1 files changed, 57 insertions, 0 deletions
diff --git a/Jellyfin.Server.Implementations/Item/OrderMapper.cs b/Jellyfin.Server.Implementations/Item/OrderMapper.cs
new file mode 100644
index 000000000..a0c127031
--- /dev/null
+++ b/Jellyfin.Server.Implementations/Item/OrderMapper.cs
@@ -0,0 +1,57 @@
+using System;
+using System.Linq;
+using System.Linq.Expressions;
+using Jellyfin.Data.Enums;
+using Jellyfin.Database.Implementations.Entities;
+using MediaBrowser.Controller.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jellyfin.Server.Implementations.Item;
+
+/// <summary>
+/// Static class for methods which maps types of ordering to their respecting ordering functions.
+/// </summary>
+public static class OrderMapper
+{
+    /// <summary>
+    /// Creates Func to be executed later with a given BaseItemEntity input for sorting items on query.
+    /// </summary>
+    /// <param name="sortBy">Item property to sort by.</param>
+    /// <param name="query">Context Query.</param>
+    /// <returns>Func to be executed later for sorting query.</returns>
+    public static Expression<Func<BaseItemEntity, object?>> MapOrderByField(ItemSortBy sortBy, InternalItemsQuery query)
+    {
+        return sortBy switch
+        {
+            ItemSortBy.AirTime => e => e.SortName, // TODO
+            ItemSortBy.Runtime => e => e.RunTimeTicks,
+            ItemSortBy.Random => e => EF.Functions.Random(),
+            ItemSortBy.DatePlayed => e => e.UserData!.FirstOrDefault(f => f.UserId.Equals(query.User!.Id))!.LastPlayedDate,
+            ItemSortBy.PlayCount => e => e.UserData!.FirstOrDefault(f => f.UserId.Equals(query.User!.Id))!.PlayCount,
+            ItemSortBy.IsFavoriteOrLiked => e => e.UserData!.FirstOrDefault(f => f.UserId.Equals(query.User!.Id))!.IsFavorite,
+            ItemSortBy.IsFolder => e => e.IsFolder,
+            ItemSortBy.IsPlayed => e => e.UserData!.FirstOrDefault(f => f.UserId.Equals(query.User!.Id))!.Played,
+            ItemSortBy.IsUnplayed => e => !e.UserData!.FirstOrDefault(f => f.UserId.Equals(query.User!.Id))!.Played,
+            ItemSortBy.DateLastContentAdded => e => e.DateLastMediaAdded,
+            ItemSortBy.Artist => e => e.ItemValues!.Where(f => f.ItemValue.Type == ItemValueType.Artist).Select(f => f.ItemValue.CleanValue).FirstOrDefault(),
+            ItemSortBy.AlbumArtist => e => e.ItemValues!.Where(f => f.ItemValue.Type == ItemValueType.AlbumArtist).Select(f => f.ItemValue.CleanValue).FirstOrDefault(),
+            ItemSortBy.Studio => e => e.ItemValues!.Where(f => f.ItemValue.Type == ItemValueType.Studios).Select(f => f.ItemValue.CleanValue).FirstOrDefault(),
+            ItemSortBy.OfficialRating => e => e.InheritedParentalRatingValue,
+            // ItemSortBy.SeriesDatePlayed => "(Select MAX(LastPlayedDate) from TypedBaseItems B" + GetJoinUserDataText(query) + " where Played=1 and B.SeriesPresentationUniqueKey=A.PresentationUniqueKey)",
+            ItemSortBy.SeriesSortName => e => e.SeriesName,
+            // ItemSortBy.AiredEpisodeOrder => "AiredEpisodeOrder",
+            ItemSortBy.Album => e => e.Album,
+            ItemSortBy.DateCreated => e => e.DateCreated,
+            ItemSortBy.PremiereDate => e => (e.PremiereDate ?? (e.ProductionYear.HasValue ? DateTime.MinValue.AddYears(e.ProductionYear.Value - 1) : null)),
+            ItemSortBy.StartDate => e => e.StartDate,
+            ItemSortBy.Name => e => e.CleanName,
+            ItemSortBy.CommunityRating => e => e.CommunityRating,
+            ItemSortBy.ProductionYear => e => e.ProductionYear,
+            ItemSortBy.CriticRating => e => e.CriticRating,
+            ItemSortBy.VideoBitRate => e => e.TotalBitrate,
+            ItemSortBy.ParentIndexNumber => e => e.ParentIndexNumber,
+            ItemSortBy.IndexNumber => e => e.IndexNumber,
+            _ => e => e.SortName
+        };
+    }
+}