# 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.i18n import gettext
from trytond.model import DictSchemaMixin, ModelSQL, ModelView, Unique, fields
from trytond.pool import PoolMeta
from trytond.pyson import Eval


class AttributeSet(ModelSQL, ModelView):
    __name__ = 'product.attribute.set'
    name = fields.Char('Name', required=True, translate=True,
        help="The main identifier of product attribute set.")
    attributes = fields.Many2Many('product.attribute-product.attribute-set',
        'attribute_set', 'attribute', 'Attributes',
        help="Add attributes to the set.")


class Attribute(DictSchemaMixin, ModelSQL, ModelView):
    __name__ = 'product.attribute'
    sets = fields.Many2Many('product.attribute-product.attribute-set',
        'attribute', 'attribute_set', 'Sets',
        help="Add sets to the attribute.")

    @classmethod
    def __setup__(cls):
        super().__setup__()
        t = cls.__table__()
        cls._sql_constraints += [
            ('name_unique', Unique(t, t.name),
                'product_attribute.msg_product_attribute_name_unique'),
            ]


class AttributeAttributeSet(ModelSQL):
    __name__ = 'product.attribute-product.attribute-set'
    attribute = fields.Many2One(
        'product.attribute', "Attribute",
        ondelete='CASCADE', required=True)
    attribute_set = fields.Many2One(
        'product.attribute.set', "Set",
        ondelete='CASCADE', required=True)


class Template(metaclass=PoolMeta):
    __name__ = 'product.template'
    attribute_set = fields.Many2One('product.attribute.set', 'Attribute Set',
        help="Select a set of attributes to apply on the variants.")


class Product(metaclass=PoolMeta):
    __name__ = 'product.product'
    attributes = fields.Dict('product.attribute', 'Attributes',
        domain=[
            ('sets', '=', Eval('_parent_template', {}).get('attribute_set',
                    Eval('attribute_set', -1))),
            ],
        states={
            'readonly': (~Eval('attribute_set')
                & ~Eval('_parent_template', {}).get('attribute_set')),
            },
        depends={'template'},
        help="Add attributes to the variant.")
    attributes_name = fields.Function(fields.Char(
            "Attributes Name",
            states={
                'invisible': ~Eval('attribute_set'),
                }),
        'on_change_with_attributes_name')

    @fields.depends('attribute_set', 'attributes')
    def on_change_with_attributes_name(self, name=None):
        if not self.attribute_set or not self.attributes:
            return

        def key(attribute):
            return getattr(attribute, 'sequence', attribute.name)

        values = []
        for attribute in sorted(self.attribute_set.attributes, key=key):
            if attribute.name in self.attributes:
                value = self.attributes[attribute.name]
                values.append(gettext('product_attribute.msg_label_value',
                        label=attribute.string,
                        value=attribute.format(value)))
        return " | ".join(filter(None, values))