"""Consistent API error handling with stable error codes."""


class ApiError(Exception):
    """Raised by service/domain layers; converted to a consistent response."""

    def __init__(self, code: str, message: str, details=None, status: int = 400):
        self.code = code
        self.message = message
        self.details = details or {}
        self.status = status
        super().__init__(message)


def error_response(code: str, message: str, details=None) -> dict:
    return {"success": False, "error": {"code": code, "message": message, "details": details or {}}}


def api_exception_handler(exc, context):
    """DRF exception handler that emits the stable error envelope."""
    from rest_framework.views import exception_handler
    from rest_framework.response import Response

    if isinstance(exc, ApiError):
        return Response(error_response(exc.code, exc.message, exc.details), status=exc.status)

    response = exception_handler(exc, context)
    if response is not None:
        if isinstance(response.data, dict) and "detail" in response.data and len(response.data) == 1:
            return Response(
                error_response("API_ERROR", str(response.data["detail"])),
                status=response.status_code,
            )
        return Response(error_response("API_ERROR", "Request failed", {"errors": response.data}), status=response.status_code)
    return None