properly fix infinite playout build loop (#952)

CHANGELOG.md

@@ -12,7 +12,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix bug with XMLTV that caused some filler to display with primary content details
 - Multiple fixes for content scaling with `Nvidia`, `Qsv` and `Vaapi` accelerations
 - Properly scale image-based subtitles
-- Abort when an infinite playout building loop is detected; proper bug fix will be released soon
+- Fix bug where a schedule containing a single item (fixed start and flood) would never finish building a playout
+  - Logic was also added to detect infinite playout build loops in the future and stop them
 
 ### Added
 - Add `Preferred Audio Title` feature

ErsatzTV.Core.Tests/Scheduling/PlayoutBuilderTests.cs

@@ -515,6 +515,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -523,6 +524,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemOne
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -605,6 +607,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -613,6 +616,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemOne
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -742,6 +746,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -750,6 +755,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemMultiple
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -839,6 +845,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -847,6 +854,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemOne
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -934,6 +942,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -942,6 +951,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemOne
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -1040,6 +1050,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -1048,6 +1059,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemDuration
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -1141,6 +1153,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemMultiple
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = multipleCollection,
                     CollectionId = multipleCollection.Id,
@@ -1150,6 +1163,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemDuration
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = dynamicCollection,
                     CollectionId = dynamicCollection.Id,
@@ -2329,6 +2343,7 @@ public class PlayoutBuilderTests
             {
                 new ProgramScheduleItemFlood
                 {
+                    Id = 1,
                     Index = 1,
                     Collection = floodCollection,
                     CollectionId = floodCollection.Id,
@@ -2337,6 +2352,7 @@ public class PlayoutBuilderTests
                 },
                 new ProgramScheduleItemOne
                 {
+                    Id = 2,
                     Index = 2,
                     Collection = fixedCollection,
                     CollectionId = fixedCollection.Id,
@@ -2622,6 +2638,7 @@ public class PlayoutBuilderTests
     private static ProgramScheduleItem Flood(Collection mediaCollection, PlaybackOrder playbackOrder) =>
         new ProgramScheduleItemFlood
         {
+            Id = 1,
             Index = 1,
             Collection = mediaCollection,
             CollectionId = mediaCollection.Id,

ErsatzTV.Core.Tests/Scheduling/PlayoutModeSchedulerFloodTests.cs

@@ -86,6 +86,98 @@ public class PlayoutModeSchedulerFloodTests : SchedulerTestBase
         playoutItems[2].CustomTitle.Should().Be("CustomTitle");
     }
     
+    [Test]
+    public void Should_Schedule_Single_Item_Fixed_Start_Flood()
+    {
+        Collection collectionOne = TwoItemCollection(1, 2, TimeSpan.FromHours(1));
+
+        var scheduleItem = new ProgramScheduleItemFlood
+        {
+            Id = 1,
+            Index = 1,
+            Collection = collectionOne,
+            CollectionId = collectionOne.Id,
+            StartTime = TimeSpan.Zero,
+            PlaybackOrder = PlaybackOrder.Chronological,
+            TailFiller = null,
+            FallbackFiller = null,
+            CustomTitle = "CustomTitle"
+        };
+
+        var enumerator = new ChronologicalMediaCollectionEnumerator(
+            collectionOne.MediaItems,
+            new CollectionEnumeratorState());
+
+        var sortedScheduleItems = new List<ProgramScheduleItem>
+        {
+            scheduleItem
+        };
+
+        var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+            sortedScheduleItems,
+            new CollectionEnumeratorState());
+
+        PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+        var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
+        (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
+            startState,
+            CollectionEnumerators(scheduleItem, enumerator),
+            scheduleItem,
+            scheduleItem,
+            HardStop(scheduleItemsEnumerator));
+
+        playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(6));
+        playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
+
+        playoutBuilderState.NextGuideGroup.Should().Be(2); // one guide group here because of custom title
+        playoutBuilderState.DurationFinish.IsNone.Should().BeTrue();
+        playoutBuilderState.InFlood.Should().BeTrue();
+        playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
+        playoutBuilderState.InDurationFiller.Should().BeFalse();
+        playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
+
+        enumerator.State.Index.Should().Be(0);
+
+        playoutItems.Count.Should().Be(6);
+
+        playoutItems[0].MediaItemId.Should().Be(1);
+        playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
+        playoutItems[0].GuideGroup.Should().Be(1);
+        playoutItems[0].FillerKind.Should().Be(FillerKind.None);
+        playoutItems[0].CustomTitle.Should().Be("CustomTitle");
+
+        playoutItems[1].MediaItemId.Should().Be(2);
+        playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
+        playoutItems[1].GuideGroup.Should().Be(1);
+        playoutItems[1].FillerKind.Should().Be(FillerKind.None);
+        playoutItems[1].CustomTitle.Should().Be("CustomTitle");
+
+        playoutItems[2].MediaItemId.Should().Be(1);
+        playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
+        playoutItems[2].GuideGroup.Should().Be(1);
+        playoutItems[2].FillerKind.Should().Be(FillerKind.None);
+        playoutItems[2].CustomTitle.Should().Be("CustomTitle");
+
+        playoutItems[3].MediaItemId.Should().Be(2);
+        playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.AddHours(3));
+        playoutItems[3].GuideGroup.Should().Be(1);
+        playoutItems[3].FillerKind.Should().Be(FillerKind.None);
+        playoutItems[3].CustomTitle.Should().Be("CustomTitle");
+    
+        playoutItems[4].MediaItemId.Should().Be(1);
+        playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.AddHours(4));
+        playoutItems[4].GuideGroup.Should().Be(1);
+        playoutItems[4].FillerKind.Should().Be(FillerKind.None);
+        playoutItems[4].CustomTitle.Should().Be("CustomTitle");
+    
+        playoutItems[5].MediaItemId.Should().Be(2);
+        playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.AddHours(5));
+        playoutItems[5].GuideGroup.Should().Be(1);
+        playoutItems[5].FillerKind.Should().Be(FillerKind.None);
+        playoutItems[5].CustomTitle.Should().Be("CustomTitle");
+    }
+
     [Test]
     public void Should_Fill_Exactly_To_Next_Schedule_Item_Flood()
     {

ErsatzTV.Core/Scheduling/PlayoutBuilder.cs

@@ -423,21 +423,21 @@ public class PlayoutBuilder : IPlayoutBuilder
         var schedulerDuration = new PlayoutModeSchedulerDuration(_logger);
         var schedulerFlood = new PlayoutModeSchedulerFlood(_logger);
 
-        var timeHash = new Dictionary<DateTimeOffset, int>();
+        var timeCount = new Dictionary<DateTimeOffset, int>();
         
         // loop until we're done filling the desired amount of time
         while (playoutBuilderState.CurrentTime < playoutFinish)
         {
-            if (timeHash.TryGetValue(playoutBuilderState.CurrentTime, out int count))
+            if (timeCount.TryGetValue(playoutBuilderState.CurrentTime, out int count))
             {
-                timeHash[playoutBuilderState.CurrentTime] = count + 1;
+                timeCount[playoutBuilderState.CurrentTime] = count + 1;
             }
             else
             {
-                timeHash[playoutBuilderState.CurrentTime] = 1;
+                timeCount[playoutBuilderState.CurrentTime] = 1;
             }
 
-            if (timeHash[playoutBuilderState.CurrentTime] == 6)
+            if (timeCount[playoutBuilderState.CurrentTime] == 6)
             {
                 _logger.LogWarning(
                     "Failed to schedule beyond {Time}; aborting playout build - this is a bug",

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerFlood.cs

@@ -67,8 +67,9 @@ public class PlayoutModeSchedulerFlood : PlayoutModeSchedulerBase<ProgramSchedul
                 SubtitleMode = scheduleItem.SubtitleMode
             };
 
+            // never block scheduling when there is only one schedule item (with fixed start and flood) 
             DateTimeOffset peekScheduleItemStart =
-                peekScheduleItem.StartType == StartType.Fixed
+                scheduleItem.Id != peekScheduleItem.Id && peekScheduleItem.StartType == StartType.Fixed
                     ? GetStartTimeAfter(nextState with { InFlood = false }, peekScheduleItem)
                     : DateTimeOffset.MaxValue;