import models as rego

from django import forms

def CategoryForm(category):

    PREFIX = "product_"

    def field_name(product):

        return PREFIX + ("%d" % product.id)

    class _CategoryForm(forms.Form):

        @staticmethod

        def initial_data(product_quantities):

            ''' Prepares initial data for an instance of this form.

            product_quantities is a sequence of (product,quantity) tuples '''

            initial = {}

            for product, quantity in product_quantities:

                initial[field_name(product)] = quantity

            return initial

        def product_quantities(self):

            ''' Yields a sequence of (product, quantity) tuples from the

            cleaned form data. '''

            for name, value in self.cleaned_data.items():

                if name.startswith(PREFIX):

                    product_id = int(name[len(PREFIX):])

                    yield (product_id, value, name)

        def disable_product(self, product):

            ''' Removes a given product from this form. '''

            del self.fields[field_name(product)]

    products = rego.Product.objects.filter(category=category).order_by("order")

    for product in products:

        help_text = "$%d -- %s" % (product.price, product.description)

        field = forms.IntegerField(

            label=product.name,

            help_text=help_text,

        )

        _CategoryForm.base_fields[field_name(product)] = field

    return _CategoryForm

class VoucherForm(forms.Form):

    voucher = forms.CharField(

        label="Voucher code",

        help_text="If you have a voucher code, enter it here",

        required=True,

    )