"""全局中间件模块 - 异常处理与请求日志"""

import logging
import time

from fastapi import Request
from fastapi.responses import JSONResponse
from starlette.middleware.base import BaseHTTPMiddleware

logger = logging.getLogger(__name__)


class BusinessError(Exception):
    """业务逻辑异常基类。"""

    def __init__(self, message: str, code: str = "BUSINESS_ERROR") -> None:
        self.message = message
        self.code = code
        super().__init__(message)


class DataNotFoundError(BusinessError):
    """数据未找到异常。"""

    def __init__(self, message: str = "数据不存在", code: str = "DATA_NOT_FOUND") -> None:
        super().__init__(message=message, code=code)


class GlobalExceptionMiddleware(BaseHTTPMiddleware):
    """全局异常处理中间件 - 捕获 BusinessError / ValueError / Exception。"""

    async def dispatch(self, request: Request, call_next):
        start_time = time.time()
        try:
            response = await call_next(request)
            return response
        except BusinessError as exc:
            logger.warning("业务异常: [%s] %s", exc.code, exc.message)
            return JSONResponse(
                status_code=400,
                content={"success": False, "message": exc.message, "code": exc.code},
            )
        except ValueError as exc:
            logger.warning("参数错误: %s", exc)
            return JSONResponse(
                status_code=422,
                content={"success": False, "message": str(exc), "code": "VALIDATION_ERROR"},
            )
        except Exception as exc:
            logger.exception("未预期的服务器错误: %s", exc)
            return JSONResponse(
                status_code=500,
                content={"success": False, "message": "服务器内部错误", "code": "INTERNAL_ERROR"},
            )
        finally:
            duration = time.time() - start_time
            logger.info("%s %s %.3fs", request.method, request.url.path, duration)


class RequestLoggingMiddleware(BaseHTTPMiddleware):
    """请求日志中间件 - 记录每个请求的基本信息。"""

    async def dispatch(self, request: Request, call_next):
        logger.info("请求开始: %s %s", request.method, request.url.path)
        response = await call_next(request)
        logger.info("请求完成: %s %s -> %s", request.method, request.url.path, response.status_code)
        return response