add reply context extraction for Telegram messages

nanobot/channels/telegram.py

@@ -20,6 +20,7 @@ from nanobot.config.schema import TelegramConfig
 from nanobot.utils.helpers import split_message
 
 TELEGRAM_MAX_MESSAGE_LEN = 4000  # Telegram message character limit
+TELEGRAM_REPLY_CONTEXT_MAX_LEN = TELEGRAM_MAX_MESSAGE_LEN  # Max length for reply context in user message
 
 
 def _strip_md(s: str) -> str:
@@ -451,6 +452,7 @@ class TelegramChannel(BaseChannel):
     @staticmethod
     def _build_message_metadata(message, user) -> dict:
         """Build common Telegram inbound metadata payload."""
+        reply_to = getattr(message, "reply_to_message", None)
         return {
             "message_id": message.message_id,
             "user_id": user.id,
@@ -459,8 +461,37 @@ class TelegramChannel(BaseChannel):
             "is_group": message.chat.type != "private",
             "message_thread_id": getattr(message, "message_thread_id", None),
             "is_forum": bool(getattr(message.chat, "is_forum", False)),
+            "reply_to_message_id": getattr(reply_to, "message_id", None) if reply_to else None,
         }
 
+    @staticmethod
+    def _extract_reply_context(message) -> str | None:
+        """Extract content from the message being replied to, if any. Truncated to TELEGRAM_REPLY_CONTEXT_MAX_LEN."""
+        reply = getattr(message, "reply_to_message", None)
+        if not reply:
+            return None
+        text = getattr(reply, "text", None) or getattr(reply, "caption", None)
+        if text:
+            truncated = (
+                text[:TELEGRAM_REPLY_CONTEXT_MAX_LEN]
+                + ("..." if len(text) > TELEGRAM_REPLY_CONTEXT_MAX_LEN else "")
+            )
+            return f"[Reply to: {truncated}]"
+        # Reply has no text/caption; use type placeholder when it has media
+        if getattr(reply, "photo", None):
+            return "[Reply to: (image)]"
+        if getattr(reply, "document", None):
+            return "[Reply to: (document)]"
+        if getattr(reply, "voice", None):
+            return "[Reply to: (voice)]"
+        if getattr(reply, "video_note", None) or getattr(reply, "video", None):
+            return "[Reply to: (video)]"
+        if getattr(reply, "audio", None):
+            return "[Reply to: (audio)]"
+        if getattr(reply, "animation", None):
+            return "[Reply to: (animation)]"
+        return "[Reply to: (no text)]"
+
     async def _ensure_bot_identity(self) -> tuple[int | None, str | None]:
         """Load bot identity once and reuse it for mention/reply checks."""
         if self._bot_user_id is not None or self._bot_username is not None:
@@ -542,10 +573,14 @@ class TelegramChannel(BaseChannel):
         message = update.message
         user = update.effective_user
         self._remember_thread_context(message)
+        reply_ctx = self._extract_reply_context(message)
+        content = message.text or ""
+        if reply_ctx:
+            content = reply_ctx + "\n\n" + content
         await self._handle_message(
             sender_id=self._sender_id(user),
             chat_id=str(message.chat_id),
-            content=message.text,
+            content=content,
             metadata=self._build_message_metadata(message, user),
             session_key=self._derive_topic_session_key(message),
         )
@@ -625,6 +660,9 @@ class TelegramChannel(BaseChannel):
                 logger.error("Failed to download media: {}", e)
                 content_parts.append(f"[{media_type}: download failed]")
 
+        reply_ctx = self._extract_reply_context(message)
+        if reply_ctx is not None:
+            content_parts.insert(0, reply_ctx)
         content = "\n".join(content_parts) if content_parts else "[empty message]"
 
         logger.debug("Telegram message from {}: {}...", sender_id, content[:50])

tests/test_telegram_channel.py

@@ -1,10 +1,11 @@
+import asyncio
 from types import SimpleNamespace
 
 import pytest
 
 from nanobot.bus.events import OutboundMessage
 from nanobot.bus.queue import MessageBus
-from nanobot.channels.telegram import TelegramChannel
+from nanobot.channels.telegram import TELEGRAM_REPLY_CONTEXT_MAX_LEN, TelegramChannel
 from nanobot.config.schema import TelegramConfig
 
 
@@ -336,3 +337,86 @@ async def test_group_policy_open_accepts_plain_group_message() -> None:
 
     assert len(handled) == 1
     assert channel._app.bot.get_me_calls == 0
+
+
+def test_extract_reply_context_no_reply() -> None:
+    """When there is no reply_to_message, _extract_reply_context returns None."""
+    message = SimpleNamespace(reply_to_message=None)
+    assert TelegramChannel._extract_reply_context(message) is None
+
+
+def test_extract_reply_context_with_text() -> None:
+    """When reply has text, return prefixed string."""
+    reply = SimpleNamespace(text="Hello world", caption=None)
+    message = SimpleNamespace(reply_to_message=reply)
+    assert TelegramChannel._extract_reply_context(message) == "[Reply to: Hello world]"
+
+
+def test_extract_reply_context_with_caption_only() -> None:
+    """When reply has only caption (no text), caption is used."""
+    reply = SimpleNamespace(text=None, caption="Photo caption")
+    message = SimpleNamespace(reply_to_message=reply)
+    assert TelegramChannel._extract_reply_context(message) == "[Reply to: Photo caption]"
+
+
+def test_extract_reply_context_truncation() -> None:
+    """Reply text is truncated at TELEGRAM_REPLY_CONTEXT_MAX_LEN."""
+    long_text = "x" * (TELEGRAM_REPLY_CONTEXT_MAX_LEN + 100)
+    reply = SimpleNamespace(text=long_text, caption=None)
+    message = SimpleNamespace(reply_to_message=reply)
+    result = TelegramChannel._extract_reply_context(message)
+    assert result is not None
+    assert result.startswith("[Reply to: ")
+    assert result.endswith("...]")
+    assert len(result) == len("[Reply to: ]") + TELEGRAM_REPLY_CONTEXT_MAX_LEN + len("...")
+
+
+def test_extract_reply_context_no_text_no_media() -> None:
+    """When reply has no text/caption and no media, return (no text) placeholder."""
+    reply = SimpleNamespace(
+        text=None,
+        caption=None,
+        photo=None,
+        document=None,
+        voice=None,
+        video_note=None,
+        video=None,
+        audio=None,
+        animation=None,
+    )
+    message = SimpleNamespace(reply_to_message=reply)
+    assert TelegramChannel._extract_reply_context(message) == "[Reply to: (no text)]"
+
+
+def test_extract_reply_context_reply_to_photo() -> None:
+    """When reply has photo but no text/caption, return (image) placeholder."""
+    reply = SimpleNamespace(
+        text=None,
+        caption=None,
+        photo=[SimpleNamespace(file_id="x")],
+    )
+    message = SimpleNamespace(reply_to_message=reply)
+    assert TelegramChannel._extract_reply_context(message) == "[Reply to: (image)]"
+
+
+@pytest.mark.asyncio
+async def test_on_message_includes_reply_context() -> None:
+    """When user replies to a message, content passed to bus starts with reply context."""
+    channel = TelegramChannel(
+        TelegramConfig(enabled=True, token="123:abc", allow_from=["*"], group_policy="open"),
+        MessageBus(),
+    )
+    channel._app = _FakeApp(lambda: None)
+    handled = []
+    async def capture_handle(**kwargs) -> None:
+        handled.append(kwargs)
+    channel._handle_message = capture_handle
+    channel._start_typing = lambda _chat_id: None
+
+    reply = SimpleNamespace(text="Hello", message_id=2, from_user=SimpleNamespace(id=1))
+    update = _make_telegram_update(text="translate this", reply_to_message=reply)
+    await channel._on_message(update, None)
+
+    assert len(handled) == 1
+    assert handled[0]["content"].startswith("[Reply to: Hello]")
+    assert "translate this" in handled[0]["content"]