+            dateTime.ToLocalTime().ToString(format, CultureInfo.InvariantCulture);
+    }
+}

DiscordChatExporter.Core/Utils/Extensions/GenericExtensions.cs

@@ -1,8 +1,8 @@
 using System;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Core.Utils.Extensions
 {
-    internal static class GenericExtensions
+    public static class GenericExtensions
     {
         public static TOut Pipe<TIn, TOut>(this TIn input, Func<TIn, TOut> transform) => transform(input);