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 _prepare_move_line_default_vals(self, write_off_line_vals=None, force_balance=None):
        """Override to use correct accounts for advance payments"""
        line_vals_list = super()._prepare_move_line_default_vals(write_off_line_vals=write_off_line_vals, force_balance=force_balance)
        
        if self.is_advance_payment and self.purchase_order_id:
            # Get expense account from default deposit product
            deposit_product_id = self.env['ir.config_parameter'].sudo().get_param(
                'purchase_advance_payment.deposit_product_id')
            
            if deposit_product_id:
                product = self.env['product.product'].browse(int(deposit_product_id))
                expense_account = product.property_account_expense_id or product.categ_id.property_account_expense_categ_id
                
                if expense_account:
                    # Get outstanding payment account from journal
                    # For outbound payments, first check journal-specific account, then company default
                    outstanding_account = None
                    
                    # Try to get from journal's outbound payment method
                    if self.journal_id.outbound_payment_method_line_ids:
                        outstanding_account = self.journal_id.outbound_payment_method_line_ids[0].payment_account_id
                    
                    # Fall back to company default if not set on journal
                    if not outstanding_account:
                        outstanding_account = self.journal_id.company_id.account_journal_payment_credit_account_id
                    
                    if outstanding_account:
                        # Modify the line vals to use correct accounts
                        for line_vals in line_vals_list:
                            # The debit line (expense) - partner line
                            if line_vals.get('debit', 0) > 0 and line_vals.get('partner_id'):
                                line_vals['account_id'] = expense_account.id
                            # The credit line (outstanding payment)
                            elif line_vals.get('credit', 0) > 0:
                                line_vals['account_id'] = outstanding_account.id
        
        return line_vals_list

    def action_post(self):
        res = super().action_post()
        # When an advance payment is posted, update deposit line in purchase order
        for payment in self:
            if payment.is_advance_payment and payment.purchase_order_id:
                # Update the deposit line with the actual posted amount
                payment.purchase_order_id._update_deposit_line()
        return res