package catalog

import (
	"strings"
	"testing"
	"time"
)

func TestEncodeDecodeProductCursorRoundTrip(t *testing.T) {
	ts := time.Date(2026, 8, 4, 12, 0, 0, 0, time.UTC)
	f := ListFilter{SortBy: "updatedAt", SortOrder: "desc"}
	item := map[string]any{
		"id":         "00000000-0000-4000-8000-000000000099",
		"updated_at": ts,
	}
	enc, err := EncodeProductCursor(f, item)
	if err != nil {
		t.Fatal(err)
	}
	if enc == "" {
		t.Fatal("empty cursor")
	}
	cur, err := DecodeProductCursor(enc)
	if err != nil {
		t.Fatal(err)
	}
	if cur.ID != "00000000-0000-4000-8000-000000000099" {
		t.Fatalf("id=%q", cur.ID)
	}
	if cur.SB != "updatedAt" || cur.SO != "desc" {
		t.Fatalf("sort meta: %+v", cur)
	}
	if !strings.HasPrefix(cur.K, "2026-08-04T12:00:00") {
		t.Fatalf("key=%q", cur.K)
	}
}

func TestNextProductCursor(t *testing.T) {
	f := ListFilter{SortBy: "updatedAt", SortOrder: "desc"}
	items := []map[string]any{
		{"id": "00000000-0000-4000-8000-000000000001", "updated_at": time.Now().UTC()},
		{"id": "00000000-0000-4000-8000-000000000002", "updated_at": time.Now().UTC()},
	}
	next, after := NextProductCursor(f, items, 2)
	if next == "" || after != "00000000-0000-4000-8000-000000000002" {
		t.Fatalf("next=%q after=%q", next, after)
	}
	none, noneAfter := NextProductCursor(f, items[:1], 2)
	if none != "" || noneAfter != "" {
		t.Fatalf("short page should end: next=%q after=%q", none, noneAfter)
	}
}

func TestHasProductCursorClearsOffset(t *testing.T) {
	f := NormalizeListFilter(ListFilter{Offset: 500, AfterID: "00000000-0000-4000-8000-000000000001"})
	if !HasProductCursor(f) {
		t.Fatal("expected cursor")
	}
	if f.Offset != 0 {
		t.Fatalf("offset should clear with cursor: %d", f.Offset)
	}
}