from odoo import api, models


class StockLot(models.Model):
    _inherit = 'stock.lot'

    @api.model_create_multi
    def create(self, vals_list):
        # For each lot being created without a name, assign the next serial from the product's template sequence
        for vals in vals_list:
            if not vals.get('name') and vals.get('product_id'):
                product = self.env['product.product'].browse(vals['product_id'])
                seq = getattr(product.product_tmpl_id, 'lot_sequence_id', False)
                if seq:
                    vals['name'] = seq.next_by_id()
                else:
                    # Fallback to global sequence if no product sequence
                    vals['name'] = self.env['ir.sequence'].next_by_code('stock.lot.serial')
        return super().create(vals_list)