add random start point option (#804)

CHANGELOG.md

@@ -19,6 +19,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Add filler preset option to allow watermarks to overlay on top of filler (disabled by default)
   - This option is applied when new items are added to a playout; rebuilding is needed if you want the change to take effect immediately
 - Read `track` field from music video NFO metadata and use it for chronological sorting (after release date)
+- Add `Random Start Point` option to schedules
+  - When this option is enabled, all `Chronological` or `Shuffle In Order` content groups will have their start points randomized
+  - When this option is disabled, all `Chronological` or `Shuffle In Order` content groups will start with the chronologically earliest item
 
 ### Changed
 - Replace invalid (control) characters in NFO metadata with replacement character `<EFBFBD>` before parsing

ErsatzTV.Application/ProgramSchedules/Commands/CreateProgramSchedule.cs

@@ -6,4 +6,5 @@ public record CreateProgramSchedule(
     string Name,
     bool KeepMultiPartEpisodesTogether,
     bool TreatCollectionsAsShows,
-    bool ShuffleScheduleItems) : IRequest<Either<BaseError, CreateProgramScheduleResult>>;
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint) : IRequest<Either<BaseError, CreateProgramScheduleResult>>;

ErsatzTV.Application/ProgramSchedules/Commands/CreateProgramScheduleHandler.cs

@@ -44,7 +44,8 @@ public class CreateProgramScheduleHandler :
                     Name = name,
                     KeepMultiPartEpisodesTogether = keepMultiPartEpisodesTogether,
                     TreatCollectionsAsShows = keepMultiPartEpisodesTogether && request.TreatCollectionsAsShows,
-                    ShuffleScheduleItems = request.ShuffleScheduleItems
+                    ShuffleScheduleItems = request.ShuffleScheduleItems,
+                    RandomStartPoint = request.RandomStartPoint
                 };
             });
 

ErsatzTV.Application/ProgramSchedules/Commands/UpdateProgramSchedule.cs

@@ -8,4 +8,5 @@ public record UpdateProgramSchedule
     string Name,
     bool KeepMultiPartEpisodesTogether,
     bool TreatCollectionsAsShows,
-    bool ShuffleScheduleItems) : IRequest<Either<BaseError, UpdateProgramScheduleResult>>;
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint) : IRequest<Either<BaseError, UpdateProgramScheduleResult>>;

ErsatzTV.Application/ProgramSchedules/Commands/UpdateProgramScheduleHandler.cs

@@ -41,13 +41,15 @@ public class UpdateProgramScheduleHandler :
         bool needToRefreshPlayout =
             programSchedule.KeepMultiPartEpisodesTogether != request.KeepMultiPartEpisodesTogether ||
             programSchedule.TreatCollectionsAsShows != request.TreatCollectionsAsShows ||
-            programSchedule.ShuffleScheduleItems != request.ShuffleScheduleItems;
+            programSchedule.ShuffleScheduleItems != request.ShuffleScheduleItems ||
+            programSchedule.RandomStartPoint != request.RandomStartPoint;
 
         programSchedule.Name = request.Name;
         programSchedule.KeepMultiPartEpisodesTogether = request.KeepMultiPartEpisodesTogether;
         programSchedule.TreatCollectionsAsShows = programSchedule.KeepMultiPartEpisodesTogether &&
                                                   request.TreatCollectionsAsShows;
         programSchedule.ShuffleScheduleItems = request.ShuffleScheduleItems;
+        programSchedule.RandomStartPoint = request.RandomStartPoint;
 
         await dbContext.SaveChangesAsync();
 

ErsatzTV.Application/ProgramSchedules/Mapper.cs

@@ -10,7 +10,8 @@ internal static class Mapper
             programSchedule.Name,
             programSchedule.KeepMultiPartEpisodesTogether,
             programSchedule.TreatCollectionsAsShows,
-            programSchedule.ShuffleScheduleItems);
+            programSchedule.ShuffleScheduleItems,
+            programSchedule.RandomStartPoint);
 
     internal static ProgramScheduleItemViewModel ProjectToViewModel(ProgramScheduleItem programScheduleItem) =>
         programScheduleItem switch

ErsatzTV.Application/ProgramSchedules/ProgramScheduleViewModel.cs

@@ -5,4 +5,5 @@ public record ProgramScheduleViewModel(
     string Name,
     bool KeepMultiPartEpisodesTogether,
     bool TreatCollectionsAsShows,
-    bool ShuffleScheduleItems);
+    bool ShuffleScheduleItems,
+    bool RandomStartPoint);

ErsatzTV.Application/ProgramSchedules/Queries/GetAllProgramSchedulesHandler.cs

@@ -22,7 +22,8 @@ public class GetAllProgramSchedulesHandler : IRequestHandler<GetAllProgramSchedu
                     ps.Name,
                     ps.KeepMultiPartEpisodesTogether,
                     ps.TreatCollectionsAsShows,
-                    ps.ShuffleScheduleItems))
+                    ps.ShuffleScheduleItems,
+                    ps.RandomStartPoint))
             .ToListAsync(cancellationToken);
     }
 }

ErsatzTV.Core/Domain/ProgramSchedule.cs

@@ -7,6 +7,7 @@ public class ProgramSchedule
     public bool KeepMultiPartEpisodesTogether { get; set; }
     public bool TreatCollectionsAsShows { get; set; }
     public bool ShuffleScheduleItems { get; set; }
+    public bool RandomStartPoint { get; set; }
     public List<ProgramScheduleItem> Items { get; set; }
     public List<Playout> Playouts { get; set; }
 }

ErsatzTV.Core/Scheduling/PlayoutBuilder.cs

@@ -175,7 +175,8 @@ public class PlayoutBuilder : IPlayoutBuilder
             playout,
             parameters.Start,
             parameters.Finish,
-            parameters.CollectionMediaItems);
+            parameters.CollectionMediaItems,
+            false);
     }
 
     private async Task<Playout> ResetPlayout(Playout playout, PlayoutParameters parameters)
@@ -194,7 +195,8 @@ public class PlayoutBuilder : IPlayoutBuilder
             playout,
             parameters.Start,
             parameters.Finish,
-            parameters.CollectionMediaItems);
+            parameters.CollectionMediaItems,
+            playout.ProgramSchedule.RandomStartPoint);
 
         return playout;
     }
@@ -217,7 +219,8 @@ public class PlayoutBuilder : IPlayoutBuilder
             playout,
             parameters.Start,
             parameters.Finish,
-            parameters.CollectionMediaItems);
+            parameters.CollectionMediaItems,
+            false);
 
         return playout;
     }
@@ -282,7 +285,8 @@ public class PlayoutBuilder : IPlayoutBuilder
         Playout playout,
         DateTimeOffset playoutStart,
         DateTimeOffset playoutFinish,
-        Map<CollectionKey, List<MediaItem>> collectionMediaItems)
+        Map<CollectionKey, List<MediaItem>> collectionMediaItems,
+        bool randomStartPoint)
     {
         DateTimeOffset trimBefore = playoutStart.AddHours(-4);
         DateTimeOffset trimAfter = playoutFinish;
@@ -301,7 +305,10 @@ public class PlayoutBuilder : IPlayoutBuilder
         while (finish < playoutFinish)
         {
             _logger.LogDebug("Building playout from {Start} to {Finish}", start, finish);
-            playout = await BuildPlayoutItems(playout, start, finish, collectionMediaItems, true);
+            playout = await BuildPlayoutItems(playout, start, finish, collectionMediaItems, true, randomStartPoint);
+
+            // only randomize once (at the start of the playout)
+            randomStartPoint = false;
 
             start = playout.Anchor.NextStartOffset;
             finish = finish.AddDays(1);
@@ -316,7 +323,8 @@ public class PlayoutBuilder : IPlayoutBuilder
                 start,
                 playoutFinish,
                 collectionMediaItems,
-                false);
+                false,
+                randomStartPoint);
         }
 
         // remove any items outside the desired range
@@ -330,7 +338,8 @@ public class PlayoutBuilder : IPlayoutBuilder
         DateTimeOffset playoutStart,
         DateTimeOffset playoutFinish,
         Map<CollectionKey, List<MediaItem>> collectionMediaItems,
-        bool saveAnchorDate)
+        bool saveAnchorDate,
+        bool randomStartPoint)
     {
         var sortedScheduleItems = playout.ProgramSchedule.Items.OrderBy(i => i.Index).ToList();
         CollectionEnumeratorState scheduleItemsEnumeratorState =
@@ -348,7 +357,7 @@ public class PlayoutBuilder : IPlayoutBuilder
             PlaybackOrder playbackOrder = maybeScheduleItem
                 .Match(item => item.PlaybackOrder, () => PlaybackOrder.Shuffle);
             IMediaCollectionEnumerator enumerator =
-                await GetMediaCollectionEnumerator(playout, collectionKey, mediaItems, playbackOrder);
+                await GetMediaCollectionEnumerator(playout, collectionKey, mediaItems, playbackOrder, randomStartPoint);
             collectionEnumerators.Add(collectionKey, enumerator);
         }
 
@@ -643,7 +652,8 @@ public class PlayoutBuilder : IPlayoutBuilder
         Playout playout,
         CollectionKey collectionKey,
         List<MediaItem> mediaItems,
-        PlaybackOrder playbackOrder)
+        PlaybackOrder playbackOrder,
+        bool randomStartPoint)
     {
         Option<PlayoutProgramScheduleAnchor> maybeAnchor = playout.ProgramScheduleAnchors
             .OrderByDescending(a => a.AnchorDate is null)
@@ -681,9 +691,21 @@ public class PlayoutBuilder : IPlayoutBuilder
             }
         }
 
+        // index shouldn't ever be greater than zero with randomStartPoint since anchors shouldn't exist, but
+        randomStartPoint = randomStartPoint && state.Index == 0;
+
         switch (playbackOrder)
         {
             case PlaybackOrder.Chronological:
+                if (randomStartPoint)
+                {
+                    state = new CollectionEnumeratorState
+                    {
+                        Seed = state.Seed,
+                        Index = Random.Next(0, mediaItems.Count - 1)
+                    };
+                }
+
                 return new ChronologicalMediaCollectionEnumerator(mediaItems, state);
             case PlaybackOrder.Random:
                 return new RandomizedMediaCollectionEnumerator(mediaItems, state);
@@ -694,7 +716,8 @@ public class PlayoutBuilder : IPlayoutBuilder
             case PlaybackOrder.ShuffleInOrder:
                 return new ShuffleInOrderCollectionEnumerator(
                     await GetCollectionItemsForShuffleInOrder(collectionKey),
-                    state);
+                    state,
+                    playout.ProgramSchedule.RandomStartPoint);
             default:
                 // TODO: handle this error case differently?
                 return new RandomizedMediaCollectionEnumerator(mediaItems, state);

ErsatzTV.Core/Scheduling/ShuffleInOrderCollectionEnumerator.cs

@@ -7,14 +7,17 @@ public class ShuffleInOrderCollectionEnumerator : IMediaCollectionEnumerator
 {
     private readonly IList<CollectionWithItems> _collections;
     private readonly int _mediaItemCount;
+    private readonly bool _randomStartPoint;
     private Random _random;
     private IList<MediaItem> _shuffled;
 
     public ShuffleInOrderCollectionEnumerator(
         IList<CollectionWithItems> collections,
-        CollectionEnumeratorState state)
+        CollectionEnumeratorState state,
+        bool randomStartPoint)
     {
         _collections = collections;
+        _randomStartPoint = randomStartPoint;
         _mediaItemCount = collections.Sum(c => c.MediaItems.Count);
 
         if (state.Index >= _mediaItemCount)
@@ -87,7 +90,14 @@ public class ShuffleInOrderCollectionEnumerator : IMediaCollectionEnumerator
         var result = new List<MediaItem>();
         for (var i = 0; i < filled[0].Items.Count; i++)
         {
-            var batch = filled.Select(collection => collection.Items[i]).ToList();
+            var batch = new List<Option<MediaItem>>();
+
+            foreach (OrderedCollection collection in filled)
+            {
+                int index = (collection.Index + i) % collection.Items.Count;
+                batch.Add(collection.Items[index]);
+            }
+
             foreach (Option<MediaItem> maybeItem in Shuffle(batch, random))
             {
                 result.AddRange(maybeItem);
@@ -144,7 +154,13 @@ public class ShuffleInOrderCollectionEnumerator : IMediaCollectionEnumerator
                 ordered.AddRange(larger);
             }
 
-            result.Add(new OrderedCollection { Index = 0, Items = ordered });
+            var index = 0;
+            if (_randomStartPoint)
+            {
+                index = random.Next(0, ordered.Count - 1);
+            }
+
+            result.Add(new OrderedCollection { Index = index, Items = ordered });
         }
 
         return result;

ErsatzTV.Infrastructure/Migrations/20220513230433_Add_ProgramSchedule_RandomStartPoint.cs

@@ -0,0 +1,26 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.Migrations
+{
+    public partial class Add_ProgramSchedule_RandomStartPoint : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "RandomStartPoint",
+                table: "ProgramSchedule",
+                type: "INTEGER",
+                nullable: false,
+                defaultValue: false);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "RandomStartPoint",
+                table: "ProgramSchedule");
+        }
+    }
+}

ErsatzTV.Infrastructure/Migrations/TvContextModelSnapshot.cs

@@ -1548,6 +1548,9 @@ namespace ErsatzTV.Infrastructure.Migrations
                     b.Property<string>("Name")
                         .HasColumnType("TEXT");
 
+                    b.Property<bool>("RandomStartPoint")
+                        .HasColumnType("INTEGER");
+
                     b.Property<bool>("ShuffleScheduleItems")
                         .HasColumnType("INTEGER");
 

ErsatzTV/Pages/ScheduleEditor.razor

@@ -38,6 +38,11 @@
                                          For="@(() => _model.ShuffleScheduleItems)"/>
                         </MudTooltip>
                     </MudElement>
+                    <MudElement HtmlTag="div" Class="mt-3">
+                        <MudCheckBox Label="Random Start Point"
+                                     @bind-Checked="@_model.RandomStartPoint"
+                                     For="@(() => _model.RandomStartPoint)"/>
+                    </MudElement>
                 </MudCardContent>
                 <MudCardActions>
                     <MudButton ButtonType="ButtonType.Submit" Variant="Variant.Filled" Color="Color.Primary">
@@ -78,6 +83,7 @@
                     _model.ShuffleScheduleItems = viewModel.ShuffleScheduleItems;
                     _model.KeepMultiPartEpisodesTogether = viewModel.KeepMultiPartEpisodesTogether;
                     _model.TreatCollectionsAsShows = viewModel.TreatCollectionsAsShows;
+                    _model.RandomStartPoint = viewModel.RandomStartPoint;
                 },
                 () => _navigationManager.NavigateTo("404"));
         }

ErsatzTV/ViewModels/ProgramScheduleEditViewModel.cs

@@ -9,10 +9,11 @@ public class ProgramScheduleEditViewModel
     public bool KeepMultiPartEpisodesTogether { get; set; }
     public bool TreatCollectionsAsShows { get; set; }
     public bool ShuffleScheduleItems { get; set; }
+    public bool RandomStartPoint { get; set; }
 
     public UpdateProgramSchedule ToUpdate() =>
-        new(Id, Name, KeepMultiPartEpisodesTogether, TreatCollectionsAsShows, ShuffleScheduleItems);
+        new(Id, Name, KeepMultiPartEpisodesTogether, TreatCollectionsAsShows, ShuffleScheduleItems, RandomStartPoint);
 
     public CreateProgramSchedule ToCreate() =>
-        new(Name, KeepMultiPartEpisodesTogether, TreatCollectionsAsShows, ShuffleScheduleItems);
+        new(Name, KeepMultiPartEpisodesTogether, TreatCollectionsAsShows, ShuffleScheduleItems, RandomStartPoint);
 }