# 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.pool import PoolMeta
from trytond.pyson import Eval
from trytond.tools import grouped_slice, reduce_ids
from trytond.transaction import Transaction


class Purchase(metaclass=PoolMeta):
    __name__ = 'purchase.purchase'
    _history = True
    revision = fields.Integer(
        "Revision", required=True, readonly=True,
        states={
            'invisible': Eval('revision', 0) == 0,
            })

    @classmethod
    def default_revision(cls):
        return 0

    @property
    def full_number(self):
        number = super().full_number
        if number is not None and self.revision:
            number += '/%d' % self.revision
        return number

    @classmethod
    def copy(cls, purchases, default=None):
        if default is None:
            default = {}
        else:
            default = default.copy()
        default.setdefault('revision', cls.default_revision())
        return super().copy(purchases, default=default)

    @classmethod
    @ModelView.button
    @Workflow.transition('draft')
    def draft(cls, purchases):
        cursor = Transaction().connection.cursor()
        table = cls.__table__()

        # Use SQL and before super to avoid two history entries
        for sub_purchases in grouped_slice(purchases):
            cursor.execute(*table.update(
                    [table.revision],
                    [table.revision + 1],
                    where=reduce_ids(table.id, sub_purchases)))

        super().draft(purchases)


class Line(metaclass=PoolMeta):
    __name__ = 'purchase.line'
    _history = True


class LineTax(metaclass=PoolMeta):
    __name__ = 'purchase.line-account.tax'
    _history = True