Option to Offload non-technical PR discussion to a Discord Thread (#86068)

This was discussed in #maintainerbus on the Discord.
@tgstation/commit-access

Result of this PR: 

- Add the `Discord Discussion` label to the PR. 
- The bot will create the thread, link it in the PR, and lock the PR.
Slowmode set to 1 minute. Auto-archive duration set to max of 1 week.
- The thread will be archived if the PR is merged or closed, unarchived
if it's reopened.
- You can also set a join link for the Discord to appear in the GitHub
comment. I'll be setting it to our official link at
https://tgstation13.org/phpBB/viewforum.php?f=60


![image](https://github.com/user-attachments/assets/2cdbe762-2339-4467-8b80-d1bf939b43e4)


![image](https://github.com/user-attachments/assets/b5cb25a4-18ee-40a0-a3eb-c36cf38ca8dc)
Let the bikeshed commence

.github/workflows/discord_discussions.yml

@@ -0,0 +1,52 @@
+name: Discord Discussions
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - reopened
+      - edited
+      - labeled
+      - closed
+    branches:
+      - master
+
+concurrency:
+  group: "discord-discussions-${{ github.head_ref }}"
+  cancel-in-progress: true
+
+jobs:
+  manage-discord-discussion:
+    name: Manage Discord Discussion
+    runs-on: ubuntu-latest
+    if: contains(github.event.pull_request.labels.*.name, 'Discord Discussion')
+    steps:
+      - name: Fail if vars.DISCORD_DISCUSSIONS_CHANNEL_ID is unset
+        if: ${{ vars.DISCORD_DISCUSSIONS_CHANNEL_ID == '' }}
+        run: |
+          echo "vars.DISCORD_DISCUSSIONS_CHANNEL_ID (${{ vars.DISCORD_DISCUSSIONS_CHANNEL_ID }}) must be set to use this label!"
+          exit 1
+
+      - name: Setup dotnet
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 8.0.x
+          dotnet-quality: ga
+
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build Tgstation.DiscordDiscussions
+        run: dotnet publish -c Release -o discord_discussions_bins tools/Tgstation.DiscordDiscussions/Tgstation.DiscordDiscussions.csproj
+
+      - name: Generate App Token
+        id: app-token-generation
+        uses: getsentry/action-github-app-token@d4b5da6c5e37703f8c3b3e43abb5705b46e159cc
+        with:
+          app_id: ${{ secrets.APP_ID }}
+          private_key: ${{ secrets.APP_PRIVATE_KEY }}
+
+      - name: Run Tgstation.DiscordDiscussions
+        run: dotnet discord_discussions_bins/Tgstation.DiscordDiscussions.dll ${{ steps.app-token-generation.outputs.token }} ${{ github.repository_owner }} ${{ github.event.repository.name }} ${{ github.event.pull_request.number }} ${{ github.event.pull_request.merged && 'merged' || github.event.pull_request.state }} ${{ secrets.DISCORD_DISCUSSIONS_TOKEN }} ${{ vars.DISCORD_DISCUSSIONS_CHANNEL_ID }} ${{ github.event.action == 'reopened' && 'true' || 'false' }} ${{ vars.DISCORD_JOIN_LINK }}
+        env:
+          GITHUB_PULL_REQUEST_TITLE: ${{ github.event.pull_request.title }}

.gitignore

@@ -180,6 +180,10 @@ Temporary Items
 /tools/MapAtmosFixer/MapAtmosFixer/bin/*
 /tools/CreditsTool/bin/*
 /tools/CreditsTool/obj/*
+/tools/Tgstation.DiscordDiscussions/.vs/*
+/tools/Tgstation.DiscordDiscussions/bin/*
+/tools/Tgstation.DiscordDiscussions/obj/*
+/tools/Tgstation.DiscordDiscussions/Properties/launchSettings.json
 
 #GitHub Atom
 .atom-build.json

tools/Tgstation.DiscordDiscussions/DiscordForwardingResponder.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+using Remora.Discord.API.Abstractions.Gateway.Events;
+using Remora.Discord.Gateway.Responders;
+using Remora.Results;
+
+namespace Tgstation.DiscordDiscussions
+{
+	/// <summary>
+	/// An <see cref="IResponder{TGatewayEvent}"/> that forwards to another <see cref="targetResponder"/>.
+	/// </summary>
+	/// <remarks>
+	/// Initializes a new instance of the <see cref="DiscordForwardingResponder"/> class.
+	/// </remarks>
+	/// <param name="targetResponder">The value of <see cref="targetResponder"/>.</param>
+	sealed class DiscordForwardingResponder(IDiscordResponders targetResponder) : IDiscordResponders
+	{
+		/// <summary>
+		/// The <see cref="IResponder{TGatewayEvent}"/> to forward the event to.
+		/// </summary>
+		readonly IDiscordResponders targetResponder = targetResponder ?? throw new ArgumentNullException(nameof(targetResponder));
+
+		/// <inheritdoc />
+		public Task<Result> RespondAsync(IReady gatewayEvent, CancellationToken ct) => targetResponder.RespondAsync(gatewayEvent, ct);
+	}
+}

tools/Tgstation.DiscordDiscussions/IDiscordResponders.cs

@@ -0,0 +1,9 @@
+using Remora.Discord.API.Abstractions.Gateway.Events;
+using Remora.Discord.Gateway.Responders;
+
+namespace Tgstation.DiscordDiscussions
+{
+	internal interface IDiscordResponders : IResponder<IReady>
+	{
+	}
+}

tools/Tgstation.DiscordDiscussions/Program.cs

@@ -0,0 +1,307 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading;
+using System.Threading.Tasks;
+
+using Microsoft.Extensions.DependencyInjection;
+
+using Octokit;
+
+using Remora.Discord.API.Abstractions.Gateway.Events;
+using Remora.Discord.API.Abstractions.Objects;
+using Remora.Discord.API.Abstractions.Rest;
+using Remora.Discord.API.Objects;
+using Remora.Discord.Gateway;
+using Remora.Discord.Gateway.Extensions;
+using Remora.Rest.Core;
+using Remora.Rest.Results;
+using Remora.Results;
+
+namespace Tgstation.DiscordDiscussions
+{
+	public sealed partial class Program : IDiscordResponders
+	{
+		const bool LockPullRequest = true;
+		const int InitSlowModeSeconds = 60;
+
+		[GeneratedRegex(@"https://discord.com/channels/[0-9]+/([0-9]+)")]
+		private static partial Regex ChannelLinkRegex();
+
+		readonly TaskCompletionSource gatewayReadyTcs;
+
+		public static Task<int> Main(string[] args)
+			=> new Program().RunAsync(args);
+
+		/// <summary>
+		/// Converts a given <paramref name="result"/> into a log entry <see cref="string"/>.
+		/// </summary>
+		/// <param name="result">The <see cref="IResult"/> to convert.</param>
+		/// <param name="level">Used internally for nesting.</param>
+		/// <returns>The <see cref="string"/> formatted <paramref name="result"/>.</returns>
+		static string LogFormat(IResult result, uint level = 0)
+		{
+			ArgumentNullException.ThrowIfNull(result);
+
+			if (result.IsSuccess)
+				return "SUCCESS?";
+
+			var stringBuilder = new StringBuilder();
+			if (result.Error != null)
+			{
+				stringBuilder.Append(result.Error.Message);
+				if (result.Error is RestResultError<RestError> restError)
+				{
+					stringBuilder.Append(" (");
+					if (restError.Error != null)
+					{
+						stringBuilder.Append(restError.Error.Code);
+						stringBuilder.Append(": ");
+						stringBuilder.Append(restError.Error.Message);
+						stringBuilder.Append('|');
+					}
+
+					stringBuilder.Append(restError.Message);
+					if ((restError.Error?.Errors.HasValue ?? false) && restError.Error.Errors.Value.Count > 0)
+					{
+						stringBuilder.Append(" (");
+						foreach (var error in restError.Error.Errors.Value)
+						{
+							stringBuilder.Append(error.Key);
+							stringBuilder.Append(':');
+							if (error.Value.IsT0)
+							{
+								FormatErrorDetails(error.Value.AsT0, stringBuilder);
+							}
+							else
+								FormatErrorDetails(error.Value.AsT1, stringBuilder);
+							stringBuilder.Append(',');
+						}
+
+						stringBuilder.Remove(stringBuilder.Length - 1, 1);
+					}
+
+					stringBuilder.Append(')');
+				}
+			}
+
+			if (result.Inner != null)
+			{
+				stringBuilder.Append(Environment.NewLine);
+				++level;
+				for (var i = 0; i < level; ++i)
+					stringBuilder.Append('\t');
+				stringBuilder.Append(LogFormat(result.Inner, level));
+			}
+
+			return stringBuilder.ToString();
+		}
+
+		/// <summary>
+		/// Formats given <paramref name="propertyErrorDetails"/> into a given <paramref name="stringBuilder"/>.
+		/// </summary>
+		/// <param name="propertyErrorDetails">The <see cref="IPropertyErrorDetails"/>.</param>
+		/// <param name="stringBuilder">The <see cref="StringBuilder"/> to mutate.</param>
+		static void FormatErrorDetails(IPropertyErrorDetails propertyErrorDetails, StringBuilder stringBuilder)
+		{
+			if (propertyErrorDetails == null)
+				return;
+
+			FormatErrorDetails(propertyErrorDetails.Errors, stringBuilder);
+
+			if (propertyErrorDetails.Errors != null && propertyErrorDetails.MemberErrors != null)
+			{
+				stringBuilder.Append(',');
+			}
+
+			if (propertyErrorDetails.MemberErrors != null)
+			{
+				stringBuilder.Append('{');
+				foreach (var error in propertyErrorDetails.MemberErrors)
+				{
+					stringBuilder.Append(error.Key);
+					stringBuilder.Append(':');
+					FormatErrorDetails(error.Value, stringBuilder);
+					stringBuilder.Append(',');
+				}
+
+				stringBuilder.Remove(stringBuilder.Length - 1, 1);
+				stringBuilder.Append('}');
+			}
+		}
+
+		/// <summary>
+		/// Formats given <paramref name="errorDetails"/> into a given <paramref name="stringBuilder"/>.
+		/// </summary>
+		/// <param name="errorDetails">The <see cref="IEnumerable{T}"/> of <see cref="IErrorDetails"/>.</param>
+		/// <param name="stringBuilder">The <see cref="StringBuilder"/> to mutate.</param>
+		static void FormatErrorDetails(IEnumerable<IErrorDetails>? errorDetails, StringBuilder stringBuilder)
+		{
+			if (errorDetails == null)
+				return;
+
+			stringBuilder.Append('[');
+			foreach (var error in errorDetails)
+			{
+				stringBuilder.Append(error.Code);
+				stringBuilder.Append(':');
+				stringBuilder.Append(error.Message);
+				stringBuilder.Append(',');
+			}
+
+			stringBuilder.Remove(stringBuilder.Length - 1, 1);
+			stringBuilder.Append(']');
+		}
+
+		Program()
+		{
+			gatewayReadyTcs = new TaskCompletionSource();
+		}
+
+		async Task<int> RunAsync(string[] args)
+		{
+			try
+			{
+				var gitHubToken = args[0];
+				var repoOwner = args[1];
+				var repoName = args[2];
+				var prNumber = Int32.Parse(args[3]);
+				var state = Enum.Parse<PullRequestState>(args[4]);
+				var discordToken = args[5];
+				var discussionsChannelId = UInt64.Parse(args[6]);
+				var isReopen = Boolean.Parse(args[7]);
+				var joinLink = args.Length > 8 ? args[8] : null;
+
+				var prTitle = Environment.GetEnvironmentVariable("GITHUB_PULL_REQUEST_TITLE");
+
+				var gitHubClient = new GitHubClient(new ProductHeaderValue("Tgstation.DiscordDiscussions"))
+				{
+					Credentials = new Credentials(gitHubToken),
+				};
+
+				const string GitHubCommentPrefix = "Maintainers have requested non-technical related discussion regarding this pull request be moved to the Discord.";
+
+				async ValueTask<ulong?> FindThreadID()
+				{
+					var comments = await gitHubClient.Issue.Comment.GetAllForIssue(repoOwner, repoName, prNumber);
+
+					var commentInQuestion = comments.FirstOrDefault(comment => comment.Body.StartsWith(GitHubCommentPrefix));
+					if (commentInQuestion == null)
+						return null;
+
+					// https://discord.com/channels/<guild ID>/<thread ID>
+					var threadId = UInt64.Parse(ChannelLinkRegex().Match(commentInQuestion.Body).Groups[1].Value);
+					return threadId;
+				}
+
+				var threadIdTask = FindThreadID();
+
+				await using var serviceProvider = new ServiceCollection()
+					.AddDiscordGateway(serviceProvider => discordToken)
+					.AddSingleton(serviceProvider => (IDiscordResponders)this)
+					.AddResponder<DiscordForwardingResponder>()
+					.BuildServiceProvider();
+
+				var gatewayClient = serviceProvider.GetRequiredService<DiscordGatewayClient>();
+				using var gatewayCts = new CancellationTokenSource();
+				var localGatewayTask = gatewayClient.RunAsync(gatewayCts.Token);
+				try
+				{
+					await gatewayReadyTcs.Task.WaitAsync(TimeSpan.FromMinutes(5));
+
+					var prLink = $"https://github.com/{repoOwner}/{repoName}/pull/{prNumber}";
+					var messageContent = $"#{prNumber} - {prTitle}";
+
+					var channelsClient = serviceProvider.GetRequiredService<IDiscordRestChannelAPI>();
+
+					var channelId = new Snowflake(discussionsChannelId);
+
+					var threadId = await threadIdTask;
+					Snowflake messageId;
+					if (!threadId.HasValue)
+					{
+						var channel = await channelsClient.GetChannelAsync(channelId);
+						if (!channel.IsSuccess)
+							throw new Exception(LogFormat(channel));
+
+						var threadMessage = await channelsClient.StartThreadInForumChannelAsync(channelId, messageContent, AutoArchiveDuration.Week, InitSlowModeSeconds, $"Maintainers have requested that discussion for [this pull request]({prLink}) be moved here.");
+						if (!threadMessage.IsSuccess)
+							throw new Exception(LogFormat(threadMessage));
+
+						messageId = threadMessage.Entity.ID;
+
+						var gitHubComment = $"{GitHubCommentPrefix}\nClick [here](https://discord.com/channels/{channel.Entity.GuildID.Value}/{messageId.Value}) to view the discussion.";
+						if (joinLink != null)
+							gitHubComment += $"\nClick [here]({joinLink}) to join the Discord!";
+
+						await gitHubClient.Issue.Comment.Create(repoOwner, repoName, prNumber, gitHubComment);
+					}
+					else
+					{
+						messageId = new Snowflake(threadId.Value);
+
+						// open/close thread
+						if (state != PullRequestState.open)
+						{
+							var archiveMessage = await channelsClient.CreateMessageAsync(messageId, $"The associated pull request for this thread has been {state.ToString().ToLowerInvariant()}. This thread will now be archived.");
+							if (!archiveMessage.IsSuccess)
+								throw new Exception(LogFormat(archiveMessage));
+
+							var archiveAction = await channelsClient.ModifyThreadChannelAsync(messageId, messageContent, autoArchiveDuration: AutoArchiveDuration.Hour, isArchived: true);
+							if (!archiveAction.IsSuccess)
+								throw new Exception(LogFormat(archiveAction));
+						}
+						else if (isReopen)
+						{
+							var unarchiveMessage = await channelsClient.CreateMessageAsync(messageId, "The associated pull request for this thread has been reopened. This thread will now be reopened.");
+							if (!unarchiveMessage.IsSuccess)
+								throw new Exception(LogFormat(unarchiveMessage));
+
+							var unarchiveAction = await channelsClient.ModifyThreadChannelAsync(messageId, messageContent, autoArchiveDuration: AutoArchiveDuration.Week, isArchived: false);
+							if (!unarchiveMessage.IsSuccess)
+								throw new Exception(LogFormat(unarchiveMessage));
+						}
+						else
+						{
+							var response = await channelsClient.ModifyThreadChannelAsync(messageId, messageContent);
+							if (!response.IsSuccess)
+								throw new Exception(LogFormat(response));
+						}
+					}
+
+					// ensure the PR is locked
+					if (LockPullRequest)
+					{
+						await gitHubClient.PullRequest.LockUnlock.Lock(repoOwner, repoName, prNumber);
+					}
+
+					return 0;
+				}
+				finally
+				{
+					gatewayCts.Cancel();
+					try
+					{
+						await localGatewayTask.WaitAsync(TimeSpan.FromSeconds(10));
+					}
+					catch (OperationCanceledException)
+					{
+					}
+				}
+			}
+			catch (Exception ex)
+			{
+				Console.WriteLine(ex.ToString());
+				return 1;
+			}
+		}
+
+		public Task<Result> RespondAsync(IReady gatewayEvent, CancellationToken ct = default)
+		{
+			gatewayReadyTcs.TrySetResult();
+			return Task.FromResult(Result.FromSuccess());
+		}
+	}
+}

tools/Tgstation.DiscordDiscussions/PullRequestState.cs

@@ -0,0 +1,9 @@
+namespace Tgstation.DiscordDiscussions
+{
+	enum PullRequestState
+	{
+		closed,
+		open,
+		merged
+	}
+}

tools/Tgstation.DiscordDiscussions/Tgstation.DiscordDiscussions.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Octokit" Version="13.0.1" />
+    <PackageReference Include="Remora.Discord" Version="2024.2.0" />
+  </ItemGroup>
+
+</Project>

tools/Tgstation.DiscordDiscussions/Tgstation.DiscordDiscussions.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.9.34728.123
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tgstation.DiscordDiscussions", "Tgstation.DiscordDiscussions.csproj", "{345EAB82-40E0-4F20-A4A6-8052CB8D1A01}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{345EAB82-40E0-4F20-A4A6-8052CB8D1A01}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{345EAB82-40E0-4F20-A4A6-8052CB8D1A01}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{345EAB82-40E0-4F20-A4A6-8052CB8D1A01}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{345EAB82-40E0-4F20-A4A6-8052CB8D1A01}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {CBA935A0-8BBA-40CB-BC53-C339683858F4}
+	EndGlobalSection
+EndGlobal