"""
自定义异常定义

所有业务异常都应该继承自 APIException，
由全局异常处理器统一处理并返回标准格式的错误响应
"""
from fastapi import HTTPException, status
from typing import Optional, Any


class APIException(HTTPException):
    """
    API基础异常

    所有业务异常的基类，可以被全局异常处理器捕获和统一处理
    """

    def __init__(
        self,
        status_code: int = status.HTTP_400_BAD_REQUEST,
        detail: str = None,
        error_code: str = None,
        data: Any = None,
        headers: dict = None,
    ):
        super().__init__(status_code=status_code, detail=detail, headers=headers)
        self.error_code = error_code or "UNKNOWN_ERROR"
        self.data = data


class UnauthorizedException(APIException):
    """未授权异常 - 认证失败"""

    def __init__(self, detail: str = "未授权", error_code: str = "UNAUTHORIZED"):
        super().__init__(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=detail,
            error_code=error_code
        )


class ForbiddenException(APIException):
    """禁止访问异常 - 权限不足"""

    def __init__(self, detail: str = "禁止访问", error_code: str = "FORBIDDEN"):
        super().__init__(
            status_code=status.HTTP_403_FORBIDDEN,
            detail=detail,
            error_code=error_code
        )


class NotFoundException(APIException):
    """资源不存在异常"""

    def __init__(self, detail: str = "资源不存在", error_code: str = "NOT_FOUND"):
        super().__init__(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=detail,
            error_code=error_code
        )


class ConflictException(APIException):
    """冲突异常 - 资源已存在"""

    def __init__(self, detail: str = "资源已存在", error_code: str = "CONFLICT"):
        super().__init__(
            status_code=status.HTTP_409_CONFLICT,
            detail=detail,
            error_code=error_code
        )


class ValidationException(APIException):
    """验证异常 - 输入验证失败"""

    def __init__(self, detail: str = "验证失败", error_code: str = "VALIDATION_ERROR"):
        super().__init__(
            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
            detail=detail,
            error_code=error_code
        )


class BusinessException(APIException):
    """业务异常 - 业务规则验证失败"""

    def __init__(
        self,
        detail: str = "业务操作失败",
        error_code: str = "BUSINESS_ERROR",
        status_code: int = status.HTTP_500_INTERNAL_SERVER_ERROR,
    ):
        super().__init__(
            status_code=status_code,
            detail=detail,
            error_code=error_code
        )


class InternalServerException(APIException):
    """内部服务器异常"""

    def __init__(
        self,
        detail: str = "内部服务器错误",
        error_code: str = "INTERNAL_SERVER_ERROR",
    ):
        super().__init__(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=detail,
            error_code=error_code
        )


class DatabaseException(APIException):
    """数据库异常"""

    def __init__(
        self,
        detail: str = "数据库操作失败",
        error_code: str = "DATABASE_ERROR",
    ):
        super().__init__(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=detail,
            error_code=error_code
        )


class ExternalServiceException(APIException):
    """外部服务异常 - 调用第三方服务失败"""

    def __init__(
        self,
        detail: str = "外部服务调用失败",
        error_code: str = "EXTERNAL_SERVICE_ERROR",
    ):
        super().__init__(
            status_code=status.HTTP_502_BAD_GATEWAY,
            detail=detail,
            error_code=error_code
        )


class RateLimitException(APIException):
    """限流异常 - 请求过于频繁"""

    def __init__(
        self,
        detail: str = "请求过于频繁，请稍后再试",
        error_code: str = "RATE_LIMIT_EXCEEDED",
    ):
        super().__init__(
            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
            detail=detail,
            error_code=error_code
        )