DEV: Redesign chat mentions

plugins/chat/app/jobs/regular/chat/notify_mentioned.rb

@@ -145,13 +145,43 @@ def process_mentions(user_ids, mention_type)
         memberships = get_memberships(user_ids)
 
         memberships.each do |membership|
-          mention = ::Chat::Mention.find_by(user: membership.user, chat_message: @chat_message)
+          mention = find_mention(@chat_message, mention_type, membership.user.id)
           if mention.present?
             create_notification!(membership, mention, mention_type)
             send_notifications(membership, mention_type)
           end
         end
       end
+
+      def find_mention(chat_message, mention_type, user_id)
+        mention_klass = resolve_mention_klass(mention_type)
+
+        target_id = nil
+        if mention_klass == ::Chat::UserMention
+          target_id = user_id
+        elsif mention_klass == ::Chat::GroupMention
+          begin
+            target_id = Group.where("LOWER(name) = ?", "#{mention_type}").first.id
+          rescue => e
+            Discourse.warn_exception(e, message: "Mentioned group doesn't exist")
+          end
+        end
+
+        mention_klass.find_by(chat_message: chat_message, target_id: target_id)
+      end
+
+      def resolve_mention_klass(mention_type)
+        case mention_type
+        when :global_mentions
+          ::Chat::AllMention
+        when :here_mentions
+          ::Chat::HereMention
+        when :direct_mentions
+          ::Chat::UserMention
+        else
+          ::Chat::GroupMention
+        end
+      end
     end
   end
 end

plugins/chat/app/models/chat/all_mention.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+module Chat
+  class AllMention < Mention
+  end
+end

plugins/chat/app/models/chat/group_mention.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module Chat
+  class GroupMention < Mention
+    belongs_to :group, foreign_key: :target_id
+  end
+end

plugins/chat/app/models/chat/here_mention.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+module Chat
+  class HereMention < Mention
+  end
+end

plugins/chat/app/models/chat/mention.rb

@@ -3,9 +3,8 @@
 module Chat
   class Mention < ActiveRecord::Base
     self.table_name = "chat_mentions"
-    self.ignored_columns = ["notification_id"]
+    self.ignored_columns = %w[notification_id user_id]
 
-    belongs_to :user
     belongs_to :chat_message, class_name: "Chat::Message"
     has_many :mention_notifications,
              class_name: "Chat::MentionNotification",
@@ -20,12 +19,15 @@ class Mention < ActiveRecord::Base
 #
 #  id              :bigint           not null, primary key
 #  chat_message_id :integer          not null
-#  user_id         :integer          not null
+#  user_id         :integer
 #  notification_id :integer          not null
+#  target_id       :integer
+#  type            :integer          not null
 #  created_at      :datetime         not null
 #  updated_at      :datetime         not null
 #
 # Indexes
 #
-#  chat_mentions_index  (chat_message_id,user_id,notification_id) UNIQUE
+# index_chat_mentions_on_chat_message_id    (chat_message_id)
+# index_chat_mentions_on_target_id          (target_id)
 #

plugins/chat/app/models/chat/message.rb

@@ -51,6 +51,22 @@ class Message < ActiveRecord::Base
              dependent: :destroy,
              class_name: "Chat::Mention",
              foreign_key: :chat_message_id
+    has_many :user_mentions,
+             dependent: :destroy,
+             class_name: "Chat::UserMention",
+             foreign_key: :chat_message_id
+    has_many :group_mentions,
+             dependent: :destroy,
+             class_name: "Chat::GroupMention",
+             foreign_key: :chat_message_id
+    has_one :all_mention,
+            dependent: :destroy,
+            class_name: "Chat::AllMention",
+            foreign_key: :chat_message_id
+    has_one :here_mention,
+            dependent: :destroy,
+            class_name: "Chat::HereMention",
+            foreign_key: :chat_message_id
 
     scope :in_public_channel,
           -> do
@@ -248,14 +264,10 @@ def url
     end
 
     def upsert_mentions
-      mentioned_user_ids = parsed_mentions.all_mentioned_users_ids
-      old_mentions = chat_mentions.pluck(:user_id)
-
-      mentioned_user_ids_to_drop = old_mentions - mentioned_user_ids
-      delete_mentions(mentioned_user_ids_to_drop)
-
-      mentioned_user_ids_to_add = mentioned_user_ids - old_mentions
-      insert_mentions(mentioned_user_ids_to_add)
+      upsert_user_mentions
+      upsert_group_mentions
+      create_or_delete_all_mention
+      create_or_delete_here_mention
     end
 
     def in_thread?
@@ -280,24 +292,16 @@ def invalidate_parsed_mentions
 
     private
 
-    def delete_mentions(user_ids)
-      chat_mentions.where(user_id: user_ids).destroy_all
+    def delete_mentions(mention_type, target_ids)
+      chat_mentions.where(type: mention_type, target_id: target_ids).destroy_all
     end
 
-    def insert_mentions(user_ids)
-      return if user_ids.empty?
-
-      now = Time.zone.now
-      mentions = []
-      User
-        .where(id: user_ids)
-        .find_each do |user|
-          mentions << {
-            chat_message_id: self.id,
-            user_id: user.id,
-            created_at: now,
-            updated_at: now,
-          }
+    def insert_mentions(type, target_ids)
+      return if target_ids.empty?
+
+      mentions =
+        target_ids.map do |target_id|
+          { chat_message_id: self.id, target_id: target_id, type: type }
         end
 
       Chat::Mention.insert_all(mentions)
@@ -314,6 +318,38 @@ def message_too_long?
     def ensure_last_editor_id
       self.last_editor_id ||= self.user_id
     end
+
+    def create_or_delete_all_mention
+      if !parsed_mentions.has_global_mention && all_mention.present?
+        all_mention.destroy!
+        association(:all_mention).reload
+      elsif parsed_mentions.has_global_mention && all_mention.blank?
+        build_all_mention.save!
+      end
+    end
+
+    def create_or_delete_here_mention
+      if !parsed_mentions.has_here_mention && here_mention.present?
+        here_mention.destroy!
+        association(:here_mention).reload
+      elsif parsed_mentions.has_here_mention && here_mention.blank?
+        build_here_mention.save!
+      end
+    end
+
+    def upsert_group_mentions
+      old_mentions = group_mentions.pluck(:target_id)
+      new_mentions = parsed_mentions.groups_to_mention.pluck(:id)
+      delete_mentions("Chat::GroupMention", old_mentions - new_mentions)
+      insert_mentions("Chat::GroupMention", new_mentions - old_mentions)
+    end
+
+    def upsert_user_mentions
+      old_mentions = user_mentions.pluck(:target_id)
+      new_mentions = parsed_mentions.direct_mentions.pluck(:id)
+      delete_mentions("Chat::UserMention", old_mentions - new_mentions)
+      insert_mentions("Chat::UserMention", new_mentions - old_mentions)
+    end
   end
 end
 

plugins/chat/app/models/chat/user_mention.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module Chat
+  class UserMention < Mention
+    belongs_to :user, foreign_key: :target_id
+  end
+end

plugins/chat/app/queries/chat/messages_query.rb

@@ -87,9 +87,9 @@ def self.base_query(channel:)
 
       if SiteSetting.enable_user_status
         query = query.includes(user: :user_status)
-        query = query.includes(chat_mentions: { user: :user_status })
+        query = query.includes(user_mentions: { user: :user_status })
       else
-        query = query.includes(chat_mentions: :user)
+        query = query.includes(user_mentions: :user)
       end
 
       query

plugins/chat/app/serializers/chat/message_serializer.rb

@@ -36,7 +36,7 @@ class MessageSerializer < ::ApplicationSerializer
 
     def mentioned_users
       object
-        .chat_mentions
+        .user_mentions
         .limit(SiteSetting.max_mentions_per_chat_message)
         .map(&:user)
         .compact

plugins/chat/app/serializers/chat/thread_original_message_serializer.rb

@@ -17,7 +17,7 @@ def excerpt
 
     def mentioned_users
       object
-        .chat_mentions
+        .user_mentions
         .limit(SiteSetting.max_mentions_per_chat_message)
         .map(&:user)
         .compact

plugins/chat/db/migrate/20231227160001_add_type_and_target_id_to_chat_mentions.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class AddTypeAndTargetIdToChatMentions < ActiveRecord::Migration[7.0]
+  def up
+    add_column :chat_mentions, :type, :string, null: true
+    add_column :chat_mentions, :target_id, :integer, null: true
+    change_column_null :chat_mentions, :user_id, true
+  end
+
+  def down
+    change_column_null :chat_mentions, :user_id, false
+    remove_column :chat_mentions, :target_id
+    remove_column :chat_mentions, :type
+  end
+end

plugins/chat/db/migrate/20231227160002_set_type_and_target_id_on_chat_mentions.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class SetTypeAndTargetIdOnChatMentions < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+  BATCH_SIZE = 5000
+
+  def up
+    begin
+      updated_count = DB.exec(<<~SQL, batch_size: BATCH_SIZE)
+        WITH cte AS (SELECT id, user_id
+                     FROM chat_mentions
+                     WHERE type IS NULL AND target_id IS NULL
+                     LIMIT :batch_size)
+        UPDATE chat_mentions
+        SET type = 'Chat::UserMention', target_id = cte.user_id
+        FROM cte
+        WHERE chat_mentions.id = cte.id;
+      SQL
+    end while updated_count > 0
+  end
+
+  def down
+  end
+end

plugins/chat/db/migrate/20231227160003_add_and_remove_indexes_on_chat_mentions.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class AddAndRemoveIndexesOnChatMentions < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+  def up
+    remove_index :chat_mentions,
+                 name: :chat_mentions_index,
+                 algorithm: :concurrently,
+                 if_exists: true
+    add_index :chat_mentions, %i[chat_message_id], algorithm: :concurrently
+    add_index :chat_mentions, %i[target_id], algorithm: :concurrently
+  end
+
+  def down
+    remove_index :chat_mentions, %i[target_id], algorithm: :concurrently, if_exists: true
+    remove_index :chat_mentions, %i[chat_message_id], algorithm: :concurrently, if_exists: true
+    add_index :chat_mentions,
+              %i[chat_message_id user_id notification_id],
+              unique: true,
+              name: "chat_mentions_index",
+              algorithm: :concurrently
+  end
+end

plugins/chat/db/post_migrate/20231227160004_set_type_and_target_id_on_chat_mentions_post_migrate.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class SetTypeAndTargetIdOnChatMentionsPostMigrate < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+  BATCH_SIZE = 5000
+
+  def up
+    # we're setting it again in post-migration
+    # in case some mentions have been created after we run
+    # this query the first time in the regular migration
+    begin
+      updated_count = DB.exec(<<~SQL, batch_size: BATCH_SIZE)
+        WITH cte AS (SELECT id, user_id
+                     FROM chat_mentions
+                     WHERE type IS NULL AND target_id IS NULL
+                     LIMIT :batch_size)
+        UPDATE chat_mentions
+        SET type = 'Chat::UserMention', target_id = cte.user_id
+        FROM cte
+        WHERE chat_mentions.id = cte.id;
+      SQL
+    end while updated_count > 0
+  end
+
+  def down
+  end
+end

plugins/chat/db/post_migrate/20231227160005_make_type_on_chat_mentions_non_nullable.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class MakeTypeOnChatMentionsNonNullable < ActiveRecord::Migration[7.0]
+  def up
+    change_column_null :chat_mentions, :type, false
+  end
+
+  def down
+    change_column_null :chat_mentions, :type, true
+  end
+end

plugins/chat/lib/chat/group_extension.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Chat
+  module GroupExtension
+    extend ActiveSupport::Concern
+
+    prepended do
+      has_many :chat_mentions, class_name: "Chat::GroupMention", foreign_key: "target_id"
+    end
+  end
+end

plugins/chat/lib/chat/mailer.rb

@@ -52,13 +52,17 @@ def self.users_with_unprocessed_unread_mentions
         .joins("INNER JOIN chat_channels cc ON cc.id = uccm.chat_channel_id")
         .joins("INNER JOIN chat_messages c_msg ON c_msg.chat_channel_id = uccm.chat_channel_id")
         .joins("LEFT OUTER JOIN chat_mentions c_mentions ON c_mentions.chat_message_id = c_msg.id")
+        .joins(
+          "LEFT OUTER JOIN chat_mention_notifications cmn ON cmn.chat_mention_id = c_mentions.id",
+        )
+        .joins("LEFT OUTER JOIN notifications n ON cmn.notification_id = n.id")
         .where("c_msg.deleted_at IS NULL AND c_msg.user_id <> users.id")
         .where("c_msg.created_at > ?", 1.week.ago)
         .where(<<~SQL)
         (uccm.last_read_message_id IS NULL OR c_msg.id > uccm.last_read_message_id) AND
         (uccm.last_unread_mention_when_emailed_id IS NULL OR c_msg.id > uccm.last_unread_mention_when_emailed_id) AND
         (
-          (uccm.user_id = c_mentions.user_id AND uccm.following IS true AND cc.chatable_type = 'Category') OR
+          (uccm.user_id = n.user_id AND uccm.following IS true AND cc.chatable_type = 'Category') OR
           (cc.chatable_type = 'DirectMessage')
         )
       SQL