# -*- coding: utf-8 -*-
# © 2017 Akretion (http://www.akretion.com)
# @author: Alexis de Lattre <alexis.delattre@akretion.com>
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).

from odoo import models, fields


class AccountInvoice(models.Model):
    _inherit = 'account.invoice'

    sale_agreement_id = fields.Many2one(
        'sale.agreement', string='Sale Agreement', ondelete='restrict',
        readonly=True, states={'draft': [('readonly', False)]},
        track_visibility='onchange')