custom collection playback order (#64)

* add custom index to collection items

* add custom collection order to ui

* cleanup

ErsatzTV.Core/Domain/Collection/Collection.cs

@@ -6,6 +6,7 @@ namespace ErsatzTV.Core.Domain
     {
         public int Id { get; set; }
         public string Name { get; set; }
+        public bool UseCustomPlaybackOrder { get; set; }
         public List<MediaItem> MediaItems { get; set; }
         public List<CollectionItem> CollectionItems { get; set; }
     }

ErsatzTV.Core/Domain/Collection/CollectionItem.cs

@@ -6,5 +6,6 @@
         public Collection Collection { get; set; }
         public int MediaItemId { get; set; }
         public MediaItem MediaItem { get; set; }
+        public int? CustomIndex { get; set; }
     }
 }

ErsatzTV.Core/Interfaces/Repositories/IMediaCollectionRepository.cs

@@ -13,10 +13,12 @@ namespace ErsatzTV.Core.Interfaces.Repositories
         Task<Option<Collection>> Get(int id);
         Task<Option<Collection>> GetCollectionWithItems(int id);
         Task<Option<Collection>> GetCollectionWithItemsUntracked(int id);
+        Task<Option<Collection>> GetCollectionWithCollectionItemsUntracked(int id);
         Task<List<Collection>> GetAll();
         Task<Option<List<MediaItem>>> GetItems(int id);
         Task<bool> Update(Collection collection);
         Task Delete(int collectionId);
         Task<List<int>> PlayoutIdsUsingCollection(int collectionId);
+        Task<bool> IsCustomPlaybackOrder(int collectionId);
     }
 }

ErsatzTV.Core/Scheduling/CustomOrderCollectionEnumerator.cs

@@ -0,0 +1,38 @@
+using System.Collections.Generic;
+using System.Linq;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Scheduling;
+using LanguageExt;
+using static LanguageExt.Prelude;
+
+namespace ErsatzTV.Core.Scheduling
+{
+    public class CustomOrderCollectionEnumerator : IMediaCollectionEnumerator
+    {
+        private readonly IList<MediaItem> _sortedMediaItems;
+
+        public CustomOrderCollectionEnumerator(
+            Collection collection,
+            List<MediaItem> mediaItems,
+            CollectionEnumeratorState state)
+        {
+            // TODO: this will break if we allow shows and seasons
+            _sortedMediaItems = collection.CollectionItems
+                .OrderBy(ci => ci.CustomIndex)
+                .Map(ci => mediaItems.First(mi => mi.Id == ci.MediaItemId))
+                .ToList();
+
+            State = new CollectionEnumeratorState { Seed = state.Seed };
+            while (State.Index < state.Index)
+            {
+                MoveNext();
+            }
+        }
+
+        public CollectionEnumeratorState State { get; }
+
+        public Option<MediaItem> Current => _sortedMediaItems.Any() ? _sortedMediaItems[State.Index] : None;
+
+        public void MoveNext() => State.Index = (State.Index + 1) % _sortedMediaItems.Count;
+    }
+}

ErsatzTV.Core/Scheduling/PlayoutBuilder.cs

@@ -78,7 +78,8 @@ namespace ErsatzTV.Core.Scheduling
                 playout.Channel.Number,
                 playout.Channel.Name);
 
-            Option<CollectionKey> emptyCollection = collectionMediaItems.Find(c => !c.Value.Any()).Map(c => c.Key);
+            Option<CollectionKey> emptyCollection =
+                collectionMediaItems.Find(c => !c.Value.Any()).Map(c => c.Key);
             if (emptyCollection.IsSome)
             {
                 _logger.LogError(
@@ -117,9 +118,15 @@ namespace ErsatzTV.Core.Scheduling
                 playout.ProgramScheduleAnchors.Clear();
             }
 
-            var sortedScheduleItems = playout.ProgramSchedule.Items.OrderBy(i => i.Index).ToList();
-            Map<CollectionKey, IMediaCollectionEnumerator> collectionEnumerators =
-                MapExtensions.Map(collectionMediaItems, (c, i) => GetMediaCollectionEnumerator(playout, c, i));
+            var sortedScheduleItems =
+                playout.ProgramSchedule.Items.OrderBy(i => i.Index).ToList();
+            var collectionEnumerators = new Dictionary<CollectionKey, IMediaCollectionEnumerator>();
+            foreach ((CollectionKey collectionKey, List<MediaItem> mediaItems) in collectionMediaItems)
+            {
+                IMediaCollectionEnumerator enumerator =
+                    await GetMediaCollectionEnumerator(playout, collectionKey, mediaItems);
+                collectionEnumerators.Add(collectionKey, enumerator);
+            }
 
             // find start anchor
             PlayoutAnchor startAnchor = FindStartAnchor(playout, playoutStart, sortedScheduleItems);
@@ -357,20 +364,20 @@ namespace ErsatzTV.Core.Scheduling
 
         private static List<PlayoutProgramScheduleAnchor> BuildProgramScheduleAnchors(
             Playout playout,
-            Map<CollectionKey, IMediaCollectionEnumerator> collectionEnumerators)
+            Dictionary<CollectionKey, IMediaCollectionEnumerator> collectionEnumerators)
         {
             var result = new List<PlayoutProgramScheduleAnchor>();
 
             foreach (CollectionKey collectionKey in collectionEnumerators.Keys)
             {
-                Option<PlayoutProgramScheduleAnchor> maybeExisting = playout.ProgramScheduleAnchors
-                    .FirstOrDefault(
-                        a => a.CollectionType == collectionKey.CollectionType
-                             && a.CollectionId == collectionKey.CollectionId
-                             && a.MediaItemId == collectionKey.MediaItemId);
+                Option<PlayoutProgramScheduleAnchor> maybeExisting = playout.ProgramScheduleAnchors.FirstOrDefault(
+                    a => a.CollectionType == collectionKey.CollectionType
+                         && a.CollectionId == collectionKey.CollectionId
+                         && a.MediaItemId == collectionKey.MediaItemId);
 
-                var maybeEnumeratorState = collectionEnumerators.GroupBy(e => e.Key, e => e.Value.State)
-                    .ToDictionary(mcs => mcs.Key, mcs => mcs.Head());
+                var maybeEnumeratorState = collectionEnumerators.GroupBy(e => e.Key, e => e.Value.State).ToDictionary(
+                    mcs => mcs.Key,
+                    mcs => mcs.Head());
 
                 PlayoutProgramScheduleAnchor scheduleAnchor = maybeExisting.Match(
                     existing =>
@@ -396,22 +403,37 @@ namespace ErsatzTV.Core.Scheduling
             return result;
         }
 
-        private static IMediaCollectionEnumerator GetMediaCollectionEnumerator(
+        private async Task<IMediaCollectionEnumerator> GetMediaCollectionEnumerator(
             Playout playout,
             CollectionKey collectionKey,
             List<MediaItem> mediaItems)
         {
-            Option<PlayoutProgramScheduleAnchor> maybeAnchor = playout.ProgramScheduleAnchors
-                .FirstOrDefault(
-                    a => a.ProgramScheduleId == playout.ProgramScheduleId
-                         && a.CollectionType == collectionKey.CollectionType
-                         && a.CollectionId == collectionKey.CollectionId
-                         && a.MediaItemId == collectionKey.MediaItemId);
+            Option<PlayoutProgramScheduleAnchor> maybeAnchor = playout.ProgramScheduleAnchors.FirstOrDefault(
+                a => a.ProgramScheduleId == playout.ProgramScheduleId
+                     && a.CollectionType == collectionKey.CollectionType
+                     && a.CollectionId == collectionKey.CollectionId
+                     && a.MediaItemId == collectionKey.MediaItemId);
 
             CollectionEnumeratorState state = maybeAnchor.Match(
                 anchor => anchor.EnumeratorState,
                 () => new CollectionEnumeratorState { Seed = Random.Next(), Index = 0 });
 
+            if (await _mediaCollectionRepository.IsCustomPlaybackOrder(collectionKey.CollectionId ?? 0))
+            {
+                Option<Collection> collectionWithItems =
+                    await _mediaCollectionRepository.GetCollectionWithCollectionItemsUntracked(
+                        collectionKey.CollectionId ?? 0);
+
+                if (collectionKey.CollectionType == ProgramScheduleItemCollectionType.Collection &&
+                    collectionWithItems.IsSome)
+                {
+                    return new CustomOrderCollectionEnumerator(
+                        collectionWithItems.ValueUnsafe(),
+                        mediaItems,
+                        state);
+                }
+            }
+
             switch (playout.ProgramSchedule.MediaCollectionPlaybackOrder)
             {
                 case PlaybackOrder.Chronological: