from openerp import api, fields, models

class SaleOrder(models.Model):
    _inherit = 'sale.order'

    @api.model
    def process_pos_order(self, cart_items, customer_id):
        order_line_values = []
        for item in cart_items:
            order_line_values.append([0, False, {
                'product_id': int(item['id']),
                'product_uom_qty': float(item['qty']),
                'price_unit': float(item['list_price']),
                'discount': 0
            }])

        order_values = {
            'partner_id': customer_id,
            'partner_invoice_id': customer_id,
            'partner_shipping_id': customer_id,
            'order_line': order_line_values,
            'picking_policy': 'direct',
            'order_policy': 'manual'
        }

        order = self.env['sale.order'].create(order_values)

        # Process order now
        order.action_button_confirm()
        invoice_id = order.action_invoice_create()
        invoice = {}

        if invoice_id:
            invoice = self.env['account.invoice'].browse(invoice_id)
            invoice.signal_workflow('invoice_open')

        for picking in order.picking_ids:
            picking.force_assign()
            picking.action_done()

        dummy, view_id = self.env['ir.model.data'].get_object_reference('account_voucher', 'view_vendor_receipt_dialog_form')

        return {
                'id': invoice.id,
                'view_id': view_id,
                'name': invoice.name,
                'display_name': invoice.display_name,
                'currency_id': invoice.currency_id.id,
                'partner_account_id': self.env['res.partner']._find_accounting_partner(invoice.partner_id).id,
                'amount': invoice.type in ('out_refund', 'in_refund') and -invoice.residual or invoice.residual,
                'reference': invoice.name,
                'invoice_type': invoice.type,
                'default_type': invoice.type in ('out_invoice', 'out_refund') and 'receipt' or 'payment',
                'type': invoice.type in ('out_invoice','out_refund') and 'receipt' or 'payment'
        } if invoice_id else {}