"""Validation utils."""

from functools import wraps

from oto import response
from oto.adaptors.flask import flaskify

from marketing.constants import header


def reject_grass_headers(request):
    """Decorator that rejects grass headers.

    Returns:
        callable: the wrapped function.
    """
    def decorator(f):

        @wraps(f)
        def _validate(*args, **kwargs):
            account_type = request.headers.get(header.GRASS_ACCOUNT_TYPE)
            account_id = request.headers.get(header.GRASS_ACCOUNT_ID)

            if account_type or account_id:
                return flaskify(response.Response(
                    status=400,
                    message=(
                        'Direct access through ows-grass is blocked. Only'
                        ' non-ows-grass microservice-to-microservice requests'
                        ' are allowed.')
                ))

            return f(*args, **kwargs)
        return _validate
    return decorator