"""Util for package."""


from boto3.dynamodb.types import TypeDeserializer


class AsDictModelMixin:
    """Mixin that adds method for converting Pynamo model to python dict."""

    _deserializer = TypeDeserializer()

    @property
    def hash_key_name(self):
        """Get name of a hash key.

        Returns:
            str: hash key name or None
        """
        return next(
            (k for k, v in self._attributes.items() if v.is_hash_key), None)

    @property
    def range_key_name(self):
        """Get name of a range key.

        Returns:
            str: range key name or None
        """
        return next(
            (k for k, v in self._attributes.items() if v.is_range_key), None)

    def as_dict(self):
        """Get dictionary representation of a Pynamo model.

        Returns:
            dict: pynamo model as python dictionary
        """
        result = {}
        hash_key, json_data = self._get_json()
        # hash key
        if self.hash_key_name:
            result[self.hash_key_name] = hash_key
        # range key
        if self.range_key_name:
            result[self.range_key_name] = json_data.get('range_key')
        # attributes
        model_attributes = json_data.get('attributes', {})
        for k, v in model_attributes.items():
            try:
                value = self._deserializer.deserialize(v)
            except TypeError:
                value = None
            finally:
                result[k] = value
        return result