Source code for shoop.utils.money

# This file is part of Shoop.
#
# Copyright (c) 2012-2016, Shoop Ltd. All rights reserved.
#
# This source code is licensed under the AGPLv3 license found in the
# LICENSE file in the root directory of this source tree.
from . import numbers


class Money(numbers.UnittedDecimal):
    """
    Money value with currency.

    The pure decimal value is available from the base classes
    `~shoop.utils.numbers.UnittedDecimal.value` property (preferred way)
    or by casting to `Decimal`.

    Money objects with different currencies cannot be compared or
    calculated with and will raise `~shoop.utils.numbers.UnitMixupError`.

    See `__new__`.
    """
    def __new__(cls, value="0", currency=None, *args, **kwargs):
        """
        Create new Money instance with given value and currency.

        If no currency is given explicitly and `value` has a property
        named `currency`, then that will be used.  Otherwise currency is
        a required argument and not passing one will raise a TypeError.

        :param str|numbers.Number value:
          Value as string or number
        :param str|None currency:
          Currency as ISO-4217 code (3-letter string) or None.
        """
        if currency is None and hasattr(value, 'currency'):
            currency = value.currency
        if not currency:
            raise TypeError('%s: currency must be given' % cls.__name__)
        instance = super(Money, cls).__new__(cls, value, *args, **kwargs)
        instance.currency = currency
        return instance

    def __repr__(self):
        cls_name = type(self).__name__
        return "%s('%s', %r)" % (cls_name, self.value, self.currency)

    def __reduce_ex__(self, protocol):
        return (type(self), (self.value, self.currency))

    def __str__(self):
        return "%s %s" % (self.value, self.currency)

    @classmethod
    def from_data(cls, value, currency):
        return cls(value, currency)

    def unit_matches_with(self, other):
        return (self.currency == getattr(other, 'currency', None))

    def new(self, value):
        return type(self)(value, currency=self.currency)