package main

import (
	"testing"
)

// helper to create a cart grain with items and deliveries
func newTestCart() *CartGrain {
	return &CartGrain{Items: []*CartItem{}, Deliveries: []*CartDelivery{}, Vouchers: []*Voucher{}, Notifications: []CartNotification{}}
}

func TestCartGrainUpdateTotalsBasic(t *testing.T) {
	c := newTestCart()
	// Item1 price 1250 (ex 1000 vat 250) org price higher -> discount 200 per unit
	item1Price := Price{IncVat: 1250, VatRates: map[float32]int64{25: 250}}
	item1Org := &Price{IncVat: 1500, VatRates: map[float32]int64{25: 300}}
	item2Price := Price{IncVat: 2000, VatRates: map[float32]int64{25: 400}}
	c.Items = []*CartItem{
		{Id: 1, Price: item1Price, OrgPrice: item1Org, Quantity: 2},
		{Id: 2, Price: item2Price, OrgPrice: &item2Price, Quantity: 1},
	}
	deliveryPrice := Price{IncVat: 4900, VatRates: map[float32]int64{25: 980}}
	c.Deliveries = []*CartDelivery{{Id: 1, Price: deliveryPrice, Items: []uint32{1, 2}}}

	c.UpdateTotals()

	// Expected totals: sum inc vat of items * qty plus delivery
	// item1 total inc = 1250*2 = 2500
	// item2 total inc = 2000*1 = 2000
	// delivery inc = 4900
	expectedInc := int64(2500 + 2000 + 4900)
	if c.TotalPrice.IncVat != expectedInc {
		t.Fatalf("TotalPrice IncVat expected %d got %d", expectedInc, c.TotalPrice.IncVat)
	}

	// Discount: current implementation computes (OrgPrice - Price) ignoring quantity -> 1500-1250=250
	if c.TotalDiscount.IncVat != 250 {
		t.Fatalf("TotalDiscount expected 250 got %d", c.TotalDiscount.IncVat)
	}
}

func TestCartGrainUpdateTotalsNoItems(t *testing.T) {
	c := newTestCart()
	c.UpdateTotals()
	if c.TotalPrice.IncVat != 0 || c.TotalDiscount.IncVat != 0 {
		t.Fatalf("expected zero totals got %+v", c)
	}
}