Source code for shuup.core.models._currencies

import decimal

import babel
from django.core.exceptions import ValidationError
from django.core.validators import MaxValueValidator, MinLengthValidator
from django.db import models
from django.utils.translation import gettext_lazy as _

from shuup.core import cache
from shuup.utils.analog import define_log_model


class Currency(models.Model):
    identifier_attr = "code"

    code = models.CharField(
        verbose_name=_("code"),
        max_length=3,
        unique=True,
        editable=True,
        validators=[MinLengthValidator(3)],
        help_text=_("The ISO-4217 code of the currency"),
    )

    decimal_places = models.PositiveSmallIntegerField(
        verbose_name=_("decimal places"),
        validators=[MaxValueValidator(10)],
        default=2,
        help_text=_("The number of decimal places supported by this currency."),
    )



    def clean(self):
        super().clean()

        # make sure the code is a valid ISO-4217 currency
        if self.code not in babel.Locale("en").currencies:
            raise ValidationError(_("Enter a valid ISO-4217 currency code."))




    def save(self, *args, **kwargs):
        super().save(*args, **kwargs)
        cache.bump_version("currency_precision")


    class Meta:
        verbose_name = _("currency")
        verbose_name_plural = _("currencies")

    def __str__(self):
        return self.code


def get_currency_precision(currency):
    """
    Get precision by currency code.

    Precision values will be populated from the ``decimal_places``
    fields of the `Currency` objects in the database.

    :type currency: str
    :param currency: Currency code as 3-letter string (ISO-4217).

    :rtype: decimal.Decimal|None
    :return: Precision value for a given currency code or None for unknown.
    """
    cache_key = "currency_precision:" + currency
    precision = cache.get(cache_key)
    if precision is None:
        currency_obj = Currency.objects.filter(code=currency).first()
        precision = decimal.Decimal("0.1") ** currency_obj.decimal_places if currency_obj else None
        cache.set(cache_key, precision)
    return precision


CurrencyLogEntry = define_log_model(Currency)