feat: 添加重试机制和消息转换器，并支持Gemini v1beta API

app/services/gemini_chat_service.py

@@ -0,0 +1,89 @@
+# app/services/chat_service.py
+
+import json
+from typing import Dict, Any, AsyncGenerator, List
+from app.core.logger import get_gemini_logger
+from app.services.chat.api_client import GeminiApiClient
+from app.schemas.gemini_models import GeminiRequest
+from app.core.config import settings
+from app.services.chat.response_handler import GeminiResponseHandler
+from app.services.key_manager import KeyManager
+
+logger = get_gemini_logger()
+class GeminiChatService:
+    """聊天服务"""
+
+    def __init__(self, base_url: str, key_manager: KeyManager):
+        self.api_client = GeminiApiClient(base_url)
+        self.key_manager = key_manager
+        self.response_handler = GeminiResponseHandler()
+        
+    def generate_content(self, model: str, request: GeminiRequest, api_key: str) -> Dict[str, Any]:
+        """生成内容"""
+        payload = self._build_payload(model, request)
+        response = self.api_client.generate_content(payload, model, api_key)
+        return self.response_handler.handle_response(response, model, stream=False)
+    
+    async def stream_generate_content(self, model: str, request: GeminiRequest, api_key: str) -> AsyncGenerator[str, None]:
+        """流式生成内容"""
+        retries = 0
+        max_retries = 3
+        payload = self._build_payload(model, request)
+        while retries < max_retries:
+            try:
+                async for line in self.api_client.stream_generate_content(payload, model, api_key):
+                    if line.startswith("data:"):
+                        line = line[6:]
+                        line = json.dumps(self.response_handler.handle_response(json.loads(line), model, stream=True))
+                        yield "data: " + line + "\n\n"
+                logger.info("Streaming completed successfully")
+                break
+            except Exception as e:
+                retries += 1
+                logger.warning(f"Streaming API call failed with error: {str(e)}. Attempt {retries} of {max_retries}")
+                api_key = await self.key_manager.handle_api_failure(api_key)
+                logger.info(f"Switched to new API key: {api_key}")
+                if retries >= max_retries:
+                    logger.error(f"Max retries ({max_retries}) reached for streaming. Raising error")
+                    break
+            
+    def _build_payload(self,model: str, request: GeminiRequest) -> Dict[str, Any]:
+        """构建请求payload"""
+        payload = request.model_dump()
+        return {
+            "contents": payload.get("contents", []),
+            "tools": self._build_tools(model, payload),
+            "safetySettings": self._get_safety_settings(),
+            "generationConfig": payload.get("generationConfig", {}),
+            "systemInstruction": payload.get("systemInstruction", [])
+        }
+        
+    def _build_tools(self, model: str, payload: Dict[str, Any]) -> List[Dict[str, Any]]:
+        """构建工具"""
+        tools = []
+        if settings.TOOLS_CODE_EXECUTION_ENABLED and not (
+            model.endswith("-search") or "-thinking" in model
+        ) and not self._has_image_parts(payload.get("contents", [])):
+            tools.append({"code_execution": {}})
+        if model.endswith("-search"):
+            tools.append({"googleSearch": {}})
+        return tools
+    
+    def _has_image_parts(self, contents: List[Dict[str, Any]]) -> bool:
+        """判断消息是否包含图片部分"""
+        for content in contents:
+            if "parts" in content:
+                for part in content["parts"]:
+                    if "image_url" in part or "inline_data" in part:
+                        return True
+        return False
+        
+    def _get_safety_settings(self) -> List[Dict[str, str]]:
+        """获取安全设置"""
+        return [
+            {"category": "HARM_CATEGORY_HARASSMENT", "threshold": "BLOCK_NONE"},
+            {"category": "HARM_CATEGORY_HATE_SPEECH", "threshold": "BLOCK_NONE"},
+            {"category": "HARM_CATEGORY_SEXUALLY_EXPLICIT", "threshold": "BLOCK_NONE"},
+            {"category": "HARM_CATEGORY_DANGEROUS_CONTENT", "threshold": "BLOCK_NONE"},
+            {"category": "HARM_CATEGORY_CIVIC_INTEGRITY", "threshold": "BLOCK_NONE"}
+        ]