"""Module for json requests validation."""

from functools import wraps

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

from timed_release.constants import error


def validate_json(function):
    """Validate json request decorator.

    Returns:
        callable: the wrapped function.
    """
    @wraps(function)
    def wrapper(*args, **kw):
        valid_request_json = True
        try:
            data = request.get_json()
            if not isinstance(data, dict) or not data:
                valid_request_json = False
        except BadRequest:
            valid_request_json = False

        if not valid_request_json:
            return flaskify(response.create_error_response(
                code=error.ERROR_CODE_BAD_REQUEST,
                message=error.ERROR_MESSAGE_INVALID_REQUEST_BODY))

        return function(*args, **kw)
    return wrapper