refactor(3): VideoDownloader.Browser library - tabs/find/search-engine/zoom/bookmark-history stores extracted from App (66 GREEN)

VideoDownloader.Browser/Tabs/TabManager.cs

@@ -0,0 +1,164 @@
+using System.Collections.ObjectModel;
+
+namespace VideoDownloader.Browser.Tabs;
+
+/// <summary>
+/// 탭 관리 순수 로직(Phase A). WebView2 생성은 주입된 팩토리/어태처가 담당해
+/// 단위 테스트에서 UI 없이 검증 가능. 닫힌 탭 스택(25) · 핀 좌측 정렬 · 세션 캡처/복원 포함.
+/// </summary>
+public sealed class TabManager
+{
+    private const int MaxClosed = 25;
+
+    private readonly Func<TabItem> _createTab;
+    private readonly Action<TabItem>? _attachView;
+    private readonly List<(TabItem Tab, int Index)> _closed = new();
+
+    public ObservableCollection<TabItem> Tabs { get; } = new();
+    public TabItem? ActiveTab { get; private set; }
+
+    public event Action<TabItem>? ActiveChanged;
+    public event Action<TabItem>? TabAdded;
+    public event Action<TabItem>? TabRemoved;
+
+    /// <summary>닫힌 탭(LIFO — 최신 우선). Ctrl+Shift+T 복원 대상.</summary>
+    public IReadOnlyList<TabItem> ClosedStack => _closed.Select(e => e.Tab).ToList();
+
+    public TabManager(Func<TabItem> createTab, Action<TabItem>? attachView = null)
+    {
+        _createTab = createTab;
+        _attachView = attachView;
+    }
+
+    public TabItem NewTab(string? url = null, bool activate = true)
+    {
+        var tab = _createTab();
+        if (!string.IsNullOrEmpty(url)) tab.Url = url;
+        _attachView?.Invoke(tab);
+        Tabs.Add(tab); // 신규 탭은 핀 여부와 무관하게 끝에(핀 상태로 만들면 SetPinned 이동)
+        TabAdded?.Invoke(tab);
+        if (activate) Activate(tab);
+        else tab.IsActive = false;
+        return tab;
+    }
+
+    public void Activate(TabItem tab)
+    {
+        if (!Tabs.Contains(tab)) return;
+        foreach (var t in Tabs) t.IsActive = ReferenceEquals(t, tab);
+        ActiveTab = tab;
+        tab.LastActivated = DateTime.UtcNow;
+        ActiveChanged?.Invoke(tab);
+    }
+
+    /// <summary>탭 닫기. 활성 탭이면 오른쪽 이웃(없으면 왼쪽) 활성화. 마지막 탭이면 새 빈 탭으로 대체.</summary>
+    public bool CloseTab(TabItem tab)
+    {
+        var index = Tabs.IndexOf(tab);
+        if (index < 0) return false;
+
+        _closed.Insert(0, (tab, index));
+        while (_closed.Count > MaxClosed) _closed.RemoveAt(_closed.Count - 1);
+        tab.ClosedIndex = index;
+
+        var wasActive = ReferenceEquals(ActiveTab, tab);
+        Tabs.RemoveAt(index);
+        TabRemoved?.Invoke(tab);
+
+        if (Tabs.Count == 0)
+        {
+            NewTab(); // 창 유지 — 마지막 탭은 새 빈 탭으로 대체
+        }
+        else if (wasActive)
+        {
+            var next = Tabs[Math.Min(index, Tabs.Count - 1)]; // 오른쪽 우선, 끝이면 왼쪽
+            Activate(next);
+        }
+        return true;
+    }
+
+    /// <summary>Ctrl+Shift+T: 닫힌 탭을 닫힌 위치에 복원.</summary>
+    public TabItem? ReopenClosedTab()
+    {
+        if (_closed.Count == 0) return null;
+        var (tab, index) = _closed[0];
+        _closed.RemoveAt(0);
+
+        if (tab.View == null) _attachView?.Invoke(tab); // 뷰가 정리된 경우 재생성
+        Tabs.Insert(Math.Min(index, Tabs.Count), tab);
+        TabAdded?.Invoke(tab);
+        Activate(tab);
+        return tab;
+    }
+
+    public void ActivateNext()
+    {
+        if (ActiveTab == null || Tabs.Count < 2) return;
+        var i = Tabs.IndexOf(ActiveTab);
+        Activate(Tabs[(i + 1) % Tabs.Count]);
+    }
+
+    public void ActivatePrevious()
+    {
+        if (ActiveTab == null || Tabs.Count < 2) return;
+        var i = Tabs.IndexOf(ActiveTab);
+        Activate(Tabs[(i - 1 + Tabs.Count) % Tabs.Count]);
+    }
+
+    public void ActivateAt(int index)
+    {
+        if (index >= 0 && index < Tabs.Count) Activate(Tabs[index]);
+    }
+
+    public void ActivateLast() => ActivateAt(Tabs.Count - 1);
+
+    public void Move(TabItem tab, int newIndex)
+    {
+        var old = Tabs.IndexOf(tab);
+        if (old < 0) return;
+        newIndex = Math.Clamp(newIndex, 0, Tabs.Count - 1);
+        if (newIndex == old) return;
+        Tabs.Move(old, newIndex);
+    }
+
+    /// <summary>핀 설정. 핀 탭은 좌측 끝에 정렬(Chrome 동작).</summary>
+    public void SetPinned(TabItem tab, bool pinned)
+    {
+        if (!Tabs.Contains(tab)) return;
+        tab.IsPinned = pinned;
+        if (pinned)
+        {
+            var target = Tabs.Count(t => t.IsPinned) - 1; // 자신 포함 핀 탭 수 - 1
+            Move(tab, Math.Max(0, target));
+        }
+        else
+        {
+            var target = Tabs.Count(t => t.IsPinned); // 핀 탭 블록 바로 뒤
+            Move(tab, target);
+        }
+    }
+
+    public SessionSnapshot CaptureSession()
+    {
+        var active = ActiveTab == null ? 0 : Math.Max(0, Tabs.IndexOf(ActiveTab));
+        return new SessionSnapshot(
+            Tabs.Select(t => t.Url).ToList(),
+            active,
+            Tabs.Select(t => t.IsPinned).ToList());
+    }
+
+    public void RestoreSession(SessionSnapshot snap)
+    {
+        foreach (var t in Tabs.ToList())
+        {
+            Tabs.Remove(t);
+            TabRemoved?.Invoke(t);
+        }
+        for (var i = 0; i < snap.Urls.Count; i++)
+        {
+            var tab = NewTab(snap.Urls[i], activate: false);
+            if (i < snap.Pinned.Count && snap.Pinned[i]) tab.IsPinned = true; // 순서 유지(핀 우선 저장됨)
+        }
+        ActivateAt(Math.Clamp(snap.ActiveIndex, 0, Math.Max(0, Tabs.Count - 1)));
+    }
+}