"""
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 typing import Dict, Any

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

from ErrorHandlers.bases import (
    BaseErrorModelClass,
    StatusesModelClass,
    LanguageModelClass,
)
from ErrorHandlers import statuses
from middleware.auth_middleware import MiddlewareModule


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

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


async def http_exception_handler(request: Request, exc: HTTPException) -> JSONResponse:
    """
    Handle HTTP exceptions and return formatted error responses.

    Args:
        request: FastAPI request object
        exc: HTTP exception instance

    Returns:
        JSONResponse: Formatted error response
    """
    error_code = getattr(exc, "error_code", None)
    if error_code:
        status_code = StatusesModelClass.retrieve_error_by_code(error_code)
        error_message = LanguageModelClass.retrieve_error_by_code(
            error_code, request.headers.get("accept-language", "en")
        )
    else:
        status_code = exc.status_code
        error_message = str(exc.detail)

    return JSONResponse(
        status_code=status_code,
        content={"detail": error_message, "error_code": error_code},
    )


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
    """
    app.add_exception_handler(HTTPException, http_exception_handler)
    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(MiddlewareModule.RequestTimingMiddleware)
    setup_exception_handlers(app)


def get_uvicorn_config() -> Dict[str, Any]:
    """
    Get Uvicorn server configuration.

    Returns:
        Dict[str, Any]: Uvicorn configuration dictionary
    """
    return {
        "app": "app:app",
        "host": "0.0.0.0",
        "port": 41575,
        "log_level": "info",
        "reload": True,
    }