Implement level tagging (#585)

This is the first part of #260, implementing in-game level tagging for
LBP1.

This also exposes an APIv3 endpoint for getting a list of levels by tag,
and also shows the tags of a level on API level responses.

Refresh.GameServer/Database/GameDatabaseContext.Levels.cs

@@ -153,6 +153,7 @@ public void DeleteLevel(GameLevel level)
             this.QueueLevelRelations.RemoveRange(r => r.Level == level);
             this.RateLevelRelations.RemoveRange(r => r.Level == level);
             this.UniquePlayLevelRelations.RemoveRange(r => r.Level == level);
+            this.TagLevelRelations.RemoveRange(r => r.Level == level);
 
             IQueryable<GameSubmittedScore> scores = this.GameSubmittedScores.Where(r => r.Level == level);
 
@@ -241,6 +242,24 @@ public DatabaseList<GameLevel> GetMostHeartedLevels(int count, int skip, GameUse
         return new DatabaseList<GameLevel>(mostHeartedLevels, skip, count);
     }
 
+    [Pure]
+    public DatabaseList<GameLevel> GetLevelsByTag(int count, int skip, GameUser? user, Tag tag, LevelFilterSettings levelFilterSettings)
+    {
+        IQueryable<TagLevelRelation> tagRelations = this.TagLevelRelations;
+
+        IEnumerable<GameLevel> filteredTaggedLevels = tagRelations
+            .Where(x => x._Tag == (int)tag)
+            .AsEnumerable()
+            .Select(x => x.Level)
+            .Distinct()
+            .Where(l => l._Source == (int)GameLevelSource.User)
+            .OrderByDescending(l => l.PublishDate)
+            .FilterByLevelFilterSettings(user, levelFilterSettings)
+            .FilterByGameVersion(levelFilterSettings.GameVersion);
+
+        return new DatabaseList<GameLevel>(filteredTaggedLevels, skip, count);
+    }
+
     [Pure]
     public DatabaseList<GameLevel> GetMostUniquelyPlayedLevels(int count, int skip, GameUser? user, LevelFilterSettings levelFilterSettings)
     {

Refresh.GameServer/Database/GameDatabaseContext.Relations.cs

@@ -1,5 +1,4 @@
 using System.Diagnostics.Contracts;
-using Realms;
 using Refresh.GameServer.Authentication;
 using Refresh.GameServer.Endpoints.Game.Levels.FilterSettings;
 using Refresh.GameServer.Extensions;
@@ -493,4 +492,36 @@ public bool RateLevelComment(GameUser user, GameLevelComment comment, RatingType
         => this.RateComment(user, comment, ratingType, this.LevelCommentRelations);
 
     #endregion
+
+    #region Tags
+
+    public void AddTagRelation(GameUser user, GameLevel level, Tag tag)
+    {
+        this.Write(() =>
+        {
+            // Remove any old tags from this user on this level
+            this.TagLevelRelations.RemoveRange(this.TagLevelRelations.Where(t => t.User == user && t.Level == level));
+
+            this.TagLevelRelations.Add(new TagLevelRelation
+            {
+                Tag = tag,
+                User = user,
+                Level = level,
+            });
+        });
+    }
+
+    public IEnumerable<TagLevelRelation> GetTagsForLevel(GameLevel level)
+    {
+        IQueryable<TagLevelRelation> levelTags = this.TagLevelRelations.Where(t => t.Level == level);
+
+        IOrderedEnumerable<TagLevelRelation> tags = levelTags
+            .AsEnumerable()
+            .DistinctBy(t => t._Tag)
+            .OrderByDescending(t => levelTags.Count(levelTag => levelTag._Tag == t._Tag));
+
+        return tags;
+    }
+
+    #endregion
 }

Refresh.GameServer/Database/GameDatabaseContext.cs

@@ -56,6 +56,7 @@ public partial class GameDatabaseContext : RealmDatabaseContext
     private RealmDbSet<GameReview> GameReviews => new(this._realm);
     private RealmDbSet<DisallowedUser> DisallowedUsers => new(this._realm);
     private RealmDbSet<RateReviewRelation> RateReviewRelations => new(this._realm);
+    private RealmDbSet<TagLevelRelation> TagLevelRelations => new(this._realm);
 
     internal GameDatabaseContext(IDateTimeProvider time)
     {

Refresh.GameServer/Database/GameDatabaseProvider.cs

@@ -70,6 +70,7 @@ protected GameDatabaseProvider(IDateTimeProvider time)
         typeof(GameReview),
         typeof(DisallowedUser),
         typeof(RateReviewRelation),
+        typeof(TagLevelRelation),
     };
 
     public override void Warmup()

Refresh.GameServer/Endpoints/ApiV3/DataTypes/Response/Levels/ApiGameLevelResponse.cs

@@ -49,6 +49,7 @@ public class ApiGameLevelResponse : IApiResponse, IDataConvertableFrom<ApiGameLe
     public required bool IsSubLevel { get; set; }
     public required bool IsCopyable { get; set; }
     public required float Score { get; set; }
+    public required IEnumerable<Tag> Tags { get; set; }
 
     public static ApiGameLevelResponse? FromOld(GameLevel? level, DataContext dataContext)
     {
@@ -86,6 +87,7 @@ public class ApiGameLevelResponse : IApiResponse, IDataConvertableFrom<ApiGameLe
             PhotosTaken = dataContext.Database.GetTotalPhotosInLevel(level),
             LevelComments = dataContext.Database.GetTotalCommentsForLevel(level),
             Reviews = dataContext.Database.GetTotalReviewsForLevel(level),
+            Tags = dataContext.Database.GetTagsForLevel(level).Select(t => t.Tag),
         };
     }
 

Refresh.GameServer/Endpoints/Game/DataTypes/Response/GameLevelResponse.cs

@@ -79,6 +79,7 @@ public class GameLevelResponse : IDataConvertableFrom<GameLevelResponse, GameLev
     [XmlElement("reviewsEnabled")] public bool ReviewsEnabled { get; set; } = true;
     [XmlElement("commentCount")] public int CommentCount { get; set; } = 0;
     [XmlElement("commentsEnabled")] public bool CommentsEnabled { get; set; } = true;
+    [XmlElement("tags")] public string Tags { get; set; } = "";
 
     /// <summary>
     /// Provides a unique level ID for ~1.1 billion hashed levels, uses the hash directly, so this is deterministic
@@ -174,6 +175,7 @@ public static GameLevelResponse FromHash(string hash, DataContext dataContext)
             AverageStarRating = old.CalculateAverageStarRating(dataContext.Database),
             ReviewCount = old.Reviews.Count,
             CommentCount = dataContext.Database.GetTotalCommentsForLevel(old),
+            Tags = string.Join(',', dataContext.Database.GetTagsForLevel(old).Select(t => t.Tag.ToLbpString())) ,
         };
 
         response.Type = "user";

Refresh.GameServer/Endpoints/Game/Handshake/MetadataEndpoints.cs

@@ -1,4 +1,3 @@
-using System.Xml.Serialization;
 using Bunkum.Core;
 using Bunkum.Core.Endpoints;
 using Bunkum.Core.Endpoints.Debugging;
@@ -7,8 +6,8 @@
 using Bunkum.Protocols.Http;
 using Refresh.GameServer.Database;
 using Refresh.GameServer.Time;
-using Refresh.GameServer.Types;
 using Refresh.GameServer.Types.Challenges;
+using Refresh.GameServer.Types.Levels;
 using Refresh.GameServer.Types.Roles;
 using Refresh.GameServer.Types.UserData;
 
@@ -191,4 +190,7 @@ public SerializedGameChallengeList ChallengeConfig(RequestContext context, IDate
             Challenges = [],
         };
     }
+
+    [GameEndpoint("tags")]
+    public string Tags(RequestContext context) => TagExtensions.AllTags;
 }

Refresh.GameServer/Endpoints/Game/RelationEndpoints.cs

@@ -124,4 +124,27 @@ public Response ClearQueue(RequestContext context, GameDatabaseContext database,
         database.ClearQueue(user);
         return OK;
     }
+
+    [GameEndpoint("tag/{slotType}/{id}", HttpMethods.Post)]
+    public Response SubmitTagsForLevel(RequestContext context, GameDatabaseContext database, GameUser user, string slotType, int id, string body)
+    {
+        GameLevel? level = database.GetLevelByIdAndType(slotType, id);
+
+        if (level == null)
+            return NotFound;
+
+        // The format of the POST body is `t=TAG_Name`, so assert this is followed
+        if (!body.StartsWith("t="))
+            return BadRequest;
+
+        Tag? tag = TagExtensions.FromLbpString(body[2..]);
+
+        // If it was an invalid tag, return BadRequest
+        if (tag == null)
+            return BadRequest;
+
+        database.AddTagRelation(user, level, tag.Value);
+
+        return OK;
+    }
 }

Refresh.GameServer/Types/Levels/Categories/ByTagCategory.cs

@@ -0,0 +1,37 @@
+using Bunkum.Core;
+using Refresh.GameServer.Database;
+using Refresh.GameServer.Endpoints.Game.Levels.FilterSettings;
+using Refresh.GameServer.Services;
+using Refresh.GameServer.Types.UserData;
+
+namespace Refresh.GameServer.Types.Levels.Categories;
+
+public class ByTagCategory : LevelCategory
+{
+    internal ByTagCategory() : base("tag", "tag", false)
+    {
+        // Technically this category can apply to any user, but since we fallback to the regular user this name & description still applies
+        this.Name = "Tag Search";
+        this.Description = "Search for levels using tags given by users like you!";
+        this.IconHash = "g820605";
+        this.FontAwesomeIcon = "tag";
+        this.Hidden = true; // The by-tag category is not meant to be shown, as it requires a special implementation on all frontends
+    }
+
+    public override DatabaseList<GameLevel>? Fetch(RequestContext context, int skip, int count,
+        MatchService matchService, GameDatabaseContext database, GameUser? accessor, 
+        LevelFilterSettings levelFilterSettings, GameUser? user)
+    {
+        string? tagStr = context.QueryString["tag"];
+
+        if (tagStr == null) 
+            return null;
+
+        Tag? tag = TagExtensions.FromLbpString(tagStr);
+
+        if (tag == null)
+            return null;
+
+        return database.GetLevelsByTag(count, skip, user, tag.Value, levelFilterSettings);
+    }
+}

Refresh.GameServer/Types/Levels/Categories/CategoryService.cs

@@ -28,6 +28,7 @@ public class CategoryService : EndpointService
         new QueuedLevelsByUserCategory(),
 
         new SearchLevelCategory(),
+        new ByTagCategory(),
         new DeveloperLevelsCategory(),
         new ContestCategory(),
     ];

Refresh.GameServer/Types/Levels/GameMinimalLevelResponse.cs

@@ -47,7 +47,8 @@ public class GameMinimalLevelResponse : IDataConvertableFrom<GameMinimalLevelRes
     [XmlElement("initiallyLocked")] public bool IsLocked { get; set; }
     [XmlElement("isSubLevel")] public bool IsSubLevel { get; set; }
     [XmlElement("shareable")] public int IsCopyable { get; set; }
-
+    [XmlElement("tags")] public string Tags { get; set; } = "";
+
     private GameMinimalLevelResponse() {}
 
     /// <summary>
@@ -99,6 +100,7 @@ public static GameMinimalLevelResponse FromHash(string hash, DataContext dataCon
             IsSubLevel = level.IsSubLevel,
             IsCopyable = level.IsCopyable,
             PlayerCount = dataContext.Match.GetPlayerCountForLevel(RoomSlotType.Online, level.LevelId),
+            Tags = level.Tags,
         };
     }