Remove giant ActivityDto ternary and add more documentation in some areas

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "dotnet-ef": {
-      "version": "7.0.13",
+      "version": "8.0.0",
       "commands": [
         "dotnet-ef"
       ]

ProjectLighthouse.Servers.GameServer/Controllers/ActivityController.cs

@@ -56,7 +56,7 @@ public class ActivityController : ControllerBase
             .ToListAsync();
 
         List<int>? friendIds = UserFriendStore.GetUserFriendData(token.UserId)?.FriendIds;
-        friendIds ??= new List<int>();
+        friendIds ??= [];
 
         // This is how lbp3 does its filtering
         GameStreamFilter? filter = await this.DeserializeBody<GameStreamFilter>();
@@ -89,7 +89,7 @@ public class ActivityController : ControllerBase
             predicate = predicate.Or(dto => dto.TargetSlotCreatorId == token.UserId);
         }
 
-        List<int> includedUserIds = new();
+        List<int> includedUserIds = [];
 
         if (!excludeFriends)
         {
@@ -168,7 +168,7 @@ public class ActivityController : ControllerBase
 
     private static DateTime GetOldestTime
         (IReadOnlyCollection<IGrouping<ActivityGroup, ActivityDto>> groups, DateTime defaultTimestamp) =>
-        groups.Any()
+        groups.Count != 0
             ? groups.Min(g => g.MinBy(a => a.Activity.Timestamp)?.Activity.Timestamp ?? defaultTimestamp)
             : defaultTimestamp;
 
@@ -247,7 +247,7 @@ public class ActivityController : ControllerBase
     {
         GameTokenEntity token = this.GetToken();
 
-        if (token.GameVersion == GameVersion.LittleBigPlanet1) return this.NotFound();
+        if (token.GameVersion is GameVersion.LittleBigPlanet1 or GameVersion.LittleBigPlanetPSP) return this.NotFound();
 
         IQueryable<ActivityDto> activityEvents = await this.GetFilters(this.database.Activities.ToActivityDto(true),
             token,
@@ -305,10 +305,11 @@ public class ActivityController : ControllerBase
     {
         GameTokenEntity token = this.GetToken();
 
-        if (token.GameVersion == GameVersion.LittleBigPlanet1) return this.NotFound();
+        if (token.GameVersion is GameVersion.LittleBigPlanet1 or GameVersion.LittleBigPlanetPSP) return this.NotFound();
 
         if ((SlotHelper.IsTypeInvalid(slotType) || slotId == 0) == (username == null)) return this.BadRequest();
 
+        // User and Level activity will never contain news posts or MM pick events.
         IQueryable<ActivityDto> activityQuery = this.database.Activities.ToActivityDto()
             .Where(a => a.Activity.Type != EventType.NewsPost && a.Activity.Type != EventType.MMPickLevel);
 
@@ -343,6 +344,8 @@ public class ActivityController : ControllerBase
 
         List<OuterActivityGroup> outerGroups = groups.ToOuterActivityGroups();
 
+        PrintOuterGroups(outerGroups);
+
         long oldestTimestamp = GetOldestTime(groups, times.Start).ToUnixTimeMilliseconds();
 
         await this.CacheEntities(outerGroups);

ProjectLighthouse.Tests.GameApiTests/Unit/Activity/ActivityGroupingTests.cs

@@ -1,31 +1,345 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
+using LBPUnion.ProjectLighthouse.Database;
 using LBPUnion.ProjectLighthouse.Extensions;
+using LBPUnion.ProjectLighthouse.Tests.Helpers;
 using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Activity;
+using LBPUnion.ProjectLighthouse.Types.Entities.Level;
+using LBPUnion.ProjectLighthouse.Types.Entities.Profile;
+using LBPUnion.ProjectLighthouse.Types.Entities.Website;
+using LBPUnion.ProjectLighthouse.Types.Users;
+using Microsoft.EntityFrameworkCore;
 using Xunit;
 
 namespace ProjectLighthouse.Tests.GameApiTests.Unit.Activity;
 
+[Trait("Category", "Unit")]
 public class ActivityGroupingTests
 {
      [Fact]
-     public void ActivityGroupingTest()
+     public void ToOuterActivityGroups_ShouldCreateGroupPerObject_WhenGroupedBy_ObjectThenActor()
      {
-          List<ActivityDto> activities = new()
+          List<ActivityEntity> activities = [
+               new LevelActivityEntity
                {
-               new ActivityDto
+                    UserId = 1,
+                    SlotId = 1,
+                    Slot = new SlotEntity
                     {
-                    TargetPlaylistId = 1,
+                         GameVersion = GameVersion.LittleBigPlanet2,
-                    Activity = new ActivityEntity(),
                     },
-          };
+                    Timestamp = DateTime.Now,
-          List<OuterActivityGroup> groups = activities.AsQueryable().ToActivityGroups().ToList().ToOuterActivityGroups();
+                    Type = EventType.PlayLevel,
+               },
+               new LevelActivityEntity
+               {
+                    UserId = 1,
+                    SlotId = 1,
+                    Slot = new SlotEntity
+                    {
+                         GameVersion = GameVersion.LittleBigPlanet2,
+                    },
+                    Timestamp = DateTime.Now,
+                    Type = EventType.ReviewLevel,
+               },
+               new LevelActivityEntity
+               {
+                    UserId = 2,
+                    SlotId = 1,
+                    Slot = new SlotEntity
+                    {
+                         GameVersion = GameVersion.LittleBigPlanet2,
+                    },
+                    Timestamp = DateTime.Now,
+                    Type = EventType.PlayLevel,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 2,
+                    UserId = 1,
+                    Type = EventType.HeartUser,
+                    Timestamp = DateTime.Now,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 2,
+                    UserId = 1,
+                    Type = EventType.CommentOnUser,
+                    Timestamp = DateTime.Now,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 1,
+                    UserId = 2,
+                    Type = EventType.HeartUser,
+                    Timestamp = DateTime.Now,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 1,
+                    UserId = 2,
+                    Type = EventType.CommentOnUser,
+                    Timestamp = DateTime.Now,
+               },
+          ];
+
+          //TODO: fix test
+          List<OuterActivityGroup> groups = activities.ToActivityDto().AsQueryable().ToActivityGroups().ToList().ToOuterActivityGroups();
           Assert.NotNull(groups);
           Assert.Single(groups);
-          OuterActivityGroup groupEntry = groups.First();
+          OuterActivityGroup outerGroup = groups.First();
 
-          Assert.Equal(ActivityGroupType.Playlist, groupEntry.Key.GroupType);
+          Assert.Equal(ActivityGroupType.Level, outerGroup.Key.GroupType);
-          Assert.Equal(1, groupEntry.Key.TargetId);
+          Assert.Equal(1, outerGroup.Key.TargetSlotId);
+
+          IGrouping<InnerActivityGroup, ActivityDto>? firstGroup = outerGroup.Groups.First();
+          IGrouping<InnerActivityGroup, ActivityDto>? secondGroup = outerGroup.Groups.Last();
+
+          Assert.NotNull(secondGroup);
+          Assert.Equal(ActivityGroupType.User, secondGroup.Key.Type);
+          Assert.Equal(1, secondGroup.Key.TargetId); // user group should have the user id
+          Assert.Equal(1, secondGroup.ToList()[0].TargetSlotId); // events in user group should have t
+          Assert.Equal(1, secondGroup.ToList()[1].TargetSlotId);
+
+          Assert.NotNull(firstGroup);
+          Assert.Equal(ActivityGroupType.User, firstGroup.Key.Type);
+          Assert.Equal(2, firstGroup.Key.TargetId);
+          Assert.Equal(1, firstGroup.ToList()[0].TargetSlotId);
+     }
+
+     [Fact]
+     public void ToOuterActivityGroups_ShouldCreateGroupPerObject_WhenGroupedBy_ActorThenObject()
+     {
+                    List<ActivityEntity> activities = [
+               new LevelActivityEntity
+               {
+                    UserId = 1,
+                    SlotId = 1,
+                    Slot = new SlotEntity
+                    {
+                         GameVersion = GameVersion.LittleBigPlanet2,
+                    },
+                    Timestamp = DateTime.Now,
+                    Type = EventType.PlayLevel,
+               },
+               new LevelActivityEntity
+               {
+                    UserId = 1,
+                    SlotId = 1,
+                    Slot = new SlotEntity
+                    {
+                         GameVersion = GameVersion.LittleBigPlanet2,
+                    },
+                    Timestamp = DateTime.Now,
+                    Type = EventType.ReviewLevel,
+               },
+               new LevelActivityEntity
+               {
+                    UserId = 2,
+                    SlotId = 1,
+                    Slot = new SlotEntity
+                    {
+                         GameVersion = GameVersion.LittleBigPlanet2,
+                    },
+                    Timestamp = DateTime.Now,
+                    Type = EventType.PlayLevel,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 2,
+                    UserId = 1,
+                    Type = EventType.HeartUser,
+                    Timestamp = DateTime.Now,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 2,
+                    UserId = 1,
+                    Type = EventType.CommentOnUser,
+                    Timestamp = DateTime.Now,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 1,
+                    UserId = 2,
+                    Type = EventType.HeartUser,
+                    Timestamp = DateTime.Now,
+               },
+               new UserActivityEntity
+               {
+                    TargetUserId = 1,
+                    UserId = 2,
+                    Type = EventType.CommentOnUser,
+                    Timestamp = DateTime.Now,
+               },
+          ];
+          List<OuterActivityGroup> groups = activities.ToActivityDto()
+               .AsQueryable()
+               .ToActivityGroups(true)
+               .ToList()
+               .ToOuterActivityGroups(true);
+          //TODO: fix test
+          Assert.Multiple(() =>
+          {
+               Assert.NotNull(groups);
+               Assert.Equal(2, groups.Count);
+               OuterActivityGroup firstUserGroup = groups.FirstOrDefault(g => g.Key.UserId == 1);
+               OuterActivityGroup secondUserGroup = groups.FirstOrDefault(g => g.Key.UserId == 2);
+               Assert.NotNull(firstUserGroup.Groups);
+               Assert.NotNull(secondUserGroup.Groups);
+
+               Assert.Equal(ActivityGroupType.User, firstUserGroup.Key.GroupType);
+               Assert.Equal(ActivityGroupType.User, secondUserGroup.Key.GroupType);
+
+               Assert.Single(firstUserGroup.Groups);
+               Assert.Single(secondUserGroup.Groups);
+
+               Assert.Equal(2, firstUserGroup.Groups.ToList()[0].Count());
+               Assert.Single(secondUserGroup.Groups.ToList()[0]);
+
+               // Assert.Equal(ActivityGroupType.Level, outerGroup.Key.GroupType);
+               // Assert.Equal(1, outerGroup.Key.TargetSlotId);
+               //
+               // IGrouping<InnerActivityGroup, ActivityDto>? firstGroup = outerGroup.Groups.First();
+               // IGrouping<InnerActivityGroup, ActivityDto>? secondGroup = outerGroup.Groups.Last();
+               //
+               // Assert.NotNull(secondGroup);
+               // Assert.Equal(ActivityGroupType.User, secondGroup.Key.Type);
+               // Assert.Equal(1, secondGroup.Key.TargetId); // user group should have the user id
+               // Assert.Equal(1, secondGroup.ToList()[0].TargetSlotId); // events in user group should have t
+               // Assert.Equal(1, secondGroup.ToList()[1].TargetSlotId);
+               //
+               // Assert.NotNull(firstGroup);
+               // Assert.Equal(ActivityGroupType.User, firstGroup.Key.Type);
+               // Assert.Equal(2, firstGroup.Key.TargetId);
+               // Assert.Equal(1, firstGroup.ToList()[0].TargetSlotId);
+          });
+     }
+
+     [Fact]
+     public async Task ToActivityDtoTest()
+     {
+          DatabaseContext db = await MockHelper.GetTestDatabase();
+          db.Slots.Add(new SlotEntity
+          {
+               SlotId = 1,
+               CreatorId = 1,
+               GameVersion = GameVersion.LittleBigPlanet2,
+          });
+          db.Slots.Add(new SlotEntity
+          {
+               SlotId = 2,
+               CreatorId = 1,
+               GameVersion = GameVersion.LittleBigPlanet2,
+               TeamPickTime = 1,
+          });
+          db.Reviews.Add(new ReviewEntity
+          {
+               Timestamp = DateTime.Now.ToUnixTimeMilliseconds(),
+               SlotId = 1,
+               ReviewerId = 1,
+               ReviewId = 1,
+          });
+          db.Comments.Add(new CommentEntity
+          {
+               TargetSlotId = 1,
+               PosterUserId = 1,
+               Message = "comment on level test",
+               CommentId = 1,
+          });
+          db.Comments.Add(new CommentEntity
+          {
+               TargetUserId = 1,
+               PosterUserId = 1,
+               Message = "comment on user test",
+               CommentId = 2,
+          });
+          db.WebsiteAnnouncements.Add(new WebsiteAnnouncementEntity
+          {
+               PublisherId = 1,
+               AnnouncementId = 1,
+          });
+          db.Playlists.Add(new PlaylistEntity
+          {
+               PlaylistId = 1,
+               CreatorId = 1,
+          });
+          db.Activities.Add(new LevelActivityEntity
+          {
+               Timestamp = DateTime.Now,
+               SlotId = 1,
+               Type = EventType.PlayLevel,
+               UserId = 1,
+          });
+          db.Activities.Add(new ReviewActivityEntity
+          {
+               Timestamp = DateTime.Now,
+               SlotId = 1,
+               Type = EventType.ReviewLevel,
+               ReviewId = 1,
+               UserId = 1,
+          });
+          db.Activities.Add(new UserCommentActivityEntity
+          {
+               Timestamp = DateTime.Now,
+               Type = EventType.CommentOnUser,
+               UserId = 1,
+               TargetUserId = 1,
+               CommentId = 2,
+          });
+          db.Activities.Add(new LevelCommentActivityEntity
+          {
+               Timestamp = DateTime.Now,
+               Type = EventType.CommentOnLevel,
+               UserId = 1,
+               SlotId = 1,
+               CommentId = 1,
+          });
+          db.Activities.Add(new NewsActivityEntity
+          {
+               Type = EventType.NewsPost,
+               NewsId = 1,
+               UserId = 1,
+          });
+          db.Activities.Add(new PlaylistActivityEntity
+          {
+               Type = EventType.CreatePlaylist,
+               PlaylistId = 1,
+               UserId = 1,
+          });
+          db.Activities.Add(new LevelActivityEntity
+          {
+               Type = EventType.MMPickLevel,
+               SlotId = 2,
+               UserId = 1,
+          });
+          await db.SaveChangesAsync();
+
+          var sql = db.Activities.ToActivityDto().ToQueryString();
+
+          List<ActivityDto> resultDto = await db.Activities.ToActivityDto(includeSlotCreator: true, includeTeamPick: true).ToListAsync();
+
+          Assert.Equal(2, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.MMPickLevel)?.TargetTeamPickId);
+          Assert.Equal(2, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.MMPickLevel)?.TargetSlotId);
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.MMPickLevel)?.TargetSlotCreatorId);
+
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.CreatePlaylist)?.TargetPlaylistId);
+
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.NewsPost)?.TargetNewsId);
+
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.CommentOnUser)?.TargetUserId);
+
+          Assert.Null(resultDto.FirstOrDefault(a => a.Activity.Type == EventType.CommentOnLevel)?.TargetTeamPickId);
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.CommentOnLevel)?.TargetSlotId);
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.CommentOnLevel)?.TargetSlotCreatorId);
+
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.ReviewLevel)?.TargetSlotId);
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.ReviewLevel)?.TargetSlotCreatorId);
+
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.PlayLevel)?.TargetSlotId);
+          Assert.Equal(1, resultDto.FirstOrDefault(a => a.Activity.Type == EventType.PlayLevel)?.TargetSlotCreatorId);
      }
 }

ProjectLighthouse/Database/ActivityInterceptor.cs

@@ -93,7 +93,7 @@ public class ActivityInterceptor : SaveChangesInterceptor
     {
         if (eventData.Context is not DatabaseContext context) return;
 
-        HashSet<CustomTrackedEntity> entities = new();
+        HashSet<CustomTrackedEntity> entities = [];
 
         List<EntityEntry> entries = context.ChangeTracker.Entries().ToList();
 

ProjectLighthouse/Database/DatabaseContext.cs

@@ -109,13 +109,15 @@ public partial class DatabaseContext : DbContext
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
         modelBuilder.Entity<LevelActivityEntity>().UseTphMappingStrategy();
-        modelBuilder.Entity<PhotoActivityEntity>().UseTphMappingStrategy();
+        modelBuilder.Entity<UserPhotoActivity>().UseTphMappingStrategy();
+        modelBuilder.Entity<LevelPhotoActivity>().UseTphMappingStrategy();
         modelBuilder.Entity<PlaylistActivityEntity>().UseTphMappingStrategy();
         modelBuilder.Entity<PlaylistWithSlotActivityEntity>().UseTphMappingStrategy();
         modelBuilder.Entity<ScoreActivityEntity>().UseTphMappingStrategy();
         modelBuilder.Entity<UserActivityEntity>().UseTphMappingStrategy();
         modelBuilder.Entity<NewsActivityEntity>().UseTphMappingStrategy();
-        modelBuilder.Entity<CommentActivityEntity>().UseTphMappingStrategy();
+        modelBuilder.Entity<LevelCommentActivityEntity>().UseTphMappingStrategy();
+        modelBuilder.Entity<UserCommentActivityEntity>().UseTphMappingStrategy();
         modelBuilder.Entity<UserActivityEntity>().UseTphMappingStrategy();
         modelBuilder.Entity<ReviewActivityEntity>().UseTphMappingStrategy();
         base.OnModelCreating(modelBuilder);

ProjectLighthouse/Extensions/ActivityQueryExtensions.cs

@@ -2,7 +2,6 @@
 using System.Linq;
 using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Activity;
-using LBPUnion.ProjectLighthouse.Types.Entities.Profile;
 
 namespace LBPUnion.ProjectLighthouse.Extensions;
 
@@ -10,7 +9,7 @@ public static class ActivityQueryExtensions
 {
     public static List<int> GetIds(this IReadOnlyCollection<OuterActivityGroup> groups, ActivityGroupType type)
     {
-        List<int> ids = new();
+        List<int> ids = [];
         // Add outer group ids
         ids.AddRange(groups.Where(g => g.Key.GroupType == type)
             .Where(g => g.Key.TargetId != 0)
@@ -29,6 +28,12 @@ public static class ActivityQueryExtensions
         return ids.Distinct().ToList();
     }
 
+    /// <summary>
+    /// Turns a list of <see cref="ActivityDto"/> into a group based on its timestamp 
+    /// </summary>
+    /// <param name="activityQuery">An <see cref="IQueryable{ActivityDto}"/> to group</param>
+    /// <param name="groupByActor">Whether or not the groups should be created based on the initiator of the event or the target of the event</param>
+    /// <returns>The transformed query containing groups of <see cref="ActivityDto"/></returns>
     public static IQueryable<IGrouping<ActivityGroup, ActivityDto>> ToActivityGroups
         (this IQueryable<ActivityDto> activityQuery, bool groupByActor = false) =>
         groupByActor
@@ -59,74 +64,65 @@ public static class ActivityQueryExtensions
                 Groups = g.OrderByDescending(a => a.Activity.Timestamp)
                     .GroupBy(gr => new InnerActivityGroup
                     {
-                        Type = groupByActor ? gr.GroupType : gr.GroupType != ActivityGroupType.News ? ActivityGroupType.User : ActivityGroupType.News,
+                        Type = groupByActor
+                            ? gr.GroupType
+                            : gr.GroupType != ActivityGroupType.News
+                                ? ActivityGroupType.User
+                                : ActivityGroupType.News,
                         UserId = gr.Activity.UserId,
-                        TargetId = groupByActor ? gr.TargetId : gr.GroupType != ActivityGroupType.News ? gr.Activity.UserId : gr.TargetNewsId ?? 0,
+                        TargetId = groupByActor
+                            ? gr.TargetId
+                            : gr.GroupType != ActivityGroupType.News
+                                ? gr.Activity.UserId
+                                : gr.TargetNewsId ?? 0,
                     })
                     .ToList(),
             })
             .ToList();
 
-    // WARNING - To the next person who tries to improve this code: As of writing this, it's not possible
+    /// <summary>
-    // to build a pattern matching switch statement with expression trees. so the only other option
+    /// Converts an <see cref="IQueryable"/>&lt;<see cref="ActivityEntity"/>&gt; into an <see cref="IQueryable"/>&lt;<see cref="ActivityDto"/>&gt; for grouping.
-    // is to basically rewrite this nested ternary mess with expression trees which isn't much better
+    /// </summary>
-    // The resulting SQL generated by EntityFramework uses a CASE statement which is probably fine
+    /// <param name="activityQuery">The activity query to be converted.</param>
-    // TOTAL HOURS WASTED: 3
+    /// <param name="includeSlotCreator">Whether or not the <see cref="ActivityDto.TargetSlotCreatorId"/> field should be included.</param>
+    /// <param name="includeTeamPick">Whether or not the <see cref="ActivityDto.TargetTeamPickId"/> field should be included.</param>
+    /// <returns>The converted <see cref="IQueryable"/>&lt;<see cref="ActivityDto"/>&gt;</returns>
     public static IQueryable<ActivityDto> ToActivityDto
         (this IQueryable<ActivityEntity> activityQuery, bool includeSlotCreator = false, bool includeTeamPick = false)
     {
         return activityQuery.Select(a => new ActivityDto
         {
             Activity = a,
-            TargetSlotId = a is LevelActivityEntity
+            TargetSlotId = (a as LevelActivityEntity).SlotId,
-                ? ((LevelActivityEntity)a).SlotId
+            TargetSlotGameVersion = (a as LevelActivityEntity).Slot.GameVersion,
-                : a is PhotoActivityEntity && ((PhotoActivityEntity)a).Photo.SlotId != 0
+            TargetSlotCreatorId = includeSlotCreator ? (a as LevelActivityEntity).Slot.CreatorId : null,
-                    ? ((PhotoActivityEntity)a).Photo.SlotId
+            TargetUserId = (a as UserActivityEntity).TargetUserId,
-                    : a is CommentActivityEntity && ((CommentActivityEntity)a).Comment.Type == CommentType.Level
+            TargetNewsId = (a as NewsActivityEntity).NewsId,
-                        ? ((CommentActivityEntity)a).Comment.TargetSlotId
+            TargetPlaylistId = (a as PlaylistActivityEntity).PlaylistId,
-                        : a is ScoreActivityEntity
+            TargetTeamPickId =
-                            ? ((ScoreActivityEntity)a).Score.SlotId
+                includeTeamPick && a.Type == EventType.MMPickLevel ? (a as LevelActivityEntity).SlotId : null, });
-                            : a is ReviewActivityEntity
+    }
-                                ? ((ReviewActivityEntity)a).Review.SlotId
-                                : 0,
-            TargetSlotGameVersion = a is LevelActivityEntity
-                ? ((LevelActivityEntity)a).Slot.GameVersion
-                : a is PhotoActivityEntity && ((PhotoActivityEntity)a).Photo.SlotId != 0
-                    ? ((PhotoActivityEntity)a).Photo.Slot.GameVersion
-                    : a is CommentActivityEntity && ((CommentActivityEntity)a).Comment.Type == CommentType.Level
-                        ? ((CommentActivityEntity)a).Comment.TargetSlot.GameVersion
-                        : a is ScoreActivityEntity
-                            ? ((ScoreActivityEntity)a).Score.Slot.GameVersion
-                            : a is ReviewActivityEntity
-                                ? ((ReviewActivityEntity)a).Review.Slot.GameVersion
-                                : 0,
-            TargetSlotCreatorId = includeSlotCreator
-                ? a is LevelActivityEntity
-                    ? ((LevelActivityEntity)a).Slot.CreatorId
-                    : a is PhotoActivityEntity && ((PhotoActivityEntity)a).Photo.SlotId != 0
-                        ? ((PhotoActivityEntity)a).Photo.Slot!.CreatorId
-                        : a is CommentActivityEntity && ((CommentActivityEntity)a).Comment.Type == CommentType.Level
-                            ? ((CommentActivityEntity)a).Comment.TargetSlot.CreatorId
-                            : a is ScoreActivityEntity
-                                ? ((ScoreActivityEntity)a).Score.Slot.CreatorId
-                                : a is ReviewActivityEntity
-                                    ? ((ReviewActivityEntity)a).Review.Slot!.CreatorId
-                                    : 0
-                : 0,
 
-            TargetUserId = a is UserActivityEntity
+    /// <summary>
-                ? ((UserActivityEntity)a).TargetUserId
+    /// Converts an IEnumerable&lt;<see cref="ActivityEntity"/>&gt; into an IEnumerable&lt;<see cref="ActivityDto"/>&gt; for grouping.
-                : a is CommentActivityEntity && ((CommentActivityEntity)a).Comment.Type == CommentType.Profile
+    /// </summary>
-                    ? ((CommentActivityEntity)a).Comment.TargetUserId
+    /// <param name="activityEnumerable">The activity query to be converted.</param>
-                    : a is PhotoActivityEntity && ((PhotoActivityEntity)a).Photo.SlotId == 0
+    /// <param name="includeSlotCreator">Whether or not the <see cref="ActivityDto.TargetSlotCreatorId"/> field should be included.</param>
-                        ? ((PhotoActivityEntity)a).Photo.CreatorId
+    /// <param name="includeTeamPick">Whether or not the <see cref="ActivityDto.TargetTeamPickId"/> field should be included.</param>
-                        : 0,
+    /// <returns>The converted IEnumerable&lt;<see cref="ActivityDto"/>&gt;</returns>
-            TargetPlaylistId = a is PlaylistActivityEntity || a is PlaylistWithSlotActivityEntity
+    public static IEnumerable<ActivityDto> ToActivityDto
-                ? ((PlaylistActivityEntity)a).PlaylistId
+        (this IEnumerable<ActivityEntity> activityEnumerable, bool includeSlotCreator = false, bool includeTeamPick = false)
-                : 0,
+    {
-            TargetNewsId = a is NewsActivityEntity ? ((NewsActivityEntity)a).NewsId : 0,
+        return activityEnumerable.Select(a => new ActivityDto
-            TargetTeamPickId = includeTeamPick
+        {
-                ? a.Type == EventType.MMPickLevel && a is LevelActivityEntity ? ((LevelActivityEntity)a).SlotId : 0
+            Activity = a,
-                : 0, });
+            TargetSlotId = (a as LevelActivityEntity)?.SlotId,
+            TargetSlotGameVersion = (a as LevelActivityEntity)?.Slot.GameVersion,
+            TargetSlotCreatorId = includeSlotCreator ? (a as LevelActivityEntity)?.Slot.CreatorId : null,
+            TargetUserId = (a as UserActivityEntity)?.TargetUserId,
+            TargetNewsId = (a as NewsActivityEntity)?.NewsId,
+            TargetPlaylistId = (a as PlaylistActivityEntity)?.PlaylistId,
+            TargetTeamPickId =
+                includeTeamPick && a.Type == EventType.MMPickLevel ? (a as LevelActivityEntity)?.SlotId : null, });
     }
 }

ProjectLighthouse/Migrations/20240325034658_InitialActivity.cs

@@ -6,10 +6,10 @@ using Microsoft.EntityFrameworkCore.Migrations;
 
 #nullable disable
 
-namespace ProjectLighthouse.Migrations
+namespace LBPUnion.ProjectLighthouse.Migrations
 {
     [DbContext(typeof(DatabaseContext))]
-    [Migration("20240120214525_InitialActivity")]
+    [Migration("20240325034658_InitialActivity")]
     public partial class InitialActivity : Migration
     {
         /// <inheritdoc />
@@ -24,12 +24,12 @@ namespace ProjectLighthouse.Migrations
                     Timestamp = table.Column<DateTime>(type: "datetime(6)", nullable: false),
                     UserId = table.Column<int>(type: "int", nullable: false),
                     Type = table.Column<int>(type: "int", nullable: false),
-                    Discriminator = table.Column<string>(type: "longtext", nullable: false)
+                    Discriminator = table.Column<string>(type: "varchar(34)", maxLength: 34, nullable: false)
                         .Annotation("MySql:CharSet", "utf8mb4"),
-                    CommentId = table.Column<int>(type: "int", nullable: true),
                     SlotId = table.Column<int>(type: "int", nullable: true),
-                    NewsId = table.Column<int>(type: "int", nullable: true),
+                    CommentId = table.Column<int>(type: "int", nullable: true),
                     PhotoId = table.Column<int>(type: "int", nullable: true),
+                    NewsId = table.Column<int>(type: "int", nullable: true),
                     PlaylistId = table.Column<int>(type: "int", nullable: true),
                     ReviewId = table.Column<int>(type: "int", nullable: true),
                     ScoreId = table.Column<int>(type: "int", nullable: true),

ProjectLighthouse/Migrations/DatabaseContextModelSnapshot.cs

@@ -27,7 +27,8 @@ namespace ProjectLighthouse.Migrations
 
                     b.Property<string>("Discriminator")
                         .IsRequired()
-                        .HasColumnType("longtext");
+                        .HasMaxLength(34)
+                        .HasColumnType("varchar(34)");
 
                     b.Property<DateTime>("Timestamp")
                         .HasColumnType("datetime(6)");
@@ -1123,18 +1124,6 @@ namespace ProjectLighthouse.Migrations
                     b.ToTable("WebsiteAnnouncements");
                 });
 
-            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.CommentActivityEntity", b =>
-                {
-                    b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
-
-                    b.Property<int>("CommentId")
-                        .HasColumnType("int");
-
-                    b.HasIndex("CommentId");
-
-                    b.HasDiscriminator().HasValue("CommentActivityEntity");
-                });
-
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.LevelActivityEntity", b =>
                 {
                     b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
@@ -1149,6 +1138,46 @@ namespace ProjectLighthouse.Migrations
                     b.HasDiscriminator().HasValue("LevelActivityEntity");
                 });
 
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.LevelCommentActivityEntity", b =>
+                {
+                    b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
+
+                    b.Property<int>("CommentId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int");
+
+                    b.Property<int>("SlotId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("SlotId");
+
+                    b.HasIndex("CommentId");
+
+                    b.HasIndex("SlotId");
+
+                    b.HasDiscriminator().HasValue("LevelCommentActivityEntity");
+                });
+
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.LevelPhotoActivity", b =>
+                {
+                    b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
+
+                    b.Property<int>("PhotoId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int");
+
+                    b.Property<int>("SlotId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("SlotId");
+
+                    b.HasIndex("PhotoId");
+
+                    b.HasIndex("SlotId");
+
+                    b.HasDiscriminator().HasValue("LevelPhotoActivity");
+                });
+
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.NewsActivityEntity", b =>
                 {
                     b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
@@ -1161,18 +1190,6 @@ namespace ProjectLighthouse.Migrations
                     b.HasDiscriminator().HasValue("NewsActivityEntity");
                 });
 
-            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.PhotoActivityEntity", b =>
-                {
-                    b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
-
-                    b.Property<int>("PhotoId")
-                        .HasColumnType("int");
-
-                    b.HasIndex("PhotoId");
-
-                    b.HasDiscriminator().HasValue("PhotoActivityEntity");
-                });
-
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.PlaylistActivityEntity", b =>
                 {
                     b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
@@ -1213,8 +1230,15 @@ namespace ProjectLighthouse.Migrations
                     b.Property<int>("ReviewId")
                         .HasColumnType("int");
 
+                    b.Property<int>("SlotId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("SlotId");
+
                     b.HasIndex("ReviewId");
 
+                    b.HasIndex("SlotId");
+
                     b.HasDiscriminator().HasValue("ReviewActivityEntity");
                 });
 
@@ -1225,8 +1249,15 @@ namespace ProjectLighthouse.Migrations
                     b.Property<int>("ScoreId")
                         .HasColumnType("int");
 
+                    b.Property<int>("SlotId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("SlotId");
+
                     b.HasIndex("ScoreId");
 
+                    b.HasIndex("SlotId");
+
                     b.HasDiscriminator().HasValue("ScoreActivityEntity");
                 });
 
@@ -1235,13 +1266,55 @@ namespace ProjectLighthouse.Migrations
                     b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
 
                     b.Property<int>("TargetUserId")
-                        .HasColumnType("int");
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("TargetUserId");
 
                     b.HasIndex("TargetUserId");
 
                     b.HasDiscriminator().HasValue("UserActivityEntity");
                 });
 
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.UserCommentActivityEntity", b =>
+                {
+                    b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
+
+                    b.Property<int>("CommentId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int");
+
+                    b.Property<int>("TargetUserId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("TargetUserId");
+
+                    b.HasIndex("CommentId");
+
+                    b.HasIndex("TargetUserId");
+
+                    b.HasDiscriminator().HasValue("UserCommentActivityEntity");
+                });
+
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.UserPhotoActivity", b =>
+                {
+                    b.HasBaseType("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity");
+
+                    b.Property<int>("PhotoId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int");
+
+                    b.Property<int>("TargetUserId")
+                        .ValueGeneratedOnUpdateSometimes()
+                        .HasColumnType("int")
+                        .HasColumnName("TargetUserId");
+
+                    b.HasIndex("PhotoId");
+
+                    b.HasIndex("TargetUserId");
+
+                    b.HasDiscriminator().HasValue("UserPhotoActivity");
+                });
+
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ActivityEntity", b =>
                 {
                     b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.UserEntity", "User")
@@ -1646,17 +1719,6 @@ namespace ProjectLighthouse.Migrations
                     b.Navigation("Publisher");
                 });
 
-            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.CommentActivityEntity", b =>
-                {
-                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.CommentEntity", "Comment")
-                        .WithMany()
-                        .HasForeignKey("CommentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("Comment");
-                });
-
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.LevelActivityEntity", b =>
                 {
                     b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Level.SlotEntity", "Slot")
@@ -1668,6 +1730,44 @@ namespace ProjectLighthouse.Migrations
                     b.Navigation("Slot");
                 });
 
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.LevelCommentActivityEntity", b =>
+                {
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.CommentEntity", "Comment")
+                        .WithMany()
+                        .HasForeignKey("CommentId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Level.SlotEntity", "Slot")
+                        .WithMany()
+                        .HasForeignKey("SlotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Comment");
+
+                    b.Navigation("Slot");
+                });
+
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.LevelPhotoActivity", b =>
+                {
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.PhotoEntity", "Photo")
+                        .WithMany()
+                        .HasForeignKey("PhotoId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Level.SlotEntity", "Slot")
+                        .WithMany()
+                        .HasForeignKey("SlotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Photo");
+
+                    b.Navigation("Slot");
+                });
+
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.NewsActivityEntity", b =>
                 {
                     b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Website.WebsiteAnnouncementEntity", "News")
@@ -1679,17 +1779,6 @@ namespace ProjectLighthouse.Migrations
                     b.Navigation("News");
                 });
 
-            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.PhotoActivityEntity", b =>
-                {
-                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.PhotoEntity", "Photo")
-                        .WithMany()
-                        .HasForeignKey("PhotoId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("Photo");
-                });
-
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.PlaylistActivityEntity", b =>
                 {
                     b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Level.PlaylistEntity", "Playlist")
@@ -1720,7 +1809,15 @@ namespace ProjectLighthouse.Migrations
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Level.SlotEntity", "Slot")
+                        .WithMany()
+                        .HasForeignKey("SlotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
                     b.Navigation("Review");
+
+                    b.Navigation("Slot");
                 });
 
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.ScoreActivityEntity", b =>
@@ -1731,7 +1828,15 @@ namespace ProjectLighthouse.Migrations
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Level.SlotEntity", "Slot")
+                        .WithMany()
+                        .HasForeignKey("SlotId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
                     b.Navigation("Score");
+
+                    b.Navigation("Slot");
                 });
 
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.UserActivityEntity", b =>
@@ -1745,6 +1850,44 @@ namespace ProjectLighthouse.Migrations
                     b.Navigation("TargetUser");
                 });
 
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.UserCommentActivityEntity", b =>
+                {
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.CommentEntity", "Comment")
+                        .WithMany()
+                        .HasForeignKey("CommentId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.UserEntity", "TargetUser")
+                        .WithMany()
+                        .HasForeignKey("TargetUserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Comment");
+
+                    b.Navigation("TargetUser");
+                });
+
+            modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Activity.UserPhotoActivity", b =>
+                {
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.PhotoEntity", "Photo")
+                        .WithMany()
+                        .HasForeignKey("PhotoId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("LBPUnion.ProjectLighthouse.Types.Entities.Profile.UserEntity", "TargetUser")
+                        .WithMany()
+                        .HasForeignKey("TargetUserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Photo");
+
+                    b.Navigation("TargetUser");
+                });
+
             modelBuilder.Entity("LBPUnion.ProjectLighthouse.Types.Entities.Profile.PhotoEntity", b =>
                 {
                     b.Navigation("PhotoSubjects");

ProjectLighthouse/Types/Activity/ActivityDto.cs

@@ -25,11 +25,11 @@ public class ActivityDto
         };
 
     public ActivityGroupType GroupType =>
-        this.TargetSlotId != 0
+        this.TargetSlotId != null
             ? ActivityGroupType.Level
-            : this.TargetUserId != 0
+            : this.TargetUserId != null
                 ? ActivityGroupType.User
-                : this.TargetPlaylistId != 0
+                : this.TargetPlaylistId != null
                     ? ActivityGroupType.Playlist
                     : ActivityGroupType.News;
 }

ProjectLighthouse/Types/Activity/ActivityEntityEventHandler.cs

@@ -41,40 +41,44 @@ public class ActivityEntityEventHandler : IEntityEventHandler
             {
                 CommentType.Level => comment.TargetSlot?.Type switch
                 {
-                    SlotType.User => new CommentActivityEntity
+                    SlotType.User => new LevelCommentActivityEntity
                     {
                         Type = EventType.CommentOnLevel,
                         CommentId = comment.CommentId,
                         UserId = comment.PosterUserId,
+                        SlotId = comment.TargetSlotId ?? throw new NullReferenceException("SlotId in Level comment is null, this shouldn't happen."),
                     },
                     _ => null,
                 },
-                CommentType.Profile => new CommentActivityEntity
+                CommentType.Profile => new UserCommentActivityEntity()
                 {
                     Type = EventType.CommentOnUser,
                     CommentId = comment.CommentId,
                     UserId = comment.PosterUserId,
+                    TargetUserId = comment.TargetUserId ?? throw new NullReferenceException("TargetUserId in User comment is null, this shouldn't happen."),
                 }, 
                 _ => null,
             },
             PhotoEntity photo => photo.SlotId switch
             {
                 // Photos without levels
-                null => new PhotoActivityEntity
+                null => new UserPhotoActivity
                 {
                     Type = EventType.UploadPhoto,
                     PhotoId = photo.PhotoId,
                     UserId = photo.CreatorId,
+                    TargetUserId = photo.CreatorId,
                 },
                 _ => photo.Slot?.Type switch
                 {
                     SlotType.Developer => null,
                     // Non-story levels (moon, pod, etc)
-                    _ => new PhotoActivityEntity
+                    _ => new LevelPhotoActivity
                     {
                         Type = EventType.UploadPhoto,
                         PhotoId = photo.PhotoId,
                         UserId = photo.CreatorId,
+                        SlotId = photo.SlotId ?? throw new NullReferenceException("SlotId in Photo is null"),
                     },
                 },
             },
@@ -86,6 +90,7 @@ public class ActivityEntityEventHandler : IEntityEventHandler
                     Type = EventType.Score,
                     ScoreId = score.ScoreId,
                     UserId = score.UserId,
+                    SlotId = score.SlotId,
                 },
                 _ => null,
             },
@@ -122,6 +127,7 @@ public class ActivityEntityEventHandler : IEntityEventHandler
                 Type = EventType.ReviewLevel,
                 ReviewId = review.ReviewId,
                 UserId = review.ReviewerId,
+                SlotId = review.SlotId,
             },
             RatedLevelEntity ratedLevel => new LevelActivityEntity
             {

ProjectLighthouse/Types/Activity/EventType.cs

@@ -3,7 +3,12 @@
 namespace LBPUnion.ProjectLighthouse.Types.Activity;
 
 /// <summary>
-/// UnheartLevel, UnheartUser, DeleteLevelComment, and UnpublishLevel don't actually do anything
+/// An enum of all possible event types that LBP recognizes in Recent Activity
+/// <remarks>
+/// <para>
+/// <see cref="UnheartLevel"/>, <see cref="UnheartUser"/>, <see cref="DeleteLevelComment"/>, <see cref="UnpublishLevel"/> are ignored by the game
+/// </para>
+/// </remarks>
 /// </summary>
 public enum EventType
 {
@@ -61,12 +66,21 @@ public enum EventType
     [XmlEnum("comment_on_user")]
     CommentOnUser = 17,
 
+    /// <remarks>
+    /// This event is only used in LBP3
+    /// </remarks>>
     [XmlEnum("create_playlist")]
     CreatePlaylist = 18,
 
+    /// <remarks>
+    /// This event is only used in LBP3
+    /// </remarks>>
     [XmlEnum("heart_playlist")]
     HeartPlaylist = 19,
 
+    /// <remarks>
+    /// This event is only used in LBP3
+    /// </remarks>>
     [XmlEnum("add_level_to_playlist")]
     AddLevelToPlaylist = 20,
 }

ProjectLighthouse/Types/Entities/Activity/ActivityEntity.cs

@@ -11,12 +11,21 @@ public class ActivityEntity
     [Key]
     public int ActivityId { get; set; }
 
+    /// <summary>
+    /// The time that this event took place.
+    /// </summary>
     public DateTime Timestamp { get; set; }
 
+    /// <summary>
+    /// The <see cref="UserEntity.UserId"/> of the <see cref="UserEntity"/> that triggered this event.
+    /// </summary>
     public int UserId { get; set; }
 
     [ForeignKey(nameof(UserId))]
     public UserEntity User { get; set; }
 
+    /// <summary>
+    /// The type of this event.
+    /// </summary>
     public EventType Type { get; set; }
 }

ProjectLighthouse/Types/Entities/Activity/CommentActivityEntity.cs

@@ -1,15 +1,38 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
+using LBPUnion.ProjectLighthouse.Types.Entities.Level;
 using LBPUnion.ProjectLighthouse.Types.Entities.Profile;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: CommentOnUser, CommentOnLevel, DeleteLevelComment
+/// Supported event types: <see cref="EventType.CommentOnUser"/>, <see cref="EventType.CommentOnLevel"/>, and <see cref="EventType.DeleteLevelComment"/>.
 /// </summary>
 public class CommentActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="CommentEntity.CommentId"/> of the <see cref="CommentEntity"/> that this event refers to.
+    /// </summary>
     public int CommentId { get; set; }
 
     [ForeignKey(nameof(CommentId))]
     public CommentEntity Comment { get; set; }
 }
+
+public class LevelCommentActivityEntity : CommentActivityEntity
+{
+    [Column("SlotId")]
+    public int SlotId { get; set; }
+
+    [ForeignKey(nameof(SlotId))]
+    public SlotEntity Slot { get; set; }
+}
+
+public class UserCommentActivityEntity : CommentActivityEntity
+{
+    [Column("TargetUserId")]
+    public int TargetUserId { get; set; }
+
+    [ForeignKey(nameof(TargetUserId))]
+    public UserEntity TargetUser { get; set; }
+}

ProjectLighthouse/Types/Entities/Activity/LevelActivityEntity.cs

@@ -1,13 +1,18 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Level;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: play_level, heart_level, publish_level, unheart_level, dpad_rate_level, rate_level, tag_level, mm_pick_level  
+/// Supported event types: <see cref="EventType.PlayLevel"/>, <see cref="EventType.HeartLevel"/>, <see cref="EventType.PublishLevel"/>,
+/// <see cref="EventType.UnheartLevel"/>, and <see cref="EventType.MMPickLevel"/>.
 /// </summary>
 public class LevelActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="SlotEntity.SlotId"/> of the <see cref="SlotEntity"/> that this event refers to.
+    /// </summary>
     [Column("SlotId")]
     public int SlotId { get; set; }
 

ProjectLighthouse/Types/Entities/Activity/NewsActivityEntity.cs

@@ -1,13 +1,22 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Website;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: NewsPost
+/// Supported event types: <see cref="EventType.NewsPost"/>.
+/// <remarks>
+/// <para>
+/// This event type can only be grouped with other <see cref="NewsActivityEntity"/>.
+/// </para>
+/// </remarks>
 /// </summary>
 public class NewsActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="WebsiteAnnouncementEntity.AnnouncementId"/> of the <see cref="WebsiteAnnouncementEntity"/> that this event refers to.
+    /// </summary>
     public int NewsId { get; set; }
 
     [ForeignKey(nameof(NewsId))]

ProjectLighthouse/Types/Entities/Activity/PhotoActivityEntity.cs

@@ -1,16 +1,38 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
+using LBPUnion.ProjectLighthouse.Types.Entities.Level;
 using LBPUnion.ProjectLighthouse.Types.Entities.Profile;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: UploadPhoto
+/// Supported event types: <see cref="EventType.UploadPhoto"/>.
 /// </summary>
 public class PhotoActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="PhotoEntity.PhotoId"/> of the <see cref="PhotoEntity"/> that this event refers to.
+    /// </summary>
     public int PhotoId { get; set; }
 
     [ForeignKey(nameof(PhotoId))]
     public PhotoEntity Photo { get; set; }
-    
+}
+
+public class LevelPhotoActivity : PhotoActivityEntity
+{
+    [Column("SlotId")]
+    public int SlotId { get; set; }
+
+    [ForeignKey(nameof(SlotId))]
+    public SlotEntity Slot { get; set; }
+}
+
+public class UserPhotoActivity : PhotoActivityEntity
+{
+    [Column("TargetUserId")]
+    public int TargetUserId { get; set; }
+
+    [ForeignKey(nameof(TargetUserId))]
+    public UserEntity TargetUser { get; set; }
 }

ProjectLighthouse/Types/Entities/Activity/PlaylistActivityEntity.cs

@@ -1,13 +1,17 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Level;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: CreatePlaylist, HeartPlaylist
+/// Supported event types: <see cref="EventType.CreatePlaylist"/> and <see cref="EventType.HeartPlaylist"/>.
 /// </summary>
 public class PlaylistActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="PlaylistEntity.PlaylistId"/> of the <see cref="PlaylistEntity"/> that this event refers to.
+    /// </summary>
     [Column("PlaylistId")]
     public int PlaylistId { get; set; }
 
@@ -16,15 +20,19 @@ public class PlaylistActivityEntity : ActivityEntity
 }
 
 /// <summary>
-/// Supported event types: AddLevelToPlaylist
+/// Supported event types: <see cref="EventType.AddLevelToPlaylist"/>.
+/// <remarks>
 /// <para>
 /// The relationship between <see cref="PlaylistActivityEntity"/> and <see cref="PlaylistWithSlotActivityEntity"/>
-/// is slightly hacky but it allows conditional reuse of columns from other ActivityEntity's 
+/// is slightly hacky but it allows us to reuse columns that would normally only be user with other <see cref="ActivityEntity"/> types.
-/// 
 /// </para> 
+/// </remarks>
 /// </summary>
 public class PlaylistWithSlotActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="PlaylistEntity.PlaylistId"/> of the <see cref="PlaylistEntity"/> that this event refers to.
+    /// </summary> 
     [Column("PlaylistId")]
     public int PlaylistId { get; set; }
 
@@ -33,7 +41,11 @@ public class PlaylistWithSlotActivityEntity : ActivityEntity
 
     /// <summary>
     /// This reuses the SlotId column of <see cref="LevelActivityEntity"/> but has no ForeignKey definition so that it can be null
-    /// <para>It effectively serves as extra storage for PlaylistActivityEntity to use for the AddLevelToPlaylistEvent</para>
+    /// <remarks>
+    /// <para>
+    /// It effectively serves as extra storage for PlaylistActivityEntity to use for the AddLevelToPlaylistEvent
+    /// </para>
+    /// </remarks>
     /// </summary>
     [Column("SlotId")]
     public int SlotId { get; set; }

ProjectLighthouse/Types/Entities/Activity/ReviewActivityEntity.cs

@@ -1,15 +1,25 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Level;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: DpadRateLevel, ReviewLevel, RateLevel, TagLevel
+/// Supported event types: <see cref="EventType.DpadRateLevel"/>, <see cref="EventType.ReviewLevel"/>, <see cref="EventType.RateLevel"/>, and <see cref="EventType.TagLevel"/>.
 /// </summary>
 public class ReviewActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="ReviewEntity.ReviewId"/> of the <see cref="ReviewEntity"/> that this event refers to.
+    /// </summary>
     public int ReviewId { get; set; }
 
     [ForeignKey(nameof(ReviewId))]
     public ReviewEntity Review { get; set; }
+
+    [Column("SlotId")]
+    public int SlotId { get; set; }
+
+    [ForeignKey(nameof(SlotId))]
+    public SlotEntity Slot { get; set; }
 }

ProjectLighthouse/Types/Entities/Activity/ScoreActivityEntity.cs

@@ -1,15 +1,25 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Level;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: Score
+/// Supported event types: <see cref="EventType.Score"/>.
 /// </summary>
 public class ScoreActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="ScoreEntity.ScoreId"/> of the <see cref="ScoreEntity"/> that this event refers to.
+    /// </summary>
     public int ScoreId { get; set; }
 
     [ForeignKey(nameof(ScoreId))]
     public ScoreEntity Score { get; set; }
+
+    [Column("SlotId")]
+    public int SlotId { get; set; }
+
+    [ForeignKey(nameof(SlotId))]
+    public SlotEntity Slot { get; set; }
 }

ProjectLighthouse/Types/Entities/Activity/UserActivityEntity.cs

@@ -1,13 +1,18 @@
 using System.ComponentModel.DataAnnotations.Schema;
+using LBPUnion.ProjectLighthouse.Types.Activity;
 using LBPUnion.ProjectLighthouse.Types.Entities.Profile;
 
 namespace LBPUnion.ProjectLighthouse.Types.Entities.Activity;
 
 /// <summary>
-/// Supported event types: HeartUser, UnheartUser
+/// Supported event types: <see cref="EventType.HeartUser"/> and <see cref="EventType.UnheartUser"/>.
 /// </summary>
 public class UserActivityEntity : ActivityEntity
 {
+    /// <summary>
+    /// The <see cref="UserEntity.UserId"/> of the <see cref="UserEntity"/> that this event refers to.
+    /// </summary>
+    [Column("TargetUserId")]
     public int TargetUserId { get; set; }
 
     [ForeignKey(nameof(TargetUserId))]

ProjectLighthouse/Types/Serialization/Activity/Events/GameEvent.cs

@@ -58,7 +58,7 @@ public class GameEvent : ILbpSerializable, INeedsPreparationForSerialization
 
     public static IEnumerable<GameEvent> CreateFromActivities(IEnumerable<ActivityDto> activities)
     {
-        List<GameEvent> events = new();
+        List<GameEvent> events = [];
         List<IGrouping<EventType, ActivityDto>> typeGroups = activities.GroupBy(g => g.Activity.Type).ToList();
         foreach (IGrouping<EventType, ActivityDto> typeGroup in typeGroups)
         {

ProjectLighthouse/Types/Serialization/Activity/GameStream.cs

@@ -26,21 +26,34 @@ namespace LBPUnion.ProjectLighthouse.Types.Serialization.Activity;
 [XmlRoot("stream")]
 public class GameStream : ILbpSerializable, INeedsPreparationForSerialization
 {
+    /// <summary>
+    /// A list of <see cref="SlotEntity.SlotId"/> that should be included in the root
+    /// of the stream object. These will be loaded into <see cref="Slots"/> 
+    /// </summary>
     [XmlIgnore]
     public List<int> SlotIds { get; set; }
 
+    /// <summary>
+    /// A list of <see cref="UserEntity.UserId"/> that should be included in the root
+    /// of the stream object. These will be loaded into <see cref="Users"/> 
+    /// </summary>
     [XmlIgnore]
     public List<int> UserIds { get; set; }
 
+    /// <summary>
+    /// A list of <see cref="PlaylistEntity.PlaylistId"/> that should be included in the root
+    /// of the stream object. These will be loaded into <see cref="Playlists"/> 
+    /// </summary>
     [XmlIgnore]
     public List<int> PlaylistIds { get; set; }
 
+    /// <summary>
+    /// A list of <see cref="WebsiteAnnouncementEntity.AnnouncementId"/> that should be included in the root
+    /// of the stream object. These will be loaded into <see cref="News"/> 
+    /// </summary>
     [XmlIgnore]
     public List<int> NewsIds { get; set; }
 
-    [XmlIgnore]
-    private int TargetUserId { get; set; }
-
     [XmlIgnore]
     private GameVersion TargetGame { get; set; }
 
@@ -77,7 +90,7 @@ public class GameStream : ILbpSerializable, INeedsPreparationForSerialization
 
     public async Task PrepareSerialization(DatabaseContext database)
     {
-        this.Slots = await LoadEntities<SlotEntity, SlotBase>(this.SlotIds, slot => SlotBase.CreateFromEntity(slot, this.TargetGame, this.TargetUserId), s => s.Type == SlotType.User);
+        this.Slots = await LoadEntities<SlotEntity, SlotBase>(this.SlotIds, slot => SlotBase.CreateFromEntity(slot, this.TargetGame, 0), s => s.Type == SlotType.User);
         this.Users = await LoadEntities<UserEntity, GameUser>(this.UserIds, user => GameUser.CreateFromEntity(user, this.TargetGame));
         this.Playlists = await LoadEntities<PlaylistEntity, GamePlaylist>(this.PlaylistIds, GamePlaylist.CreateFromEntity);
         this.News = await LoadEntities<WebsiteAnnouncementEntity, GameNewsObject>(this.NewsIds, a => GameNewsObject.CreateFromEntity(a, this.TargetGame));
@@ -86,16 +99,16 @@ public class GameStream : ILbpSerializable, INeedsPreparationForSerialization
         async Task<List<TResult>> LoadEntities<TFrom, TResult>(List<int> ids, Func<TFrom, TResult> transformation, Func<TFrom, bool> predicate = null) 
             where TFrom : class
         {
-            List<TResult> results = new();
+            List<TResult> results = [];
             if (ids.Count <= 0) return null;
             foreach (int id in ids)
             {
                 TFrom entity = await database.Set<TFrom>().FindAsync(id);
 
-                if (predicate != null && !predicate(entity)) continue;
-
                 if (entity == null) continue;
 
+                if (predicate != null && !predicate(entity)) continue;
+
                 results.Add(transformation(entity));
             }
 
@@ -108,7 +121,6 @@ public class GameStream : ILbpSerializable, INeedsPreparationForSerialization
     {
         GameStream gameStream = new()
         {
-            TargetUserId = token.UserId,
             TargetGame = token.GameVersion,
             StartTimestamp = startTimestamp,
             EndTimestamp = endTimestamp,

ProjectLighthouse/Types/Serialization/Activity/GameStreamGroup.cs

@@ -37,8 +37,6 @@ public class GameStreamGroup : ILbpSerializable
     [XmlArray("events")]
     [XmlArrayItem("event")]
     [DefaultValue(null)]
-    // ReSharper disable once MemberCanBePrivate.Global
-    // (the serializer can't see this if it's private)
     public List<GameEvent> Events { get; set; }
 
     public static GameStreamGroup CreateFromGroup(OuterActivityGroup group)
@@ -56,8 +54,7 @@ public class GameStreamGroup : ILbpSerializable
                 g.Key.TargetId,
                 streamGroup =>
                 {
-                    streamGroup.Timestamp =
+                    streamGroup.Timestamp = g.Max(a => a.Activity.Timestamp).ToUnixTimeMilliseconds();
-                        g.MaxBy(a => a.Activity.Timestamp).Activity.Timestamp.ToUnixTimeMilliseconds();
                     streamGroup.Events = GameEvent.CreateFromActivities(g).ToList();
                 }))
             .ToList());