from django.db import models
from decimal import Decimal

try:
    from south.modelsinspector import add_introspection_rules
except ImportError:
    SOUTH = False
else:
    SOUTH = True


class CurrencyField(models.DecimalField):
    __metaclass__ = models.SubfieldBase

    def __init__(self, verbose_name=None, name=None, **kwargs):
        decimal_places = kwargs.pop('decimal_places', 2)
        max_digits = kwargs.pop('max_digits', 10)

        super(CurrencyField, self). __init__(
            verbose_name=verbose_name, name=name, max_digits=max_digits,
            decimal_places=decimal_places, **kwargs)

    def to_python(self, value):
        try:
            return super(CurrencyField, self).to_python(value).quantize(Decimal("0.01"))
        except AttributeError:
            return None


if SOUTH:
    add_introspection_rules([
        (
            [CurrencyField],
            [],
            {
                "decimal_places": ["decimal_places", {"default": "2"}],
                "max_digits": ["max_digits", {"default": "10"}],
            },
        ),
    ], ['^myutils\.models\.CurrencyField'])