from odoo import api, fields, models

class MrpBom(models.Model):
    _inherit = 'mrp.bom'

    packaging_id = fields.Many2one('mrp.packaging', string='Packaging', domain="[('product_tmpl_id', '=', product_tmpl_id)]", check_company=True)
    packaging_qty = fields.Float('Quantity Packaging', default=0.0)

    @api.onchange('packaging_qty')
    def _onchange_packaging_qty(self):
        if self.packaging_id and self.packaging_qty:
            self.product_qty = round(self.packaging_id.qty * self.packaging_qty, 8)

    @api.onchange('packaging_id')
    def _onchange_packaging_id(self):
        if self.packaging_id and self.packaging_id.qty:
            self.packaging_qty = round(self.product_qty / self.packaging_id.qty, 8)

    @api.onchange('product_qty')
    def _onchange_product_qty(self):
        if self.packaging_id and self.packaging_id.qty:
            self.packaging_qty = round(self.product_qty / self.packaging_id.qty, 8)