[backend/federation] Properly handle hashtags in notes & user profiles (ISH-114, ISH-125)

Iceshrimp.Backend/Core/Database/DatabaseContext.cs

@@ -461,15 +461,7 @@ public class DatabaseContext(DbContextOptions<DatabaseContext> options)
 			entity.HasOne(d => d.User).WithMany(p => p.GalleryPosts);
 		});
 
-		modelBuilder.Entity<Hashtag>(entity =>
+		modelBuilder.Entity<Hashtag>();
-		{
-			entity.Property(e => e.AttachedLocalUsersCount).HasDefaultValue(0);
-			entity.Property(e => e.AttachedRemoteUsersCount).HasDefaultValue(0);
-			entity.Property(e => e.AttachedUsersCount).HasDefaultValue(0);
-			entity.Property(e => e.MentionedLocalUsersCount).HasDefaultValue(0);
-			entity.Property(e => e.MentionedRemoteUsersCount).HasDefaultValue(0);
-			entity.Property(e => e.MentionedUsersCount).HasDefaultValue(0);
-		});
 
 		modelBuilder.Entity<Instance>(entity =>
 		{

Iceshrimp.Backend/Core/Database/Migrations/20240304201225_RemoveHashtagStatisticsColumns.cs

@@ -0,0 +1,199 @@
+using System.Collections.Generic;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Iceshrimp.Backend.Core.Database.Migrations
+{
+    /// <inheritdoc />
+    public partial class RemoveHashtagStatisticsColumns : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_hashtag_attachedLocalUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropIndex(
+                name: "IX_hashtag_attachedRemoteUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropIndex(
+                name: "IX_hashtag_attachedUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropIndex(
+                name: "IX_hashtag_mentionedLocalUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropIndex(
+                name: "IX_hashtag_mentionedRemoteUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropIndex(
+                name: "IX_hashtag_mentionedUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "attachedLocalUserIds",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "attachedLocalUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "attachedRemoteUserIds",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "attachedRemoteUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "attachedUserIds",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "attachedUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "mentionedLocalUserIds",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "mentionedLocalUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "mentionedRemoteUserIds",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "mentionedRemoteUsersCount",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "mentionedUserIds",
+                table: "hashtag");
+
+            migrationBuilder.DropColumn(
+                name: "mentionedUsersCount",
+                table: "hashtag");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<List<string>>(
+                name: "attachedLocalUserIds",
+                table: "hashtag",
+                type: "character varying(32)[]",
+                nullable: false);
+
+            migrationBuilder.AddColumn<int>(
+                name: "attachedLocalUsersCount",
+                table: "hashtag",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<List<string>>(
+                name: "attachedRemoteUserIds",
+                table: "hashtag",
+                type: "character varying(32)[]",
+                nullable: false);
+
+            migrationBuilder.AddColumn<int>(
+                name: "attachedRemoteUsersCount",
+                table: "hashtag",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<List<string>>(
+                name: "attachedUserIds",
+                table: "hashtag",
+                type: "character varying(32)[]",
+                nullable: false);
+
+            migrationBuilder.AddColumn<int>(
+                name: "attachedUsersCount",
+                table: "hashtag",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<List<string>>(
+                name: "mentionedLocalUserIds",
+                table: "hashtag",
+                type: "character varying(32)[]",
+                nullable: false);
+
+            migrationBuilder.AddColumn<int>(
+                name: "mentionedLocalUsersCount",
+                table: "hashtag",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<List<string>>(
+                name: "mentionedRemoteUserIds",
+                table: "hashtag",
+                type: "character varying(32)[]",
+                nullable: false);
+
+            migrationBuilder.AddColumn<int>(
+                name: "mentionedRemoteUsersCount",
+                table: "hashtag",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<List<string>>(
+                name: "mentionedUserIds",
+                table: "hashtag",
+                type: "character varying(32)[]",
+                nullable: false);
+
+            migrationBuilder.AddColumn<int>(
+                name: "mentionedUsersCount",
+                table: "hashtag",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_hashtag_attachedLocalUsersCount",
+                table: "hashtag",
+                column: "attachedLocalUsersCount");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_hashtag_attachedRemoteUsersCount",
+                table: "hashtag",
+                column: "attachedRemoteUsersCount");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_hashtag_attachedUsersCount",
+                table: "hashtag",
+                column: "attachedUsersCount");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_hashtag_mentionedLocalUsersCount",
+                table: "hashtag",
+                column: "mentionedLocalUsersCount");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_hashtag_mentionedRemoteUsersCount",
+                table: "hashtag",
+                column: "mentionedRemoteUsersCount");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_hashtag_mentionedUsersCount",
+                table: "hashtag",
+                column: "mentionedUsersCount");
+        }
+    }
+}

Iceshrimp.Backend/Core/Database/Migrations/DatabaseContextModelSnapshot.cs

@@ -1488,72 +1488,6 @@ namespace Iceshrimp.Backend.Core.Database.Migrations
                         .HasColumnType("character varying(32)")
                         .HasColumnName("id");
 
-                    b.Property<List<string>>("AttachedLocalUserIds")
-                        .IsRequired()
-                        .HasColumnType("character varying(32)[]")
-                        .HasColumnName("attachedLocalUserIds");
-
-                    b.Property<int>("AttachedLocalUsersCount")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer")
-                        .HasDefaultValue(0)
-                        .HasColumnName("attachedLocalUsersCount");
-
-                    b.Property<List<string>>("AttachedRemoteUserIds")
-                        .IsRequired()
-                        .HasColumnType("character varying(32)[]")
-                        .HasColumnName("attachedRemoteUserIds");
-
-                    b.Property<int>("AttachedRemoteUsersCount")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer")
-                        .HasDefaultValue(0)
-                        .HasColumnName("attachedRemoteUsersCount");
-
-                    b.Property<List<string>>("AttachedUserIds")
-                        .IsRequired()
-                        .HasColumnType("character varying(32)[]")
-                        .HasColumnName("attachedUserIds");
-
-                    b.Property<int>("AttachedUsersCount")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer")
-                        .HasDefaultValue(0)
-                        .HasColumnName("attachedUsersCount");
-
-                    b.Property<List<string>>("MentionedLocalUserIds")
-                        .IsRequired()
-                        .HasColumnType("character varying(32)[]")
-                        .HasColumnName("mentionedLocalUserIds");
-
-                    b.Property<int>("MentionedLocalUsersCount")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer")
-                        .HasDefaultValue(0)
-                        .HasColumnName("mentionedLocalUsersCount");
-
-                    b.Property<List<string>>("MentionedRemoteUserIds")
-                        .IsRequired()
-                        .HasColumnType("character varying(32)[]")
-                        .HasColumnName("mentionedRemoteUserIds");
-
-                    b.Property<int>("MentionedRemoteUsersCount")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer")
-                        .HasDefaultValue(0)
-                        .HasColumnName("mentionedRemoteUsersCount");
-
-                    b.Property<List<string>>("MentionedUserIds")
-                        .IsRequired()
-                        .HasColumnType("character varying(32)[]")
-                        .HasColumnName("mentionedUserIds");
-
-                    b.Property<int>("MentionedUsersCount")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer")
-                        .HasDefaultValue(0)
-                        .HasColumnName("mentionedUsersCount");
-
                     b.Property<string>("Name")
                         .IsRequired()
                         .HasMaxLength(128)
@@ -1562,18 +1496,6 @@ namespace Iceshrimp.Backend.Core.Database.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("AttachedLocalUsersCount");
-
-                    b.HasIndex("AttachedRemoteUsersCount");
-
-                    b.HasIndex("AttachedUsersCount");
-
-                    b.HasIndex("MentionedLocalUsersCount");
-
-                    b.HasIndex("MentionedRemoteUsersCount");
-
-                    b.HasIndex("MentionedUsersCount");
-
                     b.HasIndex("Name")
                         .IsUnique();
 

Iceshrimp.Backend/Core/Database/Tables/Hashtag.cs

@@ -5,13 +5,7 @@ using Microsoft.EntityFrameworkCore;
 namespace Iceshrimp.Backend.Core.Database.Tables;
 
 [Table("hashtag")]
-[Index("AttachedRemoteUsersCount")]
-[Index("AttachedLocalUsersCount")]
-[Index("MentionedLocalUsersCount")]
-[Index("MentionedUsersCount")]
 [Index("Name", IsUnique = true)]
-[Index("MentionedRemoteUsersCount")]
-[Index("AttachedUsersCount")]
 public class Hashtag : IEntity
 {
 	[Key]
@@ -20,34 +14,4 @@ public class Hashtag : IEntity
 	public string Id { get; set; } = null!;
 
 	[Column("name")] [StringLength(128)] public string Name { get; set; } = null!;
-
-	[Column("mentionedUserIds", TypeName = "character varying(32)[]")]
-	public List<string> MentionedUserIds { get; set; } = null!;
-
-	[Column("mentionedUsersCount")] public int MentionedUsersCount { get; set; }
-
-	[Column("mentionedLocalUserIds", TypeName = "character varying(32)[]")]
-	public List<string> MentionedLocalUserIds { get; set; } = null!;
-
-	[Column("mentionedLocalUsersCount")] public int MentionedLocalUsersCount { get; set; }
-
-	[Column("mentionedRemoteUserIds", TypeName = "character varying(32)[]")]
-	public List<string> MentionedRemoteUserIds { get; set; } = null!;
-
-	[Column("mentionedRemoteUsersCount")] public int MentionedRemoteUsersCount { get; set; }
-
-	[Column("attachedUserIds", TypeName = "character varying(32)[]")]
-	public List<string> AttachedUserIds { get; set; } = null!;
-
-	[Column("attachedUsersCount")] public int AttachedUsersCount { get; set; }
-
-	[Column("attachedLocalUserIds", TypeName = "character varying(32)[]")]
-	public List<string> AttachedLocalUserIds { get; set; } = null!;
-
-	[Column("attachedLocalUsersCount")] public int AttachedLocalUsersCount { get; set; }
-
-	[Column("attachedRemoteUserIds", TypeName = "character varying(32)[]")]
-	public List<string> AttachedRemoteUserIds { get; set; } = null!;
-
-	[Column("attachedRemoteUsersCount")] public int AttachedRemoteUsersCount { get; set; }
 }

Iceshrimp.Backend/Core/Federation/ActivityPub/NoteRenderer.cs

@@ -59,15 +59,19 @@ public class NoteRenderer(IOptions<Config.InstanceSection> config, MfmConverter
 			_                        => []
 		};
 
-		var tags = mentions
+		var tags = note.Tags.Select(tag => new ASHashtag
-		           .Select(mention => new ASMention
+		               {
+			               Name = $"#{tag}",
+			               Href = new ASObjectBase($"https://{config.Value.WebDomain}/tags/{tag}")
+		               })
+		               .Concat<ASTag>(mentions.Select(mention => new ASMention
 		               {
 			               Name = $"@{mention.Username}@{mention.Host}",
 			               Href = new ASObjectBase(mention.Uri)
-		           })
+		               }))
-		           .Cast<ASTag>()
 		               .ToList();
 
+
 		var attachments = note.FileIds.Count > 0
 			? await db.DriveFiles
 			          .Where(p => note.FileIds.Contains(p.Id) && p.UserHost == null)

Iceshrimp.Backend/Core/Federation/ActivityPub/UserRenderer.cs

@@ -46,6 +46,15 @@ public class UserRenderer(IOptions<Config.InstanceSection> config, DatabaseConte
 				? ASActor.Types.Service
 				: ASActor.Types.Person;
 
+		var tags = user.Tags
+		               .Select(tag => new ASHashtag
+		               {
+			               Name = $"#{tag}",
+			               Href = new ASObjectBase($"https://{config.Value.WebDomain}/tags/{tag}")
+		               })
+		               .Cast<ASTag>()
+		               .ToList();
+
 		return new ASActor
 		{
 			Id = id,
@@ -74,7 +83,8 @@ public class UserRenderer(IOptions<Config.InstanceSection> config, DatabaseConte
 			PublicKey = new ASPublicKey
 			{
 				Id = $"{id}#main-key", Owner = new ASObjectBase(id), PublicKey = keypair.PublicKey
-			}
+			},
+			Tags = tags
 		};
 	}
 }

Iceshrimp.Backend/Core/Services/NoteService.cs

@@ -77,6 +77,8 @@ public class NoteService(
 		if ((user.UserSettings?.PrivateMode ?? false) && visibility < Note.NoteVisibility.Followers)
 			visibility = Note.NoteVisibility.Followers;
 
+		var tags = ResolveHashtags(text);
+
 		var note = new Note
 		{
 			Id                   = IdHelpers.GenerateSlowflakeId(),
@@ -97,7 +99,8 @@ public class NoteService(
 			Mentions             = mentionedUserIds,
 			VisibleUserIds       = visibility == Note.NoteVisibility.Specified ? mentionedUserIds : [],
 			MentionedRemoteUsers = remoteMentions,
-			ThreadId             = reply?.ThreadId ?? reply?.Id
+			ThreadId             = reply?.ThreadId ?? reply?.Id,
+			Tags                 = tags
 		};
 
 		await UpdateNoteCountersAsync(note, true);
@@ -213,7 +216,7 @@ public class NoteService(
 
 		mentionedLocalUserIds = mentionedLocalUserIds.Except(previousMentionedLocalUserIds).ToList();
 		note.Text             = text;
-
+		note.Tags             = ResolveHashtags(text);
 
 		if (text is not null)
 		{
@@ -396,8 +399,6 @@ public class NoteService(
 		if (actor.IsSuspended)
 			throw GracefulException.Forbidden("User is suspended");
 
-		//TODO: resolve emoji
-
 		var (mentionedUserIds, mentionedLocalUserIds, mentions, remoteMentions, splitDomainMapping) =
 			await ResolveNoteMentionsAsync(note);
 
@@ -461,6 +462,7 @@ public class NoteService(
 			}
 
 			dbNote.Text = mentionsResolver.ResolveMentions(dbNote.Text, dbNote.UserHost, mentions, splitDomainMapping);
+			dbNote.Tags = ResolveHashtags(dbNote.Text, note);
 		}
 
 		var sensitive = (note.Sensitive ?? false) || dbNote.Cw != null;
@@ -544,6 +546,7 @@ public class NoteService(
 			}
 
 			dbNote.Text = mentionsResolver.ResolveMentions(dbNote.Text, dbNote.UserHost, mentions, splitDomainMapping);
+			dbNote.Tags = ResolveHashtags(dbNote.Text, note);
 		}
 
 		//TODO: handle updated alt text et al
@@ -608,6 +611,49 @@ public class NoteService(
 		return ResolveNoteMentions(users.Where(p => p != null).Select(p => p!).ToList());
 	}
 
+	private List<string> ResolveHashtags(string? text, ASNote? note = null)
+	{
+		List<string> tags = [];
+
+		if (text != null)
+		{
+			tags = MfmParser.Parse(text)
+			                .SelectMany(p => p.Children.Append(p))
+			                .OfType<MfmHashtagNode>()
+			                .Select(p => p.Hashtag.ToLowerInvariant())
+			                .Select(p => p.Trim('#'))
+			                .Distinct()
+			                .ToList();
+		}
+
+		var extracted = note?.Tags?.OfType<ASHashtag>()
+		                    .Select(p => p.Name?.ToLowerInvariant())
+		                    .Where(p => p != null)
+		                    .Cast<string>()
+		                    .Select(p => p.Trim('#'))
+		                    .Distinct()
+		                    .ToList();
+
+		if (extracted != null)
+			tags.AddRange(extracted);
+
+		if (tags.Count == 0) return [];
+
+		tags = tags.Distinct().ToList();
+
+		_ = followupTaskSvc.ExecuteTask("UpdateHashtagsTable", async provider =>
+		{
+			var bgDb     = provider.GetRequiredService<DatabaseContext>();
+			var existing = await bgDb.Hashtags.Where(p => tags.Contains(p.Name)).Select(p => p.Name).ToListAsync();
+			var dbTags = tags.Except(existing)
+			                 .Select(p => new Hashtag { Id = IdHelpers.GenerateSlowflakeId(), Name = p });
+			await bgDb.AddRangeAsync(dbTags);
+			await bgDb.SaveChangesAsync();
+		});
+
+		return tags;
+	}
+
 	private MentionQuintuple ResolveNoteMentions(IReadOnlyCollection<User> users)
 	{
 		var userIds      = users.Select(p => p.Id).Distinct().ToList();

Iceshrimp.Backend/Core/Services/UserService.cs

@@ -10,6 +10,8 @@ using Iceshrimp.Backend.Core.Extensions;
 using Iceshrimp.Backend.Core.Federation.ActivityStreams.Types;
 using Iceshrimp.Backend.Core.Helpers;
 using Iceshrimp.Backend.Core.Helpers.LibMfm.Conversion;
+using Iceshrimp.Backend.Core.Helpers.LibMfm.Parsing;
+using Iceshrimp.Backend.Core.Helpers.LibMfm.Types;
 using Iceshrimp.Backend.Core.Middleware;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Options;
@@ -115,11 +117,6 @@ public class UserService(
 		var host = AcctToTuple(acct).Host ?? throw new Exception("Host must not be null at this stage");
 
 		var emoji = await emojiSvc.ProcessEmojiAsync(actor.Tags?.OfType<ASEmoji>().ToList(), host);
-		var tags = actor.Tags?.OfType<ASHashtag>()
-		                .Select(p => p.Name?.ToLowerInvariant())
-		                .Where(p => p != null)
-		                .Cast<string>()
-		                .ToList();
 
 		var fields = actor.Attachments != null
 			? await actor.Attachments
@@ -134,6 +131,8 @@ public class UserService(
 
 		var bio = actor.MkSummary ?? await MfmConverter.FromHtmlAsync(actor.Summary);
 
+		var tags = ResolveHashtags(bio, actor);
+
 		user = new User
 		{
 			Id            = IdHelpers.GenerateSlowflakeId(),
@@ -261,12 +260,6 @@ public class UserService(
 		                                             user.Host ??
 		                                             throw new Exception("User host must not be null at this stage"));
 
-		var tags = actor.Tags?.OfType<ASHashtag>()
-		                .Select(p => p.Name?.ToLowerInvariant())
-		                .Where(p => p != null)
-		                .Cast<string>()
-		                .ToList();
-
 		var fields = actor.Attachments != null
 			? await actor.Attachments
 			             .OfType<ASField>()
@@ -279,7 +272,6 @@ public class UserService(
 			: null;
 
 		user.Emojis = emoji.Select(p => p.Id).ToList();
-		user.Tags   = tags ?? [];
 		//TODO: FollowersCount
 		//TODO: FollowingCount
 
@@ -296,6 +288,8 @@ public class UserService(
 
 		user.UserProfile.MentionsResolved = false;
 
+		user.Tags = ResolveHashtags(user.UserProfile.Description, actor);
+
 		db.Update(user);
 		await db.SaveChangesAsync();
 		await processPendingDeletes();
@@ -309,6 +303,8 @@ public class UserService(
 		if (user.Host != null) throw new Exception("This method is only valid for local users");
 		if (user.UserProfile == null) throw new Exception("user.UserProfile must not be null at this stage");
 		
+		user.Tags = ResolveHashtags(user.UserProfile.Description);
+
 		db.Update(user);
 		db.Update(user.UserProfile);
 		await db.SaveChangesAsync();
@@ -786,4 +782,47 @@ public class UserService(
 
 		return user;
 	}
+
+	private List<string> ResolveHashtags(string? text, ASActor? actor = null)
+	{
+		List<string> tags = [];
+
+		if (text != null)
+		{
+			tags = MfmParser.Parse(text)
+			                .SelectMany(p => p.Children.Append(p))
+			                .OfType<MfmHashtagNode>()
+			                .Select(p => p.Hashtag.ToLowerInvariant())
+			                .Select(p => p.Trim('#'))
+			                .Distinct()
+			                .ToList();
+		}
+
+		var extracted = actor?.Tags?.OfType<ASHashtag>()
+		                     .Select(p => p.Name?.ToLowerInvariant())
+		                     .Where(p => p != null)
+		                     .Cast<string>()
+		                     .Select(p => p.Trim('#'))
+		                     .Distinct()
+		                     .ToList();
+
+		if (extracted != null)
+			tags.AddRange(extracted);
+
+		if (tags.Count == 0) return [];
+		
+		tags = tags.Distinct().ToList();
+
+		_ = followupTaskSvc.ExecuteTask("UpdateHashtagsTable", async provider =>
+		{
+			var bgDb     = provider.GetRequiredService<DatabaseContext>();
+			var existing = await bgDb.Hashtags.Where(p => tags.Contains(p.Name)).Select(p => p.Name).ToListAsync();
+			var dbTags = tags.Except(existing)
+			                 .Select(p => new Hashtag { Id = IdHelpers.GenerateSlowflakeId(), Name = p });
+			await bgDb.AddRangeAsync(dbTags);
+			await bgDb.SaveChangesAsync();
+		});
+
+		return tags;
+	}
 }