fix(tapes): a tape written after another run began is not the launch's before it, and a session with only a black box shows no other session's tape

StarterNG.Tests/BlackBox/BlackBoxListingTests.cs

@@ -121,6 +121,30 @@ public class BlackBoxListingTests
         Assert.EndsWith(own, Assert.Single(launched.BlackBoxes).Path);
     }
 
+    [Fact]
+    public void A_tape_written_after_another_run_began_is_not_taken_for_the_launch_before()
+    {
+        // The starter launched Bałtyk; later a run of another scenery, not launched from it, wrote its tape and black box.
+        var files = new InMemoryFileSystem();
+        var installation = new TestInstallation(files);
+        installation.Clock.Now = Launched;
+        installation.Tapes.RecordLaunch("baltyk.scn", TimeSpan.Zero, Array.Empty<TapeVehicle>(), "ep07", new[] { "ep07" }, "Bałtyk");
+        string box = Box("td", Launched.AddHours(5));
+        files.WithFile(Log("ep07.dat"), "t").WrittenAt(Log("ep07.dat"), Launched.AddMinutes(50))
+             .WithFile(Log("bb-su45.dat"), "t").WrittenAt(Log("bb-su45.dat"), Launched.AddHours(5).AddMinutes(8))
+             .WithFile(Log(box), "b").WrittenAt(Log(box), Launched.AddHours(5).AddMinutes(8));
+
+        var sessions = installation.Tapes.Sessions();
+
+        var baltyk = Assert.Single(sessions, session => session.Launch is not null);
+        Assert.Equal("ep07", Assert.Single(baltyk.Tapes).Vehicle);
+        Assert.Empty(baltyk.BlackBoxes);
+        var other = Assert.Single(sessions, session => session.Launch is null);
+        Assert.Equal("bb-su45", Assert.Single(other.Tapes).Vehicle);
+        Assert.Single(other.BlackBoxes);
+        Assert.Null(installation.Tapes.ContextOf(other.Tapes[0]).StartClock);
+    }
+
     [Fact]
     public void A_black_box_started_before_a_launch_is_not_taken_for_it()
     {

StarterNG/Application/HaslerTapes.cs

@@ -227,7 +227,7 @@ public sealed class HaslerTapes
 
     public TapeContext ContextOf(TapeFile file)
     {
-        var launch = Launches().LastOrDefault(l => l.Covers(file.LastWriteUtc));
+        var launch = LaunchOf(file, Launches(), ReadBlackBoxes());
         if (launch is null)
             return new TapeContext(null, Recorders.Guess(null, file.Vehicle));
 
@@ -243,8 +243,9 @@ public sealed class HaslerTapes
 
     /// <summary>
     /// The runs the tapes came from, the running or latest one first. A tape belongs
-    /// to the last launch before it was written; one written before any known launch
-    /// goes with those written about the same time, as a run writes them all at its end.
+    /// to the last launch before it was written, unless a run the starter didn't launch
+    /// began between them; one with no launch goes with those written about the same
+    /// time, as a run writes them all at its end.
     /// </summary>
     public IReadOnlyList<TapeSession> Sessions()
     {
@@ -254,12 +255,11 @@ public sealed class HaslerTapes
             var tapes = _files.DirectoryExists(Folder)
                 ? _files.GetFiles(Folder, "*.dat").Select(ReadTape).ToList()
                 : new List<TapeFile>();
-            var behind = tapes.GroupBy(tape => launches.LastOrDefault(l => l.Covers(tape.LastWriteUtc)))
+            var boxes = ReadBlackBoxes();
+            var tapeLaunch = tapes.ToDictionary(tape => tape, tape => LaunchOf(tape, launches, boxes));
+            var behind = tapes.GroupBy(tape => tapeLaunch[tape])
                               .Where(group => group.Key is not null)
                               .ToDictionary(group => group.Key!, group => group.ToList());
-            var boxes = _files.DirectoryExists(Folder)
-                ? _files.GetFiles(Folder, "*.blackbox").Select(ReadBlackBox).ToList()
-                : new List<BlackBoxRecording>();
             var boxesBehind = boxes.GroupBy(box => LaunchOf(box, launches))
                                    .Where(group => group.Key is not null)
                                    .ToDictionary(group => group.Key!, group => group.ToList());
@@ -279,7 +279,7 @@ public sealed class HaslerTapes
             }
 
             // What no launch covers goes together by when it was written: a run writes it all at its end.
-            var loose = tapes.Where(t => !launches.Any(l => l.Covers(t.LastWriteUtc)))
+            var loose = tapes.Where(t => tapeLaunch[t] is null)
                              .Select(t => (Written: t.LastWriteUtc, Tape: (TapeFile?)t, Box: (BlackBoxRecording?)null))
                              .Concat(boxes.Where(b => LaunchOf(b, launches) is null)
                                           .Select(b => (Written: b.LastWriteUtc, Tape: (TapeFile?)null, Box: (BlackBoxRecording?)b)))
@@ -318,6 +318,27 @@ public sealed class HaslerTapes
     private TapeFile ReadTape(string path) =>
         new(path, Path.GetFileNameWithoutExtension(path), _files.GetLastWriteTimeUtc(path), _files.GetFileSize(path));
 
+    private List<BlackBoxRecording> ReadBlackBoxes() =>
+        _files.DirectoryExists(Folder)
+            ? _files.GetFiles(Folder, "*.blackbox").Select(ReadBlackBox).ToList()
+            : new List<BlackBoxRecording>();
+
+    /// <summary>
+    /// The launch a tape came from. A tape tells nothing of its run but when it was written: the last launch
+    /// before then, unless a black box shows another run, one the starter didn't launch, began between the two.
+    /// That run wrote the tape, not the launch's.
+    /// </summary>
+    public static TapeLaunch? LaunchOf(TapeFile tape, IReadOnlyList<TapeLaunch> launches, IReadOnlyList<BlackBoxRecording> boxes)
+    {
+        var launch = launches.LastOrDefault(l => l.Covers(tape.LastWriteUtc));
+        if (launch is null)
+            return null;
+        bool another = boxes.Any(box => NamedBy(box.Path) is { } named
+                                        && named.StartedUtc > launch.LaunchedUtc && named.StartedUtc < tape.LastWriteUtc
+                                        && LaunchOf(box, launches) != launch);
+        return another ? null : launch;
+    }
+
     /// <summary>
     /// The launch a black box came from. Unlike a tape, it says which: its name has the scenery and the moment
     /// the recording started. So it is the last launch before that moment, and only if that launch was of the

StarterNG/Views/Tapes/HaslerTapeWindow.cs

@@ -121,19 +121,28 @@ public sealed class HaslerTapeWindow : Window
         };
         _list.SelectionChanged += async (_, _) =>
         {
-            // A black box opens in a window of its own on a click or Enter, not when the arrows go over it; the tape shown stays.
-            if (_list.SelectedItem is TreeViewItem { Tag: BlackBoxRecording })
-                return;
             // A session stands for its first tape, the player's own if it has one.
-            if (_list.SelectedItem is TreeViewItem { Tag: TapeSession } session)
-                session.IsExpanded = true;
-            var file = _list.SelectedItem switch
+            if (_list.SelectedItem is TreeViewItem { Tag: TapeSession } node)
+                node.IsExpanded = true;
+            // A black box opens in a window of its own on a click or Enter, not when the arrows go over it; the
+            // tape beside it is one of its session's, the one shown if it is.
+            var session = _list.SelectedItem switch
             {
-                TreeViewItem { Tag: TapeFile tape } => tape,
-                TreeViewItem { Tag: TapeSession { Tapes.Count: > 0 } run } => run.Tapes[0],
+                TreeViewItem { Tag: TapeSession run } => run,
+                TreeViewItem { Tag: BlackBoxRecording box } =>
+                    _sessions.FirstOrDefault(s => s.BlackBoxes.Any(b => b.Path == box.Path)),
                 _ => null
             };
-            if (file is null || file == _shown)
+            if (_list.SelectedItem is TreeViewItem { Tag: BlackBoxRecording } && session?.Tapes.Any(t => t.Path == _shown?.Path) == true)
+                return;
+            var file = _list.SelectedItem is TreeViewItem { Tag: TapeFile tape } ? tape : session?.Tapes.FirstOrDefault();
+            if (file is null)
+            {
+                if (session is not null)
+                    ShowNoTape();
+                return;
+            }
+            if (file == _shown)
                 return;
 
             ApplyContext(_tapes.ContextOf(file));
@@ -586,6 +595,16 @@ public sealed class HaslerTapeWindow : Window
         _recorder.SelectedIndex = context.Recorder == RecorderKind.Electronic ? 1 : 0;
     }
 
+    /// <summary>A session with a black box and no tape: no tape of another session left beside it.</summary>
+    private void ShowNoTape()
+    {
+        _shown = null;
+        _view.Tape = null;
+        _view.Mark = null;
+        _cursor.Text = "";
+        _summary.Text = App.Loc["HaslerSessionNoTape"];
+    }
+
     private async Task ShowAsync(TapeFile file, bool scrollToEnd)
     {
         if (_loading)

StarterNG/startercfg/lang/cz.xml

@@ -853,6 +853,7 @@
     <String key="HaslerBlackBox">Černá skříňka</String>
     <String key="HaslerBlackBoxTip">Celá relace na mapě: jízda oproti AI, povely, návěstidla, kabina</String>
     <String key="HaslerClickBlackBox">klikněte na pásku: černá skříňka v tom okamžiku</String>
+    <String key="HaslerSessionNoTape">Tato relace nemá pásku, jen černou skříňku.</String>
     <String key="WarehouseSaved">Ve skladu: {0}</String>
     <String key="WarehouseNothingToAdd">Vyberte soupravu s vozidly</String>
     <String key="GfxGroupLevelTip">Úroveň jen pro tuto část grafiky</String>

StarterNG/startercfg/lang/en.xml

@@ -1082,6 +1082,7 @@
     <String key="HaslerBlackBox">Black box</String>
     <String key="HaslerBlackBoxTip">The whole session on a map: the driving against the AI, the commands, the signals, the cab</String>
     <String key="HaslerClickBlackBox">click the tape: the black box at that moment</String>
+    <String key="HaslerSessionNoTape">This session has no tape, only the black box.</String>
     <String key="WarehouseSaved">In the warehouse: {0}</String>
     <String key="WarehouseNothingToAdd">Pick a consist with vehicles</String>
     <String key="GfxGroupLevelTip">Level for this part of the graphics only</String>

StarterNG/startercfg/lang/hu.xml

@@ -853,6 +853,7 @@
     <String key="HaslerBlackBox">Fekete doboz</String>
     <String key="HaslerBlackBoxTip">A teljes menet a térképen: vezetés az AI-hoz képest, parancsok, jelzők, vezetőfülke</String>
     <String key="HaslerClickBlackBox">kattintson a szalagra: a fekete doboz abban a pillanatban</String>
+    <String key="HaslerSessionNoTape">Ebben a munkamenetben nincs szalag, csak a fekete doboz.</String>
     <String key="WarehouseSaved">A raktárban: {0}</String>
     <String key="WarehouseNothingToAdd">Válassz járműveket tartalmazó szerelvényt</String>
     <String key="GfxGroupLevelTip">Csak a grafika ezen részének szintje</String>

StarterNG/startercfg/lang/pl.xml

@@ -904,6 +904,7 @@
     <String key="HaslerBlackBox">Czarna skrzynka</String>
     <String key="HaslerBlackBoxTip">Cała sesja na mapie: jazda względem AI, komendy, sygnalizatory, kabina</String>
     <String key="HaslerClickBlackBox">kliknij taśmę: czarna skrzynka w tym momencie</String>
+    <String key="HaslerSessionNoTape">W tej sesji nie ma taśmy, jest tylko czarna skrzynka.</String>
     <String key="WarehouseSaved">W magazynie: {0}</String>
     <String key="WarehouseNothingToAdd">Wybierz skład z pojazdami</String>
     <String key="GfxGroupLevelTip">Poziom tylko tej części grafiki</String>

StarterNG/startercfg/lang/ru.xml

@@ -853,6 +853,7 @@
     <String key="HaslerBlackBox">Чёрный ящик</String>
     <String key="HaslerBlackBoxTip">Вся сессия на карте: езда по сравнению с ИИ, команды, светофоры, кабина</String>
     <String key="HaslerClickBlackBox">щёлкните по ленте: чёрный ящик в этот момент</String>
+    <String key="HaslerSessionNoTape">В этом сеансе нет ленты, только чёрный ящик.</String>
     <String key="WarehouseSaved">На складе: {0}</String>
     <String key="WarehouseNothingToAdd">Выберите состав с транспортом</String>
     <String key="GfxGroupLevelTip">Уровень только для этой части графики</String>