"""
Global error handlers and exceptions
"""
from fastapi import FastAPI, Request, status
from fastapi.responses import JSONResponse
from sqlalchemy.exc import SQLAlchemyError
from typing import Union, Dict, Any

class AppException(Exception):
    """Base application exception"""
    def __init__(
        self,
        status_code: int,
        detail: Union[str, Dict[str, Any]],
        headers: Dict[str, str] = None
    ):
        self.status_code = status_code
        self.detail = detail
        self.headers = headers

def setup_error_handlers(app: FastAPI):
    """Setup global error handlers"""
    
    @app.exception_handler(AppException)
    async def app_exception_handler(request: Request, exc: AppException):
        headers = exc.headers if exc.headers else {}
        return JSONResponse(
            status_code=exc.status_code,
            content={"detail": exc.detail},
            headers=headers
        )

    @app.exception_handler(SQLAlchemyError)
    async def sqlalchemy_exception_handler(request: Request, exc: SQLAlchemyError):
        return JSONResponse(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            content={
                "detail": "Database error occurred",
                "message": str(exc)
            }
        )

    @app.exception_handler(Exception)
    async def general_exception_handler(request: Request, exc: Exception):
        return JSONResponse(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            content={
                "detail": "An unexpected error occurred",
                "message": str(exc)
            }
        )