using VideoDownloader.App.Browser.Tabs;

namespace VideoDownloader.Tests.Browser;

// Phase A 탭 아키텍처: TabManager 순수 로직(뷰 팩토리 주입 — WebView2 없이 검증).
public class TabManagerTests
{
    private static TabManager NewManager() => new(() => new TabItem());

    [Fact]
    public void NewTab은_탭을_추가하고_활성화한다()
    {
        var m = NewManager();
        var t = m.NewTab("https://a.com");
        Assert.Single(m.Tabs);
        Assert.Same(t, m.ActiveTab);
        Assert.Equal("https://a.com", t.Url);
    }

    [Fact]
    public void 두_번째_탭은_이전_탭을_비활성화하고_활성화된다()
    {
        var m = NewManager();
        var t1 = m.NewTab("https://a.com");
        var t2 = m.NewTab("https://b.com");
        Assert.Same(t2, m.ActiveTab);
        Assert.False(t1.IsActive);
        Assert.True(t2.IsActive);
    }

    [Fact]
    public void Activate는_활성_탭을_바꾸고_이벤트를_발생시킨다()
    {
        var m = NewManager();
        var t1 = m.NewTab();
        var t2 = m.NewTab();
        var fired = 0;
        m.ActiveChanged += _ => fired++;
        m.Activate(t1);
        Assert.Same(t1, m.ActiveTab);
        Assert.True(t1.IsActive);
        Assert.False(t2.IsActive);
        Assert.Equal(1, fired);
    }

    [Fact]
    public void CloseTab은_제거하고_이웃_탭을_활성화한다()
    {
        var m = NewManager();
        m.NewTab("https://a.com");            // index 0
        var t2 = m.NewTab("https://b.com");   // index 1 (active)
        var t3 = m.NewTab("https://c.com");   // index 2
        m.Activate(t2);

        m.CloseTab(t2);
        Assert.Equal(2, m.Tabs.Count);
        Assert.DoesNotContain(t2, m.Tabs);
        // 닫힌 탭 오른쪽이 있으면 그 탭(t3) 활성화 (Chrome 동작)
        Assert.Same(t3, m.ActiveTab);
    }

    [Fact]
    public void 마지막_탭을_닫으면_새_빈_탭으로_대체된다()
    {
        var m = NewManager();
        var only = m.NewTab("https://solo.com");
        m.CloseTab(only);
        Assert.Single(m.Tabs);
        Assert.NotSame(only, m.ActiveTab);
        Assert.Same(m.ActiveTab, m.Tabs[0]);
    }

    [Fact]
    public void 닫힌_탭은_스택에_쌓이고_ReopenClosedTab으로_원래_위치에_복원된다()
    {
        var m = NewManager();
        var t1 = m.NewTab("https://a.com");
        m.NewTab("https://b.com");
        m.NewTab("https://c.com");      // index 2, active
        m.CloseTab(m.Tabs[2]);          // 마지막 인덱스 탭 닫기

        var reopened = m.ReopenClosedTab();
        Assert.NotNull(reopened);
        Assert.Equal("https://c.com", reopened!.Url);
        Assert.Equal(3, m.Tabs.Count);
        Assert.Equal(2, m.Tabs.IndexOf(reopened)); // 원래 인덱스 복원
        Assert.Same(reopened, m.ActiveTab);
        Assert.Empty(m.ClosedStack);
    }

    [Fact]
    public void 닫힌_탭_스택은_최대_25개다()
    {
        var m = NewManager();
        for (int i = 0; i < 30; i++)
        {
            var t = m.NewTab($"https://x{i}.com");
            m.CloseTab(t);
        }
        Assert.Equal(25, m.ClosedStack.Count);
        Assert.Equal("https://x29.com", m.ClosedStack.First().Url); // LIFO 최신 우선
    }

    [Fact]
    public void ActivateNext_Previous는_순환한다()
    {
        var m = NewManager();
        var t1 = m.NewTab("https://a.com");
        var t2 = m.NewTab("https://b.com");
        m.Activate(t1);

        m.ActivateNext();
        Assert.Same(t2, m.ActiveTab);
        m.ActivateNext(); // 순환
        Assert.Same(t1, m.ActiveTab);
        m.ActivatePrevious();
        Assert.Same(t2, m.ActiveTab);
    }

    [Fact]
    public void ActivateAt와_ActivateLast가_동작한다()
    {
        var m = NewManager();
        m.NewTab("a"); m.NewTab("b"); var last = m.NewTab("c");
        m.ActivateAt(0);
        Assert.Same(m.Tabs[0], m.ActiveTab);
        m.ActivateLast();
        Assert.Same(last, m.ActiveTab);
    }

    [Fact]
    public void Move는_탭_순서를_바꾼다()
    {
        var m = NewManager();
        var t1 = m.NewTab("a"); var t2 = m.NewTab("b"); var t3 = m.NewTab("c");
        m.Move(t1, 2); // a 를 끝으로
        Assert.Equal(2, m.Tabs.IndexOf(t1));
        Assert.Equal(0, m.Tabs.IndexOf(t2));
        Assert.Equal(1, m.Tabs.IndexOf(t3));
    }

    [Fact]
    public void Pin은_탭을_좌측_끝으로_이동시키고_핀_표시한다()
    {
        var m = NewManager();
        m.NewTab("a"); m.NewTab("b");
        var t3 = m.NewTab("c");
        m.SetPinned(t3, true);
        Assert.True(t3.IsPinned);
        Assert.Equal(0, m.Tabs.IndexOf(t3)); // 핀 탭은 좌측 정렬
        m.SetPinned(t3, false);
        Assert.False(t3.IsPinned);
    }

    [Fact]
    public void CaptureSession은_URL과_활성_인덱스와_핀을_담는다()
    {
        var m = NewManager();
        m.NewTab("https://a.com");
        var t2 = m.NewTab("https://b.com");
        m.NewTab("https://c.com");
        m.SetPinned(t2, true); // b 가 좌측으로 이동 → 순서: b,a,c
        m.Activate(t2);

        var s = m.CaptureSession();
        Assert.Equal(new[] { "https://b.com", "https://a.com", "https://c.com" }, s.Urls);
        Assert.Equal(0, s.ActiveIndex);
        Assert.Equal(new[] { true, false, false }, s.Pinned);
    }

    [Fact]
    public void RestoreSession은_저장된_탭들을_재생성한다()
    {
        var m = NewManager();
        // CaptureSession 불변식: 핀 탭이 먼저 오는 순서로 저장됨
        var snap = new SessionSnapshot(
            new() { "https://b.com", "https://a.com" }, 0, new() { true, false });
        m.RestoreSession(snap);
        Assert.Equal(2, m.Tabs.Count);
        Assert.Equal("https://b.com", m.ActiveTab!.Url);
        Assert.True(m.Tabs[0].IsPinned); // 핀 탭이 좌측
        Assert.False(m.Tabs[1].IsPinned);
    }

    [Fact]
    public void RestoreSession은_기존_탭을_치환한다()
    {
        var m = NewManager();
        m.NewTab("https://old.com");
        m.RestoreSession(new SessionSnapshot(new() { "https://new.com" }, 0, new() { false }));
        Assert.Single(m.Tabs);
        Assert.Equal("https://new.com", m.Tabs[0].Url);
    }
}

// 세션 JSON 저장소(T1-10) 분리 테스트
public class TabSessionStoreTests : IDisposable
{
    private readonly string _path = Path.Combine(Path.GetTempPath(), $"session_{Guid.NewGuid():N}.json");

    [Fact]
    public void 저장_후_로드_라운드트립()
    {
        var snap = new SessionSnapshot(
            new() { "https://a.com", "https://b.com", "https://c.com" }, 2, new() { true, false, false });
        TabSessionStore.Save(_path, snap);
        var loaded = TabSessionStore.Load(_path);
        Assert.NotNull(loaded);
        Assert.Equal(snap.Urls, loaded!.Urls);
        Assert.Equal(2, loaded.ActiveIndex);
        Assert.Equal(snap.Pinned, loaded.Pinned);
    }

    [Fact]
    public void 파일_없으면_null()
    {
        Assert.Null(TabSessionStore.Load(_path));
    }

    [Fact]
    public void 손상된_JSON이면_null()
    {
        File.WriteAllText(_path, "{ broken");
        Assert.Null(TabSessionStore.Load(_path));
    }

    public void Dispose() { try { File.Delete(_path); } catch { } }
}