Add WeWork XiaoAi TTS bot - WeChat Work long connection bridge

Receives messages from WeChat Work bot via WebSocket long connection
and speaks them through XiaoAi smart speaker TTS.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/services/tts.py

@@ -0,0 +1,101 @@
+import asyncio
+import json
+import logging
+import threading
+from pathlib import Path
+from typing import Tuple, Any, Dict
+
+from aiohttp import ClientSession
+from miservice import MiAccount, MiNAService, MiTokenStore
+
+import config
+
+logger = logging.getLogger(__name__)
+
+
+class SafeTokenStore(MiTokenStore):
+    """Wraps MiTokenStore to never lose passToken on auth failure."""
+
+    def __init__(self, token_path):
+        super().__init__(token_path)
+        self._saved_pass_token = ""
+        self._load_backup()
+
+    def _load_backup(self):
+        path = Path(self.token_path)
+        backup = Path(str(path) + ".backup")
+        if backup.exists():
+            try:
+                data = json.loads(backup.read_text("utf-8"))
+                self._saved_pass_token = data.get("passToken", "")
+            except Exception:
+                pass
+
+    def _save_backup(self, token):
+        path = Path(self.token_path)
+        backup = Path(str(path) + ".backup")
+        try:
+            backup.write_text(json.dumps(token, ensure_ascii=False, indent=2), encoding="utf-8")
+        except Exception:
+            pass
+
+    def save_token(self, token=None):
+        if token and token.get("passToken"):
+            self._saved_pass_token = token["passToken"]
+            self._save_backup(token)
+        elif token is None and self._saved_pass_token:
+            # miservice is trying to delete token after auth failure
+            # Don't let it — restore from backup
+            logger.warning("miservice tried to wipe token, restoring passToken...")
+            return
+        super().save_token(token)
+
+
+def _run_async_in_thread(coro, timeout: float = 15.0):
+    result = None
+    error = None
+
+    def _target():
+        nonlocal result, error
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        try:
+            result = loop.run_until_complete(coro)
+        except Exception as e:
+            error = e
+        finally:
+            loop.close()
+
+    t = threading.Thread(target=_target)
+    t.start()
+    t.join(timeout=timeout)
+    if error:
+        raise error
+    return result
+
+
+def speak(text: str) -> Tuple[bool, Dict[str, Any]]:
+    if not config.TTS_ENABLED:
+        logger.info("TTS disabled, skipping: %s", text)
+        return True, {"skipped": True}
+
+    text = text[: config.TTS_MAX_TEXT_LENGTH].strip()
+    if not text:
+        return False, {"error": "empty text after truncation"}
+
+    async def _tts():
+        token_store = SafeTokenStore(config.XIAOMI_TOKEN_PATH)
+        async with ClientSession() as session:
+            account = MiAccount(
+                session, config.XIAOMI_USER_ID, None, token_store
+            )
+            mina = MiNAService(account)
+            return await mina.text_to_speech(config.XIAOMI_SPEAKER_DID, text)
+
+    try:
+        result = _run_async_in_thread(_tts(), timeout=config.TTS_TIMEOUT_SECONDS)
+        ok = isinstance(result, dict) and result.get("code") == 0
+        return ok, result or {}
+    except Exception as e:
+        logger.exception("TTS call failed")
+        return False, {"error": str(e)}