Add channel system with CLI, Telegram, and Web channel implementations

Define channel abstractions (IChannel, IChannelManager) with event-driven message and connection handling. Implement ChannelManager for multi-channel orchestration, CliChannel for terminal I/O, TelegramChannel with adapter pattern for bot API integration, and WebChannel stub. Includes DI registration and channel type enumeration.
2026-04-04 04:12:11 +02:00
parent dd35e1dea6
commit 9a05bae4a9
13 changed files with 642 additions and 0 deletions
@@ -0,0 +1,161 @@
+using System.Text;
+using Luna.Channels.Abstractions;
+using Luna.Configuration;
+using Luna.Shared;
+using Microsoft.Extensions.Logging;
+using Telegram.Bot;
+using Telegram.Bot.Types.Enums;
+
+namespace Luna.Channels.Telegram;
+
+public class TelegramChannel(
+    string chatId,
+    ITelegramBotClient botClient,
+    ILogger<TelegramChannel> logger,
+    TelegramOptions options) : IChannel
+{
+    private const int TelegramMessageCharLimit = 4096;
+
+    public string ChannelId { get; } = chatId;
+    public string ChannelType => Abstractions.ChannelType.Telegram;
+    public string DisplayName { get; } = $"Telegram Chat {chatId}";
+    public bool IsConnected { get; private set; } = true;
+
+    public event ChannelMessageReceivedEventHandler? MessageReceived;
+    public event ChannelConnectionChangedEventHandler? ConnectionStateChanged;
+
+    public async Task SendMessageAsync(ChannelMessage message, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var targetChatId = long.Parse(ChannelId);
+            await botClient.SendMessage(targetChatId, message.Content, cancellationToken: cancellationToken);
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Failed to send message to Telegram chat {ChatId}", ChannelId);
+        }
+    }
+
+    public async Task SendStreamingMessageAsync(
+        IAsyncEnumerable<ChatStreamUpdate> messageStream,
+        CancellationToken cancellationToken = default)
+    {
+        var targetChatId = long.Parse(ChannelId);
+        int? currentMessageId = null;
+
+        var typingCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        var typingTask = KeepTypingAsync(targetChatId, typingCts.Token);
+
+        var messageBuilder = new StringBuilder();
+        await foreach (var update in messageStream.WithCancellation(cancellationToken))
+        {
+            if (update.Content is not null)
+                messageBuilder.Append(update.Content);
+
+            if (messageBuilder.Length <= TelegramMessageCharLimit) 
+                continue;
+            
+            try
+            {
+                var currentMessageContent = messageBuilder.ToString();
+                var splitByParagraph = currentMessageContent.Split('\n');
+
+                var i = 0;
+                var builder = new StringBuilder();
+                foreach (var paragraph in splitByParagraph)
+                {
+                    if (builder.Length + paragraph.Length < TelegramMessageCharLimit)
+                    {
+                        builder.AppendLine(paragraph);
+                        i++;
+                        continue;
+                    }
+
+                    await botClient.SendMessage(
+                        targetChatId,
+                        builder.ToString(),
+                        cancellationToken: cancellationToken);
+
+                    messageBuilder.Clear();
+                    messageBuilder.Append(string.Join('\n', splitByParagraph[i..]));
+                    break;
+                }
+            }
+            catch (Exception ex)
+            {
+                await typingCts.CancelAsync();
+                logger.LogError(ex, "Failed to send streaming update to Telegram chat {ChatId}", ChannelId);
+            }
+        }
+        
+        try
+        {
+            if (messageBuilder.Length > 0)
+            {
+                await botClient.SendMessage(
+                    targetChatId,
+                    messageBuilder.ToString(),
+                    cancellationToken: cancellationToken);
+            }
+        }
+        catch (Exception ex)
+        {
+            await typingCts.CancelAsync();
+            logger.LogError(ex, "Failed to send streaming update to Telegram chat {ChatId}", ChannelId);
+        }
+        
+        await typingCts.CancelAsync();
+    }
+
+    /// <summary>
+    /// Called by TelegramAdapter when an incoming message is received for this chat.
+    /// Applies AllowedUserIds filtering and null/empty text filtering before raising the event.
+    /// </summary>
+    public void RaiseMessageReceived(ChannelMessage message)
+    {
+        if (string.IsNullOrEmpty(message.Content))
+            return;
+
+        if (options.AllowedUserIds.Length > 0 &&
+            !options.AllowedUserIds.Contains(message.SenderId))
+            return;
+
+        MessageReceived?.Invoke(this, new ChannelMessageReceivedEventArgs
+        {
+            Channel = this,
+            Message = message,
+            IsHandled = false
+        });
+    }
+
+    public void Dispose()
+    {
+        IsConnected = false;
+        ConnectionStateChanged?.Invoke(this, new ChannelConnectionEventArgs
+        {
+            Channel = this,
+            IsConnected = false
+        });
+    }
+
+    private async Task KeepTypingAsync(long chatId, CancellationToken ct)
+    {
+        while (!ct.IsCancellationRequested)
+        {
+            try
+            {
+                await botClient.SendChatAction(chatId, ChatAction.Typing, null, null, ct);
+                await Task.Delay(4000, ct);
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                logger.LogError(ex, "Failed to send typing action to Telegram chat {ChatId}", chatId);
+            }
+        }
+    }
+}