from flask import request
from app.helpers.response_helper import ResponseHelper
from app.utils.logger import logger
import os

VALID_APP_IDS = os.getenv("VALID_APP_ID", "")

def require_app_id():
    """Middleware to check if App-ID is present and valid."""
    app_id = request.headers.get("App-ID")

    if not app_id:
        logger.error("Unauthorized access: Missing App-ID.")
        return ResponseHelper.unauthorized("Missing App-ID")

    if app_id not in VALID_APP_IDS:
        logger.error(f"Unauthorized access: Invalid App-ID {app_id}.")
        return ResponseHelper.unauthorized("Invalid App-ID")

    return None