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

from trytond.model import fields
from trytond.pyson import Eval, Bool, Or
from trytond.pool import Pool
from trytond.transaction import Transaction
from trytond.modules.product.uom import uom_conversion_digits
from trytond.modules.cashbook.mixin import STATES, DEPENDS
from decimal import Decimal

STATESQ = {}
STATESQ.update(STATES)
DEPENDSQ = []
DEPENDSQ.extend(DEPENDS)


class SecondUomMixin(object):
    """ two fields for second uom: quantity, rate
    """
    quantity_2nd_uom = fields.Numeric(string='Quantity Second UOM',
        digits=(16, Eval('quantity2nd_digits', 4)),
        states={
            'readonly': Or(
                    STATESQ['readonly'],
                    ~Bool(Eval('quantity2nd'))
                ),
            'required': Bool(Eval('quantity2nd')),
            'invisible': ~Bool(Eval('quantity2nd')),
        }, depends=DEPENDSQ+['quantity2nd_digits', 'quantity2nd'])
    factor_2nd_uom = fields.Function(fields.Numeric(string='Conversion factor',
        help='Conversion factor between the units of the participating cash books.',
        digits=uom_conversion_digits,
        states={
            'readonly': Or(
                    STATESQ['readonly'],
                    ~Bool(Eval('quantity2nd'))
                ),
            'required': Bool(Eval('quantity2nd')),
            'invisible': ~Bool(Eval('quantity2nd')),
        }, depends=DEPENDSQ+['quantity2nd_digits', 'quantity2nd']),
        'on_change_with_rate_2nd_uom', setter='set_rate_2nd_uom')

    quantity2nd = fields.Function(fields.Many2One(model_name='product.uom',
        string="2nd UOM", readonly=True), 'on_change_with_quantity2nd')
    quantity2nd_digits = fields.Function(fields.Integer(string='2nd UOM Digits',
        readonly=True), 'on_change_with_quantity2nd_digits')

    @fields.depends('quantity', 'quantity_2nd_oum')
    def on_change_with_factor_2nd_uom(self, name=None):
        """ get factor from uom
        """
        Rate =  Pool().get('currency.currency.rate')

        if (self.quantity is not None) and \
            (self.quantity_2nd_oum is not None):
            if self.quantity != Decimal('0.0'):
                exp = Decimal(Decimal(1) / 10 ** Rate.rate.digits[1])
                return (self.quantity_2nd_oum / self.quantity).quantize(exp)

    @fields.depends('booktransf', '_parent_booktransf.quantity_uom', 'quantity_uom')
    def on_change_with_quantity2nd(self, name=None):
        """ uom of transfer-target
        """
        if self.booktransf:
            if self.quantity_uom:
                if self.booktransf.quantity_uom:
                    if self.quantity_uom.id != \
                        self.booktransf.quantity_uom.id:
                        return self.booktransf.quantity_uom.id

    @fields.depends('booktransf', '_parent_booktransf.quantity_digits')
    def on_change_with_quantity2nd_digits(self, name=None):
        """ uom of transfer-target
        """
        if self.booktransf:
            return self.booktransf.quantity_digits
        else:
            return 2

# end SecondUomMixin