From f479c93c5cdf43e94dc270535ac36cce17ce7ff8 Mon Sep 17 00:00:00 2001
From: redxef <redxef@redxef.at>
Date: Tue, 19 Nov 2024 17:33:33 +0100
Subject: [PATCH] feat: add SortProgram.

Works similar to Program, but receives the list of matched items
and should return the same list but sorted.
This can actually also be used for further filtering.
---
 .../ScheduledTasks/GeneratePlaylist.cs        | 29 +++++++++++++++----
 .../SmartPlaylistDto.cs                       |  8 +++++
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/Jellyfin.Plugin.SmartPlaylist/ScheduledTasks/GeneratePlaylist.cs b/Jellyfin.Plugin.SmartPlaylist/ScheduledTasks/GeneratePlaylist.cs
index 4af2d60..174c3f8 100644
--- a/Jellyfin.Plugin.SmartPlaylist/ScheduledTasks/GeneratePlaylist.cs
+++ b/Jellyfin.Plugin.SmartPlaylist/ScheduledTasks/GeneratePlaylist.cs
@@ -95,25 +95,42 @@ namespace Jellyfin.Plugin.SmartPlaylist.ScheduledTasks {
         }
 
         private IEnumerable<Guid> FilterPlaylistItems(IEnumerable<BaseItem> items, User user, SmartPlaylistDto smartPlaylist) {
-            List<Guid> results = new List<Guid>();
-            Expression expression = new Parser(StringTokenStream.generate(smartPlaylist.Program)).parse();
+            List<BaseItem> results = new List<BaseItem>();
+            Expression expression = new Parser(StringTokenStream.generate(smartPlaylist.Program)).parse(); // parse here, so that we don't repeat the work for each item
             Executor executor = new Executor(new DefaultEnvironment());
-            executor.environment.Set("user", new Lisp_Object(user));
+            executor.environment.Set("user", Lisp_Object.FromBase(user));
             if (Plugin.Instance is not null) {
                 executor.eval(Plugin.Instance.Configuration.InitialProgram);
             } else {
                 throw new ApplicationException("Plugin Instance is not yet initialized");
             }
             foreach (var i in items) {
-                executor.environment.Set("item", new Lisp_Object(i));
+                executor.environment.Set("item", Lisp_Object.FromBase(i));
                 var r = executor.eval(expression);
                 _logger.LogTrace("Item {0} evaluated to {1}", i, r.ToString());
                 if ((r is not Lisp_Boolean r_bool) || (r_bool.Value())) {
                     _logger.LogDebug("Added '{0}' to Smart Playlist {1}", i, smartPlaylist.Name);
-                    results.Add(i.Id);
+                    results.Add(i);
                 }
             }
-            return results;
+            executor = new Executor(new DefaultEnvironment());
+            executor.environment.Set("user", Lisp_Object.FromBase(user));
+            executor.environment.Set("items", Lisp_Object.FromBase(results));
+            results = new List<BaseItem>();
+            var sort_result = executor.eval(smartPlaylist.SortProgram);
+            if (sort_result is Cons sorted_items) {
+                foreach (var i in sorted_items.ToList()) {
+                    if (i is Lisp_Object iObject && iObject.Value() is BaseItem iBaseItem) {
+                        results.Add(iBaseItem);
+                        continue;
+                    }
+                    throw new ApplicationException($"Returned sorted list does contain unexpected items, got {i}");
+                }
+            } else if (sort_result == Lisp_Boolean.FALSE) {
+            } else {
+                throw new ApplicationException($"Did not return a list of items, returned {sort_result}");
+            }
+            return results.Select(x => x.Id);
         }
 
         private IEnumerable<BaseItem> GetAllUserMedia(User user) {
diff --git a/Jellyfin.Plugin.SmartPlaylist/SmartPlaylistDto.cs b/Jellyfin.Plugin.SmartPlaylist/SmartPlaylistDto.cs
index 75bd102..7d2e05a 100644
--- a/Jellyfin.Plugin.SmartPlaylist/SmartPlaylistDto.cs
+++ b/Jellyfin.Plugin.SmartPlaylist/SmartPlaylistDto.cs
@@ -42,10 +42,12 @@ namespace Jellyfin.Plugin.SmartPlaylist {
     [Serializable]
     public class SmartPlaylistDto : ISerializable {
         private static string DEFAULT_PROGRAM = "(begin (invoke item \"IsFavoriteOrLiked\" (list user)))";
+        private static string DEFAULT_SORT_PROGRAM = "(begin items)";
         public SmartPlaylistId Id { get; set; }
         public SmartPlaylistLinkDto[] Playlists { get; set; }
         public string Name { get; set; }
         public string Program { get; set; }
+        public string SortProgram { get; set; }
         public string? Filename { get; set; }
         public bool Enabled { get; set; }
 
@@ -54,6 +56,7 @@ namespace Jellyfin.Plugin.SmartPlaylist {
             Playlists = [];
             Name = Id.ToString();
             Program = DEFAULT_PROGRAM;
+            SortProgram = DEFAULT_SORT_PROGRAM;
             Filename = null;
             Enabled = true;
         }
@@ -79,6 +82,11 @@ namespace Jellyfin.Plugin.SmartPlaylist {
             } else {
                 Program = DEFAULT_PROGRAM;
             }
+            if (info.GetValue("SortProgram", typeof(string)) is string _SortProgram) {
+                SortProgram = _SortProgram;
+            } else {
+                SortProgram = DEFAULT_SORT_PROGRAM;
+            }
             if (info.GetValue("Filename", typeof(string)) is string _Filename) {
                 Filename = _Filename;
             } else {