Add media download functionality

tests/test_telegram_channel.py

@@ -1,5 +1,7 @@
 import asyncio
+from pathlib import Path
 from types import SimpleNamespace
+from unittest.mock import AsyncMock
 
 import pytest
 
@@ -43,6 +45,12 @@ class _FakeBot:
     async def send_chat_action(self, **kwargs) -> None:
         pass
 
+    async def get_file(self, file_id: str):
+        """Return a fake file that 'downloads' to a path (for reply-to-media tests)."""
+        async def _fake_download(path) -> None:
+            pass
+        return SimpleNamespace(download_to_drive=_fake_download)
+
 
 class _FakeApp:
     def __init__(self, on_start_polling) -> None:
@@ -389,14 +397,14 @@ def test_extract_reply_context_no_text_no_media() -> None:
 
 
 def test_extract_reply_context_reply_to_photo() -> None:
-    """When reply has photo but no text/caption, return (image) placeholder."""
+    """When reply has photo but no text/caption, return (image — not attached) 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)]"
+    assert TelegramChannel._extract_reply_context(message) == "[Reply to: (image — not attached)]"
 
 
 @pytest.mark.asyncio
@@ -420,3 +428,125 @@ async def test_on_message_includes_reply_context() -> None:
     assert len(handled) == 1
     assert handled[0]["content"].startswith("[Reply to: Hello]")
     assert "translate this" in handled[0]["content"]
+
+
+@pytest.mark.asyncio
+async def test_download_message_media_returns_path_when_download_succeeds(
+    monkeypatch, tmp_path
+) -> None:
+    """_download_message_media returns (paths, content_parts) when bot.get_file and download succeed."""
+    media_dir = tmp_path / "media" / "telegram"
+    media_dir.mkdir(parents=True)
+    monkeypatch.setattr(
+        "nanobot.channels.telegram.get_media_dir",
+        lambda channel=None: media_dir if channel else tmp_path / "media",
+    )
+
+    channel = TelegramChannel(
+        TelegramConfig(enabled=True, token="123:abc", allow_from=["*"]),
+        MessageBus(),
+    )
+    channel._app = _FakeApp(lambda: None)
+    channel._app.bot.get_file = AsyncMock(
+        return_value=SimpleNamespace(download_to_drive=AsyncMock(return_value=None))
+    )
+
+    msg = SimpleNamespace(
+        photo=[SimpleNamespace(file_id="fid123", mime_type="image/jpeg")],
+        voice=None,
+        audio=None,
+        document=None,
+        video=None,
+        video_note=None,
+        animation=None,
+    )
+    paths, parts = await channel._download_message_media(msg)
+    assert len(paths) == 1
+    assert len(parts) == 1
+    assert "fid123" in paths[0]
+    assert "[image:" in parts[0]
+
+
+@pytest.mark.asyncio
+async def test_on_message_attaches_reply_to_media_when_available(monkeypatch, tmp_path) -> None:
+    """When user replies to a message with media, that media is downloaded and attached to the turn."""
+    media_dir = tmp_path / "media" / "telegram"
+    media_dir.mkdir(parents=True)
+    monkeypatch.setattr(
+        "nanobot.channels.telegram.get_media_dir",
+        lambda channel=None: media_dir if channel else tmp_path / "media",
+    )
+
+    channel = TelegramChannel(
+        TelegramConfig(enabled=True, token="123:abc", allow_from=["*"], group_policy="open"),
+        MessageBus(),
+    )
+    app = _FakeApp(lambda: None)
+    app.bot.get_file = AsyncMock(
+        return_value=SimpleNamespace(download_to_drive=AsyncMock(return_value=None))
+    )
+    channel._app = app
+    handled = []
+    async def capture_handle(**kwargs) -> None:
+        handled.append(kwargs)
+    channel._handle_message = capture_handle
+    channel._start_typing = lambda _chat_id: None
+
+    reply_with_photo = SimpleNamespace(
+        text=None,
+        caption=None,
+        photo=[SimpleNamespace(file_id="reply_photo_fid", mime_type="image/jpeg")],
+        document=None,
+        voice=None,
+        audio=None,
+        video=None,
+        video_note=None,
+        animation=None,
+    )
+    update = _make_telegram_update(
+        text="what is the image?",
+        reply_to_message=reply_with_photo,
+    )
+    await channel._on_message(update, None)
+
+    assert len(handled) == 1
+    assert handled[0]["content"].startswith("[Reply to: [image:")
+    assert "what is the image?" in handled[0]["content"]
+    assert len(handled[0]["media"]) == 1
+    assert "reply_photo_fid" in handled[0]["media"][0]
+
+
+@pytest.mark.asyncio
+async def test_on_message_reply_to_media_fallback_when_download_fails() -> None:
+    """When reply has media but download fails, keep placeholder and do not attach."""
+    channel = TelegramChannel(
+        TelegramConfig(enabled=True, token="123:abc", allow_from=["*"], group_policy="open"),
+        MessageBus(),
+    )
+    channel._app = _FakeApp(lambda: None)
+    # No get_file on bot -> download will fail
+    channel._app.bot.get_file = None
+    handled = []
+    async def capture_handle(**kwargs) -> None:
+        handled.append(kwargs)
+    channel._handle_message = capture_handle
+    channel._start_typing = lambda _chat_id: None
+
+    reply_with_photo = SimpleNamespace(
+        text=None,
+        caption=None,
+        photo=[SimpleNamespace(file_id="x", mime_type="image/jpeg")],
+        document=None,
+        voice=None,
+        audio=None,
+        video=None,
+        video_note=None,
+        animation=None,
+    )
+    update = _make_telegram_update(text="what is this?", reply_to_message=reply_with_photo)
+    await channel._on_message(update, None)
+
+    assert len(handled) == 1
+    assert "[Reply to: (image — not attached)]" in handled[0]["content"]
+    assert "what is this?" in handled[0]["content"]
+    assert handled[0]["media"] == []