feat(github-bridge): send GitHub events as Telegram posts

src/HuaJiBot.NET.Plugin.GitHubBridge/EventDispatch/Broadcast.cs

@@ -1,6 +1,7 @@
 using HuaJiBot.NET.Bot;
 using HuaJiBot.NET.Interfaces;
 using HuaJiBot.NET.Plugin.GitHubBridge.Types.Generic;
+using HuaJiBot.NET.Utils;
 
 namespace HuaJiBot.NET.Plugin.GitHubBridge.EventDispatch;
 
@@ -9,15 +10,13 @@ internal static class Broadcast
     internal static async Task SendAsync(
         IPluginService service,
         IEnumerable<string> targets,
-        Func<Task<SendingMessageBase[]>> build
+        params SendingMessageBase[] messages
     )
     {
-        SendingMessageBase[]? messages = null;
         foreach (var target in targets)
         {
             try
             {
-                messages ??= await build();
                 await service.SendGroupMessageAsync(null, target, messages);
             }
             catch (Exception e)
@@ -30,3 +29,30 @@ Func<Task<SendingMessageBase[]>> build
     internal static bool IsBot(Sender sender) =>
         sender.Type == "Bot" || sender.Login.EndsWith("[bot]");
 }
+
+// Each card renders at most once per broadcast, however many targets and platforms use it.
+internal sealed class Cards : IDisposable
+{
+    private readonly List<TempFile.AutoDeleteFile> _files = [];
+
+    internal static Func<Task<T>> Once<T>(Func<Task<T>> build)
+    {
+        Lazy<Task<T>> value = new(build);
+        return () => value.Value;
+    }
+
+    internal Func<Task<string>> Card(Func<Task<TempFile.AutoDeleteFile>> build) =>
+        Once(async () =>
+        {
+            var file = await build();
+            lock (_files)
+                _files.Add(file);
+            return (string)file;
+        });
+
+    public void Dispose()
+    {
+        foreach (var file in _files)
+            file.Dispose();
+    }
+}

src/HuaJiBot.NET.Plugin.GitHubBridge/EventDispatch/GitHubPosts.cs

@@ -0,0 +1,79 @@
+using HuaJiBot.NET.Bot;
+using HuaJiBot.NET.Plugin.GitHubBridge.Types.IssueCommentEventBody;
+using HuaJiBot.NET.Plugin.GitHubBridge.Types.IssuesEventBody;
+using HuaJiBot.NET.Plugin.GitHubBridge.Types.PushEventBody;
+
+namespace HuaJiBot.NET.Plugin.GitHubBridge.EventDispatch;
+
+internal static class GitHubPosts
+{
+    internal const int ExcerptLimit = 280;
+
+    internal static Post Issue(
+        IssuesEventBody body,
+        Func<Task<string>> card,
+        Func<Task<SendingMessageBase[]>> fallback
+    ) =>
+        new(
+            $"{Post.Escape(body.Sender.Login)} {Verb(body.Action)} #{body.Issue.Number}",
+            fallback
+        )
+        {
+            Image = card,
+            Tags = ["issue", body.Repository.Name],
+            Links = [new($"打开 #{body.Issue.Number}", body.Issue.HtmlUrl.ToString())],
+        };
+
+    internal static Post Comment(
+        IssueCommentEventBody body,
+        Func<Task<string>> card,
+        Func<Task<SendingMessageBase[]>> fallback
+    ) =>
+        new($"{Post.Escape(body.Sender.Login)} 评论了 #{body.Issue.Number}", fallback)
+        {
+            Image = card,
+            Tags = ["comment", body.Repository.Name],
+            Links = [new("查看评论", body.Comment.HtmlUrl.ToString())],
+        };
+
+    internal static Post Push(
+        PushEventBody body,
+        Func<Task<string>> card,
+        Func<Task<SendingMessageBase[]>> fallback
+    ) =>
+        new(
+            $"{Post.Escape(body.Sender.Login)} 向 {Post.Escape(body.Ref.Split('/').Last())} 推送了 {body.Commits.Length} 个提交",
+            fallback
+        )
+        {
+            Image = card,
+            Tags = ["push", body.Repository.Name],
+            Links = [new("查看改动", body.Compare.ToString())],
+        };
+
+    internal static string? Excerpt(string? body)
+    {
+        if (body is null)
+            return null;
+        var text = body.ReplaceLineEndings("\n").Trim();
+        var lines = text.Split('\n');
+        if (lines.Length <= 6 && text.Length <= ExcerptLimit)
+            return text;
+        var head = string.Join('\n', lines.Take(3));
+        if (lines.Length > 3 && head.Length < ExcerptLimit)
+            return head + '…';
+        var end = ExcerptLimit - 1;
+        if (char.IsLowSurrogate(head[end]))
+            end--;
+        return head[..end] + '…';
+    }
+
+    private static string Verb(string action) =>
+        action switch
+        {
+            "opened" => "打开了",
+            "closed" => "关闭了",
+            "reopened" => "重新打开了",
+            _ => action,
+        };
+}

src/HuaJiBot.NET.Plugin.GitHubBridge/EventDispatch/IssuesEventDispatcher.cs

@@ -26,23 +26,22 @@ IssueCommentEventBody body
         plugin.Info($"IssueCommentEvent {repositoryFullName} {body.Action}");
         if (!ShouldBroadcast(body))
             return;
-        TempFile.AutoDeleteFile? tempImage = null;
-        try
-        {
-            await Broadcast.SendAsync(
-                plugin.Service,
-                plugin.GetBroadcastTargets(body.Repository),
-                async () =>
-                    [
-                        new ImageMessage(tempImage = await BuildCommentCardAsync(body)),
-                        new LinkMessage("View comment", await plugin.OrRawAsync(body.Issue.HtmlUrl)),
-                    ]
-            );
-        }
-        finally
-        {
-            tempImage?.Dispose();
-        }
+        using Cards cards = new();
+        var post = GitHubPosts.Comment(
+            body,
+            cards.Card(() => BuildCommentCardAsync(body, GitHubPosts.Excerpt(body.Comment.Body))),
+            Cards.Once<SendingMessageBase[]>(async () =>
+                [
+                    new ImageMessage(await cards.Card(() => BuildCommentCardAsync(body, body.Comment.Body))()),
+                    new LinkMessage("View comment", await plugin.OrRawAsync(body.Issue.HtmlUrl)),
+                ]
+            )
+        );
+        await Broadcast.SendAsync(
+            plugin.Service,
+            plugin.GetBroadcastTargets(body.Repository),
+            post
+        );
     }
 
     public static async Task DispatchIssuesEventAsync(this PluginMain plugin, IssuesEventBody body)
@@ -51,45 +50,50 @@ public static async Task DispatchIssuesEventAsync(this PluginMain plugin, Issues
         plugin.Info($"IssuesEvent {repositoryFullName} {body.Action}");
         if (!ShouldBroadcast(body))
             return;
-        TempFile.AutoDeleteFile? tempImage = null;
-        try
-        {
-            await Broadcast.SendAsync(
-                plugin.Service,
-                plugin.GetBroadcastTargets(body.Repository),
-                async () =>
-                    [
-                        new ImageMessage(tempImage = await BuildIssueCardAsync(body)),
-                        new LinkMessage(
-                            $"Open #{body.Issue.Number}",
-                            await plugin.OrRawAsync(body.Issue.HtmlUrl)
-                        ),
-                    ]
-            );
-        }
-        finally
-        {
-            tempImage?.Dispose();
-        }
+        using Cards cards = new();
+        var post = GitHubPosts.Issue(
+            body,
+            cards.Card(() => BuildIssueCardAsync(body, GitHubPosts.Excerpt(body.Issue.Body))),
+            Cards.Once<SendingMessageBase[]>(async () =>
+                [
+                    new ImageMessage(await cards.Card(() => BuildIssueCardAsync(body, body.Issue.Body))()),
+                    new LinkMessage(
+                        $"Open #{body.Issue.Number}",
+                        await plugin.OrRawAsync(body.Issue.HtmlUrl)
+                    ),
+                ]
+            )
+        );
+        await Broadcast.SendAsync(
+            plugin.Service,
+            plugin.GetBroadcastTargets(body.Repository),
+            post
+        );
     }
 
-    private static Task<TempFile.AutoDeleteFile> BuildCommentCardAsync(IssueCommentEventBody body) =>
+    private static Task<TempFile.AutoDeleteFile> BuildCommentCardAsync(
+        IssueCommentEventBody body,
+        string? content
+    ) =>
         BuildCardAsync(
             body.Repository,
             body.Issue,
             body.Sender,
             body.Issue.State,
-            body.Comment.Body,
+            content,
             $"@{body.Sender.Login} {body.Action} comment."
         );
 
-    private static Task<TempFile.AutoDeleteFile> BuildIssueCardAsync(IssuesEventBody body) =>
+    private static Task<TempFile.AutoDeleteFile> BuildIssueCardAsync(
+        IssuesEventBody body,
+        string? content
+    ) =>
         BuildCardAsync(
             body.Repository,
             body.Issue,
             body.Sender,
             body.Action is "opened" or "reopened" ? "open" : body.Action,
-            body.Issue.Body,
+            content,
             $"@{body.Sender.Login} {body.Action} issue"
         );
 

src/HuaJiBot.NET.Plugin.GitHubBridge/EventDispatch/PushEventDispatcher.cs

@@ -27,28 +27,24 @@ public static async Task DispatchPushEventAsync(this PluginMain plugin, PushEven
         }
         var repositoryFullName = body.Repository.FullName;
         plugin.Info($"PushEvent {repositoryFullName} {body.Ref}");
-        {
-            if (!ShouldBroadcast(body))
-                return;
-
-            TempFile.AutoDeleteFile? tempImage = null;
-            try
-            {
-                await Broadcast.SendAsync(
-                    plugin.Service,
-                    plugin.GetBroadcastTargets(body.Repository),
-                    async () =>
-                        [
-                            new ImageMessage(tempImage = await BuildPushCardAsync(body)),
-                            new LinkMessage("View changes", await plugin.OrRawAsync(body.Compare)),
-                        ]
-                );
-            }
-            finally
-            {
-                tempImage?.Dispose();
-            }
-        }
+        if (!ShouldBroadcast(body))
+            return;
+        using Cards cards = new();
+        var card = cards.Card(() => BuildPushCardAsync(body));
+        await Broadcast.SendAsync(
+            plugin.Service,
+            plugin.GetBroadcastTargets(body.Repository),
+            GitHubPosts.Push(
+                body,
+                card,
+                Cards.Once<SendingMessageBase[]>(async () =>
+                    [
+                        new ImageMessage(await card()),
+                        new LinkMessage("View changes", await plugin.OrRawAsync(body.Compare)),
+                    ]
+                )
+            )
+        );
     }
 
     private static async Task<TempFile.AutoDeleteFile> BuildPushCardAsync(PushEventBody body)

src/HuaJiBot.NET.UnitTest/BroadcastTest.cs

@@ -6,36 +6,27 @@ namespace HuaJiBot.NET.UnitTest;
 internal class BroadcastTest
 {
     [Test]
-    public async Task SendAsync_WithMultipleTargets_BuildsMessagesOnce()
+    public async Task SendAsync_SendsSameMessagesToEachTarget()
     {
         RecordingAdapter adapter = new();
-        var built = 0;
 
-        await Broadcast.SendAsync(
-            adapter,
-            ["g1", "g2"],
-            () =>
-            {
-                built++;
-                return Task.FromResult<SendingMessageBase[]>([new TextMessage("card")]);
-            }
-        );
+        await Broadcast.SendAsync(adapter, ["g1", "g2"], new TextMessage("card"));
 
         Assert.Multiple(() =>
         {
-            Assert.That(built, Is.EqualTo(1));
             Assert.That(adapter.Sends.Select(x => x.Target), Is.EqualTo(new[] { "g1", "g2" }));
             Assert.That(adapter.Sends.Select(x => x.Messages[0]), Is.All.EqualTo(new TextMessage("card")));
         });
     }
 
     [Test]
-    public async Task SendAsync_WithoutTargets_NeverBuildsMessages()
+    public async Task Cards_RenderEachCardOnce()
     {
-        await Broadcast.SendAsync(
-            new RecordingAdapter(),
-            [],
-            () => throw new InvalidOperationException("messages must not be built")
-        );
+        var renders = 0;
+        var card = Cards.Once(() => Task.FromResult(++renders));
+
+        await Task.WhenAll(card(), card(), card());
+
+        Assert.That(renders, Is.EqualTo(1));
     }
 }