#!/usr/bin/env python3

import connexion
import jsonschema
import six
from connexion.decorators.validation import RequestBodyValidator
from connexion.json_schema import Draft4RequestValidator


async def echo(body):
    return body


# via https://python-jsonschema.readthedocs.io/
def extend_with_set_default(validator_class):
    validate_properties = validator_class.VALIDATORS['properties']

    def set_defaults(validator, properties, instance, schema):
        for property, subschema in six.iteritems(properties):
            if 'default' in subschema:
                instance.setdefault(property, subschema['default'])

        for error in validate_properties(
                validator, properties, instance, schema):
            yield error

    return jsonschema.validators.extend(
        validator_class, {'properties': set_defaults})

DefaultsEnforcingDraft4Validator = extend_with_set_default(Draft4RequestValidator)


class DefaultsEnforcingRequestBodyValidator(RequestBodyValidator):
    def __init__(self, *args, **kwargs):
        super(DefaultsEnforcingRequestBodyValidator, self).__init__(
            *args, validator=DefaultsEnforcingDraft4Validator, **kwargs)


validator_map = {
    'body': DefaultsEnforcingRequestBodyValidator
}


if __name__ == '__main__':
    app = connexion.AioHttpApp(
        __name__,
        port=8080,
        specification_dir='.',
        options={'swagger_ui': True}
    )
    app.add_api(
        'enforcedefaults-api.yaml',
        arguments={'title': 'Hello World Example'},
        validator_map=validator_map,
    )
    app.run()