"""Feature Variant model."""


class FeatureVariant:
    """Feature Variant.

    A feature variant is a variation of a feature. It has 2 mandatory
    attributes: a name (which is its unique identifier), and
    an active flag (which is used for releasing the feature)

    Example from the README::

        catchy = FeatureVariant('catchy', active=False)

    """

    def __init__(self, name, active=False):
        """Create a Feature Variant.

        Args:
            name (str): the name of a variant.
            active (boolean): flag indicates if the variant is active.
        """
        self.name = name
        self.active = active
        self.validate()

    def validate(self):
        """Validate the information of the feature variant.

        Some information is required for the system to work properly (such as
        a feature name, a pool and other things.)

        Raise:
            Exception: whenever an error is found.
        """
        if not self.name:
            raise Exception('Name is mandatory for feature variants')

    def is_active(self):
        """Check if a variant is active.

        Return:
            boolean: True if the variant is active, else False.
        """
        return self.active

    def to_dict(self):
        """Return a dictionary representation of the object.

        Return:
            dict: the dictionary representation of the object.
        """
        return dict(name=self.name, active=self.active)