from odoo import models, fields, api


class AccountPayment(models.Model):
    _inherit = 'account.payment'

    purchase_order_id = fields.Many2one(
        'purchase.order',
        string='Purchase Order',
        domain="[('partner_id', '=', partner_id), ('state', 'in', ('purchase', 'done'))]"
    )
    
    is_advance_payment = fields.Boolean(
        string='Is Advance Payment',
        default=False,
        help='Identifies if this payment is an advance payment for a purchase order'
    )

    @api.onchange('purchase_order_id')
    def _onchange_purchase_order_id(self):
        if self.purchase_order_id:
            self.amount = self.purchase_order_id.amount_residual

    def action_post(self):
        res = super().action_post()
        # When an advance payment is posted, link it to the purchase order
        for payment in self:
            if payment.is_advance_payment and payment.purchase_order_id:
                # Apply the deposit to the purchase order
                payment.purchase_order_id.action_apply_deposit()
        return res