feat: Implement recent chats feature with API endpoint and UI integration

app/telegram_service.py

@@ -1,10 +1,13 @@
 import asyncio
 from dataclasses import dataclass
-from typing import Optional
+from typing import List, Optional
 
 from telethon import TelegramClient, errors
+from telethon.tl import types
+from telethon.utils import get_display_name, get_peer_id
 
 from .config import get_settings
+from .models import RecentChat
 
 
 @dataclass
@@ -124,5 +127,63 @@ class TelegramService:
     def get_login_state(self) -> LoginState:
         return self._login_state
 
+    async def fetch_recent_chats(self, limit: int = 50) -> List[RecentChat]:
+        await self.ensure_connected()
+        authorized = self.client.is_user_authorized()
+        if asyncio.iscoroutine(authorized):
+            authorized = await authorized
+        if not authorized:
+            raise PermissionError("Telegram session is not authorized")
+
+        dialogs = await self.client.get_dialogs(limit=limit)
+        results: List[RecentChat] = []
+        for dialog in dialogs:
+            entity = dialog.entity
+            if entity is None:
+                chat_id = str(getattr(dialog, "id", ""))
+                display_name = getattr(dialog, "name", chat_id) or chat_id
+                chat_type = "unknown"
+                username = None
+                phone = None
+            else:
+                try:
+                    chat_id = str(get_peer_id(entity))
+                except Exception:  # noqa: BLE001
+                    chat_id = str(getattr(entity, "id", ""))
+
+                try:
+                    display_name = get_display_name(entity) or chat_id
+                except Exception:  # noqa: BLE001
+                    display_name = chat_id
+
+                chat_type = self._classify_entity(entity)
+                username = getattr(entity, "username", None)
+                phone = getattr(entity, "phone", None) if isinstance(entity, types.User) else None
+
+            results.append(
+                RecentChat(
+                    chat_id=chat_id,
+                    display_name=display_name,
+                    chat_type=chat_type,
+                    username=username,
+                    phone_number=phone,
+                    last_used_at=getattr(dialog, "date", None),
+                )
+            )
+
+        return results
+
+    @staticmethod
+    def _classify_entity(entity: object) -> str:
+        if isinstance(entity, types.User):
+            if getattr(entity, "bot", False):
+                return "bot"
+            return "user"
+        if isinstance(entity, types.Chat):
+            return "group"
+        if isinstance(entity, types.Channel):
+            return "channel" if getattr(entity, "broadcast", False) else "group"
+        return "unknown"
+
 
 telegram_service = TelegramService()