"""Adapter exceptions and OpenAI-shaped error responses."""
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse


class AdapterError(Exception):
    """Base class; renders as an OpenAI error body."""

    def __init__(self, status: int, message: str, err_type: str, code: str | None = None):
        self.status = status
        self.message = message
        self.err_type = err_type
        self.code = code
        super().__init__(message)


class InvalidRequest(AdapterError):
    def __init__(self, message: str, code: str | None = None):
        super().__init__(400, message, "invalid_request_error", code)


class Unauthorized(AdapterError):
    def __init__(self, message: str = "Invalid API key provided"):
        super().__init__(401, message, "invalid_request_error", "invalid_api_key")


class ComfyUIError(AdapterError):
    """ComfyUI rejected validation, failed execution, or timed out."""

    def __init__(self, message: str, code: str = "comfyui_error"):
        super().__init__(502, message, "server_error", code)


class ConfigError(AdapterError):
    """Invalid model registry configuration; blocks startup."""

    def __init__(self, message: str):
        super().__init__(500, message, "server_error", "config_error")


def error_body(message: str, err_type: str, code: str | None = None) -> dict:
    return {"error": {"message": message, "type": err_type, "param": None, "code": code}}


def install_error_handlers(app: FastAPI) -> None:
    @app.exception_handler(AdapterError)
    async def adapter_error_handler(request: Request, exc: AdapterError) -> JSONResponse:
        return JSONResponse(status_code=exc.status, content=error_body(exc.message, exc.err_type, exc.code))