from functools import wraps
from flask import jsonify


def require_active_service(service_id: str):
    """Decorator: return 404 if the named service is not installed.

    Apply to all email/calendar/files routes except /status endpoints,
    so the UI can always check installation state without being blocked.
    """
    def decorator(fn):
        @wraps(fn)
        def wrapper(*args, **kwargs):
            from app import service_registry
            if service_registry.get(service_id) is None:
                return jsonify({'error': f'Service {service_id!r} is not installed'}), 404
            return fn(*args, **kwargs)
        return wrapper
    return decorator