Update version

Closes #249

.config/dotnet-tools.json

@@ -0,0 +1,12 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "xamlstyler.console": {
+      "version": "3.2001.0",
+      "commands": [
+        "xstyler"
+      ]
+    }
+  }
+}

.github/FUNDING.yml

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

.github/workflows/CD.yml

@@ -0,0 +1,66 @@
+name: CD
+
+on:
+  push:
+    tags:
+    - '*'
+
+jobs:
+  build:
+    runs-on: windows-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+
+    - name: Install .NET Core
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 3.1.100
+
+    - name: Build & publish (CLI)
+      run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
+
+    - name: Build & publish (GUI)
+      run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
+
+    - name: Pack (CLI)
+      run: Compress-Archive -Path DiscordChatExporter.Cli/bin/Publish/* -DestinationPath DiscordChatExporter.Cli/bin/Publish/Archive.zip -Force
+      shell: pwsh
+
+    - name: Pack (GUI)
+      run: Compress-Archive -Path DiscordChatExporter.Gui/bin/Publish/* -DestinationPath DiscordChatExporter.Gui/bin/Publish/Archive.zip -Force
+      shell: pwsh
+
+    - name: Create release
+      id: create_release
+      uses: actions/create-release@v1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        tag_name: ${{ github.ref }}
+        release_name: ${{ github.ref }}
+        body: |
+          [Changelog](https://github.com/Tyrrrz/DiscordChatExporter/blob/master/Changelog.md)
+        draft: false
+        prerelease: false
+
+    - name: Upload release asset (CLI)
+      uses: actions/upload-release-asset@v1.0.1
+      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@v1.0.1
+      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

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+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: windows-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+
+    - name: Install .NET Core
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 3.1.100
+
+    - name: Build & publish (CLI)
+      run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
+
+    - name: Build & publish (GUI)
+      run: dotnet publish DiscordChatExporter.Gui/ -o DiscordChatExporter.Gui/bin/Publish/ --configuration Release
+
+    - name: Upload build artifacts (CLI)
+      uses: actions/upload-artifact@master
+      with:
+        name: DiscordChatExporter.CLI
+        path: DiscordChatExporter.Cli/bin/Publish/
+
+    - name: Upload build artifact (GUI)
+      uses: actions/upload-artifact@master
+      with:
+        name: DiscordChatExporter
+        path: DiscordChatExporter.Gui/bin/Publish/

Changelog.md

@@ -1,3 +1,118 @@
+### v2.17 (12-Jan-2020)
+
+- Fixed an issue where an empty file was produced when exporting a channel with no messages (for specified period). With the new behavior, no file will be created and instead a message will be shown to the user informing of the failure.
+- [HTML/TXT] Added message count to the bottom of the file. This number shows how many messages were exported as part of the current file. Prior to 2.16 this number was present along with the rest of the metadata at the top, then removed due to changes in the exporter, and now brought back at the end of the file instead.
+- [HTML] Fixed an issue where some emojis were not properly rendered.
+- [GUI] Added a setting that lets you configure whether to remember the last used token. Previously it was the default behavior, but now you can disable it if you don't want the token persisted on your system.
+
+### v2.16 (08-Dec-2019)
+
+- Migrated from .NET Framework to .NET Core. To run this and future versions of DiscordChatExporter you will need [.NET Core runtime for desktop apps](https://dotnet.microsoft.com/download/dotnet-core/3.1/runtime) (for GUI/CLI version on Windows) or [.NET Core base runtime](https://dotnet.microsoft.com/download/dotnet-core/3.1) (for CLI version on Windows, Linux or macOS).
+- Reworked the exporter engine to render output using streaming data source. This means that only a very small portion of messages are cached in memory when exporting. In other words, you are only limited by storage space and not how much RAM you have, so you can now export terabytes of chat logs without hitting out of memory exceptions. I still recommend using partitions if you're exporting very large chat logs (250k+ messages) to HTML, unless you want your computer to catch fire when you try to open the export in browser.
+- Changed how partitioned files are named, due to the fact that total number of partitions is no longer known ahead of time.
+- Added a warning about automating user accounts to the usage guide in both GUI and CLI versions.
+- Added support for announcement (news) channels. You will now be able to see them in the list and export them.
+- Fixed various issues that resulted in exceptions during export process.
+- [HTML/TXT] Removed message count from the metadata. Due to the fact that the messages are exported as they are streamed, total number of messages is not known ahead of time.
+- [HTML] Changed default color of the embed color pill to match the theme.
+- [HTML] Changed emoji parser to be less greedy. As a result it should match fewer character sequences that look like emojis but really aren't, but on the other hand it might miss some actual emojis. This means that some standard emojis (i.e. not custom server emojis) may not look like in Discord. This is a compromise I'm willing to take because detecting emojis in text is really hard to get right and not worth it at all.
+- [HTML] Some other minor styling adjustments.
+- [CSV] Replaced semicolons (;) with (,) as separators.
+
+Please note that CSV export is most likely not going to receive future updates and will remain only as an option for those who wish to use it for text analysis. In other words, it won't contain any of the rich media features like embeds. If you're currently using CSV as a structured output to feed into your program, JSON output will replace that in the future.
+
+### v2.15 (15-Sep-2019)
+
+- Improved markdown parser and made it even faster for non-HTML formats.
+- [HTML] Added support for block quotes.
+- [HTML] Links pointing to a Discord message will now navigate to the linked message inside exported chat log if it's there.
+- [HTML] Updated light theme to match how it looks in Discord after recent changes.
+- [HTML] Added indication for when a message is pinned. Pinned messages now have a tinted background.
+- [HTML] Fixed an issue where multiline code blocks sometimes had incorrect formatting applied to them.
+- [TXT] Added indication for when a message is pinned. Pinned messages now have `(pinned)` next to timestamp and author.
+- [CSV] Added message author's user ID to output.
+- [GUI] Streamlined auto-update process a bit.
+- [GUI] Added some tooltips.
+
+### v2.14 (15-Jun-2019)
+
+- [TXT] Added support for embeds.
+- [TXT] Added support for reactions.
+- [CSV] Added support for reactions.
+- [TXT] Changed how attachments are rendered.
+
+### v2.13.1 (06-Jun-2019)
+
+- Fixed an issue where the app sometimes crashed when exporting due to `System.InvalidCastException`.
+- [HTML] Added `data-user-id` attribute to `span.chatlog__author-name`. The value of this attribute is author's Discord user ID.
+
+### v2.13 (15-May-2019)
+
+- Updated usage instructions.
+- [HTML] Added BOT tags to messages posted by bots.
+- [GUI] UI will now be disabled when exporting.
+- [GUI] Notification informing that the export has completed will now appear after all exports have completed, instead of each of them separately.
+
+### v2.12.1 (12-Apr-2019)
+
+- [GUI] Fixed an issue where the app crashed when trying to export multiple channels.
+- [HTML] Fixed an issue where some of the emojis were rendered via Twemoji while Discord renders them as plain text.
+- [HTML] Fixed an issue where emojis weren't jumbo if there were more than one of them.
+
+### v2.12 (11-Apr-2019)
+
+- Improved markdown parsing performance which speeds up the final stage of exporting by around 4.5 times.
+- Improved performance when exporting as PlainText or CSV.
+- [GUI] Fixed an issue where the app would freeze up and report as "not responding" during the final stage of exporting.
+- [CLI] Fixed an issue where it would say "Completed" after exporting a chat log, even if the process failed.
+
+### v2.11 (14-Mar-2019)
+
+- [HTML] Added syntax highlighting for multiline code blocks via Highlight.js.
+- Added retry policy for all 5xx status codes to prevent random crashes.
+
+### v2.10.2 (10-Mar-2019)
+
+- [HTML] Updated message grouping algorithm to make it the same as in Discord. Removed "message group limit" setting and parameter.
+- [HTML] Added small margin at the end of the chatlog so it doesn't look like it was truncated.
+- [CLI] Fixed an issue where the app would crash if stdout was redirected. Progress will not be reported in such cases.
+
+### v2.10.1 (06-Mar-2019)
+
+- [HTML] Fixed an issue where multiple emojis on a single line would get rendered as one emoji.
+- [HTML] Fixed an issue where an open square bracket character would incorrectly render as an emoji.
+- [HTML] Added alt text to emoji images so that they will be rendered using default font when Twemoji images are not available.
+
+### v2.10 (03-Mar-2019)
+
+- [HTML] Reworked the entire markdown parsing engine which fixes numerous rendering inconsistencies (over 15 issues fixed).
+- [HTML] Added support for animated emojis.
+- [HTML] Standard emojis are now rendered using Twemoji, the same image set that Discord uses.
+- [HTML] Fixed an issue where video attachments would render incorrectly.
+- [HTML] Minor fixes in styling.
+- [GUI] Aggregated export progress is now shown in the taskbar.
+- [GUI] Checkmarks are now displayed next to channels that are selected.
+- [CLI] Added progress reporting when exporting chat logs.
+
+### v2.9.1 (10-Feb-2019)
+
+- Fixed an issue where some of the last messages in a channel would sometimes not get exported.
+
+### v2.9 (09-Feb-2019)
+
+- Added categories to channel list in GUI. Channels are now also grouped by category.
+- Added ability to export multiple channels at once in GUI by selecting them with shift or ctrl keys.
+- Added CLI command to export all available channels in a guild (`exportguild`).
+- Added CLI command to export all direct message channels (`exportdm`).
+- Added retry policy for 503 status code errors to prevent random crashes.
+- Changed how channels are exported in GUI. Now you need to select them first and then click a button to export. You can also double click a single channel to export it as before.
+- Improved default file name generation by adding date ranges and channel ID to the file name.
+- Improved naming of files exported with partitioning.
+- Improved usage instructions.
+- Improved GUI layout and styling.
+- Fixed an issue where dialogs would sometimes appear over other windows.
+- Fixed an issue where launching DiscordChatExporter from Windows Start Menu would make it crash.
+
 ### v2.8 (03-Nov-2018)
 
 - Added support for partitioning which lets you split the output into multiple files by setting the partition message limit (`-p` parameter for CLI).

Deploy/Prepare.ps1

@@ -1,11 +0,0 @@
-New-Item "$PSScriptRoot\bin" -ItemType Directory -Force
-
-# GUI
-$files = @()
-$files += Get-ChildItem -Path "$PSScriptRoot\..\DiscordChatExporter.Gui\bin\Release\*" -Include "*.exe", "*.dll", "*.config"
-$files | Compress-Archive -DestinationPath "$PSScriptRoot\bin\DiscordChatExporter.zip" -Force
-
-# CLI
-$files = @()
-$files += Get-ChildItem -Path "$PSScriptRoot\..\DiscordChatExporter.Cli\bin\Release\net461\*" -Include "*.exe", "*.dll", "*.config"
-$files | Compress-Archive -DestinationPath "$PSScriptRoot\bin\DiscordChatExporter.CLI.zip" -Force

DiscordChatExporter.Cli/Commands/ExportChannelCommand.cs

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+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Services;
+
+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 ExportChannelCommand(SettingsService settingsService, DataService dataService, ExportService exportService)
+            : base(settingsService, dataService, exportService)
+        {
+        }
+
+        public override async Task ExecuteAsync(IConsole console) => await ExportAsync(console, ChannelId);
+    }
+}

DiscordChatExporter.Cli/Commands/ExportCommandBase.cs

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+using System;
+using System.IO;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using CliFx.Utilities;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Services;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    public abstract class ExportCommandBase : TokenCommandBase
+    {
+        protected SettingsService SettingsService { get; }
+
+        protected ExportService ExportService { get; }
+
+        [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; }
+
+        [CommandOption("after", Description = "Limit to messages sent after this date.")]
+        public DateTimeOffset? After { get; set; }
+
+        [CommandOption("before", Description = "Limit to messages sent before this date.")]
+        public DateTimeOffset? Before { get; set; }
+
+        [CommandOption("partition", 'p', Description = "Split output into partitions limited to this number of messages.")]
+        public int? PartitionLimit { get; set; }
+
+        [CommandOption("dateformat", Description = "Date format used in output.")]
+        public string? DateFormat { get; set; }
+
+        protected ExportCommandBase(SettingsService settingsService, DataService dataService, ExportService exportService)
+            : base(dataService)
+        {
+            SettingsService = settingsService;
+            ExportService = exportService;
+        }
+
+        protected async Task ExportAsync(IConsole console, Guild guild, Channel channel)
+        {
+            if (!string.IsNullOrWhiteSpace(DateFormat))
+                SettingsService.DateFormat = DateFormat;
+
+            console.Output.Write($"Exporting channel [{channel.Name}]... ");
+            var progress = console.CreateProgressTicker();
+
+            var outputPath = OutputPath ?? Directory.GetCurrentDirectory();
+            await ExportService.ExportChatLogAsync(GetToken(), guild, channel,
+                outputPath, ExportFormat, PartitionLimit,
+                After, Before, progress);
+
+            console.Output.WriteLine();
+        }
+
+        protected async Task ExportAsync(IConsole console, Channel channel)
+        {
+            var guild = await DataService.GetGuildAsync(GetToken(), channel.GuildId);
+            await ExportAsync(console, guild, channel);
+        }
+
+        protected async Task ExportAsync(IConsole console, string channelId)
+        {
+            var channel = await DataService.GetChannelAsync(GetToken(), channelId);
+            await ExportAsync(console, channel);
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/ExportDirectMessagesCommand.cs

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+using System.Linq;
+using System.Net;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Models.Exceptions;
+using DiscordChatExporter.Core.Services;
+using DiscordChatExporter.Core.Services.Exceptions;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [Command("exportdm", Description = "Export all direct message channels.")]
+    public class ExportDirectMessagesCommand : ExportCommandBase
+    {
+        public ExportDirectMessagesCommand(SettingsService settingsService, DataService dataService, ExportService exportService)
+            : base(settingsService, dataService, exportService)
+        {
+        }
+
+        public override async Task ExecuteAsync(IConsole console)
+        {
+            // Get channels
+            var channels = await DataService.GetDirectMessageChannelsAsync(GetToken());
+
+            // Order channels
+            channels = channels.OrderBy(c => c.Name).ToArray();
+
+            // Loop through channels
+            foreach (var channel in channels)
+            {
+                try
+                {
+                    await ExportAsync(console, channel);
+                }
+                catch (HttpErrorStatusCodeException ex) when (ex.StatusCode == HttpStatusCode.Forbidden)
+                {
+                    console.Error.WriteLine("You don't have access to this channel.");
+                }
+                catch (HttpErrorStatusCodeException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
+                {
+                    console.Error.WriteLine("This channel doesn't exist.");
+                }
+                catch (DomainException ex)
+                {
+                    console.Error.WriteLine(ex.Message);
+                }
+            }
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/ExportGuildCommand.cs

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+using System.Linq;
+using System.Net;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Models.Exceptions;
+using DiscordChatExporter.Core.Services;
+using DiscordChatExporter.Core.Services.Exceptions;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [Command("exportguild", Description = "Export all channels within specified guild.")]
+    public class ExportGuildCommand : ExportCommandBase
+    {
+        [CommandOption("guild", 'g', IsRequired = true, Description = "Guild ID.")]
+        public string GuildId { get; set; }
+
+        public ExportGuildCommand(SettingsService settingsService, DataService dataService, ExportService exportService)
+            : base(settingsService, dataService, exportService)
+        {
+        }
+
+        public override async Task ExecuteAsync(IConsole console)
+        {
+            // Get channels
+            var channels = await DataService.GetGuildChannelsAsync(GetToken(), GuildId);
+
+            // Filter and order channels
+            channels = channels.Where(c => c.Type.IsExportable()).OrderBy(c => c.Name).ToArray();
+
+            // Loop through channels
+            foreach (var channel in channels)
+            {
+                try
+                {
+                    await ExportAsync(console, channel);
+                }
+                catch (HttpErrorStatusCodeException ex) when (ex.StatusCode == HttpStatusCode.Forbidden)
+                {
+                    console.Error.WriteLine("You don't have access to this channel.");
+                }
+                catch (HttpErrorStatusCodeException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
+                {
+                    console.Error.WriteLine("This channel doesn't exist.");
+                }
+                catch (DomainException ex)
+                {
+                    console.Error.WriteLine(ex.Message);
+                }
+            }
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/GetChannelsCommand.cs

@@ -0,0 +1,34 @@
+using System.Linq;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Services;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [Command("channels", Description = "Get the list of channels in specified guild.")]
+    public class GetChannelsCommand : TokenCommandBase
+    {
+        [CommandOption("guild", 'g', IsRequired = true, Description = "Guild ID.")]
+        public string GuildId { get; set; }
+
+        public GetChannelsCommand(DataService dataService)
+            : base(dataService)
+        {
+        }
+
+        public override async Task ExecuteAsync(IConsole console)
+        {
+            // Get channels
+            var channels = await DataService.GetGuildChannelsAsync(GetToken(), GuildId);
+
+            // Filter and order channels
+            channels = channels.Where(c => c.Type.IsExportable()).OrderBy(c => c.Name).ToArray();
+
+            // Print result
+            foreach (var channel in channels)
+                console.Output.WriteLine($"{channel.Id} | {channel.Name}");
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/GetDirectMessageChannelsCommand.cs

@@ -0,0 +1,30 @@
+using System.Linq;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Services;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [Command("dm", Description = "Get the list of direct message channels.")]
+    public class GetDirectMessageChannelsCommand : TokenCommandBase
+    {
+        public GetDirectMessageChannelsCommand(DataService dataService)
+            : base(dataService)
+        {
+        }
+
+        public override async Task ExecuteAsync(IConsole console)
+        {
+            // Get channels
+            var channels = await DataService.GetDirectMessageChannelsAsync(GetToken());
+
+            // Order channels
+            channels = channels.OrderBy(c => c.Name).ToArray();
+
+            // Print result
+            foreach (var channel in channels)
+                console.Output.WriteLine($"{channel.Id} | {channel.Name}");
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/GetGuildsCommand.cs

@@ -0,0 +1,30 @@
+using System.Linq;
+using System.Threading.Tasks;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Services;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [Command("guilds", Description = "Get the list of accessible guilds.")]
+    public class GetGuildsCommand : TokenCommandBase
+    {
+        public GetGuildsCommand(DataService dataService)
+            : base(dataService)
+        {
+        }
+
+        public override async Task ExecuteAsync(IConsole console)
+        {
+            // Get guilds
+            var guilds = await DataService.GetUserGuildsAsync(GetToken());
+
+            // Order guilds
+            guilds = guilds.OrderBy(g => g.Name).ToArray();
+
+            // Print result
+            foreach (var guild in guilds)
+                console.Output.WriteLine($"{guild.Id} | {guild.Name}");
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/GuideCommand.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Threading.Tasks;
+using CliFx;
+using CliFx.Attributes;
+using CliFx.Services;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    [Command("guide", Description = "Explains how to obtain token, guild or channel ID.")]
+    public class GuideCommand : ICommand
+    {
+        public Task ExecuteAsync(IConsole console)
+        {
+            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(" 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:"));
+            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:"));
+            console.Output.WriteLine(" 1. Open Discord");
+            console.Output.WriteLine(" 2. Open Settings");
+            console.Output.WriteLine(" 3. Go to Appearance section");
+            console.Output.WriteLine(" 4. Enable Developer Mode");
+            console.Output.WriteLine(" 5. Right click on the desired guild or channel and click Copy ID");
+            console.Output.WriteLine();
+
+            console.WithForegroundColor(ConsoleColor.White, () => console.Output.WriteLine("To get direct message channel ID:"));
+            console.Output.WriteLine(" 1. Open Discord");
+            console.Output.WriteLine(" 2. Open the desired direct message channel");
+            console.Output.WriteLine(" 3. Press Ctrl+Shift+I to show developer tools");
+            console.Output.WriteLine(" 4. Navigate to the Console tab");
+            console.Output.WriteLine(" 5. Type \"window.location.href\" and press Enter");
+            console.Output.WriteLine(" 6. Copy the first long sequence of numbers inside the URL");
+            console.Output.WriteLine();
+
+            console.Output.WriteLine("If you still have unanswered questions, check out the wiki:");
+            console.Output.WriteLine("https://github.com/Tyrrrz/DiscordChatExporter/wiki");
+
+            return Task.CompletedTask;
+        }
+    }
+}

DiscordChatExporter.Cli/Commands/TokenCommandBase.cs

@@ -0,0 +1,29 @@
+using System.Threading.Tasks;
+using CliFx;
+using CliFx.Attributes;
+using CliFx.Services;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Services;
+
+namespace DiscordChatExporter.Cli.Commands
+{
+    public abstract class TokenCommandBase : ICommand
+    {
+        protected DataService DataService { get; }
+
+        [CommandOption("token", 't', IsRequired = true, Description = "Authorization token.")]
+        public string TokenValue { get; set; }
+
+        [CommandOption("bot", 'b', Description = "Whether this authorization token belongs to a bot.")]
+        public bool IsBotToken { get; set; }
+
+        protected TokenCommandBase(DataService dataService)
+        {
+            DataService = dataService;
+        }
+
+        protected AuthToken GetToken() => new AuthToken(IsBotToken ? AuthTokenType.Bot : AuthTokenType.User, TokenValue);
+
+        public abstract Task ExecuteAsync(IConsole console);
+    }
+}

DiscordChatExporter.Cli/Container.cs

@@ -1,26 +0,0 @@
-using CommonServiceLocator;
-using DiscordChatExporter.Core.Services;
-using GalaSoft.MvvmLight.Ioc;
-
-namespace DiscordChatExporter.Cli
-{
-    public class Container
-    {
-        public Container()
-        {
-            ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default);
-            SimpleIoc.Default.Reset();
-
-            // Services
-            SimpleIoc.Default.Register<IDataService, DataService>();
-            SimpleIoc.Default.Register<IExportService, ExportService>();
-            SimpleIoc.Default.Register<ISettingsService, SettingsService>();
-            SimpleIoc.Default.Register<IUpdateService, UpdateService>();
-        }
-
-        public T Resolve<T>(string key = null)
-        {
-            return ServiceLocator.Current.GetInstance<T>(key);
-        }
-    }
-}

DiscordChatExporter.Cli/DiscordChatExporter.Cli.csproj

@@ -1,23 +1,20 @@
 <Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="../DiscordChatExporter.props" />
 
-    <PropertyGroup>
-        <OutputType>Exe</OutputType>
-        <TargetFramework>net461</TargetFramework>
-        <Version>2.8</Version>
-        <Company>Tyrrrz</Company>
-        <Copyright>Copyright (c) 2017-2018 Alexey Golub</Copyright>
-        <ApplicationIcon>..\favicon.ico</ApplicationIcon>
-    </PropertyGroup>
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <ApplicationIcon>..\favicon.ico</ApplicationIcon>
+  </PropertyGroup>
 
-    <ItemGroup>
-        <PackageReference Include="CommandLineParser" Version="2.2.1" />
-        <PackageReference Include="CommonServiceLocator" Version="2.0.3" />
-        <PackageReference Include="MvvmLightLibs" Version="5.4.1" />
-        <PackageReference Include="Tyrrrz.Extensions" Version="1.5.1" />
-    </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="CliFx" Version="0.0.8" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="3.1.0" />
+    <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
+  </ItemGroup>
 
-    <ItemGroup>
-        <ProjectReference Include="..\DiscordChatExporter.Core\DiscordChatExporter.Core.csproj" />
-    </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\DiscordChatExporter.Core.Models\DiscordChatExporter.Core.Models.csproj" />
+    <ProjectReference Include="..\DiscordChatExporter.Core.Services\DiscordChatExporter.Core.Services.csproj" />
+  </ItemGroup>
 
 </Project>

DiscordChatExporter.Cli/Program.cs

@@ -1,71 +1,44 @@
 using System;
-using System.Linq;
-using CommandLine;
-using DiscordChatExporter.Cli.Verbs;
-using DiscordChatExporter.Cli.Verbs.Options;
+using System.Threading.Tasks;
+using CliFx;
+using DiscordChatExporter.Cli.Commands;
+using DiscordChatExporter.Core.Services;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace DiscordChatExporter.Cli
 {
     public static class Program
     {
-        private static void PrintTokenHelp()
+        private static IServiceProvider ConfigureServices()
         {
-            Console.WriteLine("# To get user token:");
-            Console.WriteLine(" 1. Open Discord app");
-            Console.WriteLine(" 2. Log in if you haven't");
-            Console.WriteLine(" 3. Press Ctrl+Shift+I to show developer tools");
-            Console.WriteLine(" 4. Press Ctrl+R to trigger reload");
-            Console.WriteLine(" 5. Navigate to the Application tab");
-            Console.WriteLine(" 6. Select \"Local Storage\" > \"https://discordapp.com\" on the left");
-            Console.WriteLine(" 7. Find \"token\" under key and copy the value");
-            Console.WriteLine();
-            Console.WriteLine("# To get bot token:");
-            Console.WriteLine(" 1. Go to Discord developer portal");
-            Console.WriteLine(" 2. Log in if you haven't");
-            Console.WriteLine(" 3. Open your application's settings");
-            Console.WriteLine(" 4. Navigate to the Bot section on the left");
-            Console.WriteLine(" 5. Under Token click Copy");
-            Console.WriteLine();
-            Console.WriteLine("# To get guild or channel ID:");
-            Console.WriteLine(" 1. Open Discord app");
-            Console.WriteLine(" 2. Log in if you haven't");
-            Console.WriteLine(" 3. Open Settings");
-            Console.WriteLine(" 4. Go to Appearance section");
-            Console.WriteLine(" 5. Enable Developer Mode");
-            Console.WriteLine(" 6. Right click on the desired guild or channel and click Copy ID");
+            var services = new ServiceCollection();
+
+            // Register services
+            services.AddSingleton<DataService>();
+            services.AddSingleton<ExportService>();
+            services.AddSingleton<SettingsService>();
+
+            // Register commands
+            services.AddTransient<ExportChannelCommand>();
+            services.AddTransient<ExportDirectMessagesCommand>();
+            services.AddTransient<ExportGuildCommand>();
+            services.AddTransient<GetChannelsCommand>();
+            services.AddTransient<GetDirectMessageChannelsCommand>();
+            services.AddTransient<GetGuildsCommand>();
+            services.AddTransient<GuideCommand>();
+
+            return services.BuildServiceProvider();
         }
 
-        public static void Main(string[] args)
+        public static Task<int> Main(string[] args)
         {
-            // Get all verb types
-            var verbTypes = new[]
-            {
-                typeof(ExportChatOptions),
-                typeof(GetChannelsOptions),
-                typeof(GetDirectMessageChannelsOptions),
-                typeof(GetGuildsOptions)
-            };
+            var serviceProvider = ConfigureServices();
 
-            // Parse command line arguments
-            var parsedArgs = Parser.Default.ParseArguments(args, verbTypes);
-
-            // Execute commands
-            parsedArgs.WithParsed<ExportChatOptions>(o => new ExportChatVerb(o).Execute());
-            parsedArgs.WithParsed<GetChannelsOptions>(o => new GetChannelsVerb(o).Execute());
-            parsedArgs.WithParsed<GetDirectMessageChannelsOptions>(o => new GetDirectMessageChannelsVerb(o).Execute());
-            parsedArgs.WithParsed<GetGuildsOptions>(o => new GetGuildsVerb(o).Execute());
-
-            // Show token help if help requested or no verb specified
-            parsedArgs.WithNotParsed(errs =>
-            {
-                var err = errs.First();
-
-                if (err.Tag == ErrorType.NoVerbSelectedError)
-                    PrintTokenHelp();
-
-                if (err.Tag == ErrorType.HelpVerbRequestedError && args.Length == 1)
-                    PrintTokenHelp();
-            });
+            return new CliApplicationBuilder()
+                .AddCommandsFromThisAssembly()
+                .UseCommandFactory(schema => (ICommand) serviceProvider.GetService(schema.Type))
+                .Build()
+                .RunAsync(args);
         }
     }
 }

DiscordChatExporter.Cli/Verbs/ExportChatVerb.cs

@@ -1,51 +0,0 @@
-using System;
-using System.IO;
-using System.Threading.Tasks;
-using DiscordChatExporter.Cli.Verbs.Options;
-using DiscordChatExporter.Core.Models;
-using DiscordChatExporter.Core.Services;
-using Tyrrrz.Extensions;
-
-namespace DiscordChatExporter.Cli.Verbs
-{
-    public class ExportChatVerb : Verb<ExportChatOptions>
-    {
-        public ExportChatVerb(ExportChatOptions options)
-            : base(options)
-        {
-        }
-
-        public override async Task ExecuteAsync()
-        {
-            // Get services
-            var container = new Container();
-            var settingsService = container.Resolve<ISettingsService>();
-            var dataService = container.Resolve<IDataService>();
-            var exportService = container.Resolve<IExportService>();
-
-            // Configure settings
-            if (Options.DateFormat.IsNotBlank())
-                settingsService.DateFormat = Options.DateFormat;
-            if (Options.MessageGroupLimit > 0)
-                settingsService.MessageGroupLimit = Options.MessageGroupLimit;
-
-            // Get chat log
-            var chatLog = await dataService.GetChatLogAsync(Options.GetToken(), Options.ChannelId, 
-                Options.After, Options.Before);
-
-            // Generate file path if not set
-            var filePath = Options.FilePath;
-            if (filePath == null || filePath.EndsWith("/") || filePath.EndsWith("\\"))
-            {
-                filePath += $"{chatLog.Guild.Name} - {chatLog.Channel.Name}.{Options.ExportFormat.GetFileExtension()}"
-                    .Replace(Path.GetInvalidFileNameChars(), '_');
-            }
-
-            // Export
-            exportService.ExportChatLog(chatLog, filePath, Options.ExportFormat, Options.PartitionLimit);
-
-            // Print result
-            Console.WriteLine($"Exported chat to [{filePath}]");
-        }
-    }
-}

DiscordChatExporter.Cli/Verbs/GetChannelsVerb.cs

@@ -1,33 +0,0 @@
-using System;
-using System.Linq;
-using System.Threading.Tasks;
-using DiscordChatExporter.Cli.Verbs.Options;
-using DiscordChatExporter.Core.Models;
-using DiscordChatExporter.Core.Services;
-using Tyrrrz.Extensions;
-
-namespace DiscordChatExporter.Cli.Verbs
-{
-    public class GetChannelsVerb : Verb<GetChannelsOptions>
-    {
-        public GetChannelsVerb(GetChannelsOptions options)
-            : base(options)
-        {
-        }
-
-        public override async Task ExecuteAsync()
-        {
-            // Get data service
-            var container = new Container();
-            var dataService = container.Resolve<IDataService>();
-
-            // Get channels
-            var channels = await dataService.GetGuildChannelsAsync(Options.GetToken(), Options.GuildId);
-
-            // Print result
-            foreach (var channel in channels.Where(c => c.Type.IsEither(ChannelType.GuildTextChat))
-                .OrderBy(c => c.Name))
-                Console.WriteLine($"{channel.Id} | {channel.Name}");
-        }
-    }
-}

DiscordChatExporter.Cli/Verbs/GetDirectMessageChannelsVerb.cs

@@ -1,30 +0,0 @@
-using System;
-using System.Linq;
-using System.Threading.Tasks;
-using DiscordChatExporter.Cli.Verbs.Options;
-using DiscordChatExporter.Core.Services;
-
-namespace DiscordChatExporter.Cli.Verbs
-{
-    public class GetDirectMessageChannelsVerb : Verb<GetDirectMessageChannelsOptions>
-    {
-        public GetDirectMessageChannelsVerb(GetDirectMessageChannelsOptions options) 
-            : base(options)
-        {
-        }
-
-        public override async Task ExecuteAsync()
-        {
-            // Get data service
-            var container = new Container();
-            var dataService = container.Resolve<IDataService>();
-
-            // Get channels
-            var channels = await dataService.GetDirectMessageChannelsAsync(Options.GetToken());
-
-            // Print result
-            foreach (var channel in channels.OrderBy(c => c.Name))
-                Console.WriteLine($"{channel.Id} | {channel.Name}");
-        }
-    }
-}

DiscordChatExporter.Cli/Verbs/GetGuildsVerb.cs

@@ -1,30 +0,0 @@
-using System;
-using System.Linq;
-using System.Threading.Tasks;
-using DiscordChatExporter.Cli.Verbs.Options;
-using DiscordChatExporter.Core.Services;
-
-namespace DiscordChatExporter.Cli.Verbs
-{
-    public class GetGuildsVerb : Verb<GetGuildsOptions>
-    {
-        public GetGuildsVerb(GetGuildsOptions options) 
-            : base(options)
-        {
-        }
-
-        public override async Task ExecuteAsync()
-        {
-            // Get data service
-            var container = new Container();
-            var dataService = container.Resolve<IDataService>();
-
-            // Get guilds
-            var guilds = await dataService.GetUserGuildsAsync(Options.GetToken());
-
-            // Print result
-            foreach (var guild in guilds.OrderBy(g => g.Name))
-                Console.WriteLine($"{guild.Id} | {guild.Name}");
-        }
-    }
-}

DiscordChatExporter.Cli/Verbs/Options/ExportChatOptions.cs

@@ -1,34 +0,0 @@
-using System;
-using CommandLine;
-using DiscordChatExporter.Core.Models;
-
-namespace DiscordChatExporter.Cli.Verbs.Options
-{
-    [Verb("export", HelpText = "Export channel chat log to a file.")]
-    public class ExportChatOptions : TokenOptions
-    {
-        [Option('c', "channel", Required = true, HelpText = "Channel ID.")]
-        public string ChannelId { get; set; }
-
-        [Option('f', "format", Default = ExportFormat.HtmlDark, HelpText = "Output file format.")]
-        public ExportFormat ExportFormat { get; set; }
-
-        [Option('o', "output", Default = null, HelpText = "Output file path.")]
-        public string FilePath { get; set; }
-
-        [Option("after", Default = null, HelpText = "Limit to messages sent after this date.")]
-        public DateTime? After { get; set; }
-
-        [Option("before", Default = null, HelpText = "Limit to messages sent before this date.")]
-        public DateTime? Before { get; set; }
-
-        [Option('p', "partition", Default = null, HelpText = "Split output into partitions limited to this number of messages.")]
-        public int? PartitionLimit { get; set; }
-
-        [Option("dateformat", Default = null, HelpText = "Date format used in output.")]
-        public string DateFormat { get; set; }
-
-        [Option("grouplimit", Default = 0, HelpText = "Message group limit.")]
-        public int MessageGroupLimit { get; set; }
-    }
-}

DiscordChatExporter.Cli/Verbs/Options/GetChannelsOptions.cs

@@ -1,11 +0,0 @@
-using CommandLine;
-
-namespace DiscordChatExporter.Cli.Verbs.Options
-{
-    [Verb("channels", HelpText = "Get the list of channels in the given guild.")]
-    public class GetChannelsOptions : TokenOptions
-    {
-        [Option('g', "guild", Required = true, HelpText = "Guild ID.")]
-        public string GuildId { get; set; }
-    }
-}

DiscordChatExporter.Cli/Verbs/Options/GetDirectMessageChannelsOptions.cs

@@ -1,9 +0,0 @@
-using CommandLine;
-
-namespace DiscordChatExporter.Cli.Verbs.Options
-{
-    [Verb("dm", HelpText = "Get the list of direct message channels.")]
-    public class GetDirectMessageChannelsOptions : TokenOptions
-    {
-    }
-}

DiscordChatExporter.Cli/Verbs/Options/GetGuildsOptions.cs

@@ -1,9 +0,0 @@
-using CommandLine;
-
-namespace DiscordChatExporter.Cli.Verbs.Options
-{
-    [Verb("guilds", HelpText = "Get the list of accessible guilds.")]
-    public class GetGuildsOptions : TokenOptions
-    {
-    }
-}

DiscordChatExporter.Cli/Verbs/Options/TokenOptions.cs

@@ -1,16 +0,0 @@
-using CommandLine;
-using DiscordChatExporter.Core.Models;
-
-namespace DiscordChatExporter.Cli.Verbs.Options
-{
-    public class TokenOptions
-    {
-        [Option('t', "token", Required = true, HelpText = "Authorization token.")]
-        public string TokenValue { get; set; }
-
-        [Option('b', "bot", Default = false, HelpText = "Whether this authorization token belongs to a bot.")]
-        public bool IsBotToken { get; set; }
-
-        public AuthToken GetToken() => new AuthToken(IsBotToken ? AuthTokenType.Bot : AuthTokenType.User, TokenValue);
-    }
-}

DiscordChatExporter.Cli/Verbs/Verb.cs

@@ -1,18 +0,0 @@
-using System.Threading.Tasks;
-
-namespace DiscordChatExporter.Cli.Verbs
-{
-    public abstract class Verb<TOptions>
-    {
-        protected TOptions Options { get; }
-
-        protected Verb(TOptions options)
-        {
-            Options = options;
-        }
-
-        public abstract Task ExecuteAsync();
-
-        public virtual void Execute() => ExecuteAsync().GetAwaiter().GetResult();
-    }
-}

DiscordChatExporter.Core.Markdown/Ast/EmojiNode.cs

@@ -0,0 +1,27 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class EmojiNode : Node
+    {
+        public string? Id { get; }
+
+        public string Name { get; }
+
+        public bool IsAnimated { get; }
+
+        public bool IsCustomEmoji => !string.IsNullOrWhiteSpace(Id);
+
+        public EmojiNode(string? id, string name, bool isAnimated)
+        {
+            Id = id;
+            Name = name;
+            IsAnimated = isAnimated;
+        }
+
+        public EmojiNode(string name)
+            : this(null, name, false)
+        {
+        }
+
+        public override string ToString() => $"<Emoji> {Name}";
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/FormattedNode.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class FormattedNode : Node
+    {
+        public TextFormatting Formatting { get; }
+
+        public IReadOnlyList<Node> Children { get; }
+
+        public FormattedNode(TextFormatting formatting, IReadOnlyList<Node> children)
+        {
+            Formatting = formatting;
+            Children = children;
+        }
+
+        public override string ToString() => $"<{Formatting}> ({Children.Count} direct children)";
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/InlineCodeBlockNode.cs

@@ -0,0 +1,14 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class InlineCodeBlockNode : Node
+    {
+        public string Code { get; }
+
+        public InlineCodeBlockNode(string code)
+        {
+            Code = code;
+        }
+
+        public override string ToString() => $"<Code> {Code}";
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/LinkNode.cs

@@ -0,0 +1,22 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class LinkNode : Node
+    {
+        public string Url { get; }
+
+        public string Title { get; }
+
+        public LinkNode(string url, string title)
+        {
+            Url = url;
+            Title = title;
+        }
+
+        public LinkNode(string url)
+            : this(url, url)
+        {
+        }
+
+        public override string ToString() => $"<Link> {Title}";
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/MentionNode.cs

@@ -0,0 +1,17 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class MentionNode : Node
+    {
+        public string Id { get; }
+
+        public MentionType Type { get; }
+
+        public MentionNode(string id, MentionType type)
+        {
+            Id = id;
+            Type = type;
+        }
+
+        public override string ToString() => $"<{Type} mention> {Id}";
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/MentionType.cs

@@ -0,0 +1,10 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public enum MentionType
+    {
+        Meta,
+        User,
+        Channel,
+        Role
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/MultiLineCodeBlockNode.cs

@@ -0,0 +1,17 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class MultiLineCodeBlockNode : Node
+    {
+        public string Language { get; }
+
+        public string Code { get; }
+
+        public MultiLineCodeBlockNode(string language, string code)
+        {
+            Language = language;
+            Code = code;
+        }
+
+        public override string ToString() => $"<Code [{Language}]> {Code}";
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/Node.cs

@@ -0,0 +1,6 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public abstract class Node
+    {
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/TextFormatting.cs

@@ -0,0 +1,12 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public enum TextFormatting
+    {
+        Bold,
+        Italic,
+        Underline,
+        Strikethrough,
+        Spoiler,
+        Quote
+    }
+}

DiscordChatExporter.Core.Markdown/Ast/TextNode.cs

@@ -0,0 +1,14 @@
+namespace DiscordChatExporter.Core.Markdown.Ast
+{
+    public class TextNode : Node
+    {
+        public string Text { get; }
+
+        public TextNode(string text)
+        {
+            Text = text;
+        }
+
+        public override string ToString() => Text;
+    }
+}

DiscordChatExporter.Core.Markdown/DiscordChatExporter.Core.Markdown.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="../DiscordChatExporter.props" />
+
+  <ItemGroup>
+    <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
+  </ItemGroup>
+
+</Project>

DiscordChatExporter.Core.Markdown/Internal/AggregateMatcher.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal class AggregateMatcher<T> : IMatcher<T>
+    {
+        private readonly IReadOnlyList<IMatcher<T>> _matchers;
+
+        public AggregateMatcher(IReadOnlyList<IMatcher<T>> matchers)
+        {
+            _matchers = matchers;
+        }
+
+        public AggregateMatcher(params IMatcher<T>[] matchers)
+            : this((IReadOnlyList<IMatcher<T>>)matchers)
+        {
+        }
+
+        public ParsedMatch<T>? Match(StringPart stringPart)
+        {
+            ParsedMatch<T>? earliestMatch = null;
+
+            // Try to match the input with each matcher and get the match with the lowest start index
+            foreach (var matcher in _matchers)
+            {
+                // Try to match
+                var match = matcher.Match(stringPart);
+
+                // If there's no match - continue
+                if (match == null)
+                    continue;
+
+                // If this match is earlier than previous earliest - replace
+                if (earliestMatch == null || match.StringPart.StartIndex < earliestMatch.StringPart.StartIndex)
+                    earliestMatch = match;
+
+                // If the earliest match starts at the very beginning - break,
+                // because it's impossible to find a match earlier than that
+                if (earliestMatch.StringPart.StartIndex == stringPart.StartIndex)
+                    break;
+            }
+
+            return earliestMatch;
+        }
+    }
+}

DiscordChatExporter.Core.Markdown/Internal/Extensions.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal static class Extensions
+    {
+        public static IEnumerable<ParsedMatch<T>> MatchAll<T>(this IMatcher<T> matcher, StringPart stringPart,
+            Func<StringPart, T> fallbackTransform)
+        {
+            // Loop through segments divided by individual matches
+            var currentIndex = stringPart.StartIndex;
+            while (currentIndex < stringPart.EndIndex)
+            {
+                // Find a match within this segment
+                var match = matcher.Match(stringPart.Slice(currentIndex, stringPart.EndIndex - currentIndex));
+
+                // If there's no match - break
+                if (match == null)
+                    break;
+
+                // If this match doesn't start immediately at current index - transform and yield fallback first
+                if (match.StringPart.StartIndex > currentIndex)
+                {
+                    var fallbackPart = stringPart.Slice(currentIndex, match.StringPart.StartIndex - currentIndex);
+                    yield return new ParsedMatch<T>(fallbackPart, fallbackTransform(fallbackPart));
+                }
+
+                // Yield match
+                yield return match;
+
+                // Shift current index to the end of the match
+                currentIndex = match.StringPart.StartIndex + match.StringPart.Length;
+            }
+
+            // If EOL wasn't reached - transform and yield remaining part as fallback
+            if (currentIndex < stringPart.EndIndex)
+            {
+                var fallbackPart = stringPart.Slice(currentIndex);
+                yield return new ParsedMatch<T>(fallbackPart, fallbackTransform(fallbackPart));
+            }
+        }
+    }
+}

DiscordChatExporter.Core.Markdown/Internal/IMatcher.cs

@@ -0,0 +1,7 @@
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal interface IMatcher<T>
+    {
+        ParsedMatch<T>? Match(StringPart stringPart);
+    }
+}

DiscordChatExporter.Core.Markdown/Internal/ParsedMatch.cs

@@ -0,0 +1,15 @@
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal class ParsedMatch<T>
+    {
+        public StringPart StringPart { get; }
+
+        public T Value { get; }
+
+        public ParsedMatch(StringPart stringPart, T value)
+        {
+            StringPart = stringPart;
+            Value = value;
+        }
+    }
+}

DiscordChatExporter.Core.Markdown/Internal/RegexMatcher.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal class RegexMatcher<T> : IMatcher<T>
+    {
+        private readonly Regex _regex;
+        private readonly Func<StringPart, Match, T> _transform;
+
+        public RegexMatcher(Regex regex, Func<StringPart, Match, T> transform)
+        {
+            _regex = regex;
+            _transform = transform;
+        }
+
+        public RegexMatcher(Regex regex, Func<Match, T> transform)
+            : this(regex, (p, m) => transform(m))
+        {
+        }
+
+        public ParsedMatch<T>? Match(StringPart stringPart)
+        {
+            var match = _regex.Match(stringPart.Target, stringPart.StartIndex, stringPart.Length);
+            if (!match.Success)
+                return null;
+
+            // Overload regex.Match(string, int, int) doesn't take the whole string into account,
+            // it effectively functions as a match check on a substring.
+            // Which is super weird because regex.Match(string, int) takes the whole input in context.
+            // So in order to properly account for ^/$ regex tokens, we need to make sure that
+            // the expression also matches on the bigger part of the input.
+            if (!_regex.IsMatch(stringPart.Target.Substring(0, stringPart.EndIndex), stringPart.StartIndex))
+                return null;
+
+            var stringPartMatch = stringPart.Slice(match.Index, match.Length);
+            return new ParsedMatch<T>(stringPartMatch, _transform(stringPartMatch, match));
+        }
+    }
+}

DiscordChatExporter.Core.Markdown/Internal/StringMatcher.cs

@@ -0,0 +1,36 @@
+using System;
+
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal class StringMatcher<T> : IMatcher<T>
+    {
+        private readonly string _needle;
+        private readonly StringComparison _comparison;
+        private readonly Func<StringPart, T> _transform;
+
+        public StringMatcher(string needle, StringComparison comparison, Func<StringPart, T> transform)
+        {
+            _needle = needle;
+            _comparison = comparison;
+            _transform = transform;
+        }
+
+        public StringMatcher(string needle, Func<StringPart, T> transform)
+            : this(needle, StringComparison.Ordinal, transform)
+        {
+        }
+
+        public ParsedMatch<T>? Match(StringPart stringPart)
+        {
+            var index = stringPart.Target.IndexOf(_needle, stringPart.StartIndex, stringPart.Length, _comparison);
+
+            if (index >= 0)
+            {
+                var stringPartMatch = stringPart.Slice(index, _needle.Length);
+                return new ParsedMatch<T>(stringPartMatch, _transform(stringPartMatch));
+            }
+
+            return null;
+        }
+    }
+}

DiscordChatExporter.Core.Markdown/Internal/StringPart.cs

@@ -0,0 +1,36 @@
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Markdown.Internal
+{
+    internal readonly struct StringPart
+    {
+        public string Target { get; }
+
+        public int StartIndex { get; }
+
+        public int Length { get; }
+
+        public int EndIndex { get; }
+
+        public StringPart(string target, int startIndex, int length)
+        {
+            Target = target;
+            StartIndex = startIndex;
+            Length = length;
+            EndIndex = startIndex + length;
+        }
+
+        public StringPart(string target)
+            : this(target, 0, target.Length)
+        {
+        }
+
+        public StringPart Slice(int newStartIndex, int newLength) => new StringPart(Target, newStartIndex, newLength);
+
+        public StringPart Slice(int newStartIndex) => Slice(newStartIndex, EndIndex - newStartIndex);
+
+        public StringPart Slice(Capture capture) => Slice(capture.Index, capture.Length);
+
+        public override string ToString() => Target.Substring(StartIndex, Length);
+    }
+}

DiscordChatExporter.Core.Markdown/MarkdownParser.cs

@@ -0,0 +1,236 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using DiscordChatExporter.Core.Markdown.Ast;
+using DiscordChatExporter.Core.Markdown.Internal;
+
+namespace DiscordChatExporter.Core.Markdown
+{
+    // The following parsing logic is meant to replicate Discord's markdown grammar as close as possible
+    public static class MarkdownParser
+    {
+        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<Node> BoldFormattedNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\*\\*(.+?)\\*\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
+            (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<Node> ItalicFormattedNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\*(?!\\s)(.+?)(?<!\\s|\\*)\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
+            (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<Node> ItalicBoldFormattedNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\*(\\*\\*.+?\\*\\*)\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
+            (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<Node> ItalicAltFormattedNodeMatcher = new RegexMatcher<Node>(
+            new Regex("_([^_]+)_(?!\\w)", DefaultRegexOptions | RegexOptions.Singleline),
+            (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<Node> UnderlineFormattedNodeMatcher = new RegexMatcher<Node>(
+            new Regex("__(.+?)__(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
+            (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<Node> ItalicUnderlineFormattedNodeMatcher = new RegexMatcher<Node>(
+            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<Node> StrikethroughFormattedNodeMatcher = new RegexMatcher<Node>(
+            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<Node> SpoilerFormattedNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\|\\|(.+?)\\|\\|", DefaultRegexOptions | RegexOptions.Singleline),
+            (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<Node> SingleLineQuoteNodeMatcher = new RegexMatcher<Node>(
+            new Regex("^>\\s(.+)\r?\n?", DefaultRegexOptions),
+            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1]))));
+
+        // Capture any character until the end of the input
+        // Opening 'greater than' characters must be followed by whitespace
+        private static readonly IMatcher<Node> MultiLineQuoteNodeMatcher = new RegexMatcher<Node>(
+            new Regex("^>>>\\s(.+)", DefaultRegexOptions | RegexOptions.Singleline),
+            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1]))));
+
+        /* Code blocks */
+
+        // Capture any character except backtick until a backtick
+        // Blank lines at the beginning and end of content are trimmed
+        private static readonly IMatcher<Node> InlineCodeBlockNodeMatcher = new RegexMatcher<Node>(
+            new Regex("`([^`]+)`", DefaultRegexOptions | RegexOptions.Singleline),
+            m => new InlineCodeBlockNode(m.Groups[1].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<Node> MultiLineCodeBlockNodeMatcher = new RegexMatcher<Node>(
+            new Regex("```(?:(\\w*)\\n)?(.+?)```", DefaultRegexOptions | RegexOptions.Singleline),
+            m => new MultiLineCodeBlockNode(m.Groups[1].Value, m.Groups[2].Value.Trim('\r', '\n')));
+
+        /* Mentions */
+
+        // Capture @everyone
+        private static readonly IMatcher<Node> EveryoneMentionNodeMatcher = new StringMatcher<Node>(
+            "@everyone",
+            p => new MentionNode("everyone", MentionType.Meta));
+
+        // Capture @here
+        private static readonly IMatcher<Node> HereMentionNodeMatcher = new StringMatcher<Node>(
+            "@here",
+            p => new MentionNode("here", MentionType.Meta));
+
+        // Capture <@123456> or <@!123456>
+        private static readonly IMatcher<Node> UserMentionNodeMatcher = new RegexMatcher<Node>(
+            new Regex("<@!?(\\d+)>", DefaultRegexOptions),
+            m => new MentionNode(m.Groups[1].Value, MentionType.User));
+
+        // Capture <#123456>
+        private static readonly IMatcher<Node> ChannelMentionNodeMatcher = new RegexMatcher<Node>(
+            new Regex("<#(\\d+)>", DefaultRegexOptions),
+            m => new MentionNode(m.Groups[1].Value, MentionType.Channel));
+
+        // Capture <@&123456>
+        private static readonly IMatcher<Node> RoleMentionNodeMatcher = new RegexMatcher<Node>(
+            new Regex("<@&(\\d+)>", DefaultRegexOptions),
+            m => new MentionNode(m.Groups[1].Value, MentionType.Role));
+
+        /* Emojis */
+
+        // Capture any country flag emoji (two regional indicator surrogate pairs)
+        // ... or "miscellaneous symbol" character
+        // ... or surrogate pair
+        // ... or digit followed by enclosing mark
+        // (this does not match all emojis in Discord but it's reasonably accurate enough)
+        private static readonly IMatcher<Node> StandardEmojiNodeMatcher = new RegexMatcher<Node>(
+            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<Node> CustomEmojiNodeMatcher = new RegexMatcher<Node>(
+            new Regex("<(a)?:(.+?):(\\d+?)>", DefaultRegexOptions),
+            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<Node> TitledLinkNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\[(.+?)\\]\\((.+?)\\)", DefaultRegexOptions),
+            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<Node> AutoLinkNodeMatcher = new RegexMatcher<Node>(
+            new Regex("(https?://\\S*[^\\.,:;\"\'\\s])", DefaultRegexOptions),
+            m => new LinkNode(m.Groups[1].Value));
+
+        // Same as auto link but also surrounded by angular brackets
+        private static readonly IMatcher<Node> HiddenLinkNodeMatcher = new RegexMatcher<Node>(
+            new Regex("<(https?://\\S*[^\\.,:;\"\'\\s])>", DefaultRegexOptions),
+            m => new LinkNode(m.Groups[1].Value));
+
+        /* Text */
+
+        // Capture the shrug emoticon
+        // This escapes it from matching for formatting
+        private static readonly IMatcher<Node> ShrugTextNodeMatcher = new StringMatcher<Node>(
+            @"¯\_(ツ)_/¯",
+            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<Node> IgnoredEmojiTextNodeMatcher = new RegexMatcher<Node>(
+            new Regex("(\\u26A7|\\u2640|\\u2642|\\u2695|\\u267E|\\u00A9|\\u00AE|\\u2122)", DefaultRegexOptions),
+            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<Node> EscapedSymbolTextNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\\\(\\p{So}|\\p{Cs}{2})", DefaultRegexOptions),
+            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<Node> EscapedCharacterTextNodeMatcher = new RegexMatcher<Node>(
+            new Regex("\\\\([^a-zA-Z0-9\\s])", DefaultRegexOptions),
+            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
+        private static readonly IMatcher<Node> AggregateNodeMatcher = new AggregateMatcher<Node>(
+            // Escaped text
+            ShrugTextNodeMatcher,
+            IgnoredEmojiTextNodeMatcher,
+            EscapedSymbolTextNodeMatcher,
+            EscapedCharacterTextNodeMatcher,
+
+            // Formatting
+            ItalicBoldFormattedNodeMatcher,
+            ItalicUnderlineFormattedNodeMatcher,
+            BoldFormattedNodeMatcher,
+            ItalicFormattedNodeMatcher,
+            UnderlineFormattedNodeMatcher,
+            ItalicAltFormattedNodeMatcher,
+            StrikethroughFormattedNodeMatcher,
+            SpoilerFormattedNodeMatcher,
+            MultiLineQuoteNodeMatcher,
+            SingleLineQuoteNodeMatcher,
+
+            // Code blocks
+            MultiLineCodeBlockNodeMatcher,
+            InlineCodeBlockNodeMatcher,
+
+            // Mentions
+            EveryoneMentionNodeMatcher,
+            HereMentionNodeMatcher,
+            UserMentionNodeMatcher,
+            ChannelMentionNodeMatcher,
+            RoleMentionNodeMatcher,
+
+            // Links
+            TitledLinkNodeMatcher,
+            AutoLinkNodeMatcher,
+            HiddenLinkNodeMatcher,
+
+            // Emoji
+            StandardEmojiNodeMatcher,
+            CustomEmojiNodeMatcher);
+
+        // Minimal set of matchers for non-multimedia formats (e.g. plain text)
+        private static readonly IMatcher<Node> MinimalAggregateNodeMatcher = new AggregateMatcher<Node>(
+            // Mentions
+            EveryoneMentionNodeMatcher,
+            HereMentionNodeMatcher,
+            UserMentionNodeMatcher,
+            ChannelMentionNodeMatcher,
+            RoleMentionNodeMatcher,
+
+            // Emoji
+            CustomEmojiNodeMatcher);
+
+        private static IReadOnlyList<Node> Parse(StringPart stringPart, IMatcher<Node> matcher) =>
+            matcher.MatchAll(stringPart, p => new TextNode(p.ToString())).Select(r => r.Value).ToArray();
+
+        private static IReadOnlyList<Node> Parse(StringPart stringPart) => Parse(stringPart, AggregateNodeMatcher);
+
+        private static IReadOnlyList<Node> ParseMinimal(StringPart stringPart) => Parse(stringPart, MinimalAggregateNodeMatcher);
+
+        public static IReadOnlyList<Node> Parse(string input) => Parse(new StringPart(input));
+
+        public static IReadOnlyList<Node> ParseMinimal(string input) => ParseMinimal(new StringPart(input));
+    }
+}

DiscordChatExporter.Core.Models/Attachment.cs

@@ -0,0 +1,50 @@
+using System;
+using System.IO;
+using System.Linq;
+
+namespace DiscordChatExporter.Core.Models
+{
+    // https://discordapp.com/developers/docs/resources/channel#attachment-object
+
+    public partial class Attachment : IHasId
+    {
+        public string Id { get; }
+
+        public string Url { get; }
+
+        public int? Width { get; }
+
+        public int? Height { get; }
+
+        public string FileName { get; }
+
+        public bool IsImage { get; }
+
+        public FileSize FileSize { get; }
+
+        public Attachment(string id, int? width, int? height, string url, string fileName, FileSize fileSize)
+        {
+            Id = id;
+            Url = url;
+            Width = width;
+            Height = height;
+            FileName = fileName;
+            FileSize = fileSize;
+
+            IsImage = GetIsImage(fileName);
+        }
+
+        public override string ToString() => FileName;
+    }
+
+    public partial class Attachment
+    {
+        private static readonly string[] ImageFileExtensions = { ".jpg", ".jpeg", ".png", ".gif", ".bmp" };
+
+        public static bool GetIsImage(string fileName)
+        {
+            var fileExtension = Path.GetExtension(fileName);
+            return ImageFileExtensions.Contains(fileExtension, StringComparer.OrdinalIgnoreCase);
+        }
+    }
+}

DiscordChatExporter.Core.Models/Channel.cs

@@ -2,21 +2,24 @@
 {
     // https://discordapp.com/developers/docs/resources/channel#channel-object
 
-    public partial class Channel
+    public partial class Channel : IHasId
     {
         public string Id { get; }
 
+        public string? ParentId { get; }
+
         public string GuildId { get; }
 
         public string Name { get; }
 
-        public string Topic { get; }
+        public string? Topic { get; }
 
         public ChannelType Type { get; }
 
-        public Channel(string id, string guildId, string name, string topic, ChannelType type)
+        public Channel(string id, string? parentId, string guildId, string name, string? topic, ChannelType type)
         {
             Id = id;
+            ParentId = parentId;
             GuildId = guildId;
             Name = name;
             Topic = topic;
@@ -29,6 +32,6 @@
     public partial class Channel
     {
         public static Channel CreateDeletedChannel(string id) =>
-            new Channel(id, null, "deleted-channel", null, ChannelType.GuildTextChat);
+            new Channel(id, null, "unknown-guild", "deleted-channel", null, ChannelType.GuildTextChat);
     }
 }

DiscordChatExporter.Core.Models/ChannelType.cs

@@ -1,6 +1,7 @@
 namespace DiscordChatExporter.Core.Models
 {
     // https://discordapp.com/developers/docs/resources/channel#channel-object-channel-types
+    // Order of enum fields needs to match the order in the docs.
 
     public enum ChannelType
     {
@@ -8,6 +9,8 @@
         DirectTextChat,
         GuildVoiceChat,
         DirectGroupTextChat,
-        Category
+        GuildCategory,
+        GuildNews,
+        GuildStore
     }
 }

DiscordChatExporter.Core.Models/DiscordChatExporter.Core.Models.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="../DiscordChatExporter.props" />
+
+  <ItemGroup>
+    <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
+  </ItemGroup>
+
+</Project>

DiscordChatExporter.Core.Models/Embed.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+
+namespace DiscordChatExporter.Core.Models
+{
+    // https://discordapp.com/developers/docs/resources/channel#embed-object
+
+    public class Embed
+    {
+        public string? Title { get; }
+
+        public string? Url { get; }
+
+        public DateTimeOffset? Timestamp { get; }
+
+        public Color? Color { get; }
+
+        public EmbedAuthor? Author { get; }
+
+        public string? Description { get; }
+
+        public IReadOnlyList<EmbedField> Fields { get; }
+
+        public EmbedImage? Thumbnail { get; }
+
+        public EmbedImage? Image { get; }
+
+        public EmbedFooter? Footer { get; }
+
+        public Embed(string? title, string? url, DateTimeOffset? timestamp, Color? color, EmbedAuthor? author, string? description,
+            IReadOnlyList<EmbedField> fields, EmbedImage? thumbnail, EmbedImage? image, EmbedFooter? footer)
+        {
+            Title = title;
+            Url = url;
+            Timestamp = timestamp;
+            Color = color;
+            Author = author;
+            Description = description;
+            Fields = fields;
+            Thumbnail = thumbnail;
+            Image = image;
+            Footer = footer;
+        }
+
+        public override string ToString() => Title ?? "<untitled embed>";
+    }
+}

DiscordChatExporter.Core.Models/EmbedAuthor.cs

@@ -4,19 +4,19 @@ namespace DiscordChatExporter.Core.Models
 
     public class EmbedAuthor
     {
-        public string Name { get; }
+        public string? Name { get; }
 
-        public string Url { get; }
+        public string? Url { get; }
 
-        public string IconUrl { get; }
+        public string? IconUrl { get; }
 
-        public EmbedAuthor(string name, string url, string iconUrl)
+        public EmbedAuthor(string? name, string? url, string? iconUrl)
         {
             Name = name;
             Url = url;
             IconUrl = iconUrl;
         }
 
-        public override string ToString() => Name;
+        public override string ToString() => Name ?? "<unnamed author>";
     }
 }

DiscordChatExporter.Core.Models/EmbedFooter.cs

@@ -6,9 +6,9 @@ namespace DiscordChatExporter.Core.Models
     {
         public string Text { get; }
 
-        public string IconUrl { get; }
+        public string? IconUrl { get; }
 
-        public EmbedFooter(string text, string iconUrl)
+        public EmbedFooter(string text, string? iconUrl)
         {
             Text = text;
             IconUrl = iconUrl;

DiscordChatExporter.Core.Models/EmbedImage.cs

@@ -4,13 +4,13 @@ namespace DiscordChatExporter.Core.Models
 
     public class EmbedImage
     {
-        public string Url { get; }
+        public string? Url { get; }
 
         public int? Width { get; }
 
         public int? Height { get; }
 
-        public EmbedImage(string url, int? width, int? height)
+        public EmbedImage(string? url, int? width, int? height)
         {
             Url = url;
             Height = height;

DiscordChatExporter.Core.Models/Emoji.cs

@@ -0,0 +1,74 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Tyrrrz.Extensions;
+
+namespace DiscordChatExporter.Core.Models
+{
+    // https://discordapp.com/developers/docs/resources/emoji#emoji-object
+
+    public partial class Emoji
+    {
+        public string? Id { get; }
+
+        public string Name { get; }
+
+        public bool IsAnimated { get; }
+
+        public string ImageUrl { get; }
+
+        public Emoji(string? id, string name, bool isAnimated)
+        {
+            Id = id;
+            Name = name;
+            IsAnimated = isAnimated;
+
+            ImageUrl = GetImageUrl(id, name, isAnimated);
+        }
+    }
+
+    public partial class Emoji
+    {
+        private static IEnumerable<Rune> GetRunes(string emoji)
+        {
+            var lastIndex = 0;
+            while (lastIndex < emoji.Length && Rune.TryGetRuneAt(emoji, lastIndex, out var rune))
+            {
+                // Skip variant selector rune
+                if (rune.Value != 0xfe0f)
+                    yield return rune;
+
+                lastIndex += rune.Utf16SequenceLength;
+            }
+        }
+
+        private static string GetTwemojiName(IEnumerable<Rune> runes) =>
+            runes.Select(r => r.Value.ToString("x")).JoinToString("-");
+
+        public static string GetImageUrl(string? id, string name, bool isAnimated)
+        {
+            // Custom emoji
+            if (!string.IsNullOrWhiteSpace(id))
+            {
+                // Animated
+                if (isAnimated)
+                    return $"https://cdn.discordapp.com/emojis/{id}.gif";
+
+                // Non-animated
+                return $"https://cdn.discordapp.com/emojis/{id}.png";
+            }
+
+            // Standard unicode emoji
+            var emojiRunes = GetRunes(name).ToArray();
+            if (emojiRunes.Any())
+            {
+                // Get corresponding Twemoji image
+                var twemojiName = GetTwemojiName(emojiRunes);
+                return $"https://twemoji.maxcdn.com/2/72x72/{twemojiName}.png";
+            }
+
+            // Fallback in case of failure
+            return name;
+        }
+    }
+}

DiscordChatExporter.Core.Models/Exceptions/DomainException.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace DiscordChatExporter.Core.Models.Exceptions
+{
+    public class DomainException : Exception
+    {
+        public DomainException(string message)
+            : base(message)
+        {
+        }
+    }
+}

DiscordChatExporter.Core.Models/Extensions.cs

@@ -0,0 +1,34 @@
+using System;
+
+namespace DiscordChatExporter.Core.Models
+{
+    public static class Extensions
+    {
+        public static bool IsExportable(this ChannelType channelType) =>
+            channelType == ChannelType.GuildTextChat ||
+            channelType == ChannelType.DirectTextChat ||
+            channelType == ChannelType.DirectGroupTextChat ||
+            channelType == ChannelType.GuildNews ||
+            channelType == ChannelType.GuildStore;
+
+        public static string GetFileExtension(this ExportFormat format) =>
+            format switch
+            {
+                ExportFormat.PlainText => "txt",
+                ExportFormat.HtmlDark => "html",
+                ExportFormat.HtmlLight => "html",
+                ExportFormat.Csv => "csv",
+                _ => throw new ArgumentOutOfRangeException(nameof(format))
+            };
+
+        public static string GetDisplayName(this ExportFormat format) =>
+            format switch
+            {
+                ExportFormat.PlainText => "Plain Text",
+                ExportFormat.HtmlDark => "HTML (Dark)",
+                ExportFormat.HtmlLight => "HTML (Light)",
+                ExportFormat.Csv => "Comma Separated Values (CSV)",
+                _ => throw new ArgumentOutOfRangeException(nameof(format))
+            };
+    }
+}

DiscordChatExporter.Core.Models/FileSize.cs

@@ -0,0 +1,82 @@
+using System;
+
+namespace DiscordChatExporter.Core.Models
+{
+    // Loosely based on https://github.com/omar/ByteSize (MIT license)
+
+    public struct FileSize
+    {
+        public const long BytesInKiloByte = 1024;
+        public const long BytesInMegaByte = 1024 * BytesInKiloByte;
+        public const long BytesInGigaByte = 1024 * BytesInMegaByte;
+        public const long BytesInTeraByte = 1024 * BytesInGigaByte;
+        public const long BytesInPetaByte = 1024 * BytesInTeraByte;
+
+        public const string ByteSymbol = "B";
+        public const string KiloByteSymbol = "KB";
+        public const string MegaByteSymbol = "MB";
+        public const string GigaByteSymbol = "GB";
+        public const string TeraByteSymbol = "TB";
+        public const string PetaByteSymbol = "PB";
+
+        public double Bytes { get; }
+        public double KiloBytes => Bytes / BytesInKiloByte;
+        public double MegaBytes => Bytes / BytesInMegaByte;
+        public double GigaBytes => Bytes / BytesInGigaByte;
+        public double TeraBytes => Bytes / BytesInTeraByte;
+        public double PetaBytes => Bytes / BytesInPetaByte;
+
+        public string LargestWholeNumberSymbol
+        {
+            get
+            {
+                if (Math.Abs(PetaBytes) >= 1)
+                    return PetaByteSymbol;
+
+                if (Math.Abs(TeraBytes) >= 1)
+                    return TeraByteSymbol;
+
+                if (Math.Abs(GigaBytes) >= 1)
+                    return GigaByteSymbol;
+
+                if (Math.Abs(MegaBytes) >= 1)
+                    return MegaByteSymbol;
+
+                if (Math.Abs(KiloBytes) >= 1)
+                    return KiloByteSymbol;
+
+                return ByteSymbol;
+            }
+        }
+
+        public double LargestWholeNumberValue
+        {
+            get
+            {
+                if (Math.Abs(PetaBytes) >= 1)
+                    return PetaBytes;
+
+                if (Math.Abs(TeraBytes) >= 1)
+                    return TeraBytes;
+
+                if (Math.Abs(GigaBytes) >= 1)
+                    return GigaBytes;
+
+                if (Math.Abs(MegaBytes) >= 1)
+                    return MegaBytes;
+
+                if (Math.Abs(KiloBytes) >= 1)
+                    return KiloBytes;
+
+                return Bytes;
+            }
+        }
+
+        public FileSize(double bytes)
+        {
+            Bytes = bytes;
+        }
+
+        public override string ToString() => $"{LargestWholeNumberValue:0.##} {LargestWholeNumberSymbol}";
+    }
+}

DiscordChatExporter.Core.Models/Guild.cs

@@ -0,0 +1,38 @@
+namespace DiscordChatExporter.Core.Models
+{
+    // https://discordapp.string.IsNullOrWhiteSpace(com/developers/docs/resources/guild#guild-object
+
+    public partial class Guild : IHasId
+    {
+        public string Id { get; }
+
+        public string Name { get; }
+
+        public string? IconHash { get; }
+
+        public string IconUrl { get; }
+
+        public Guild(string id, string name, string? iconHash)
+        {
+            Id = id;
+            Name = name;
+            IconHash = iconHash;
+
+            IconUrl = GetIconUrl(id, iconHash);
+        }
+
+        public override string ToString() => Name;
+    }
+
+    public partial class Guild
+    {
+        public static string GetIconUrl(string id, string? iconHash)
+        {
+            return !string.IsNullOrWhiteSpace(iconHash)
+                ? $"https://cdn.discordapp.com/icons/{id}/{iconHash}.png"
+                : "https://cdn.discordapp.com/embed/avatars/0.png";
+        }
+
+        public static Guild DirectMessages { get; } = new Guild("@me", "Direct Messages", null);
+    }
+}

DiscordChatExporter.Core.Models/IHasId.cs

@@ -0,0 +1,7 @@
+namespace DiscordChatExporter.Core.Models
+{
+    public interface IHasId
+    {
+        string Id { get; }
+    }
+}

DiscordChatExporter.Core.Models/IdBasedEqualityComparer.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Models
+{
+    public partial class IdBasedEqualityComparer : IEqualityComparer<IHasId>
+    {
+        public bool Equals(IHasId? x, IHasId? y) => StringComparer.Ordinal.Equals(x?.Id, y?.Id);
+
+        public int GetHashCode(IHasId obj) => StringComparer.Ordinal.GetHashCode(obj.Id);
+    }
+
+    public partial class IdBasedEqualityComparer
+    {
+        public static IdBasedEqualityComparer Instance { get; } = new IdBasedEqualityComparer();
+    }
+}

DiscordChatExporter.Core.Models/Message.cs

@@ -5,7 +5,7 @@ namespace DiscordChatExporter.Core.Models
 {
     // https://discordapp.com/developers/docs/resources/channel#message-object
 
-    public class Message
+    public class Message : IHasId
     {
         public string Id { get; }
 
@@ -15,11 +15,13 @@ namespace DiscordChatExporter.Core.Models
 
         public User Author { get; }
 
-        public DateTime Timestamp { get; }
+        public DateTimeOffset Timestamp { get; }
 
-        public DateTime? EditedTimestamp { get; }
+        public DateTimeOffset? EditedTimestamp { get; }
 
-        public string Content { get; }
+        public bool IsPinned { get; }
+
+        public string? Content { get; }
 
         public IReadOnlyList<Attachment> Attachments { get; }
 
@@ -29,9 +31,11 @@ namespace DiscordChatExporter.Core.Models
 
         public IReadOnlyList<User> MentionedUsers { get; }
 
-        public Message(string id, string channelId, MessageType type, User author, DateTime timestamp,
-            DateTime? editedTimestamp, string content, IReadOnlyList<Attachment> attachments,
-            IReadOnlyList<Embed> embeds, IReadOnlyList<Reaction> reactions, IReadOnlyList<User> mentionedUsers)
+        public Message(string id, string channelId, MessageType type, User author,
+            DateTimeOffset timestamp, DateTimeOffset? editedTimestamp, bool isPinned,
+            string content,
+            IReadOnlyList<Attachment> attachments,IReadOnlyList<Embed> embeds, IReadOnlyList<Reaction> reactions,
+            IReadOnlyList<User> mentionedUsers)
         {
             Id = id;
             ChannelId = channelId;
@@ -39,6 +43,7 @@ namespace DiscordChatExporter.Core.Models
             Author = author;
             Timestamp = timestamp;
             EditedTimestamp = editedTimestamp;
+            IsPinned = isPinned;
             Content = content;
             Attachments = attachments;
             Embeds = embeds;
@@ -46,6 +51,6 @@ namespace DiscordChatExporter.Core.Models
             MentionedUsers = mentionedUsers;
         }
 
-        public override string ToString() => Content;
+        public override string ToString() => Content ?? "<message without content>";
     }
 }

DiscordChatExporter.Core.Models/MessageGroup.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Models
+{
+    // Used for grouping contiguous messages in HTML export
+
+    public class MessageGroup
+    {
+        public User Author { get; }
+
+        public DateTimeOffset Timestamp { get; }
+
+        public IReadOnlyList<Message> Messages { get; }
+
+        public MessageGroup(User author, DateTimeOffset timestamp, IReadOnlyList<Message> messages)
+        {
+            Author = author;
+            Timestamp = timestamp;
+            Messages = messages;
+        }
+    }
+}

DiscordChatExporter.Core.Models/Reaction.cs

@@ -6,15 +6,12 @@
     {
         public int Count { get; }
 
-        public string EmojiId { get; }
+        public Emoji Emoji { get; }
 
-        public string EmojiName { get; }
-
-        public Reaction(int count, string emojiId, string emojiName) 
+        public Reaction(int count, Emoji emoji)
         {
             Count = count;
-            EmojiId = emojiId;
-            EmojiName = emojiName;
+            Emoji = emoji;
         }
     }
 }

DiscordChatExporter.Core.Models/Role.cs

@@ -2,7 +2,7 @@
 {
     // https://discordapp.com/developers/docs/topics/permissions#role-object
 
-    public partial class Role
+    public partial class Role : IHasId
     {
         public string Id { get; }
 
@@ -19,7 +19,6 @@
 
     public partial class Role
     {
-        public static Role CreateDeletedRole(string id) =>
-            new Role(id, "deleted-role");
+        public static Role CreateDeletedRole(string id) => new Role(id, "deleted-role");
     }
 }

DiscordChatExporter.Core.Models/User.cs

@@ -0,0 +1,61 @@
+using System;
+
+namespace DiscordChatExporter.Core.Models
+{
+    // https://discordapp.com/developers/docs/topics/permissions#role-object
+
+    public partial class User : IHasId
+    {
+        public string Id { get; }
+
+        public int Discriminator { get; }
+
+        public string Name { get; }
+
+        public string FullName { get; }
+
+        public string? AvatarHash { get; }
+
+        public string AvatarUrl { get; }
+
+        public bool IsBot { get; }
+
+        public User(string id, int discriminator, string name, string? avatarHash, bool isBot)
+        {
+            Id = id;
+            Discriminator = discriminator;
+            Name = name;
+            AvatarHash = avatarHash;
+            IsBot = isBot;
+
+            FullName = GetFullName(name, discriminator);
+            AvatarUrl = GetAvatarUrl(id, discriminator, avatarHash);
+        }
+
+        public override string ToString() => FullName;
+    }
+
+    public partial class User
+    {
+        public static string GetFullName(string name, int discriminator) => $"{name}#{discriminator:0000}";
+
+        public static string GetAvatarUrl(string id, int discriminator, string? avatarHash)
+        {
+            // Custom avatar
+            if (!string.IsNullOrWhiteSpace(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";
+            }
+
+            // Default avatar
+            return $"https://cdn.discordapp.com/embed/avatars/{discriminator % 5}.png";
+        }
+
+        public static User CreateUnknownUser(string id) => new User(id, 0, "Unknown", null, false);
+    }
+}

DiscordChatExporter.Core.Rendering/DiscordChatExporter.Core.Rendering.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="../DiscordChatExporter.props" />
+
+  <ItemGroup>
+    <EmbeddedResource Include="Resources\HtmlCore.css" />
+    <EmbeddedResource Include="Resources\HtmlDark.css" />
+    <EmbeddedResource Include="Resources\HtmlLight.css" />
+    <EmbeddedResource Include="Resources\HtmlLayoutTemplate.html" />
+    <EmbeddedResource Include="Resources\HtmlMessageGroupTemplate.html" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Scriban" Version="2.1.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\DiscordChatExporter.Core.Markdown\DiscordChatExporter.Core.Markdown.csproj" />
+    <ProjectReference Include="..\DiscordChatExporter.Core.Models\DiscordChatExporter.Core.Models.csproj" />
+  </ItemGroup>
+
+</Project>

DiscordChatExporter.Core.Rendering/Formatters/CsvMessageWriter.cs

@@ -0,0 +1,25 @@
+using System.IO;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Rendering.Logic;
+
+namespace DiscordChatExporter.Core.Rendering.Formatters
+{
+    public class CsvMessageWriter : MessageWriterBase
+    {
+        public CsvMessageWriter(TextWriter writer, RenderContext context)
+            : base(writer, context)
+        {
+        }
+
+        public override async Task WritePreambleAsync()
+        {
+            await Writer.WriteLineAsync(CsvRenderingLogic.FormatHeader(Context));
+        }
+
+        public override async Task WriteMessageAsync(Message message)
+        {
+            await Writer.WriteLineAsync(CsvRenderingLogic.FormatMessage(Context, message));
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/Formatters/HtmlMessageWriter.cs

@@ -0,0 +1,163 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Rendering.Logic;
+using Scriban;
+using Scriban.Runtime;
+using Tyrrrz.Extensions;
+
+namespace DiscordChatExporter.Core.Rendering.Formatters
+{
+    public partial class HtmlMessageWriter : MessageWriterBase
+    {
+        private readonly string _themeName;
+        private readonly List<Message> _messageGroupBuffer = new List<Message>();
+
+        private readonly Template _preambleTemplate;
+        private readonly Template _messageGroupTemplate;
+        private readonly Template _postambleTemplate;
+
+        private long _messageCount;
+
+        public HtmlMessageWriter(TextWriter writer, RenderContext context, string themeName)
+            : base(writer, context)
+        {
+            _themeName = themeName;
+
+            _preambleTemplate = Template.Parse(GetPreambleTemplateCode());
+            _messageGroupTemplate = Template.Parse(GetMessageGroupTemplateCode());
+            _postambleTemplate = Template.Parse(GetPostambleTemplateCode());
+        }
+
+        private MessageGroup GetCurrentMessageGroup()
+        {
+            var firstMessage = _messageGroupBuffer.First();
+            return new MessageGroup(firstMessage.Author, firstMessage.Timestamp, _messageGroupBuffer);
+        }
+
+        private TemplateContext CreateTemplateContext(IReadOnlyDictionary<string, object>? constants = null)
+        {
+            // Template context
+            var templateContext = new TemplateContext
+            {
+                MemberRenamer = m => m.Name,
+                MemberFilter = m => true,
+                LoopLimit = int.MaxValue,
+                StrictVariables = true
+            };
+
+            // Model
+            var scriptObject = new ScriptObject();
+
+            // Constants
+            scriptObject.SetValue("Context", Context, true);
+            scriptObject.SetValue("CoreStyleSheet", GetCoreStyleSheetCode(), true);
+            scriptObject.SetValue("ThemeStyleSheet", GetThemeStyleSheetCode(_themeName), true);
+            scriptObject.SetValue("HighlightJsStyleName", $"solarized-{_themeName.ToLowerInvariant()}", true);
+
+            // Additional constants
+            if (constants != null)
+            {
+                foreach (var (member, value) in constants)
+                    scriptObject.SetValue(member, value, true);
+            }
+
+            // Functions
+            scriptObject.Import("FormatDate",
+                new Func<DateTimeOffset, string>(d => SharedRenderingLogic.FormatDate(d, Context.DateFormat)));
+
+            scriptObject.Import("FormatMarkdown",
+                new Func<string, string>(m => HtmlRenderingLogic.FormatMarkdown(Context, m)));
+
+            // Push model
+            templateContext.PushGlobal(scriptObject);
+
+            // Push output
+            templateContext.PushOutput(new TextWriterOutput(Writer));
+
+            return templateContext;
+        }
+
+        private async Task RenderCurrentMessageGroupAsync()
+        {
+            var templateContext = CreateTemplateContext(new Dictionary<string, object>
+            {
+                ["MessageGroup"] = GetCurrentMessageGroup()
+            });
+
+            await templateContext.EvaluateAsync(_messageGroupTemplate.Page);
+        }
+
+        public override async Task WritePreambleAsync()
+        {
+            var templateContext = CreateTemplateContext();
+            await templateContext.EvaluateAsync(_preambleTemplate.Page);
+        }
+
+        public override async Task WriteMessageAsync(Message message)
+        {
+            // If message group is empty or the given message can be grouped, buffer the given message
+            if (!_messageGroupBuffer.Any() || HtmlRenderingLogic.CanBeGrouped(_messageGroupBuffer.Last(), message))
+            {
+                _messageGroupBuffer.Add(message);
+            }
+            // Otherwise, flush the group and render messages
+            else
+            {
+                await RenderCurrentMessageGroupAsync();
+
+                _messageGroupBuffer.Clear();
+                _messageGroupBuffer.Add(message);
+            }
+
+            // Increment message count
+            _messageCount++;
+        }
+
+        public override async Task WritePostambleAsync()
+        {
+            // Flush current message group
+            if (_messageGroupBuffer.Any())
+                await RenderCurrentMessageGroupAsync();
+
+            var templateContext = CreateTemplateContext(new Dictionary<string, object>
+            {
+                ["MessageCount"] = _messageCount
+            });
+
+            await templateContext.EvaluateAsync(_postambleTemplate.Page);
+        }
+    }
+
+    public partial class HtmlMessageWriter
+    {
+        private static readonly Assembly ResourcesAssembly = typeof(HtmlRenderingLogic).Assembly;
+        private static readonly string ResourcesNamespace = $"{ResourcesAssembly.GetName().Name}.Resources";
+
+        private static string GetCoreStyleSheetCode() =>
+            ResourcesAssembly
+                .GetManifestResourceString($"{ResourcesNamespace}.HtmlCore.css");
+
+        private static string GetThemeStyleSheetCode(string themeName) =>
+            ResourcesAssembly
+                .GetManifestResourceString($"{ResourcesNamespace}.Html{themeName}.css");
+
+        private static string GetPreambleTemplateCode() =>
+            ResourcesAssembly
+                .GetManifestResourceString($"{ResourcesNamespace}.HtmlLayoutTemplate.html")
+                .SubstringUntil("{{~ %SPLIT% ~}}");
+
+        private static string GetMessageGroupTemplateCode() =>
+            ResourcesAssembly
+                .GetManifestResourceString($"{ResourcesNamespace}.HtmlMessageGroupTemplate.html");
+
+        private static string GetPostambleTemplateCode() =>
+            ResourcesAssembly
+                .GetManifestResourceString($"{ResourcesNamespace}.HtmlLayoutTemplate.html")
+                .SubstringAfter("{{~ %SPLIT% ~}}");
+    }
+}

DiscordChatExporter.Core.Rendering/Formatters/MessageWriterBase.cs

@@ -0,0 +1,28 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+
+namespace DiscordChatExporter.Core.Rendering.Formatters
+{
+    public abstract class MessageWriterBase : IAsyncDisposable
+    {
+        protected TextWriter Writer { get; }
+
+        protected RenderContext Context { get; }
+
+        protected MessageWriterBase(TextWriter writer, RenderContext context)
+        {
+            Writer = writer;
+            Context = context;
+        }
+
+        public virtual Task WritePreambleAsync() => Task.CompletedTask;
+
+        public abstract Task WriteMessageAsync(Message message);
+
+        public virtual Task WritePostambleAsync() => Task.CompletedTask;
+
+        public async ValueTask DisposeAsync() => await Writer.DisposeAsync();
+    }
+}

DiscordChatExporter.Core.Rendering/Formatters/PlainTextMessageWriter.cs

@@ -0,0 +1,36 @@
+using System.IO;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Rendering.Logic;
+
+namespace DiscordChatExporter.Core.Rendering.Formatters
+{
+    public class PlainTextMessageWriter : MessageWriterBase
+    {
+        private long _messageCount;
+
+        public PlainTextMessageWriter(TextWriter writer, RenderContext context)
+            : base(writer, context)
+        {
+        }
+
+        public override async Task WritePreambleAsync()
+        {
+            await Writer.WriteLineAsync(PlainTextRenderingLogic.FormatPreamble(Context));
+        }
+
+        public override async Task WriteMessageAsync(Message message)
+        {
+            await Writer.WriteLineAsync(PlainTextRenderingLogic.FormatMessage(Context, message));
+            await Writer.WriteLineAsync();
+
+            _messageCount++;
+        }
+
+        public override async Task WritePostambleAsync()
+        {
+            await Writer.WriteLineAsync();
+            await Writer.WriteLineAsync(PlainTextRenderingLogic.FormatPostamble(_messageCount));
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/Internal/Extensions.cs

@@ -0,0 +1,21 @@
+using System.Text;
+
+namespace DiscordChatExporter.Core.Rendering.Internal
+{
+    internal static class Extensions
+    {
+        public static StringBuilder AppendLineIfNotEmpty(this StringBuilder builder, string value) =>
+            !string.IsNullOrWhiteSpace(value) ? builder.AppendLine(value) : builder;
+
+        public static StringBuilder Trim(this StringBuilder builder)
+        {
+            while (builder.Length > 0 && char.IsWhiteSpace(builder[0]))
+                builder.Remove(0, 1);
+
+            while (builder.Length > 0 && char.IsWhiteSpace(builder[^1]))
+                builder.Remove(builder.Length - 1, 1);
+
+            return builder;
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/Logic/CsvRenderingLogic.cs

@@ -0,0 +1,39 @@
+using System.Linq;
+using System.Text;
+using DiscordChatExporter.Core.Models;
+using Tyrrrz.Extensions;
+
+using static DiscordChatExporter.Core.Rendering.Logic.SharedRenderingLogic;
+
+namespace DiscordChatExporter.Core.Rendering.Logic
+{
+    public static class CsvRenderingLogic
+    {
+        // Header is always the same
+        public static string FormatHeader(RenderContext context) => "AuthorID,Author,Date,Content,Attachments,Reactions";
+
+        private static string EncodeValue(string value)
+        {
+            value = value.Replace("\"", "\"\"");
+            return $"\"{value}\"";
+        }
+
+        public static string FormatMarkdown(RenderContext context, string markdown) =>
+            PlainTextRenderingLogic.FormatMarkdown(context, markdown);
+
+        public static string FormatMessage(RenderContext context, Message message)
+        {
+            var buffer = new StringBuilder();
+
+            buffer
+                .Append(EncodeValue(message.Author.Id)).Append(',')
+                .Append(EncodeValue(message.Author.FullName)).Append(',')
+                .Append(EncodeValue(FormatDate(message.Timestamp, context.DateFormat))).Append(',')
+                .Append(EncodeValue(FormatMarkdown(context, message.Content ?? ""))).Append(',')
+                .Append(EncodeValue(message.Attachments.Select(a => a.Url).JoinToString(","))).Append(',')
+                .Append(EncodeValue(message.Reactions.Select(r => $"{r.Emoji.Name} ({r.Count})").JoinToString(",")));
+
+            return buffer.ToString();
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/Logic/HtmlRenderingLogic.cs

@@ -0,0 +1,160 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Text.RegularExpressions;
+using DiscordChatExporter.Core.Markdown;
+using DiscordChatExporter.Core.Markdown.Ast;
+using DiscordChatExporter.Core.Models;
+using Tyrrrz.Extensions;
+
+namespace DiscordChatExporter.Core.Rendering.Logic
+{
+    internal static class HtmlRenderingLogic
+    {
+        public static bool CanBeGrouped(Message message1, Message message2)
+        {
+            if (message1.Author.Id != message2.Author.Id)
+                return false;
+
+            if ((message2.Timestamp - message1.Timestamp).Duration().TotalMinutes > 7)
+                return false;
+
+            return true;
+        }
+
+        private static string HtmlEncode(string s) => WebUtility.HtmlEncode(s);
+
+        private static string FormatMarkdownNode(RenderContext context, Node node, bool isJumbo)
+        {
+            // Text node
+            if (node is TextNode textNode)
+            {
+                // Return HTML-encoded text
+                return HtmlEncode(textNode.Text);
+            }
+
+            // Formatted node
+            if (node is FormattedNode formattedNode)
+            {
+                // Recursively get inner html
+                var innerHtml = FormatMarkdownNodes(context, formattedNode.Children, false);
+
+                // Bold
+                if (formattedNode.Formatting == TextFormatting.Bold)
+                    return $"<strong>{innerHtml}</strong>";
+
+                // Italic
+                if (formattedNode.Formatting == TextFormatting.Italic)
+                    return $"<em>{innerHtml}</em>";
+
+                // Underline
+                if (formattedNode.Formatting == TextFormatting.Underline)
+                    return $"<u>{innerHtml}</u>";
+
+                // Strikethrough
+                if (formattedNode.Formatting == TextFormatting.Strikethrough)
+                    return $"<s>{innerHtml}</s>";
+
+                // Spoiler
+                if (formattedNode.Formatting == TextFormatting.Spoiler)
+                    return $"<span class=\"spoiler\">{innerHtml}</span>";
+
+                // Quote
+                if (formattedNode.Formatting == TextFormatting.Quote)
+                    return $"<div class=\"quote\">{innerHtml}</div>";
+            }
+
+            // Inline code block node
+            if (node is InlineCodeBlockNode inlineCodeBlockNode)
+            {
+                return $"<span class=\"pre pre--inline\">{HtmlEncode(inlineCodeBlockNode.Code)}</span>";
+            }
+
+            // Multi-line code block node
+            if (node is MultiLineCodeBlockNode multilineCodeBlockNode)
+            {
+                // Set CSS class for syntax highlighting
+                var highlightCssClass = !string.IsNullOrWhiteSpace(multilineCodeBlockNode.Language)
+                    ? $"language-{multilineCodeBlockNode.Language}"
+                    : "nohighlight";
+
+                return $"<div class=\"pre pre--multiline {highlightCssClass}\">{HtmlEncode(multilineCodeBlockNode.Code)}</div>";
+            }
+
+            // Mention node
+            if (node is MentionNode mentionNode)
+            {
+                // Meta mention node
+                if (mentionNode.Type == MentionType.Meta)
+                {
+                    return $"<span class=\"mention\">@{HtmlEncode(mentionNode.Id)}</span>";
+                }
+
+                // User mention node
+                if (mentionNode.Type == MentionType.User)
+                {
+                    var user = context.MentionableUsers.FirstOrDefault(u => u.Id == mentionNode.Id) ??
+                               User.CreateUnknownUser(mentionNode.Id);
+
+                    return $"<span class=\"mention\" title=\"{HtmlEncode(user.FullName)}\">@{HtmlEncode(user.Name)}</span>";
+                }
+
+                // Channel mention node
+                if (mentionNode.Type == MentionType.Channel)
+                {
+                    var channel = context.MentionableChannels.FirstOrDefault(c => c.Id == mentionNode.Id) ??
+                                  Channel.CreateDeletedChannel(mentionNode.Id);
+
+                    return $"<span class=\"mention\">#{HtmlEncode(channel.Name)}</span>";
+                }
+
+                // Role mention node
+                if (mentionNode.Type == MentionType.Role)
+                {
+                    var role = context.MentionableRoles.FirstOrDefault(r => r.Id == mentionNode.Id) ??
+                               Role.CreateDeletedRole(mentionNode.Id);
+
+                    return $"<span class=\"mention\">@{HtmlEncode(role.Name)}</span>";
+                }
+            }
+
+            // Emoji node
+            if (node is EmojiNode emojiNode)
+            {
+                // Get emoji image URL
+                var emojiImageUrl = Emoji.GetImageUrl(emojiNode.Id, emojiNode.Name, emojiNode.IsAnimated);
+
+                // Make emoji large if it's jumbo
+                var jumboableCssClass = isJumbo ? "emoji--large" : null;
+
+                return $"<img class=\"emoji {jumboableCssClass}\" alt=\"{emojiNode.Name}\" title=\"{emojiNode.Name}\" src=\"{emojiImageUrl}\" />";
+            }
+
+            // Link node
+            if (node is LinkNode linkNode)
+            {
+                // Extract message ID if the link points to a Discord message
+                var linkedMessageId = Regex.Match(linkNode.Url, "^https?://discordapp.com/channels/.*?/(\\d+)/?$").Groups[1].Value;
+
+                return string.IsNullOrWhiteSpace(linkedMessageId)
+                    ? $"<a href=\"{Uri.EscapeUriString(linkNode.Url)}\">{HtmlEncode(linkNode.Title)}</a>"
+                    : $"<a href=\"{Uri.EscapeUriString(linkNode.Url)}\" onclick=\"scrollToMessage(event, '{linkedMessageId}')\">{HtmlEncode(linkNode.Title)}</a>";
+            }
+
+            // Throw on unexpected nodes
+            throw new InvalidOperationException($"Unexpected node [{node.GetType()}].");
+        }
+
+        private static string FormatMarkdownNodes(RenderContext context, IReadOnlyList<Node> nodes, bool isTopLevel)
+        {
+            // Emojis are jumbo if all top-level nodes are emoji nodes or whitespace text nodes
+            var isJumbo = isTopLevel && nodes.All(n => n is EmojiNode || n is TextNode textNode && string.IsNullOrWhiteSpace(textNode.Text));
+
+            return nodes.Select(n => FormatMarkdownNode(context, n, isJumbo)).JoinToString("");
+        }
+
+        public static string FormatMarkdown(RenderContext context, string markdown) =>
+            FormatMarkdownNodes(context, MarkdownParser.Parse(markdown), true);
+    }
+}

DiscordChatExporter.Core.Rendering/Logic/PlainTextRenderingLogic.cs

@@ -0,0 +1,246 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using DiscordChatExporter.Core.Markdown;
+using DiscordChatExporter.Core.Markdown.Ast;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Rendering.Internal;
+using Tyrrrz.Extensions;
+
+using static DiscordChatExporter.Core.Rendering.Logic.SharedRenderingLogic;
+
+namespace DiscordChatExporter.Core.Rendering.Logic
+{
+    public static class PlainTextRenderingLogic
+    {
+        public static string FormatPreamble(RenderContext context)
+        {
+            var buffer = new StringBuilder();
+
+            buffer.Append('=', 62).AppendLine();
+            buffer.AppendLine($"Guild: {context.Guild.Name}");
+            buffer.AppendLine($"Channel: {context.Channel.Name}");
+
+            if (!string.IsNullOrWhiteSpace(context.Channel.Topic))
+                buffer.AppendLine($"Topic: {context.Channel.Topic}");
+
+            if (context.After != null)
+                buffer.AppendLine($"After: {FormatDate(context.After.Value, context.DateFormat)}");
+
+            if (context.Before != null)
+                buffer.AppendLine($"Before: {FormatDate(context.Before.Value, context.DateFormat)}");
+
+            buffer.Append('=', 62).AppendLine();
+
+            return buffer.ToString();
+        }
+
+        public static string FormatPostamble(long messageCount)
+        {
+            var buffer = new StringBuilder();
+
+            buffer.Append('=', 62).AppendLine();
+            buffer.AppendLine($"Exported {messageCount:N0} message(s)");
+            buffer.Append('=', 62).AppendLine();
+
+            return buffer.ToString();
+        }
+
+        private static string FormatMarkdownNode(RenderContext context, Node node)
+        {
+            // Text node
+            if (node is TextNode textNode)
+            {
+                return textNode.Text;
+            }
+
+            // Mention node
+            if (node is MentionNode mentionNode)
+            {
+                // Meta mention node
+                if (mentionNode.Type == MentionType.Meta)
+                {
+                    return $"@{mentionNode.Id}";
+                }
+
+                // User mention node
+                if (mentionNode.Type == MentionType.User)
+                {
+                    var user = context.MentionableUsers.FirstOrDefault(u => u.Id == mentionNode.Id) ??
+                               User.CreateUnknownUser(mentionNode.Id);
+
+                    return $"@{user.Name}";
+                }
+
+                // Channel mention node
+                if (mentionNode.Type == MentionType.Channel)
+                {
+                    var channel = context.MentionableChannels.FirstOrDefault(c => c.Id == mentionNode.Id) ??
+                                  Channel.CreateDeletedChannel(mentionNode.Id);
+
+                    return $"#{channel.Name}";
+                }
+
+                // Role mention node
+                if (mentionNode.Type == MentionType.Role)
+                {
+                    var role = context.MentionableRoles.FirstOrDefault(r => r.Id == mentionNode.Id) ??
+                               Role.CreateDeletedRole(mentionNode.Id);
+
+                    return $"@{role.Name}";
+                }
+            }
+
+            // Emoji node
+            if (node is EmojiNode emojiNode)
+            {
+                return emojiNode.IsCustomEmoji ? $":{emojiNode.Name}:" : emojiNode.Name;
+            }
+
+            // Throw on unexpected nodes
+            throw new InvalidOperationException($"Unexpected node [{node.GetType()}].");
+        }
+
+        public static string FormatMarkdown(RenderContext context, string markdown) =>
+            MarkdownParser.ParseMinimal(markdown).Select(n => FormatMarkdownNode(context, n)).JoinToString("");
+
+        public static string FormatMessageHeader(RenderContext context, Message message)
+        {
+            var buffer = new StringBuilder();
+
+            // Timestamp & author
+            buffer
+                .Append($"[{FormatDate(message.Timestamp, context.DateFormat)}]")
+                .Append(' ')
+                .Append($"{message.Author.FullName}");
+
+            // Whether the message is pinned
+            if (message.IsPinned)
+            {
+                buffer.Append(' ').Append("(pinned)");
+            }
+
+            return buffer.ToString();
+        }
+
+        public static string FormatMessageContent(RenderContext context, Message message)
+        {
+            if (string.IsNullOrWhiteSpace(message.Content))
+                return "";
+
+            return FormatMarkdown(context, message.Content);
+        }
+
+        public static string FormatAttachments(IReadOnlyList<Attachment> attachments)
+        {
+            if (!attachments.Any())
+                return "";
+
+            var buffer = new StringBuilder();
+
+            buffer
+                .AppendLine("{Attachments}")
+                .AppendJoin(Environment.NewLine, attachments.Select(a => a.Url))
+                .AppendLine();
+
+            return buffer.ToString();
+        }
+
+        public static string FormatEmbeds(RenderContext context, IReadOnlyList<Embed> embeds)
+        {
+            if (!embeds.Any())
+                return "";
+
+            var buffer = new StringBuilder();
+
+            foreach (var embed in embeds)
+            {
+                buffer.AppendLine("{Embed}");
+
+                // Author name
+                if (!string.IsNullOrWhiteSpace(embed.Author?.Name))
+                    buffer.AppendLine(embed.Author.Name);
+
+                // URL
+                if (!string.IsNullOrWhiteSpace(embed.Url))
+                    buffer.AppendLine(embed.Url);
+
+                // Title
+                if (!string.IsNullOrWhiteSpace(embed.Title))
+                    buffer.AppendLine(FormatMarkdown(context, embed.Title));
+
+                // Description
+                if (!string.IsNullOrWhiteSpace(embed.Description))
+                    buffer.AppendLine(FormatMarkdown(context, embed.Description));
+
+                // Fields
+                foreach (var field in embed.Fields)
+                {
+                    // Name
+                    if (!string.IsNullOrWhiteSpace(field.Name))
+                        buffer.AppendLine(field.Name);
+
+                    // Value
+                    if (!string.IsNullOrWhiteSpace(field.Value))
+                        buffer.AppendLine(field.Value);
+                }
+
+                // Thumbnail URL
+                if (!string.IsNullOrWhiteSpace(embed.Thumbnail?.Url))
+                    buffer.AppendLine(embed.Thumbnail?.Url);
+
+                // Image URL
+                if (!string.IsNullOrWhiteSpace(embed.Image?.Url))
+                    buffer.AppendLine(embed.Image?.Url);
+
+                // Footer text
+                if (!string.IsNullOrWhiteSpace(embed.Footer?.Text))
+                    buffer.AppendLine(embed.Footer?.Text);
+
+                buffer.AppendLine();
+            }
+
+            return buffer.ToString();
+        }
+
+        public static string FormatReactions(IReadOnlyList<Reaction> reactions)
+        {
+            if (!reactions.Any())
+                return "";
+
+            var buffer = new StringBuilder();
+
+            buffer.AppendLine("{Reactions}");
+
+            foreach (var reaction in reactions)
+            {
+                buffer.Append(reaction.Emoji.Name);
+
+                if (reaction.Count > 1)
+                    buffer.Append($" ({reaction.Count})");
+
+                buffer.Append(" ");
+            }
+
+            buffer.AppendLine();
+
+            return buffer.ToString();
+        }
+
+        public static string FormatMessage(RenderContext context, Message message)
+        {
+            var buffer = new StringBuilder();
+
+            buffer
+                .AppendLine(FormatMessageHeader(context, message))
+                .AppendLineIfNotEmpty(FormatMessageContent(context, message))
+                .AppendLine()
+                .AppendLineIfNotEmpty(FormatAttachments(message.Attachments))
+                .AppendLineIfNotEmpty(FormatEmbeds(context, message.Embeds))
+                .AppendLineIfNotEmpty(FormatReactions(message.Reactions));
+
+            return buffer.Trim().ToString();
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/Logic/SharedRenderingLogic.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Globalization;
+
+namespace DiscordChatExporter.Core.Rendering.Logic
+{
+    public static class SharedRenderingLogic
+    {
+        public static string FormatDate(DateTimeOffset date, string dateFormat) =>
+            date.ToLocalTime().ToString(dateFormat, CultureInfo.InvariantCulture);
+    }
+}

DiscordChatExporter.Core.Rendering/MessageRenderer.cs

@@ -0,0 +1,121 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Rendering.Formatters;
+
+namespace DiscordChatExporter.Core.Rendering
+{
+    public partial class MessageRenderer : IAsyncDisposable
+    {
+        private readonly RenderOptions _options;
+        private readonly RenderContext _context;
+
+        private long _renderedMessageCount;
+        private int _partitionIndex;
+        private MessageWriterBase? _writer;
+
+        public MessageRenderer(RenderOptions options, RenderContext context)
+        {
+            _options = options;
+            _context = context;
+        }
+
+        private async Task InitializeWriterAsync()
+        {
+            // Get partition file path
+            var filePath = GetPartitionFilePath(_options.BaseFilePath, _partitionIndex);
+
+            // Create output directory
+            var dirPath = Path.GetDirectoryName(_options.BaseFilePath);
+            if (!string.IsNullOrWhiteSpace(dirPath))
+                Directory.CreateDirectory(dirPath);
+
+            // Create writer
+            _writer = CreateMessageWriter(filePath, _options.Format, _context);
+
+            // Write preamble
+            await _writer.WritePreambleAsync();
+        }
+
+        private async Task ResetWriterAsync()
+        {
+            if (_writer != null)
+            {
+                // Write postamble
+                await _writer.WritePostambleAsync();
+
+                // Flush
+                await _writer.DisposeAsync();
+                _writer = null;
+            }
+        }
+
+        public async Task RenderMessageAsync(Message message)
+        {
+            // Ensure underlying writer is initialized
+            if (_writer == null)
+                await InitializeWriterAsync();
+
+            // Render the actual message
+            await _writer!.WriteMessageAsync(message);
+
+            // Increment count
+            _renderedMessageCount++;
+
+            // Shift partition if necessary
+            if (_options.PartitionLimit != null &&
+                _options.PartitionLimit != 0 &&
+                _renderedMessageCount % _options.PartitionLimit == 0)
+            {
+                await ResetWriterAsync();
+                _partitionIndex++;
+            }
+        }
+
+        public async ValueTask DisposeAsync() => await ResetWriterAsync();
+    }
+
+    public partial class MessageRenderer
+    {
+        private static string GetPartitionFilePath(string baseFilePath, int partitionIndex)
+        {
+            // First partition - no changes
+            if (partitionIndex <= 0)
+                return baseFilePath;
+
+            // Inject partition index into file name
+            var fileNameWithoutExt = Path.GetFileNameWithoutExtension(baseFilePath);
+            var fileExt = Path.GetExtension(baseFilePath);
+            var fileName = $"{fileNameWithoutExt} [part {partitionIndex + 1}]{fileExt}";
+
+            // Generate new path
+            var dirPath = Path.GetDirectoryName(baseFilePath);
+            if (!string.IsNullOrWhiteSpace(dirPath))
+                return Path.Combine(dirPath, fileName);
+
+            return fileName;
+        }
+
+        private static MessageWriterBase CreateMessageWriter(string filePath, ExportFormat format, RenderContext context)
+        {
+            // Create inner writer (it will get disposed by the wrapper)
+            var writer = File.CreateText(filePath);
+
+            // Create formatter
+            if (format == ExportFormat.PlainText)
+                return new PlainTextMessageWriter(writer, context);
+
+            if (format == ExportFormat.Csv)
+                return new CsvMessageWriter(writer, context);
+
+            if (format == ExportFormat.HtmlDark)
+                return new HtmlMessageWriter(writer, context, "Dark");
+
+            if (format == ExportFormat.HtmlLight)
+                return new HtmlMessageWriter(writer, context, "Light");
+
+            throw new InvalidOperationException($"Unknown export format [{format}].");
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/RenderContext.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using DiscordChatExporter.Core.Models;
+
+namespace DiscordChatExporter.Core.Rendering
+{
+    public class RenderContext
+    {
+        public Guild Guild { get; }
+
+        public Channel Channel { get; }
+
+        public DateTimeOffset? After { get; }
+
+        public DateTimeOffset? Before { get; }
+
+        public string DateFormat { get; }
+
+        public IReadOnlyCollection<User> MentionableUsers { get; }
+
+        public IReadOnlyCollection<Channel> MentionableChannels { get; }
+
+        public IReadOnlyCollection<Role> MentionableRoles { get; }
+
+        public RenderContext(Guild guild, Channel channel, DateTimeOffset? after, DateTimeOffset? before, string dateFormat,
+            IReadOnlyCollection<User> mentionableUsers, IReadOnlyCollection<Channel> mentionableChannels, IReadOnlyCollection<Role> mentionableRoles)
+        {
+            Guild = guild;
+            Channel = channel;
+            After = after;
+            Before = before;
+            DateFormat = dateFormat;
+            MentionableUsers = mentionableUsers;
+            MentionableChannels = mentionableChannels;
+            MentionableRoles = mentionableRoles;
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/RenderOptions.cs

@@ -0,0 +1,20 @@
+using DiscordChatExporter.Core.Models;
+
+namespace DiscordChatExporter.Core.Rendering
+{
+    public class RenderOptions
+    {
+        public string BaseFilePath { get; }
+
+        public ExportFormat Format { get; }
+
+        public int? PartitionLimit { get; }
+
+        public RenderOptions(string baseFilePath, ExportFormat format, int? partitionLimit)
+        {
+            BaseFilePath = baseFilePath;
+            Format = format;
+            PartitionLimit = partitionLimit;
+        }
+    }
+}

DiscordChatExporter.Core.Rendering/Resources/HtmlCore.css

@@ -0,0 +1,362 @@
+/* General */
+
+@font-face {
+    font-family: Whitney;
+    src: url(https://discordapp.com/assets/6c6374bad0b0b6d204d8d6dc4a18d820.woff);
+    font-weight: 300;
+}
+
+@font-face {
+    font-family: Whitney;
+    src: url(https://discordapp.com/assets/e8acd7d9bf6207f99350ca9f9e23b168.woff);
+    font-weight: 400;
+}
+
+@font-face {
+    font-family: Whitney;
+    src: url(https://discordapp.com/assets/3bdef1251a424500c1b3a78dea9b7e57.woff);
+    font-weight: 500;
+}
+
+@font-face {
+    font-family: Whitney;
+    src: url(https://discordapp.com/assets/be0060dafb7a0e31d2a1ca17c0708636.woff);
+    font-weight: 600;
+}
+
+@font-face {
+    font-family: Whitney;
+    src: url(https://discordapp.com/assets/8e12fb4f14d9c4592eb8ec9f22337b04.woff);
+    font-weight: 700;
+}
+
+body {
+    font-family: "Whitney", "Helvetica Neue", Helvetica, Arial, sans-serif;
+    font-size: 17px;
+}
+
+a {
+    text-decoration: none;
+}
+
+a:hover {
+    text-decoration: underline;
+}
+
+img {
+    object-fit: contain;
+}
+
+.markdown {
+    white-space: pre-wrap;
+    line-height: 1.3;
+    overflow-wrap: break-word;
+}
+
+.spoiler {
+    border-radius: 3px;
+}
+
+.quote {
+    margin: 0.5em 0;
+    padding-left: 0.6em;
+    border-left: 4px solid;
+    border-radius: 3px;
+}
+
+.pre {
+    font-family: "Consolas", "Courier New", Courier, monospace;
+}
+
+.pre--multiline {
+    margin-top: 0.25em;
+    padding: 0.5em;
+    border: 2px solid;
+    border-radius: 5px;
+}
+
+.pre--inline {
+    padding: 2px;
+    border-radius: 3px;
+    font-size: 0.85em;
+}
+
+.mention {
+    font-weight: 500;
+}
+
+.emoji {
+    width: 1.25em;
+    height: 1.25em;
+    margin: 0 0.06em;
+    vertical-align: -0.4em;
+}
+
+.emoji--small {
+    width: 1em;
+    height: 1em;
+}
+
+.emoji--large {
+    width: 2.8em;
+    height: 2.8em;
+}
+
+/* Preamble */
+
+.preamble {
+    display: grid;
+    margin: 0 0.3em 0.6em 0.3em;
+    max-width: 100%;
+    grid-template-columns: auto 1fr;
+}
+
+.preamble__guild-icon-container {
+    grid-column: 1;
+}
+
+.preamble__guild-icon {
+    max-width: 88px;
+    max-height: 88px;
+}
+
+.preamble__entries-container {
+    grid-column: 2;
+    margin-left: 0.6em;
+}
+
+.preamble__entry {
+    font-size: 1.4em;
+}
+
+.preamble__entry--small {
+    font-size: 1em;
+}
+
+/* Chatlog */
+
+.chatlog {
+    max-width: 100%;
+}
+
+.chatlog__message-group {
+    display: grid;
+    margin: 0 0.6em;
+    padding: 0.9em 0;
+    border-top: 1px solid;
+    grid-template-columns: auto 1fr;
+}
+
+.chatlog__author-avatar-container {
+    grid-column: 1;
+    width: 40px;
+    height: 40px;
+}
+
+.chatlog__author-avatar {
+    border-radius: 50%;
+    height: 40px;
+    width: 40px;
+}
+
+.chatlog__messages {
+    grid-column: 2;
+    margin-left: 1.2em;
+    min-width: 50%;
+}
+
+.chatlog__author-name {
+    font-weight: 500;
+}
+
+.chatlog__timestamp {
+    margin-left: 0.3em;
+    font-size: 0.75em;
+}
+
+.chatlog__message {
+    padding: 0.1em 0.3em;
+    margin: 0 -0.3em;
+    background-color: transparent;
+    transition: background-color 1s ease;
+}
+
+.chatlog__content {
+    font-size: 0.95em;
+    word-wrap: break-word;
+}
+
+.chatlog__edited-timestamp {
+    margin-left: 0.15em;
+    font-size: 0.8em;
+}
+
+.chatlog__attachment-thumbnail {
+    margin-top: 0.3em;
+    max-width: 50%;
+    max-height: 500px;
+    border-radius: 3px;
+}
+
+.chatlog__embed {
+    display: flex;
+    margin-top: 0.3em;
+    max-width: 520px;
+}
+
+.chatlog__embed-color-pill {
+    flex-shrink: 0;
+    width: 0.25em;
+    border-top-left-radius: 3px;
+    border-bottom-left-radius: 3px;
+}
+
+.chatlog__embed-content-container {
+    display: flex;
+    flex-direction: column;
+    padding: 0.5em 0.6em;
+    border: 1px solid;
+    border-top-right-radius: 3px;
+    border-bottom-right-radius: 3px;
+}
+
+.chatlog__embed-content {
+    display: flex;
+    width: 100%;
+}
+
+.chatlog__embed-text {
+    flex: 1;
+}
+
+.chatlog__embed-author {
+    display: flex;
+    margin-bottom: 0.3em;
+    align-items: center;
+}
+
+.chatlog__embed-author-icon {
+    margin-right: 0.5em;
+    width: 20px;
+    height: 20px;
+    border-radius: 50%;
+}
+
+.chatlog__embed-author-name {
+    font-size: 0.875em;
+    font-weight: 600;
+}
+
+.chatlog__embed-title {
+    margin-bottom: 0.2em;
+    font-size: 0.875em;
+    font-weight: 600;
+}
+
+.chatlog__embed-description {
+    font-weight: 500;
+    font-size: 0.85em;
+}
+
+.chatlog__embed-fields {
+    display: flex;
+    flex-wrap: wrap;
+}
+
+.chatlog__embed-field {
+    flex: 0;
+    min-width: 100%;
+    max-width: 506px;
+    padding-top: 0.6em;
+    font-size: 0.875em;
+}
+
+.chatlog__embed-field--inline {
+    flex: 1;
+    flex-basis: auto;
+    min-width: 150px;
+}
+
+.chatlog__embed-field-name {
+    margin-bottom: 0.2em;
+    font-weight: 600;
+}
+
+.chatlog__embed-field-value {
+    font-weight: 500;
+}
+
+.chatlog__embed-thumbnail {
+    flex: 0;
+    margin-left: 1.2em;
+    max-width: 80px;
+    max-height: 80px;
+    border-radius: 3px;
+}
+
+.chatlog__embed-image-container {
+    margin-top: 0.6em;
+}
+
+.chatlog__embed-image {
+    max-width: 500px;
+    max-height: 400px;
+    border-radius: 3px;
+}
+
+.chatlog__embed-footer {
+    margin-top: 0.6em;
+}
+
+.chatlog__embed-footer-icon {
+    margin-right: 0.2em;
+    width: 20px;
+    height: 20px;
+    border-radius: 50%;
+    vertical-align: middle;
+}
+
+.chatlog__embed-footer-text {
+    font-size: 0.75em;
+    font-weight: 500;
+}
+
+.chatlog__reactions {
+    display: flex;
+}
+
+.chatlog__reaction {
+    display: flex;
+    align-items: center;
+    margin: 0.35em 0.1em 0.1em 0.1em;
+    padding: 0.2em 0.35em;
+    border-radius: 3px;
+}
+
+.chatlog__reaction-count {
+    min-width: 9px;
+    margin-left: 0.35em;
+    font-size: 0.875em;
+}
+
+.chatlog__bot-tag {
+    position: relative;
+    top: -.2em;
+    margin-left: 0.3em;
+    padding: 0.05em 0.3em;
+    border-radius: 3px;
+    vertical-align: middle;
+    line-height: 1.3;
+    background: #7289da;
+    color: #ffffff;
+    font-size: 0.625em;
+    font-weight: 500;
+}
+
+/* Postamble */
+
+.postamble {
+    margin: 1.4em 0.3em 0.6em 0.3em;
+    padding: 1em;
+    border-top: 1px solid;
+}

DiscordChatExporter.Core.Rendering/Resources/HtmlDark.css

@@ -0,0 +1,118 @@
+/* General */
+
+body {
+    background-color: #36393e;
+    color: #dcddde;
+}
+
+a {
+    color: #0096cf;
+}
+
+.spoiler {
+    background-color: rgba(255, 255, 255, 0.1);
+}
+
+.quote {
+    border-color: #4f545c;
+}
+
+.pre {
+    background-color: #2f3136 !important;
+}
+
+.pre--multiline {
+    border-color: #282b30 !important;
+    color: #b9bbbe !important;
+}
+
+.mention {
+    color: #7289da;
+}
+
+/* === Preamble === */
+
+.preamble__entry {
+    color: #ffffff;
+}
+
+/* Chatlog */
+
+.chatlog__message-group {
+    border-color: rgba(255, 255, 255, 0.1);
+}
+
+.chatlog__author-name {
+    color: #ffffff;
+}
+
+.chatlog__timestamp {
+    color: rgba(255, 255, 255, 0.2);
+}
+
+.chatlog__message--highlighted {
+    background-color: rgba(114, 137, 218, 0.2) !important;
+}
+
+.chatlog__message--pinned {
+    background-color: rgba(249, 168, 37, 0.05);
+}
+
+.chatlog__edited-timestamp {
+    color: rgba(255, 255, 255, 0.2);
+}
+
+.chatlog__embed-color-pill--default {
+    background-color: rgba(79, 84, 92, 1);
+}
+
+.chatlog__embed-content-container {
+    background-color: rgba(46, 48, 54, 0.3);
+    border-color: rgba(46, 48, 54, 0.6);
+}
+
+.chatlog__embed-author-name {
+    color: #ffffff;
+}
+
+.chatlog__embed-author-name-link {
+    color: #ffffff;
+}
+
+.chatlog__embed-title {
+    color: #ffffff;
+}
+
+.chatlog__embed-description {
+    color: rgba(255, 255, 255, 0.6);
+}
+
+.chatlog__embed-field-name {
+    color: #ffffff;
+}
+
+.chatlog__embed-field-value {
+    color: rgba(255, 255, 255, 0.6);
+}
+
+.chatlog__embed-footer {
+    color: rgba(255, 255, 255, 0.6);
+}
+
+.chatlog__reaction {
+    background-color: rgba(255, 255, 255, 0.05);
+}
+
+.chatlog__reaction-count {
+    color: rgba(255, 255, 255, 0.3);
+}
+
+/* Postamble */
+
+.postamble {
+    border-color: rgba(255, 255, 255, 0.1);
+}
+
+.postamble__entry {
+    color: #ffffff;
+}

DiscordChatExporter.Core.Rendering/Resources/HtmlLayoutTemplate.html

@@ -0,0 +1,89 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    {{~ # Metadata ~}}
+    <title>{{ Context.Guild.Name | html.escape }} - {{ Context.Channel.Name | html.escape }}</title>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width" />
+
+    {{~ # Styles ~}}
+    <style>
+        {{ CoreStyleSheet }}
+    </style>
+    <style>
+        {{ ThemeStyleSheet }}
+    </style>
+
+    {{~ # Syntax highlighting ~}}
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/styles/{{HighlightJsStyleName}}.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>
+
+    {{~ # Local scripts ~}}
+    <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);
+            }
+        }
+    </script>
+</head>
+<body>
+
+{{~ # Preamble ~}}
+<div class="preamble">
+    <div class="preamble__guild-icon-container">
+        <img class="preamble__guild-icon" src="{{ Context.Guild.IconUrl }}" alt="Guild icon" />
+    </div>
+    <div class="preamble__entries-container">
+        <div class="preamble__entry">{{ Context.Guild.Name | html.escape }}</div>
+        <div class="preamble__entry">{{ Context.Channel.Name | html.escape }}</div>
+
+        {{~ if Context.Channel.Topic ~}}
+            <div class="preamble__entry preamble__entry--small">{{ Context.Channel.Topic | html.escape }}</div>
+        {{~ end ~}}
+
+        {{~ if Context.After || Context.Before ~}}
+            <div class="preamble__entry preamble__entry--small">
+                {{~ if Context.After && Context.Before ~}}
+                    Between {{ Context.After | FormatDate | html.escape }} and {{ Context.Before | FormatDate | html.escape }}
+                {{~ else if Context.After ~}}
+                    After {{ Context.After | FormatDate | html.escape }}
+                {{~ else if Context.Before ~}}
+                    Before {{ Context.Before | FormatDate | html.escape }}
+                {{~ end ~}}
+            </div>
+        {{~ end ~}}
+    </div>
+</div>
+
+{{~ # Log ~}}
+<div class="chatlog">
+    {{~ %SPLIT% ~}}
+</div>
+
+{{~ # Postamble ~}}
+<div class="postamble">
+    <div class="postamble__entry">Exported {{ MessageCount | object.format "N0" }} message(s)</div>
+</div>
+
+</body>
+</html>

DiscordChatExporter.Core.Rendering/Resources/HtmlLight.css

@@ -0,0 +1,121 @@
+/* General */
+
+body {
+    background-color: #ffffff;
+    color: #23262a;
+    font-weight: 500;
+}
+
+a {
+    color: #00b0f4;
+}
+
+.spoiler {
+    background-color: rgba(0, 0, 0, 0.1);
+}
+
+.quote {
+    border-color: #c7ccd1;
+}
+
+.pre {
+    background-color: #f9f9f9 !important;
+}
+
+.pre--multiline {
+    border-color: #f3f3f3 !important;
+    color: #657b83 !important;
+}
+
+.mention {
+    background-color: #f1f3fb;
+    color: #7289da;
+}
+
+/* Preamble */
+
+.preamble__entry {
+    color: #2f3136;
+}
+
+/* Chatlog */
+
+.chatlog__message-group {
+    border-color: #eceeef;
+}
+
+.chatlog__author-name {
+    font-weight: 600;
+    color: #2f3136;
+}
+
+.chatlog__timestamp {
+    color: #747f8d;
+}
+
+.chatlog__message--highlighted {
+    background-color: rgba(114, 137, 218, 0.2) !important;
+}
+
+.chatlog__message--pinned {
+    background-color: rgba(249, 168, 37, 0.05);
+}
+
+.chatlog__edited-timestamp {
+    color: #747f8d;
+}
+
+.chatlog__embed-color-pill--default {
+    background-color: rgba(227, 229, 232, 1);
+}
+
+.chatlog__embed-content-container {
+    background-color: rgba(249, 249, 249, 0.3);
+    border-color: rgba(204, 204, 204, 0.3);
+}
+
+.chatlog__embed-author-name {
+    color: #4f545c;
+}
+
+.chatlog__embed-author-name-link {
+    color: #4f545c;
+}
+
+.chatlog__embed-title {
+    color: #4f545c;
+}
+
+.chatlog__embed-description {
+    color: #737f8d;
+}
+
+.chatlog__embed-field-name {
+    color: #36393e;
+}
+
+.chatlog__embed-field-value {
+    color: #737f8d;
+}
+
+.chatlog__embed-footer {
+    color: rgba(79, 83, 91, 0.6);
+}
+
+.chatlog__reaction {
+    background-color: rgba(79, 84, 92, 0.06);
+}
+
+.chatlog__reaction-count {
+    color: #747f8d;
+}
+
+/* Postamble */
+
+.postamble {
+    border-color: #eceeef;
+}
+
+.postamble__entry {
+    color: #2f3136;
+}

DiscordChatExporter.Core.Rendering/Resources/HtmlMessageGroupTemplate.html

@@ -0,0 +1,170 @@
+<div class="chatlog__message-group">
+    {{~ # Avatar ~}}
+    <div class="chatlog__author-avatar-container">
+        <img class="chatlog__author-avatar" src="{{ MessageGroup.Author.AvatarUrl }}" alt="Avatar" />
+    </div>
+    <div class="chatlog__messages">
+        {{~ # Author name and timestamp ~}}
+        <span class="chatlog__author-name" title="{{ MessageGroup.Author.FullName | html.escape }}" data-user-id="{{ MessageGroup.Author.Id | html.escape }}">{{ MessageGroup.Author.Name | html.escape }}</span>
+
+        {{~ # Bot tag ~}}
+        {{~ if MessageGroup.Author.IsBot ~}}
+            <span class="chatlog__bot-tag">BOT</span>
+        {{~ end ~}}
+
+        <span class="chatlog__timestamp">{{ MessageGroup.Timestamp | FormatDate | html.escape }}</span>
+
+        {{~ # Messages ~}}
+        {{~ for message in MessageGroup.Messages ~}}
+            <div class="chatlog__message {{if message.IsPinned }}chatlog__message--pinned{{ end }}" data-message-id="{{ message.Id }}" id="message-{{ message.Id }}">
+            {{~ # Content ~}}
+            {{~ if message.Content ~}}
+                <div class="chatlog__content">
+                    <span class="markdown">{{ message.Content | FormatMarkdown }}</span>
+
+                    {{~ # Edited timestamp ~}}
+                    {{~ if message.EditedTimestamp ~}}
+                        <span class="chatlog__edited-timestamp" title="{{ message.EditedTimestamp | FormatDate | html.escape }}">(edited)</span>
+                    {{~ end ~}}
+                </div>
+            {{~ end ~}}
+
+            {{~ # Attachments ~}}
+            {{~ for attachment in message.Attachments ~}}
+                <div class="chatlog__attachment">
+                    <a href="{{ attachment.Url }}">
+                        {{ # Image }}
+                        {{~ if attachment.IsImage ~}}
+                            <img class="chatlog__attachment-thumbnail" src="{{ attachment.Url }}" alt="Attachment" />
+                        {{~ # Non-image ~}}
+                        {{~ else ~}}
+                            Attachment: {{ attachment.FileName }} ({{ attachment.FileSize }})
+                        {{~ end ~}}
+                    </a>
+                </div>
+            {{~ end ~}}
+
+            {{~ # Embeds ~}}
+            {{~ for embed in message.Embeds ~}}
+            <div class="chatlog__embed">
+                {{~ if embed.Color ~}}
+                <div class="chatlog__embed-color-pill" style="background-color: rgba({{ embed.Color.R }},{{ embed.Color.G }},{{ embed.Color.B }},{{ embed.Color.A }})"></div>
+                {{~ else ~}}
+                <div class="chatlog__embed-color-pill chatlog__embed-color-pill--default"></div>
+                {{~ end ~}}
+                <div class="chatlog__embed-content-container">
+                    <div class="chatlog__embed-content">
+                        <div class="chatlog__embed-text">
+                            {{~ # Author ~}}
+                            {{~ if embed.Author ~}}
+                            <div class="chatlog__embed-author">
+                                {{~ if embed.Author.IconUrl ~}}
+                                <img class="chatlog__embed-author-icon" src="{{ embed.Author.IconUrl }}" alt="Author icon" />
+                                {{~ end ~}}
+
+                                {{~ if embed.Author.Name ~}}
+                                <span class="chatlog__embed-author-name">
+                                    {{~ if embed.Author.Url ~}}
+                                    <a class="chatlog__embed-author-name-link" href="{{ embed.Author.Url }}">{{ embed.Author.Name | html.escape }}</a>
+                                    {{~ else ~}}
+                                    {{ embed.Author.Name | html.escape }}
+                                    {{~ end ~}}
+                                </span>
+                                {{~ end ~}}
+                            </div>
+                            {{~ end ~}}
+
+                            {{~ # Title ~}}
+                            {{~ if embed.Title ~}}
+                            <div class="chatlog__embed-title">
+                                {{~ if embed.Url ~}}
+                                <a class="chatlog__embed-title-link" href="{{ embed.Url }}"><span class="markdown">{{ embed.Title | FormatMarkdown }}</span></a>
+                                {{~ else ~}}
+                                <span class="markdown">{{ embed.Title | FormatMarkdown }}</span>
+                                {{~ end ~}}
+                            </div>
+                            {{~ end ~}}
+
+                            {{~ # Description ~}}
+                            {{~ if embed.Description ~}}
+                            <div class="chatlog__embed-description"><span class="markdown">{{ embed.Description | FormatMarkdown }}</span></div>
+                            {{~ end ~}}
+
+                            {{~ # Fields ~}}
+                            {{~ if embed.Fields | array.size > 0 ~}}
+                            <div class="chatlog__embed-fields">
+                                {{~ for field in embed.Fields ~}}
+                                <div class="chatlog__embed-field {{ if field.IsInline }} chatlog__embed-field--inline {{ end }}">
+                                    {{~ if field.Name ~}}
+                                    <div class="chatlog__embed-field-name"><span class="markdown">{{ field.Name | FormatMarkdown }}</span></div>
+                                    {{~ end ~}}
+                                    {{~ if field.Value ~}}
+                                    <div class="chatlog__embed-field-value"><span class="markdown">{{ field.Value | FormatMarkdown }}</span></div>
+                                    {{~ end ~}}
+                                </div>
+                                {{~ end ~}}
+                            </div>
+                            {{~ end ~}}
+                        </div>
+
+                        {{~ # Thumbnail ~}}
+                        {{~ if embed.Thumbnail ~}}
+                        <div class="chatlog__embed-thumbnail-container">
+                            <a class="chatlog__embed-thumbnail-link" href="{{ embed.Thumbnail.Url }}">
+                                <img class="chatlog__embed-thumbnail" src="{{ embed.Thumbnail.Url }}" alt="Thumbnail" />
+                            </a>
+                        </div>
+                        {{~ end ~}}
+                    </div>
+
+                    {{~ # Image ~}}
+                    {{~ if embed.Image ~}}
+                    <div class="chatlog__embed-image-container">
+                        <a class="chatlog__embed-image-link" href="{{ embed.Image.Url }}">
+                            <img class="chatlog__embed-image" src="{{ embed.Image.Url }}" alt="Image" />
+                        </a>
+                    </div>
+                    {{~ end ~}}
+
+                    {{~ # Footer ~}}
+                    {{~ if embed.Footer || embed.Timestamp ~}}
+                    <div class="chatlog__embed-footer">
+                        {{~ if embed.Footer ~}}
+                        {{~ if embed.Footer.Text && embed.Footer.IconUrl ~}}
+                        <img class="chatlog__embed-footer-icon" src="{{ embed.Footer.IconUrl }}" alt="Footer icon" />
+                        {{~ end ~}}
+                        {{~ end ~}}
+
+                        <span class="chatlog__embed-footer-text">
+                            {{~ if embed.Footer ~}}
+                            {{~ if embed.Footer.Text ~}}
+                            {{ embed.Footer.Text | html.escape }}
+                            {{ if embed.Timestamp }} • {{ end }}
+                            {{~ end ~}}
+                            {{~ end ~}}
+
+                            {{~ if embed.Timestamp ~}}
+                            {{ embed.Timestamp | FormatDate | html.escape }}
+                            {{~ end ~}}
+                        </span>
+                    </div>
+                    {{~ end ~}}
+                </div>
+            </div>
+            {{~ end ~}}
+
+            {{~ # Reactions ~}}
+            {{~ if message.Reactions | array.size > 0 ~}}
+                <div class="chatlog__reactions">
+                    {{~ for reaction in message.Reactions ~}}
+                        <div class="chatlog__reaction">
+                            <img class="emoji emoji--small" alt="{{ reaction.Emoji.Name }}" title="{{ reaction.Emoji.Name }}" src="{{ reaction.Emoji.ImageUrl }}" />
+                            <span class="chatlog__reaction-count">{{ reaction.Count }}</span>
+                        </div>
+                    {{~ end ~}}
+                </div>
+            {{~ end ~}}
+            </div>
+        {{~ end ~}}
+    </div>
+</div>

DiscordChatExporter.Core.Services/DataService.Parsers.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Drawing;
 using System.Linq;
-using DiscordChatExporter.Core.Internal;
 using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Services.Internal;
 using Newtonsoft.Json.Linq;
 using Tyrrrz.Extensions;
 
@@ -12,19 +12,20 @@ namespace DiscordChatExporter.Core.Services
     {
         private User ParseUser(JToken json)
         {
-            var id = json["id"].Value<string>();
-            var discriminator = json["discriminator"].Value<int>();
-            var name = json["username"].Value<string>();
-            var avatarHash = json["avatar"].Value<string>();
+            var id = json["id"]!.Value<string>();
+            var discriminator = json["discriminator"]!.Value<int>();
+            var name = json["username"]!.Value<string>();
+            var avatarHash = json["avatar"]!.Value<string>();
+            var isBot = json["bot"]?.Value<bool>() ?? false;
 
-            return new User(id, discriminator, name, avatarHash);
+            return new User(id, discriminator, name, avatarHash, isBot);
         }
 
         private Guild ParseGuild(JToken json)
         {
-            var id = json["id"].Value<string>();
-            var name = json["name"].Value<string>();
-            var iconHash = json["icon"].Value<string>();
+            var id = json["id"]!.Value<string>();
+            var name = json["name"]!.Value<string>();
+            var iconHash = json["icon"]!.Value<string>();
 
             return new Guild(id, name, iconHash);
         }
@@ -32,43 +33,51 @@ namespace DiscordChatExporter.Core.Services
         private Channel ParseChannel(JToken json)
         {
             // Get basic data
-            var id = json["id"].Value<string>();
-            var type = (ChannelType) json["type"].Value<int>();
+            var id = json["id"]!.Value<string>();
+            var parentId = json["parent_id"]?.Value<string>();
+            var type = (ChannelType) json["type"]!.Value<int>();
             var topic = json["topic"]?.Value<string>();
 
             // Try to extract guild ID
             var guildId = json["guild_id"]?.Value<string>();
 
             // If the guild ID is blank, it's direct messages
-            if (guildId.IsBlank())
+            if (string.IsNullOrWhiteSpace(guildId))
                 guildId = Guild.DirectMessages.Id;
 
             // Try to extract name
             var name = json["name"]?.Value<string>();
 
             // If the name is blank, it's direct messages
-            if (name.IsBlank())
-                name = json["recipients"].Select(ParseUser).Select(u => u.Name).JoinToString(", ");
+            if (string.IsNullOrWhiteSpace(name))
+                name = json["recipients"]?.Select(ParseUser).Select(u => u.Name).JoinToString(", ");
 
-            return new Channel(id, guildId, name, topic, type);
+            // If the name is still blank for some reason, fallback to ID
+            // (blind fix to https://github.com/Tyrrrz/DiscordChatExporter/issues/227)
+            if (string.IsNullOrWhiteSpace(name))
+                name = id;
+
+            return new Channel(id, parentId, guildId, name, topic, type);
         }
 
         private Role ParseRole(JToken json)
         {
-            var id = json["id"].Value<string>();
-            var name = json["name"].Value<string>();
+            var id = json["id"]!.Value<string>();
+            var name = json["name"]!.Value<string>();
 
             return new Role(id, name);
         }
 
         private Attachment ParseAttachment(JToken json)
         {
-            var id = json["id"].Value<string>();
-            var url = json["url"].Value<string>();
+            var id = json["id"]!.Value<string>();
+            var url = json["url"]!.Value<string>();
             var width = json["width"]?.Value<int>();
             var height = json["height"]?.Value<int>();
-            var fileName = json["filename"].Value<string>();
-            var fileSize = json["size"].Value<long>();
+            var fileName = json["filename"]!.Value<string>();
+            var fileSizeBytes = json["size"]!.Value<long>();
+
+            var fileSize = new FileSize(fileSizeBytes);
 
             return new Attachment(id, width, height, url, fileName, fileSize);
         }
@@ -84,8 +93,8 @@ namespace DiscordChatExporter.Core.Services
 
         private EmbedField ParseEmbedField(JToken json)
         {
-            var name = json["name"].Value<string>();
-            var value = json["value"].Value<string>();
+            var name = json["name"]!.Value<string>();
+            var value = json["value"]!.Value<string>();
             var isInline = json["inline"]?.Value<bool>() ?? false;
 
             return new EmbedField(name, value, isInline);
@@ -102,7 +111,7 @@ namespace DiscordChatExporter.Core.Services
 
         private EmbedFooter ParseEmbedFooter(JToken json)
         {
-            var text = json["text"].Value<string>();
+            var text = json["text"]!.Value<string>();
             var iconUrl = json["icon_url"]?.Value<string>();
 
             return new EmbedFooter(text, iconUrl);
@@ -114,49 +123,57 @@ namespace DiscordChatExporter.Core.Services
             var title = json["title"]?.Value<string>();
             var description = json["description"]?.Value<string>();
             var url = json["url"]?.Value<string>();
-            var timestamp = json["timestamp"]?.Value<DateTime>();
+            var timestamp = json["timestamp"]?.Value<DateTime>().ToDateTimeOffset();
 
             // Get color
             var color = json["color"] != null
-                ? Color.FromArgb(json["color"].Value<int>()).ResetAlpha()
-                : Color.FromArgb(79, 84, 92); // default color
+                ? Color.FromArgb(json["color"]!.Value<int>()).ResetAlpha()
+                : default(Color?);
 
             // Get author
-            var author = json["author"] != null ? ParseEmbedAuthor(json["author"]) : null;
+            var author = json["author"] != null ? ParseEmbedAuthor(json["author"]!) : null;
 
             // Get fields
-            var fields = json["fields"].EmptyIfNull().Select(ParseEmbedField).ToArray();
+            var fields = (json["fields"] ?? Enumerable.Empty<JToken>()).Select(ParseEmbedField).ToArray();
 
             // Get thumbnail
-            var thumbnail = json["thumbnail"] != null ? ParseEmbedImage(json["thumbnail"]) : null;
+            var thumbnail = json["thumbnail"] != null ? ParseEmbedImage(json["thumbnail"]!) : null;
 
             // Get image
-            var image = json["image"] != null ? ParseEmbedImage(json["image"]) : null;
+            var image = json["image"] != null ? ParseEmbedImage(json["image"]!) : null;
 
             // Get footer
-            var footer = json["footer"] != null ? ParseEmbedFooter(json["footer"]) : null;
+            var footer = json["footer"] != null ? ParseEmbedFooter(json["footer"]!) : null;
 
             return new Embed(title, url, timestamp, color, author, description, fields, thumbnail, image, footer);
         }
 
+        private Emoji ParseEmoji(JToken json)
+        {
+            var id = json["id"]?.Value<string>();
+            var name = json["name"]!.Value<string>();
+            var isAnimated = json["animated"]?.Value<bool>() ?? false;
+
+            return new Emoji(id, name, isAnimated);
+        }
+
         private Reaction ParseReaction(JToken json)
         {
-            var count = json["count"].Value<int>();
-            var emojiId = json["emoji"]["id"]?.Value<string>();
-            var emojiName = json["emoji"]["name"].Value<string>();
+            var count = json["count"]!.Value<int>();
+            var emoji = ParseEmoji(json["emoji"]!);
 
-            return new Reaction(count, emojiId, emojiName);
+            return new Reaction(count, emoji);
         }
 
         private Message ParseMessage(JToken json)
         {
             // Get basic data
-            var id = json["id"].Value<string>();
-            var channelId = json["channel_id"].Value<string>();
-            var timestamp = json["timestamp"].Value<DateTime>();
-            var editedTimestamp = json["edited_timestamp"]?.Value<DateTime?>();
-            var content = json["content"].Value<string>();
-            var type = (MessageType) json["type"].Value<int>();
+            var id = json["id"]!.Value<string>();
+            var channelId = json["channel_id"]!.Value<string>();
+            var timestamp = json["timestamp"]!.Value<DateTime>().ToDateTimeOffset();
+            var editedTimestamp = json["edited_timestamp"]?.Value<DateTime?>()?.ToDateTimeOffset();
+            var content = json["content"]!.Value<string>();
+            var type = (MessageType) json["type"]!.Value<int>();
 
             // Workarounds for non-default types
             if (type == MessageType.RecipientAdd)
@@ -175,21 +192,24 @@ namespace DiscordChatExporter.Core.Services
                 content = "Joined the server.";
 
             // Get author
-            var author = ParseUser(json["author"]);
+            var author = ParseUser(json["author"]!);
 
             // Get attachments
-            var attachments = json["attachments"].EmptyIfNull().Select(ParseAttachment).ToArray();
+            var attachments = (json["attachments"] ?? Enumerable.Empty<JToken>()).Select(ParseAttachment).ToArray();
 
             // Get embeds
-            var embeds = json["embeds"].EmptyIfNull().Select(ParseEmbed).ToArray();
+            var embeds = (json["embeds"] ?? Enumerable.Empty<JToken>()).Select(ParseEmbed).ToArray();
 
             // Get reactions
-            var reactions = json["reactions"].EmptyIfNull().Select(ParseReaction).ToArray();
+            var reactions = (json["reactions"] ?? Enumerable.Empty<JToken>()).Select(ParseReaction).ToArray();
 
-            // Get mentioned users
-            var mentionedUsers = json["mentions"].EmptyIfNull().Select(ParseUser).ToArray();
+            // Get mentions
+            var mentionedUsers = (json["mentions"] ?? Enumerable.Empty<JToken>()).Select(ParseUser).ToArray();
 
-            return new Message(id, channelId, type, author, timestamp, editedTimestamp, content, attachments, embeds,
+            // Get whether this message is pinned
+            var isPinned = json["pinned"]!.Value<bool>();
+
+            return new Message(id, channelId, type, author, timestamp, editedTimestamp, isPinned, content, attachments, embeds,
                 reactions, mentionedUsers);
         }
     }

DiscordChatExporter.Core.Services/DataService.cs

@@ -0,0 +1,214 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Services.Exceptions;
+using DiscordChatExporter.Core.Services.Internal;
+using Newtonsoft.Json.Linq;
+using Polly;
+
+namespace DiscordChatExporter.Core.Services
+{
+    public partial class DataService : IDisposable
+    {
+        private readonly HttpClient _httpClient = new HttpClient();
+        private readonly IAsyncPolicy<HttpResponseMessage> _httpPolicy;
+
+        public DataService()
+        {
+            _httpClient.BaseAddress = new Uri("https://discordapp.com/api/v6");
+
+            // Discord seems to always respond 429 on our 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.
+            _httpPolicy = 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);
+        }
+
+        private async Task<JToken> GetApiResponseAsync(AuthToken token, string route)
+        {
+            using var response = await _httpPolicy.ExecuteAsync(async () =>
+            {
+                using var request = new HttpRequestMessage(HttpMethod.Get, route);
+
+                request.Headers.Authorization = token.Type == AuthTokenType.Bot
+                    ? new AuthenticationHeaderValue("Bot", token.Value)
+                    : new AuthenticationHeaderValue(token.Value);
+
+                return await _httpClient.SendAsync(request);
+            });
+
+            // We throw our own exception here because default one doesn't have status code
+            if (!response.IsSuccessStatusCode)
+                throw new HttpErrorStatusCodeException(response.StatusCode, response.ReasonPhrase);
+
+            var jsonRaw = await response.Content.ReadAsStringAsync();
+            return JToken.Parse(jsonRaw);
+        }
+
+        public async Task<Guild> GetGuildAsync(AuthToken token, string guildId)
+        {
+            // Special case for direct messages pseudo-guild
+            if (guildId == Guild.DirectMessages.Id)
+                return Guild.DirectMessages;
+
+            var response = await GetApiResponseAsync(token, $"guilds/{guildId}");
+            var guild = ParseGuild(response);
+
+            return guild;
+        }
+
+        public async Task<Channel> GetChannelAsync(AuthToken token, string channelId)
+        {
+            var response = await GetApiResponseAsync(token, $"channels/{channelId}");
+            var channel = ParseChannel(response);
+
+            return channel;
+        }
+
+        public async IAsyncEnumerable<Guild> GetUserGuildsAsync(AuthToken token)
+        {
+            var afterId = "";
+
+            while (true)
+            {
+                var route = "users/@me/guilds?limit=100";
+                if (!string.IsNullOrWhiteSpace(afterId))
+                    route += $"&after={afterId}";
+
+                var response = await GetApiResponseAsync(token, route);
+
+                if (!response.HasValues)
+                    yield break;
+
+                foreach (var guild in response.Select(ParseGuild))
+                {
+                    yield return guild;
+                    afterId = guild.Id;
+                }
+            }
+        }
+
+        public async Task<IReadOnlyList<Channel>> GetDirectMessageChannelsAsync(AuthToken token)
+        {
+            var response = await GetApiResponseAsync(token, "users/@me/channels");
+            var channels = response.Select(ParseChannel).ToArray();
+
+            return channels;
+        }
+
+        public async Task<IReadOnlyList<Channel>> GetGuildChannelsAsync(AuthToken token, string guildId)
+        {
+            // Special case for direct messages pseudo-guild
+            if (guildId == Guild.DirectMessages.Id)
+                return Array.Empty<Channel>();
+
+            var response = await GetApiResponseAsync(token, $"guilds/{guildId}/channels");
+            var channels = response.Select(ParseChannel).ToArray();
+
+            return channels;
+        }
+
+        public async Task<IReadOnlyList<Role>> GetGuildRolesAsync(AuthToken token, string guildId)
+        {
+            // Special case for direct messages pseudo-guild
+            if (guildId == Guild.DirectMessages.Id)
+                return Array.Empty<Role>();
+
+            var response = await GetApiResponseAsync(token, $"guilds/{guildId}/roles");
+            var roles = response.Select(ParseRole).ToArray();
+
+            return roles;
+        }
+
+        private async Task<Message> GetLastMessageAsync(AuthToken token, string channelId, DateTimeOffset? before = null)
+        {
+            var route = $"channels/{channelId}/messages?limit=1";
+            if (before != null)
+                route += $"&before={before.Value.ToSnowflake()}";
+
+            var response = await GetApiResponseAsync(token, route);
+
+            return response.Select(ParseMessage).FirstOrDefault();
+        }
+
+        public async IAsyncEnumerable<Message> GetMessagesAsync(AuthToken token, string channelId,
+            DateTimeOffset? after = null, DateTimeOffset? before = null, IProgress<double>? progress = null)
+        {
+            // Get the last message
+            var lastMessage = await GetLastMessageAsync(token, channelId, before);
+
+            // If the last message doesn't exist or it's outside of range - return
+            if (lastMessage == null || lastMessage.Timestamp < after)
+            {
+                progress?.Report(1);
+                yield break;
+            }
+
+            // Get other messages
+            var firstMessage = default(Message);
+            var afterId = after?.ToSnowflake() ?? "0";
+            while (true)
+            {
+                // Get message batch
+                var route = $"channels/{channelId}/messages?limit=100&after={afterId}";
+                var response = await GetApiResponseAsync(token, route);
+
+                // Parse
+                var messages = response
+                    .Select(ParseMessage)
+                    .Reverse() // reverse because messages appear newest first
+                    .ToArray();
+
+                // Break if there are no messages (can happen if messages are deleted during execution)
+                if (!messages.Any())
+                    break;
+
+                // Trim messages to range (until last message)
+                var messagesInRange = messages
+                    .TakeWhile(m => m.Id != lastMessage.Id && m.Timestamp < lastMessage.Timestamp)
+                    .ToArray();
+
+                // Yield messages
+                foreach (var message in messagesInRange)
+                {
+                    // Set first message if it's not set
+                    firstMessage ??= message;
+
+                    // Report progress (based on the time range of parsed messages compared to total)
+                    progress?.Report((message.Timestamp - firstMessage.Timestamp).TotalSeconds /
+                                     (lastMessage.Timestamp - firstMessage.Timestamp).TotalSeconds);
+
+                    yield return message;
+                    afterId = message.Id;
+                }
+
+                // Break if messages were trimmed (which means the last message was encountered)
+                if (messagesInRange.Length != messages.Length)
+                    break;
+            }
+
+            // Yield last message
+            yield return lastMessage;
+            progress?.Report(1);
+        }
+
+        public void Dispose() => _httpClient.Dispose();
+    }
+}

DiscordChatExporter.Core.Services/DiscordChatExporter.Core.Services.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="../DiscordChatExporter.props" />
+
+  <ItemGroup>
+    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+    <PackageReference Include="Onova" Version="2.5.2" />
+    <PackageReference Include="Polly" Version="7.2.0" />
+    <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
+    <PackageReference Include="Tyrrrz.Settings" Version="1.3.4" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\DiscordChatExporter.Core.Models\DiscordChatExporter.Core.Models.csproj" />
+    <ProjectReference Include="..\DiscordChatExporter.Core.Rendering\DiscordChatExporter.Core.Rendering.csproj" />
+  </ItemGroup>
+
+</Project>

DiscordChatExporter.Core.Services/Exceptions/HttpErrorStatusCodeException.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Net;
 
-namespace DiscordChatExporter.Core.Exceptions
+namespace DiscordChatExporter.Core.Services.Exceptions
 {
     public class HttpErrorStatusCodeException : Exception
     {

DiscordChatExporter.Core.Services/ExportService.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using DiscordChatExporter.Core.Models;
+using DiscordChatExporter.Core.Models.Exceptions;
+using DiscordChatExporter.Core.Rendering;
+using DiscordChatExporter.Core.Services.Logic;
+using Tyrrrz.Extensions;
+
+namespace DiscordChatExporter.Core.Services
+{
+    public partial class ExportService
+    {
+        private readonly SettingsService _settingsService;
+        private readonly DataService _dataService;
+
+        public ExportService(SettingsService settingsService, DataService dataService)
+        {
+            _settingsService = settingsService;
+            _dataService = dataService;
+        }
+
+        public async Task ExportChatLogAsync(AuthToken token, Guild guild, Channel channel,
+            string outputPath, ExportFormat format, int? partitionLimit,
+            DateTimeOffset? after = null, DateTimeOffset? before = null, IProgress<double>? progress = null)
+        {
+            // Get base file path from output path
+            var baseFilePath = GetFilePathFromOutputPath(outputPath, format, guild, channel, after, before);
+
+            // Create options
+            var options = new RenderOptions(baseFilePath, format, partitionLimit);
+
+            // Create context
+            var mentionableUsers = new HashSet<User>(IdBasedEqualityComparer.Instance);
+            var mentionableChannels = await _dataService.GetGuildChannelsAsync(token, guild.Id);
+            var mentionableRoles = await _dataService.GetGuildRolesAsync(token, guild.Id);
+
+            var context = new RenderContext
+            (
+                guild, channel, after, before, _settingsService.DateFormat,
+                mentionableUsers, mentionableChannels, mentionableRoles
+            );
+
+            // Create renderer
+            await using var renderer = new MessageRenderer(options, context);
+
+            // Render messages
+            var renderedAnything = false;
+            await foreach (var message in _dataService.GetMessagesAsync(token, channel.Id, after, before, progress))
+            {
+                // Add encountered users to the list of mentionable users
+                mentionableUsers.Add(message.Author);
+                mentionableUsers.AddRange(message.MentionedUsers);
+
+                // Render message
+                await renderer.RenderMessageAsync(message);
+                renderedAnything = true;
+            }
+
+            // Throw if no messages were rendered
+            if (!renderedAnything)
+                throw new DomainException($"Channel [{channel.Name}] contains no messages for specified period");
+        }
+    }
+
+    public partial class ExportService
+    {
+        private static string GetFilePathFromOutputPath(string outputPath, ExportFormat format, Guild guild, Channel channel,
+            DateTimeOffset? after, DateTimeOffset? before)
+        {
+            // Output is a directory
+            if (Directory.Exists(outputPath) || string.IsNullOrWhiteSpace(Path.GetExtension(outputPath)))
+            {
+                var fileName = ExportLogic.GetDefaultExportFileName(format, guild, channel, after, before);
+                return Path.Combine(outputPath, fileName);
+            }
+
+            // Output is a file
+            return outputPath;
+        }
+    }
+}

DiscordChatExporter.Core.Services/Extensions.cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+
+namespace DiscordChatExporter.Core.Services
+{
+    public static class Extensions
+    {
+        private static async ValueTask<IReadOnlyList<T>> AggregateAsync<T>(this IAsyncEnumerable<T> asyncEnumerable)
+        {
+            var list = new List<T>();
+
+            await foreach (var i in asyncEnumerable)
+                list.Add(i);
+
+            return list;
+        }
+
+        public static ValueTaskAwaiter<IReadOnlyList<T>> GetAwaiter<T>(this IAsyncEnumerable<T> asyncEnumerable) =>
+            asyncEnumerable.AggregateAsync().GetAwaiter();
+    }
+}

DiscordChatExporter.Core.Services/Internal/Extensions.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Drawing;
+
+namespace DiscordChatExporter.Core.Services.Internal
+{
+    internal static class Extensions
+    {
+        public static DateTimeOffset ToDateTimeOffset(this DateTime dateTime) => new DateTimeOffset(dateTime);
+
+        public static string ToSnowflake(this DateTimeOffset dateTime)
+        {
+            var value = ((ulong) dateTime.ToUnixTimeMilliseconds() - 1420070400000UL) << 22;
+            return value.ToString();
+        }
+
+        public static Color ResetAlpha(this Color color) => Color.FromArgb(1, color);
+    }
+}

DiscordChatExporter.Core.Services/Logic/ExportLogic.cs

@@ -0,0 +1,53 @@
+using System;
+using System.IO;
+using System.Text;
+using DiscordChatExporter.Core.Models;
+
+namespace DiscordChatExporter.Core.Services.Logic
+{
+    public static class ExportLogic
+    {
+        public static string GetDefaultExportFileName(ExportFormat format,
+            Guild guild, Channel channel,
+            DateTimeOffset? after = null, DateTimeOffset? before = null)
+        {
+            var buffer = new StringBuilder();
+
+            // Append guild and channel names
+            buffer.Append($"{guild.Name} - {channel.Name} [{channel.Id}]");
+
+            // Append date range
+            if (after != null || before != null)
+            {
+                buffer.Append(" (");
+
+                // Both 'after' and 'before' are set
+                if (after != null && before != null)
+                {
+                    buffer.Append($"{after:yyyy-MM-dd} to {before:yyyy-MM-dd}");
+                }
+                // Only 'after' is set
+                else if (after != null)
+                {
+                    buffer.Append($"after {after:yyyy-MM-dd}");
+                }
+                // Only 'before' is set
+                else
+                {
+                    buffer.Append($"before {before:yyyy-MM-dd}");
+                }
+
+                buffer.Append(")");
+            }
+
+            // Append extension
+            buffer.Append($".{format.GetFileExtension()}");
+
+            // Replace invalid chars
+            foreach (var invalidChar in Path.GetInvalidFileNameChars())
+                buffer.Replace(invalidChar, '_');
+
+            return buffer.ToString();
+        }
+    }
+}