# Copyright 2017 Carlos Dauden - Tecnativa <carlos.dauden@tecnativa.com>
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

from odoo import api, fields, models


class ContractContract(models.Model):
    _inherit = "contract.contract"

    mandate_id = fields.Many2one(
        comodel_name="account.banking.mandate",
        ondelete="restrict",
        string="Direct Debit Mandate",
        help="If mandate required in payment method and not set mandate, "
        "invoice takes the first valid mandate",
        index=True,
    )
    mandate_required = fields.Boolean(
        related="payment_mode_id.payment_method_id.mandate_required", readonly=True
    )
    commercial_partner_id = fields.Many2one(
        related="partner_id.commercial_partner_id",
        readonly=True,
        string="Commercial Entity",
    )

    @api.multi
    @api.onchange("payment_mode_id")
    def _onchange_payment_mode_id(self):
        self.ensure_one()
        if not self.mandate_required:
            self.mandate_id = False

    @api.multi
    def _prepare_invoice(self, date_invoice, journal=None):
        invoice_vals = super(ContractContract, self)._prepare_invoice(
            date_invoice, journal=journal
        )
        if self.mandate_id:
            invoice_vals["mandate_id"] = self.mandate_id.id
        elif self.payment_mode_id.payment_method_id.mandate_required:
            mandate = self.env["account.banking.mandate"].search(
                [
                    ("partner_id", "=", self.partner_id.commercial_partner_id.id),
                    ("state", "=", "valid"),
                    ("company_id", "=", self.company_id.id),
                ],
                limit=1,
            )
            invoice_vals["mandate_id"] = mandate.id
        return invoice_vals

    @api.model
    def _finalize_invoice_creation(self, invoices):
        """
        This override preserves the contract when calling the partner's
        onchange.
        """
        mandates_by_invoice = {}
        for invoice in invoices:
            mandates_by_invoice[invoice] = invoice.mandate_id
        res = super(ContractContract, self)._finalize_invoice_creation(invoices)
        for invoice in invoices:
            invoice.mandate_id = mandates_by_invoice.get(invoice)
        return res