playout template pad to next fixes (#1809)

* prevent loop

* add discard attempts and fallback to pad_to_next

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplatePadToNextItem.cs

@@ -8,4 +8,9 @@ public class PlayoutTemplatePadToNextItem : PlayoutTemplateItem
     public int PadToNext { get; set; }
 
     public bool Trim { get; set; }
+
+    public string Fallback { get; set; }
+
+    [YamlMember(Alias = "discard_attempts", ApplyNamingConventions = false)]
+    public int DiscardAttempts { get; set; }
 }

ErsatzTV.Core/Scheduling/TemplateScheduling/PlayoutTemplateSchedulerPadToNext.cs

@@ -1,4 +1,5 @@
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
 using ErsatzTV.Core.Interfaces.Scheduling;
 
 namespace ErsatzTV.Core.Scheduling.TemplateScheduling;
@@ -9,7 +10,8 @@ public class PlayoutTemplateSchedulerPadToNext : PlayoutTemplateScheduler
         Playout playout,
         DateTimeOffset currentTime,
         PlayoutTemplatePadToNextItem padToNext,
-        IMediaCollectionEnumerator enumerator)
+        IMediaCollectionEnumerator enumerator,
+        Option<IMediaCollectionEnumerator> fallbackEnumerator)
     {
         int currentMinute = currentTime.Minute;
 
@@ -31,10 +33,10 @@ public class PlayoutTemplateSchedulerPadToNext : PlayoutTemplateScheduler
         if (targetTime <= currentTime)
             targetTime = targetTime.AddMinutes(padToNext.PadToNext);
 
+        int discardAttempts = padToNext.DiscardAttempts;
         bool done = false;
         TimeSpan remainingToFill = targetTime - currentTime;
-        while (!done && enumerator.Current.IsSome && remainingToFill > TimeSpan.Zero &&
-               remainingToFill >= enumerator.MinimumDuration)
+        while (!done && enumerator.Current.IsSome && remainingToFill > TimeSpan.Zero)
         {
             foreach (MediaItem mediaItem in enumerator.Current)
             {
@@ -55,21 +57,51 @@ public class PlayoutTemplateSchedulerPadToNext : PlayoutTemplateScheduler
                 if (remainingToFill - itemDuration >= TimeSpan.Zero)
                 {
                     remainingToFill -= itemDuration;
+                    currentTime += itemDuration;
+
                     playout.Items.Add(playoutItem);
                     enumerator.MoveNext();
                 }
+                else if (discardAttempts > 0)
+                {
+                    // item won't fit; try the next one
+                    discardAttempts--;
+                    enumerator.MoveNext();
+                }
                 else if (padToNext.Trim)
                 {
                     // trim item to exactly fit
                     remainingToFill = TimeSpan.Zero;
+                    currentTime = targetTime;
+
                     playoutItem.Finish = targetTime.UtcDateTime;
                     playoutItem.OutPoint = playoutItem.Finish - playoutItem.Start;
+
                     playout.Items.Add(playoutItem);
                     enumerator.MoveNext();
                 }
+                else if (fallbackEnumerator.IsSome)
+                {
+                    foreach (IMediaCollectionEnumerator fallback in fallbackEnumerator)
+                    {
+                        remainingToFill = TimeSpan.Zero;
+                        done = true;
+
+                        // replace with fallback content
+                        foreach (MediaItem fallbackItem in fallback.Current)
+                        {
+                            playoutItem.MediaItemId = fallbackItem.Id;
+                            playoutItem.Finish = targetTime.UtcDateTime;
+                            playoutItem.FillerKind = FillerKind.Fallback;
+
+                            playout.Items.Add(playoutItem);
+                            fallback.MoveNext();
+                        }
+                    }
+                }
                 else
                 {
-                    // item won't fit; we're done for now
+                    // item won't fit; we're done
                     done = true;
                 }
             }

ErsatzTV.Core/Scheduling/TemplateScheduling/TemplatePlayoutBuilder.cs

@@ -45,6 +45,7 @@ public class TemplatePlayoutBuilder(
         // load content and content enumerators on demand
         Dictionary<string, IMediaCollectionEnumerator> enumerators = new();
 
+        int itemsAfterRepeat = playout.Items.Count;
         var index = 0;
         while (currentTime < finish)
         {
@@ -60,13 +61,22 @@ public class TemplatePlayoutBuilder(
             if (playoutItem is PlayoutTemplateRepeatItem)
             {
                 index = 0;
+                if (playout.Items.Count == itemsAfterRepeat)
+                {
+                    logger.LogWarning("Repeat encountered without adding any playout items; aborting");
+                    break;
+                }
+
+                itemsAfterRepeat = playout.Items.Count;
                 continue;
             }
 
-            if (!enumerators.TryGetValue(playoutItem.Content, out IMediaCollectionEnumerator enumerator))
-            {
-                Option<IMediaCollectionEnumerator> maybeEnumerator =
-                    await GetEnumeratorForContent(playout, playoutItem.Content, playoutTemplate, cancellationToken);
+            Option<IMediaCollectionEnumerator> maybeEnumerator = await GetCachedEnumeratorForContent(
+                playout,
+                playoutTemplate,
+                enumerators,
+                playoutItem.Content,
+                cancellationToken);
 
             if (maybeEnumerator.IsNone)
             {
@@ -74,12 +84,7 @@ public class TemplatePlayoutBuilder(
                 continue;
             }
 
-                foreach (IMediaCollectionEnumerator e in maybeEnumerator)
-                {
-                    enumerator = maybeEnumerator.ValueUnsafe();
-                    enumerators.Add(playoutItem.Content, enumerator);
-                }
-            }
+            IMediaCollectionEnumerator enumerator = maybeEnumerator.ValueUnsafe();
 
             switch (playoutItem)
             {
@@ -87,11 +92,18 @@ public class TemplatePlayoutBuilder(
                     currentTime = PlayoutTemplateSchedulerCount.Schedule(playout, currentTime, count, enumerator);
                     break;
                 case PlayoutTemplatePadToNextItem padToNext:
+                    Option<IMediaCollectionEnumerator> fallbackEnumerator = await GetCachedEnumeratorForContent(
+                        playout,
+                        playoutTemplate,
+                        enumerators,
+                        padToNext.Fallback,
+                        cancellationToken);
                     currentTime = PlayoutTemplateSchedulerPadToNext.Schedule(
                         playout,
                         currentTime,
                         padToNext,
-                        enumerator);
+                        enumerator,
+                        fallbackEnumerator);
                     break;
             }
 
@@ -106,6 +118,38 @@ public class TemplatePlayoutBuilder(
             .GetValue<int>(ConfigElementKey.PlayoutDaysToBuild)
             .IfNoneAsync(2);
 
+    private async Task<Option<IMediaCollectionEnumerator>> GetCachedEnumeratorForContent(
+        Playout playout,
+        PlayoutTemplate playoutTemplate,
+        Dictionary<string, IMediaCollectionEnumerator> enumerators,
+        string contentKey,
+        CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(contentKey))
+        {
+            return Option<IMediaCollectionEnumerator>.None;
+        }
+
+        if (!enumerators.TryGetValue(contentKey, out IMediaCollectionEnumerator enumerator))
+        {
+            Option<IMediaCollectionEnumerator> maybeEnumerator =
+                await GetEnumeratorForContent(playout, contentKey, playoutTemplate, cancellationToken);
+
+            if (maybeEnumerator.IsNone)
+            {
+                return Option<IMediaCollectionEnumerator>.None;
+            }
+
+            foreach (IMediaCollectionEnumerator e in maybeEnumerator)
+            {
+                enumerator = maybeEnumerator.ValueUnsafe();
+                enumerators.Add(contentKey, enumerator);
+            }
+        }
+
+        return Some(enumerator);
+    }
+
     private async Task<Option<IMediaCollectionEnumerator>> GetEnumeratorForContent(
         Playout playout,
         string contentKey,
@@ -156,6 +200,4 @@ public class TemplatePlayoutBuilder(
 
         return deserializer.Deserialize<PlayoutTemplate>(yaml);
     }
-
-
 }