from trytond.pool import Pool, PoolMeta
from trytond.model import ModelView, ModelSQL, fields
from trytond.pyson import Eval, Bool, If
from trytond.transaction import Transaction
    
from trytond.wizard import (
    Button, StateAction, StateTransition, StateView, Wizard)


class CreateSubscriptionStart(ModelView):
    'Create Subscription Start'
    __name__ = 'sale.create.subscription.start'

    start_date = fields.Date("Start Date", required=True)
    end_date = fields.Date("End Date", required=True)
    invoice_recurrence = fields.Many2One('sale.subscription.recurrence.rule.set', "Invoice Recurrence",
                                         required=True)
    invoice_start_date = fields.Date("Invoice Start Date",
                                     help='Billing start date')

class CreateSubscription(Wizard):
    'Create Subscription'
    __name__ = 'sale.create.subscription'

    start = StateView('sale.create.subscription.start',
                      'optical_equipment.create_subscription_view_form',[
                          Button('Cancel', 'end', 'tryton-cancel'),
                          Button('Create', 'create', 'tryton-ok', default=True),
                      ])

class SaleLine(metaclass=PoolMeta):
    'SaleLine'
    __name__ = 'sale.line'

    address_equipment = fields.Many2One('party.address', "Direccion")
    product_equipment = fields.Boolean("Product Equipment")
    unit_digits = fields.Function(fields.Integer('Unit Digits'),
        'on_change_with_unit_digits')


    def on_change_with_unit_digits(self, name=None):
        if self.unit:
            return self.unit.digits
        return 2
    
    @fields.depends('product', 'unit', 'quantity', 'sale',
    '_parent_sale.party',methods=['_get_tax_rule_pattern',
    '_get_context_sale_price','on_change_with_amount'])
    def on_change_product(self):
        Product = Pool().get('product.product')
        if not self.product:
            self.product_equipment = False
            return

        party = None

        if self.sale and self.sale.party:
            self.product_equipment = False
            party = self.sale.party

        # Set taxes before unit_price to have taxes in context of sale price
        taxes = []
        pattern = self._get_tax_rule_pattern()
        for tax in self.product.customer_taxes_used:
            if party and party.customer_tax_rule:
                tax_ids = party.customer_tax_rule.apply(tax, pattern)
                if tax_ids:
                    taxes.extend(tax_ids)
                continue
            taxes.append(tax.id)

        if party and party.customer_tax_rule:
            tax_ids = party.customer_tax_rule.apply(None, pattern)
            if tax_ids:
                taxes.extend(tax_ids)
        self.taxes = taxes

        category = self.product.sale_uom.category
        if not self.unit or self.unit.category != category:
            self.unit = self.product.sale_uom
            self.unit_digits = self.product.sale_uom.digits

        with Transaction().set_context(self._get_context_sale_price()):
            self.unit_price = Product.get_sale_price([self.product],
                    self.quantity or 0)[self.product.id]

            if self.unit_price:
                self.unit_price = self.unit_price.quantize(
                    Decimal(1) / 10 ** self.__class__.unit_price.digits[1])

        self.type = 'line'
        self.amount = self.on_change_with_amount()
        self.product_equipment = True

    @classmethod
    @ModelView.button
    def process(cls, sales):
        states = {'confirmed', 'processing', 'done'}
        sales = [s for s in sales if s.state in states]
        cls.lock(sales)
        cls._process_invoice(sales)
        cls._process_shipment(sales)
        cls._process_invoice_shipment_states(sales)
        cls._process_state(sales)

    @classmethod
    def view_attributes(cls):
        return super(SaleLine, cls).view_attributes() + [
            ('//page[@id="equipment"]', 'states', {
                    'invisible': ~Eval('product_equipment', True),
                    })]