Refactor: Use TTS service only for TTS models, keep original service for others

- Remove ENABLE_TTS environment variable dependency
- Detect TTS models dynamically by model name
- Use TTS-enhanced service only when needed
- Fallback to standard service if TTS processing fails
- Maintain full backward compatibility

app/router/gemini_routes.py

@@ -35,12 +35,7 @@ async def get_next_working_key(key_manager: KeyManager = Depends(get_key_manager
 
 async def get_chat_service(key_manager: KeyManager = Depends(get_key_manager)):
     """获取Gemini聊天服务实例"""
-    # 检查是否启用TTS功能
-    import os
-    if os.getenv("ENABLE_TTS", "false").lower() in ("true", "1", "yes", "on"):
-        return await get_tts_chat_service(key_manager)
-    else:
-        return GeminiChatService(settings.BASE_URL, key_manager)
+    return GeminiChatService(settings.BASE_URL, key_manager)
 
 
 @router.get("/models")
@@ -118,27 +113,36 @@ async def generate_content(
         logger.info(f"Handling Gemini content generation request for model: {model_name}")
         logger.debug(f"Request: \n{request.model_dump_json(indent=2)}")
 
-        # 对于TTS模型，我们需要从原始请求体中提取TTS字段
-        if "tts" in model_name.lower():
-            try:
-                raw_body = await raw_request.body()
-                raw_data = json.loads(raw_body.decode('utf-8'))
-                logger.info(f"Raw request data for TTS: {json.dumps(raw_data, indent=2, ensure_ascii=False)}")
-
-                # 将TTS字段添加到请求对象中
-                if hasattr(request, '_raw_tts_data'):
-                    request._raw_tts_data = raw_data
-                else:
-                    # 动态添加属性
-                    setattr(request, '_raw_tts_data', raw_data)
-            except Exception as e:
-                logger.warning(f"Failed to parse raw request for TTS: {e}")
-
         logger.info(f"Using API key: {api_key}")
 
         if not await model_service.check_model_support(model_name):
             raise HTTPException(status_code=400, detail=f"Model {model_name} is not supported")
 
+        # 检测是否为TTS模型，如果是则使用TTS服务
+        if "tts" in model_name.lower():
+            logger.info("Detected TTS model, using TTS-enhanced service")
+            try:
+                # 从原始请求体中提取TTS字段
+                raw_body = await raw_request.body()
+                raw_data = json.loads(raw_body.decode('utf-8'))
+                logger.info(f"Raw request data for TTS: {json.dumps(raw_data, indent=2, ensure_ascii=False)}")
+
+                # 将TTS字段添加到请求对象中
+                setattr(request, '_raw_tts_data', raw_data)
+
+                # 使用TTS增强服务
+                tts_service = await get_tts_chat_service(key_manager)
+                response = await tts_service.generate_content(
+                    model=model_name,
+                    request=request,
+                    api_key=api_key
+                )
+                return response
+            except Exception as e:
+                logger.warning(f"TTS processing failed, falling back to standard service: {e}")
+                # 如果TTS处理失败，回退到标准服务
+
+        # 使用标准服务处理非TTS模型或TTS失败的情况
         response = await chat_service.generate_content(
             model=model_name,
             request=request,