package main

import (
	"fmt"

	"git.tornberg.me/go-cart-actor/pkg/messages"
)

func (ctx *MutationContext) AddVoucher(g *CartGrain, m *messages.AddVoucher) error {
	if m == nil {
		return fmt.Errorf("AddVoucher: nil payload")
	}

	voucher, err := ctx.VoucherService.GetVoucher(m.Code)
	if err != nil {
		return fmt.Errorf("AddVoucher: %w", err)
	}

	if voucher == nil {
		return nil
	}

	g.Vouchers = append(g.Vouchers, voucher)
	g.UpdateTotals()
	return nil
}