app/exception/exceptions.py

"""
异常处理模块，定义应用程序中使用的自定义异常和异常处理器
"""

from fastapi import FastAPI, Request
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from starlette.exceptions import HTTPException as StarletteHTTPException

from app.log.logger import get_exceptions_logger

logger = get_exceptions_logger()


class APIError(Exception):
    """API错误基类"""

    def __init__(self, status_code: int, detail: str, error_code: str = None):
        self.status_code = status_code
        self.detail = detail
        self.error_code = error_code or "api_error"
        super().__init__(self.detail)


class AuthenticationError(APIError):
    """认证错误"""

    def __init__(self, detail: str = "Authentication failed"):
        super().__init__(
            status_code=401, detail=detail, error_code="authentication_error"
        )


class AuthorizationError(APIError):
    """授权错误"""

    def __init__(self, detail: str = "Not authorized to access this resource"):
        super().__init__(
            status_code=403, detail=detail, error_code="authorization_error"
        )


class ResourceNotFoundError(APIError):
    """资源未找到错误"""

    def __init__(self, detail: str = "Resource not found"):
        super().__init__(
            status_code=404, detail=detail, error_code="resource_not_found"
        )


class ModelNotSupportedError(APIError):
    """模型不支持错误"""

    def __init__(self, model: str):
        super().__init__(
            status_code=400,
            detail=f"Model {model} is not supported",
            error_code="model_not_supported",
        )


class APIKeyError(APIError):
    """API密钥错误"""

    def __init__(self, detail: str = "Invalid or expired API key"):
        super().__init__(status_code=401, detail=detail, error_code="api_key_error")


class ServiceUnavailableError(APIError):
    """服务不可用错误"""

    def __init__(self, detail: str = "Service temporarily unavailable"):
        super().__init__(
            status_code=503, detail=detail, error_code="service_unavailable"
        )


def setup_exception_handlers(app: FastAPI) -> None:
    """
    设置应用程序的异常处理器

    Args:
        app: FastAPI应用程序实例
    """

    @app.exception_handler(APIError)
    async def api_error_handler(request: Request, exc: APIError):
        """处理API错误"""
        logger.error(f"API Error: {exc.detail} (Code: {exc.error_code})")
        return JSONResponse(
            status_code=exc.status_code,
            content={"error": {"code": exc.error_code, "message": exc.detail}},
        )

    @app.exception_handler(StarletteHTTPException)
    async def http_exception_handler(request: Request, exc: StarletteHTTPException):
        """处理HTTP异常"""
        logger.error(f"HTTP Exception: {exc.detail} (Status: {exc.status_code})")
        return JSONResponse(
            status_code=exc.status_code,
            content={"error": {"code": "http_error", "message": exc.detail}},
        )

    @app.exception_handler(RequestValidationError)
    async def validation_exception_handler(
        request: Request, exc: RequestValidationError
    ):
        """处理请求验证错误"""
        error_details = []
        for error in exc.errors():
            error_details.append(
                {"loc": error["loc"], "msg": error["msg"], "type": error["type"]}
            )

        logger.error(f"Validation Error: {error_details}")
        return JSONResponse(
            status_code=422,
            content={
                "error": {
                    "code": "validation_error",
                    "message": "Request validation failed",
                    "details": error_details,
                }
            },
        )

    @app.exception_handler(Exception)
    async def general_exception_handler(request: Request, exc: Exception):
        """处理通用异常"""
        logger.exception(f"Unhandled Exception: {str(exc)}")
        return JSONResponse(
            status_code=500,
            content={
                "error": {
                    "code": "internal_server_error",
                    "message": "An unexpected error occurred",
                }
            },
        )