Use Guid for adjacentTo API parameter

Jellyfin.Api/Controllers/ItemsController.cs

@@ -159,7 +159,7 @@ namespace Jellyfin.Api.Controllers
             [FromQuery] bool? hasSubtitles,
             [FromQuery] bool? hasSpecialFeature,
             [FromQuery] bool? hasTrailer,
-            [FromQuery] string? adjacentTo,
+            [FromQuery] Guid? adjacentTo,
             [FromQuery] int? parentIndexNumber,
             [FromQuery] bool? hasParentalRating,
             [FromQuery] bool? isHd,
@@ -614,7 +614,7 @@ namespace Jellyfin.Api.Controllers
             [FromQuery] bool? hasSubtitles,
             [FromQuery] bool? hasSpecialFeature,
             [FromQuery] bool? hasTrailer,
-            [FromQuery] string? adjacentTo,
+            [FromQuery] Guid? adjacentTo,
             [FromQuery] int? parentIndexNumber,
             [FromQuery] bool? hasParentalRating,
             [FromQuery] bool? isHd,

Jellyfin.Api/Controllers/TrailersController.cs

@@ -126,7 +126,7 @@ namespace Jellyfin.Api.Controllers
             [FromQuery] bool? hasSubtitles,
             [FromQuery] bool? hasSpecialFeature,
             [FromQuery] bool? hasTrailer,
-            [FromQuery] string? adjacentTo,
+            [FromQuery] Guid? adjacentTo,
             [FromQuery] int? parentIndexNumber,
             [FromQuery] bool? hasParentalRating,
             [FromQuery] bool? isHd,

Jellyfin.Api/Controllers/TvShowsController.cs

@@ -206,7 +206,7 @@ namespace Jellyfin.Api.Controllers
             [FromQuery] int? season,
             [FromQuery] Guid? seasonId,
             [FromQuery] bool? isMissing,
-            [FromQuery] string? adjacentTo,
+            [FromQuery] Guid? adjacentTo,
             [FromQuery] Guid? startItemId,
             [FromQuery] int? startIndex,
             [FromQuery] int? limit,
@@ -278,9 +278,9 @@ namespace Jellyfin.Api.Controllers
             }
 
             // This must be the last filter
-            if (!string.IsNullOrEmpty(adjacentTo))
+            if (adjacentTo.HasValue)
             {
-                episodes = UserViewBuilder.FilterForAdjacency(episodes, adjacentTo).ToList();
+                episodes = UserViewBuilder.FilterForAdjacency(episodes, adjacentTo.Value).ToList();
             }
 
             if (string.Equals(sortBy, ItemSortBy.Random, StringComparison.OrdinalIgnoreCase))
@@ -326,7 +326,7 @@ namespace Jellyfin.Api.Controllers
             [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ItemFields[] fields,
             [FromQuery] bool? isSpecialSeason,
             [FromQuery] bool? isMissing,
-            [FromQuery] string? adjacentTo,
+            [FromQuery] Guid? adjacentTo,
             [FromQuery] bool? enableImages,
             [FromQuery] int? imageTypeLimit,
             [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes,

MediaBrowser.Controller/Entities/Folder.cs

@@ -860,7 +860,7 @@ namespace MediaBrowser.Controller.Entities
                 return true;
             }
 
-            if (!string.IsNullOrEmpty(query.AdjacentTo))
+            if (query.AdjacentTo.HasValue)
             {
                 Logger.LogDebug("Query requires post-filtering due to AdjacentTo");
                 return true;
@@ -1029,9 +1029,9 @@ namespace MediaBrowser.Controller.Entities
             #pragma warning restore CA1309
 
             // This must be the last filter
-            if (!string.IsNullOrEmpty(query.AdjacentTo))
+            if (query.AdjacentTo.HasValue)
             {
-                items = UserViewBuilder.FilterForAdjacency(items.ToList(), query.AdjacentTo);
+                items = UserViewBuilder.FilterForAdjacency(items.ToList(), query.AdjacentTo.Value);
             }
 
             return UserViewBuilder.SortAndPage(items, null, query, LibraryManager, enableSorting);

MediaBrowser.Controller/Entities/InternalItemsQuery.cs

@@ -129,7 +129,7 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid[] ExcludeItemIds { get; set; }
 
-        public string? AdjacentTo { get; set; }
+        public Guid? AdjacentTo { get; set; }
 
         public string[] PersonTypes { get; set; }
 

MediaBrowser.Controller/Entities/UserViewBuilder.cs

@@ -433,9 +433,9 @@ namespace MediaBrowser.Controller.Entities
             var user = query.User;
 
             // This must be the last filter
-            if (!string.IsNullOrEmpty(query.AdjacentTo))
+            if (query.AdjacentTo.HasValue)
             {
-                items = FilterForAdjacency(items.ToList(), query.AdjacentTo);
+                items = FilterForAdjacency(items.ToList(), query.AdjacentTo.Value);
             }
 
             return SortAndPage(items, totalRecordLimit, query, libraryManager, true);
@@ -985,10 +985,9 @@ namespace MediaBrowser.Controller.Entities
             return _userViewManager.GetUserSubView(parent.Id, type, localizationKey, sortName);
         }
 
-        public static IEnumerable<BaseItem> FilterForAdjacency(List<BaseItem> list, string adjacentToId)
+        public static IEnumerable<BaseItem> FilterForAdjacency(List<BaseItem> list, Guid adjacentTo)
         {
-            var adjacentToIdGuid = new Guid(adjacentToId);
-            var adjacentToItem = list.FirstOrDefault(i => i.Id.Equals(adjacentToIdGuid));
+            var adjacentToItem = list.FirstOrDefault(i => i.Id.Equals(adjacentTo));
 
             var index = list.IndexOf(adjacentToItem);
 
@@ -1005,7 +1004,7 @@ namespace MediaBrowser.Controller.Entities
                 nextId = list[index + 1].Id;
             }
 
-            return list.Where(i => i.Id.Equals(previousId) || i.Id.Equals(nextId) || i.Id.Equals(adjacentToIdGuid));
+            return list.Where(i => i.Id.Equals(previousId) || i.Id.Equals(nextId) || i.Id.Equals(adjacentTo));
         }
     }
 }