# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
from trytond.model import ModelView, Workflow, fields
from trytond.transaction import Transaction
from trytond.pyson import Eval, Bool, If
from trytond.pool import Pool, PoolMeta

__all__ = ['Configuration', 'Sale', 'SaleLine']


class Configuration(metaclass=PoolMeta):
    __name__ = 'sale.configuration'
    sale_shipment_cost_method = fields.Property(fields.Selection([
                ('order', 'On Order'),
                ('shipment', 'On Shipment'),
                ], 'Sale Shipment Cost Method',
            states={
                'required': Bool(Eval('context', {}).get('company')),
                }))

    @staticmethod
    def default_sale_shipment_cost_method():
        return 'shipment'


class Sale(metaclass=PoolMeta):
    __name__ = 'sale.sale'
    carrier = fields.Many2One('carrier', 'Carrier',
        domain=[
            ('carrier_product.salable', '=', True),
            If(Eval('state').in_(['draft', 'quotation']),
                ('id', 'in', Eval('available_carriers', [])),
                ()),
            ],
        states={
            'readonly': Eval('state') != 'draft',
        },
        depends=['state', 'available_carriers'])
    available_carriers = fields.Function(
        fields.Many2Many('carrier', None, None, 'Available Carriers'),
        'on_change_with_available_carriers')
    shipment_cost_method = fields.Selection([
        ('order', 'On Order'),
        ('shipment', 'On Shipment'),
        ], 'Shipment Cost Method', required=True, states={
            'readonly': Eval('state') != 'draft',
            }, depends=['state'])

    @staticmethod
    def default_shipment_cost_method():
        Config = Pool().get('sale.configuration')
        config = Config(1)
        return config.sale_shipment_cost_method

    def _get_carrier_selection_pattern(self):
        pattern = {}
        if (self.warehouse
                and self.warehouse.address
                and self.warehouse.address.country):
            pattern['from_country'] = self.warehouse.address.country.id
        if self.shipment_address and self.shipment_address.country:
            pattern['to_country'] = self.shipment_address.country.id
        return pattern

    @fields.depends('warehouse', 'shipment_address')
    def on_change_with_available_carriers(self, name=None):
        pool = Pool()
        CarrierSelection = pool.get('carrier.selection')

        pattern = self._get_carrier_selection_pattern()
        carriers = CarrierSelection.get_carriers(pattern)
        return [c.id for c in carriers]

    # XXX We must have the same depends than on_change_with_available_carriers,
    # for now it is maintain manually until we can specify cross-kind depends
    # on on_changes
    @fields.depends('warehouse', 'shipment_address')
    def on_change_party(self):
        super(Sale, self).on_change_party()
        self.available_carriers = self.on_change_with_available_carriers()
        if self.available_carriers:
            self.carrier = self.available_carriers[0]
        else:
            self.carrier = None

    @fields.depends('carrier', 'warehouse', 'shipment_address')
    def on_change_shipment_party(self):
        super(Sale, self).on_change_shipment_party()
        self.available_carriers = self.on_change_with_available_carriers()
        if self.available_carriers and (not self.carrier
                or self.carrier not in self.available_carriers):
            self.carrier = self.available_carriers[0]
        else:
            self.carrier = None

    @fields.depends('carrier', 'warehouse', 'shipment_address')
    def on_change_shipment_address(self):
        try:
            super_on_change = super(Sale, self).on_change_shipment_address
        except AttributeError:
            pass
        else:
            super_on_change()

        self.available_carriers = self.on_change_with_available_carriers()
        if self.available_carriers and (not self.carrier
                or self.carrier not in self.available_carriers):
            self.carrier = self.available_carriers[0]
        else:
            self.carrier = None

    @classmethod
    @ModelView.button
    @Workflow.transition('quotation')
    def quote(cls, sales):
        super(Sale, cls).quote(sales)
        for sale in sales:
            sale.set_shipment_cost()
        cls.save(sales)

    def _get_carrier_context(self):
        return {}

    def set_shipment_cost(self):
        pool = Pool()
        Date = pool.get('ir.date')
        Currency = pool.get('currency.currency')

        cost, currency_id = 0, None
        if self.carrier:
            with Transaction().set_context(self._get_carrier_context()):
                cost, currency_id = self.carrier.get_sale_price()

        cost_line = None
        products = [line.product for line in self.lines or []
                if getattr(line, 'product', None)]
        stockable = any(product.type in ('goods', 'assets')
            for product in products)
        if cost and currency_id and stockable:
            today = Date.today()
            date = self.sale_date or today
            with Transaction().set_context(date=date):
                cost = Currency.compute(Currency(currency_id), cost,
                    self.currency)
            cost_line = self.get_shipment_cost_line(cost)

        lines = list(self.lines or [])
        for line in self.lines:
            if line.type != 'line' or not line.shipment_cost:
                continue
            if cost_line and line.shipment_cost == cost:
                cost_line = None
            else:
                lines.remove(line)
        if cost_line:
            lines.append(cost_line)
        self.lines = lines

    def get_shipment_cost_line(self, cost):
        pool = Pool()
        SaleLine = pool.get('sale.line')

        product = self.carrier.carrier_product

        sequence = None
        if self.lines:
            last_line = self.lines[-1]
            if last_line.sequence is not None:
                sequence = last_line.sequence + 1

        cost_line = SaleLine(
            sale=self,
            sequence=sequence,
            type='line',
            product=product,
            quantity=1,  # XXX
            unit=product.sale_uom,
            shipment_cost=cost,
            )
        cost_line.on_change_product()
        cost_line.unit_price = cost_line.amount = cost
        return cost_line

    def create_shipment(self, shipment_type):
        Shipment = Pool().get('stock.shipment.out')

        shipments = super(Sale, self).create_shipment(shipment_type)
        if shipment_type == 'out' and shipments and self.carrier:
            for shipment in shipments:
                shipment.carrier = self.carrier
                with Transaction().set_context(
                        shipment.get_carrier_context()):
                    cost, currency_id = self.carrier.get_sale_price()
                Shipment.write([shipment], {
                        'carrier': self.carrier.id,
                        'cost': cost,
                        'cost_currency': currency_id,
                        })
        return shipments

    def create_invoice(self):
        pool = Pool()
        Invoice = pool.get('account.invoice')
        Shipment = pool.get('stock.shipment.out')

        invoice = super(Sale, self).create_invoice()
        if invoice and self.shipment_cost_method == 'shipment':
            for shipment in self.shipments:
                if (shipment.state == 'done'
                        and shipment.carrier
                        and shipment.cost
                        and not shipment.cost_invoice_line):
                    invoice_line = shipment.get_cost_invoice_line(invoice)
                    if not invoice_line:
                        continue
                    invoice_line.invoice = invoice
                    invoice_line.save()
                    Shipment.write([shipment], {
                            'cost_invoice_line': invoice_line.id,
                            })
            Invoice.update_taxes([invoice])
        return invoice


class SaleLine(metaclass=PoolMeta):
    __name__ = 'sale.line'
    shipment_cost = fields.Numeric('Shipment Cost',
        digits=(16, Eval('_parent_sale', {}).get('currency_digits', 2)))

    def _get_invoice_line_quantity(self):
        quantity = super(SaleLine, self)._get_invoice_line_quantity()
        if (self.shipment_cost
                and self.sale.shipment_cost_method == 'shipment'):
            return 0
        return quantity
