package cart

import (
	"context"
	"testing"
	"time"

	cart_messages "git.k6n.net/go-cart-actor/proto/cart"
)

func TestAddItem_StoresCustomFields(t *testing.T) {
	reg := NewCartMultationRegistry(NewCartMutationContext(nil))
	g := NewCartGrain(1, time.Now())

	mustApply(t, reg, g, &cart_messages.AddItem{
		ItemId: 100, Sku: "P", Quantity: 1, Price: 1000,
		CustomFields: map[string]string{"engraving": "Happy Birthday", "color": "blue"},
	})

	if len(g.Items) != 1 {
		t.Fatalf("items = %d, want 1", len(g.Items))
	}
	cf := g.Items[0].CustomFields
	if cf["engraving"] != "Happy Birthday" || cf["color"] != "blue" {
		t.Fatalf("custom fields = %v, want engraving+color", cf)
	}
}

func TestSetLineItemCustomFields_Merges(t *testing.T) {
	reg := NewCartMultationRegistry(NewCartMutationContext(nil))
	g := NewCartGrain(1, time.Now())

	mustApply(t, reg, g, &cart_messages.AddItem{
		ItemId: 100, Sku: "P", Quantity: 1, Price: 1000,
		CustomFields: map[string]string{"engraving": "v1"},
	})
	line := g.Items[0].Id

	// Upsert: overwrite "engraving", add "note", leave others alone.
	mustApply(t, reg, g, &cart_messages.SetLineItemCustomFields{
		Id:           line,
		CustomFields: map[string]string{"engraving": "v2", "note": "gift wrap"},
	})

	cf := g.Items[0].CustomFields
	if cf["engraving"] != "v2" {
		t.Errorf("engraving = %q, want v2", cf["engraving"])
	}
	if cf["note"] != "gift wrap" {
		t.Errorf("note = %q, want 'gift wrap'", cf["note"])
	}
}

func TestSetLineItemCustomFields_UnknownItem(t *testing.T) {
	reg := NewCartMultationRegistry(NewCartMutationContext(nil))
	g := NewCartGrain(1, time.Now())
	// The handler error is reported per-mutation in the ApplyResult (the
	// registry only returns a top-level error for unregistered mutations).
	results, _ := reg.Apply(context.Background(), g, &cart_messages.SetLineItemCustomFields{
		Id: 999, CustomFields: map[string]string{"x": "y"},
	})
	if len(results) != 1 || results[0].Error == nil {
		t.Errorf("expected per-mutation error for unknown item id, got %+v", results)
	}
}