"""Utility Functions for Handlers."""

import functools

from flask import request
from oto import response
from oto.adaptors.flask import flaskify
from owsrequest import flask_request
from werkzeug.exceptions import BadRequest

from product_digital_marketing.constants import error
from product_digital_marketing.constants import header
from product_digital_marketing.exceptions import RequestError
from product_digital_marketing.exceptions import ValidationError
from product_digital_marketing.models import ows_product


def parse_request_json(schema=None, partial=False):
    """Parse and optionally validate request JSON.

    Args:
        schema (type): marshmallow schema to validate request
        partial (bool): parial validation flag

    Returns:
        dict: Validated request
    """
    try:
        request_json = request.get_json()
    except BadRequest:
        raise RequestError('Invalid JSON')

    # Verify request data is enveloped in dict (Marshmallow doesn't catch this)
    if not isinstance(request_json, dict):
        raise RequestError('Request envelope must be an object.')

    if not schema:
        return request_json

    result = schema().load(request_json, partial=partial)
    if result.errors:
        raise ValidationError(result.errors)
    return result.data


def no_grass_access(func):
    """Decorate function to check that request is not made from GRASS."""
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        account_type, account_id = flask_request.get_grass_headers(request)
        user_id = request.headers.get(header.ORCHARD_USER_ID)
        if any((account_type, account_id, user_id)):
            return flaskify(response.create_error_response(
                code=error.ERROR_CODE_BAD_GRASS_REQUEST,
                message=error.ERROR_GRASS_FORBIDDEN))
        return func(*args, **kwargs)

    return wrapper


def check_product_ownership(product_id, account_type, account_id):
    """Check if product is owned by the given account.

    Args:
        product_id (int): the id of the product to check
        account_type (str): type of account (vendor or subaccount)
        account_id (int): id of the account to check

    Returns:
        response.Response: status code 200 if owner, 403 if not owner
    """
    return ows_product.check_ownership(product_id, account_type, account_id)