class Lot(metaclass=PoolMeta):
    __name__ = "stock.lot"
    id_supplier_packing = fields.Char('Id Supplier Packing')
    id_preciball_po = fields.Char('Id Preciball PO')
    id_supplier_pallet = fields.Char('Id Supplier Pallet')
    packaging = fields.Selection([
        ('box', 'Box'),
        ('crate', 'Crate'),
        ('bottle', 'Bottle'),
        ('bag', 'Bag'),
        ('drum', 'Drum'),
        ('other', 'Other'),
        ], 'Packaging',
        states={'required': Bool(Eval('packaging_description')), },
        depends=['packaging_description'],
        help="The packaging used for this lot.")
    packaging_description = fields.Char('Packaging Description',
        help="Short description about quantity and unit in packaging.")
    barcode = fields.Function(fields.Binary('Barcode',
        states={
            'invisible': ~Eval('barcode'),
            }), 'get_barcode')

    @classmethod
    def __setup__(cls):
        super(Lot, cls).__setup__()
        cls.number.readonly = True

    @classmethod
    def create(cls, vlist):
        pool = Pool()
        Sequence = pool.get('ir.sequence')
        Config = pool.get('stock.configuration')

        config = Config(1)
        vlist = [v.copy() for v in vlist]
        for values in vlist:
            if not values.get('number'):
                values['number'] = Sequence.get_id(
                    config.stock_lot_sequence.id)
        return super(Lot, cls).create(vlist)

    @classmethod
    def validate(cls, lots):
        super().validate(lots)
        for lot in lots:
            lot.check_description_length()

    def check_description_length(self):
        Warning = Pool().get('res.user.warning')
        if (self.packaging_description
        and len(self.packaging_description) > 20):
            # Old key
            # key = '%s@%s' % (self.__name__, self.id)
            # New Key without ID
            key = '%s@%s-%s' % (self.__name__, self.number,
                self.product.rec_name)
            # DEBUG
            print('##########################################')
            print(key)
            print(str(self.number))
            print(self.product.rec_name)
            print('###########################################')
            # END DEBUG
            if Warning.check(key):
                raise LotPackagingWarning(key, gettext(
                    'preciball.msg_lot_packaging_description_length'))

    @classmethod
    def copy(cls, lots, default=None):
        if default is None:
            default = {}
        default = default.copy()
        default.setdefault('number')
        return super().copy(lots, default=default)

    def get_rec_name(self, name):
        name = super().get_rec_name(name)
        context = Transaction().context
        if context.get('lot_package') and self.packaging:
            packaging = self.packaging
            if self.packaging_description:
                packaging = '%s - %s' % (packaging,
                    self.packaging_description[0:20])
            name = '%s (%s)' % (name, packaging)
        return name

    def get_barcode(self, name):
        fd = BytesIO()
        barcode.generate(
            'code128', str(self.number),
            writer=ImageWriter(), output=fd)
        fd.seek(0)
        return fields.Binary.cast(fd.read())