"""JSON Draft3 Schema Validator Wrapper."""
from functools import wraps

from jsonschema import FormatChecker, ValidationError, validate
from oto import response
from oto.adaptors.flask import flaskify as oto_flaskify

from timed_release.constants import error


def validate_body(request, schema):
    """Validate HTTP request body decorator.

    Args:
        request (werkzeug.local.LocalProxy): request object from the handler.
        schema (Draft4Validator): the JSON Draft4 Schema to validate against.
    Returns:
        callable: the wrapped function.
    """
    def wrap(function):
        @wraps(function)
        def wrapped_f(*args, **kwargs):
            try:
                request_body = request.get_json(silent=True) or {}
                validate(request_body, schema, format_checker=FormatChecker())
            except ValidationError as error_message:
                return oto_flaskify(
                    response.create_error_response(
                        code=error.ERROR_CODE_BODY_VALIDATION,
                        message=str(error_message)))
            return function(*args, **kwargs)
        return wrapped_f
    return wrap