"""
Custom exception hierarchy.

All application exceptions inherit from AppException.
"""
from typing import Any, Optional


class AppException(Exception):
    """Base exception for application errors."""

    def __init__(
        self,
        message: str,
        status_code: int = 500,
        error_code: Optional[str] = None,
        details: Optional[dict[str, Any]] = None,
    ):
        self.message = message
        self.status_code = status_code
        self.error_code = error_code or self.__class__.__name__
        self.details = details or {}
        super().__init__(message)

    def to_dict(self) -> dict[str, Any]:
        """Convert to JSON-serializable dict."""
        return {
            "error": self.error_code,
            "message": self.message,
            "details": self.details,
        }


class NotFoundError(AppException):
    """Resource not found."""

    def __init__(self, resource: str, identifier: Any):
        super().__init__(
            message=f"{resource} not found: {identifier}",
            status_code=404,
            details={"resource": resource, "identifier": str(identifier)},
        )


class ValidationError(AppException):
    """Input validation failed."""

    def __init__(self, message: str, field: Optional[str] = None):
        super().__init__(
            message=message,
            status_code=422,
            details={"field": field} if field else {},
        )


class AuthenticationError(AppException):
    """Authentication required or failed."""

    def __init__(self, message: str = "Authentication required"):
        super().__init__(message=message, status_code=401)


class AuthorizationError(AppException):
    """Permission denied."""

    def __init__(self, message: str = "Permission denied"):
        super().__init__(message=message, status_code=403)


class ConflictError(AppException):
    """Resource conflict (e.g., duplicate)."""

    def __init__(self, message: str):
        super().__init__(message=message, status_code=409)


class RateLimitError(AppException):
    """Rate limit exceeded."""

    def __init__(self, retry_after: int = 60):
        super().__init__(
            message="Rate limit exceeded",
            status_code=429,
            details={"retry_after": retry_after},
        )


class ServiceUnavailableError(AppException):
    """External service unavailable."""

    def __init__(self, service: str, message: Optional[str] = None):
        super().__init__(
            message=message or f"Service unavailable: {service}",
            status_code=503,
            details={"service": service},
        )


class TimeoutError(AppException):
    """Operation timed out."""

    def __init__(self, operation: str, timeout_seconds: float):
        super().__init__(
            message=f"Operation timed out: {operation}",
            status_code=504,
            details={"operation": operation, "timeout_seconds": timeout_seconds},
        )