class PurchaseBlanketOrderLineToPurchaseOrderLine(ModelView):
    'Purchase line to create'
    __name__ = 'purchase.blanket_order.line.to.purchase.line'

    line = fields.Many2One('purchase.blanket_order.line',
        "Purchase Blanket Order Line")
    product = fields.Many2One('product.product', "Product", readonly=True)
    product_uom_category = fields.Function(
        fields.Many2One('product.uom.category', "Product UOM Category"),
        'on_change_with_product_uom_category')
    unit_price = fields.Numeric("Unit Price", digits=price_digits)
    quantity = fields.Float("Quantity", required=True, digits='unit')
    unit = fields.Many2One('product.uom', "Unit")
    remaining_quantity = fields.Float("Remaining quantity", readonly=True,
        digits='unit')

    @classmethod
    def __setup__(cls):
        super().__setup__()
        unit_categories = cls._unit_categories()
        cls.unit.domain = [
            If(Bool(Eval('product_uom_category')),
                ('category', 'in', [Eval(c) for c in unit_categories]),
                ('category', '!=', -1)),
            ]
        cls.unit.depends.extend(unit_categories)

    @classmethod
    def _unit_categories(cls):
        return ['product_uom_category']

    @fields.depends('product')
    def on_change_with_product_uom_category(self, name=None):
        if self.product:
            return self.product.default_uom_category.id


class PurchaseBlanketOrderToPurchaseOrder(ModelView):
    'Purchase line to create'
    __name__ = 'purchase.blanket_order.to.purchase'

    lines = fields.One2Many(
        'purchase.blanket_order.line.to.purchase.line', None, "Lines")


class PurchaseBlanketOrderCreatePurchaseOrder(Wizard):
    'Wizard to create a purchase from blanket order'
    __name__ = 'purchase.blanket_order.create_purchase'
    start = StateView(
        'purchase.blanket_order.to.purchase',
        'purchase_blanket_order.create_purchase_form_view', [
            Button("Cancel", 'end', 'tryton-cancel'),
            Button("Create a purchase", 'create_purchase', 'tryton-ok',
                   default=True),
        ])
    create_purchase = StateAction('purchase.act_purchase_form')

    def default_start(self, fields):
        pool = Pool()
        Line = pool.get('purchase.blanket_order.line.to.purchase.line')
        lines = [Line(
            line=line,
            quantity=line.remaining_quantity,
            product=line.product,
            remaining_quantity=line.remaining_quantity,
            unit=line.unit,
            unit_price=line.unit_price,)
            for line in self.record.lines
            if line.remaining_quantity > 0.
        ]
        return {'lines': lines}

    def do_create_purchase(self, action):
        purchase = self.record._get_purchase()
        lines = []
        print("########CREATE PURCHASE##########")
        for line in self.start.lines:
            if line.quantity <= 0:
                continue
            purchase_line = line.line.get_purchase_line(purchase)
            purchase_line.unit_price = (line.unit_price if line.unit_price
                else line.line.unit_price)
            purchase_line.taxes = purchase_line.compute_taxes(
                self.start.order.supplier)
            self._set_purchase_line_quantity(purchase_line, line)
            purchase_line.on_change_quantity()
            lines.append(purchase_line)

        if lines:
            purchase.lines = lines
            purchase.save()

            action['views'].reverse()
            return action, {'res_id': [purchase.id]}

    def _set_purchase_line_quantity(self, purchase_line, line):
        purchase_line.quantity = line.quantity
        purchase_line.unit = line.unit