"""
FastAPI Application Handler Module

This module contains all the handler functions for configuring and setting up the FastAPI application:
- CORS middleware configuration
- Exception handlers setup
- Uvicorn server configuration
"""

from fastapi import FastAPI, Request, status
from fastapi.middleware.cors import CORSMiddleware
from pydantic import ValidationError
from fastapi.responses import JSONResponse

from ApiLayers.ErrorHandlers.ErrorHandlers.api_exc_handler import (
    HTTPExceptionApiHandler,
    validation_exception_handler,
)
from ApiLayers.ErrorHandlers.Exceptions.api_exc import HTTPExceptionApi
from ApiLayers.Middleware.auth_middleware import (
    RequestTimingMiddleware,
    LoggerTimingMiddleware,
)


def setup_cors_middleware(app: FastAPI) -> None:
    """
    Configure CORS middleware for the application.

    Args:
        app: FastAPI application instance
    """
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["http://localhost:3000","*"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )


async def generic_exception_handler(request: Request, exc: Exception) -> JSONResponse:
    """
    Handle generic exceptions and return formatted error responses.

    Args:
        request: FastAPI request object
        exc: Exception instance

    Returns:
        JSONResponse: Formatted error response
    """
    return JSONResponse(
        status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
        content={"detail": "Internal server error", "error_code": "INTERNAL_ERROR"},
    )


def setup_exception_handlers(app: FastAPI) -> None:
    """
    Configure custom exception handlers for the application.

    Args:
        app: FastAPI application instance
    """
    custom_exception_handler = HTTPExceptionApiHandler(response_model=JSONResponse)
    app.add_exception_handler(ValidationError, validation_exception_handler)
    app.add_exception_handler(
        HTTPExceptionApi, custom_exception_handler.handle_exception
    )
    app.add_exception_handler(Exception, generic_exception_handler)


def setup_middleware(app: FastAPI) -> None:
    """
    Configure all middleware for the application.

    Args:
        app: FastAPI application instance
    """
    setup_cors_middleware(app)
    app.add_middleware(RequestTimingMiddleware)
    app.add_middleware(LoggerTimingMiddleware)
    setup_exception_handlers(app)