from contextlib import asynccontextmanager
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from typing import Optional
import uvicorn
import os
import sys

# 添加项目根目录到Python路径
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from chat_service import ChatService
from logging_config import setup_logging, get_logger

# 设置日志
setup_logging(
    level=os.getenv('LOG_LEVEL', 'INFO'),
    enable_file_logging=os.getenv('ENABLE_FILE_LOGGING', 'false').lower() == 'true'
)

# 获取logger
logger = get_logger(__name__)


# 请求和响应模型
class ChatRequest(BaseModel):
    message: str
    user_id: Optional[str] = None
    include_audio: Optional[bool] = True


class ChatResponse(BaseModel):
    success: bool
    response: Optional[str] = None
    tokens: Optional[int] = None
    user_id: str
    error: Optional[str] = None
    audio_data: Optional[str] = None  # base64 编码的音频数据
    audio_error: Optional[str] = None


# 全局聊天服务实例
chat_service = ChatService()


@asynccontextmanager
async def lifespan(app: FastAPI):
    """应用生命周期管理器"""
    logger.info("Starting Mem0 Memory API...")
    # 应用启动时初始化聊天服务
    chat_service.initialize()
    logger.info("Mem0 Memory API started successfully")
    yield
    # 应用关闭时可以在这里执行清理操作
    # 例如关闭数据库连接、释放资源等
    logger.info("Shutting down Mem0 Memory API...")


# 创建 FastAPI 应用
app = FastAPI(
    title="Mem0 Memory API",
    description="基于 Mem0 的记忆增强聊天服务 API",
    version="1.0.0",
    lifespan=lifespan
)


@app.get("/")
async def root():
    """根路径，返回 API 信息"""
    return {"message": "Mem0 Memory API is running", "version": "1.0.0"}


@app.get("/health")
async def health_check():
    """健康检查端点"""
    return {"status": "healthy"}


@app.post("/chat", response_model=ChatResponse)
async def chat_endpoint(request: ChatRequest):
    """
    聊天接口
    
    接收用户消息，通过 RAG 管道处理并返回回复（可包含 base64 音频数据）
    """
    try:
        # 如果请求中指定了用户ID，创建新的服务实例
        if request.user_id and request.user_id != chat_service.user_id:
            user_chat_service = ChatService(request.user_id)
            user_chat_service.initialize()
            result = user_chat_service.chat(request.message, request.include_audio)
        else:
            result = chat_service.chat(request.message, request.include_audio)
        
        return ChatResponse(**result)
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal server error: {str(e)}")


if __name__ == "__main__":
    uvicorn.run(
        "main:app",
        host="0.0.0.0",
        port=8000,
        reload=True
    )