# -*- coding: utf-8 -*-
# This file is part of the account-invoice-xrechnung-module
# from m-ds for Tryton. The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.

from trytond.pool import PoolMeta
from trytond.pyson import Eval, And, Or, Bool


class InvoiceLine(metaclass=PoolMeta):
    __name__ = 'account.invoice.line'

    @classmethod
    def __setup__(cls):
        super(InvoiceLine, cls).__setup__()
        cls.unit.states['required'] = Or(
            cls.unit.states['required'],
            And(
                Eval('type') == 'line',
                Bool(Eval('quantity'))))
        cls.unit.depends.update(['type', 'quantity'])

# end Invoice