FEATURE: New way to dismiss new topics (#11927)

This is a try to simplify logic around dismiss new topics to have one solution to work in all places - dismiss all-new, dismiss new in a specific category or even in a specific tag.

app/controllers/topics_controller.rb

@@ -897,12 +897,8 @@ class TopicsController < ApplicationController
       if params[:include_subcategories] == 'true'
         category_ids = category_ids.concat(Category.where(parent_category_id: params[:category_id]).pluck(:id))
       end
+      DismissTopics.new(current_user, Topic.where(category_id: category_ids)).perform!
       category_ids.each do |category_id|
-        current_user
-          .category_users
-          .where(category_id: category_id)
-          .first_or_initialize
-          .update!(last_seen_at: Time.zone.now)
         TopicTrackingState.publish_dismiss_new(current_user.id, category_id)
       end
     else

app/jobs/scheduled/clean_dismissed_topic_users.rb

@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+module Jobs
+  class CleanDismissedTopicUsers < ::Jobs::Scheduled
+    every 1.day
+
+    def execute(args)
+      delete_overdue_dismissals!
+      delete_over_the_limit_dismissals!
+    end
+
+    private
+
+    def delete_overdue_dismissals!
+      sql = <<~SQL
+        DELETE FROM dismissed_topic_users dtu1
+        USING dismissed_topic_users dtu2
+        JOIN topics ON topics.id = dtu2.topic_id
+        JOIN users ON users.id = dtu2.user_id
+        JOIN categories ON categories.id = topics.category_id
+        LEFT JOIN user_stats ON user_stats.user_id = users.id
+        LEFT JOIN user_options ON user_options.user_id = users.id
+        WHERE topics.created_at < GREATEST(CASE
+                    WHEN COALESCE(user_options.new_topic_duration_minutes, :default_duration) = :always THEN users.created_at
+                    WHEN COALESCE(user_options.new_topic_duration_minutes, :default_duration) = :last_visit THEN COALESCE(users.previous_visit_at,users.created_at)
+                    ELSE (:now::timestamp - INTERVAL '1 MINUTE' * COALESCE(user_options.new_topic_duration_minutes, :default_duration))
+                 END, user_stats.new_since, :min_date)
+        AND dtu1.id = dtu2.id
+      SQL
+      sql = DB.sql_fragment(sql,
+                            now: DateTime.now,
+                            last_visit: User::NewTopicDuration::LAST_VISIT,
+                            always: User::NewTopicDuration::ALWAYS,
+                            default_duration: SiteSetting.default_other_new_topic_duration_minutes,
+                            min_date: Time.at(SiteSetting.min_new_topics_time).to_datetime)
+      DB.exec(sql)
+    end
+
+    def delete_over_the_limit_dismissals!
+      user_ids = DismissedTopicUser.distinct(:user_id).pluck(:user_id)
+      sql = <<~SQL
+      DELETE FROM dismissed_topic_users
+      WHERE dismissed_topic_users.id NOT IN (
+        SELECT valid_dtu.id FROM users
+        LEFT JOIN dismissed_topic_users valid_dtu ON valid_dtu.user_id = users.id
+        AND valid_dtu.topic_id IN (
+          SELECT topic_id FROM dismissed_topic_users dtu2
+          JOIN topics ON topics.id = dtu2.topic_id
+          WHERE dtu2.user_id = users.id
+          ORDER BY topics.created_at DESC
+          LIMIT :max_new_topics
+        )
+        WHERE users.id IN(:user_ids)
+      )
+      SQL
+      sql = DB.sql_fragment(sql, max_new_topics: SiteSetting.max_new_topics, user_ids: user_ids)
+      DB.exec(sql)
+    end
+  end
+end

app/models/dismissed_topic_user.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class DismissedTopicUser < ActiveRecord::Base
+  belongs_to :user
+  belongs_to :topic
+
+  def self.lookup_for(user, topics)
+    return [] if user.blank? || topics.blank?
+
+    topic_ids = topics.map(&:id)
+    DismissedTopicUser.where(topic_id: topic_ids, user_id: user.id).pluck(:topic_id)
+  end
+end
+
+# == Schema Information
+#
+# Table name: dismissed_topic_users
+#
+#  id         :bigint           not null, primary key
+#  user_id    :integer
+#  topic_id   :integer
+#  created_at :datetime
+#
+# Indexes
+#
+#  index_dismissed_topic_users_on_user_id_and_topic_id  (user_id,topic_id) UNIQUE
+#

app/models/topic.rb

@@ -231,6 +231,7 @@ class Topic < ActiveRecord::Base
   belongs_to :featured_user4, class_name: 'User', foreign_key: :featured_user4_id
 
   has_many :topic_users
+  has_many :dismissed_topic_users
   has_many :topic_links
   has_many :topic_invites
   has_many :invites, through: :topic_invites, source: :invite
@@ -250,6 +251,7 @@ class Topic < ActiveRecord::Base
   # When we want to temporarily attach some data to a forum topic (usually before serialization)
   attr_accessor :user_data
   attr_accessor :category_user_data
+  attr_accessor :dismissed
 
   attr_accessor :posters  # TODO: can replace with posters_summary once we remove old list code
   attr_accessor :participants

app/models/topic_list.rb

@@ -84,6 +84,7 @@ class TopicList < DraftableList
 
     # Attach some data for serialization to each topic
     @topic_lookup = TopicUser.lookup_for(@current_user, @topics) if @current_user
+    @dismissed_topic_users_lookup = DismissedTopicUser.lookup_for(@current_user, @topics) if @current_user
 
     post_action_type =
       if @current_user
@@ -119,6 +120,8 @@ class TopicList < DraftableList
         ft.category_user_data = @category_user_lookup[ft.category_id]
       end
 
+      ft.dismissed = @current_user && @dismissed_topic_users_lookup.include?(ft.id)
+
       if ft.user_data && post_action_lookup && actions = post_action_lookup[ft.id]
         ft.user_data.post_action_data = { post_action_type => actions }
       end

app/models/topic_tracking_state.rb

@@ -330,7 +330,7 @@ class TopicTrackingState
       else
         TopicQuery.new_filter(Topic, "xxx").where_clause.ast.to_sql.gsub!("'xxx'", treat_as_new_topic_clause) +
           " AND topics.created_at > :min_new_topic_date" +
-          " AND (category_users.last_seen_at IS NULL OR topics.created_at > category_users.last_seen_at)"
+          " AND dismissed_topic_users.id IS NULL"
       end
 
     select = (opts[:select]) || "
@@ -396,6 +396,7 @@ class TopicTrackingState
     JOIN categories c ON c.id = topics.category_id
     LEFT JOIN topic_users tu ON tu.topic_id = topics.id AND tu.user_id = u.id
     LEFT JOIN category_users ON category_users.category_id = topics.category_id AND category_users.user_id = #{opts[:user].id}
+    LEFT JOIN dismissed_topic_users ON dismissed_topic_users.topic_id = topics.id AND dismissed_topic_users.user_id = #{opts[:user].id}
     WHERE u.id = :user_id AND
           #{filter_old_unread}
           topics.archetype <> 'private_message' AND

app/serializers/listable_topic_serializer.rb

@@ -75,7 +75,7 @@ class ListableTopicSerializer < BasicTopicSerializer
   def seen
     return true if !scope || !scope.user
     return true if object.user_data && !object.user_data.last_read_post_number.nil?
-    return true if object.category_user_data&.last_seen_at && object.created_at < object.category_user_data.last_seen_at
+    return true if object.dismissed
     return true if object.created_at < scope.user.user_option.treat_as_new_topic_start_date
     false
   end

app/services/dismiss_topics.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+class DismissTopics
+  def initialize(user, topics_scope)
+    @user = user
+    @topics_scope = topics_scope
+  end
+
+  def perform!
+    DismissedTopicUser.insert_all(rows) if rows.present?
+  end
+
+  private
+
+  def rows
+    @rows ||= @topics_scope.where("created_at >= ?", since_date).order(created_at: :desc).limit(SiteSetting.max_new_topics).map do |topic|
+      {
+        topic_id: topic.id,
+        user_id: @user.id,
+        created_at: Time.zone.now
+      }
+    end
+  end
+
+  def since_date
+    new_topic_duration_minutes = @user.user_option&.new_topic_duration_minutes || SiteSetting.default_other_new_topic_duration_minutes
+    setting_date =
+      case new_topic_duration_minutes
+      when User::NewTopicDuration::LAST_VISIT
+        @user.previous_visit_at || @user.created_at
+      when User::NewTopicDuration::ALWAYS
+        @user.created_at
+      else
+        new_topic_duration_minutes.minutes.ago
+      end
+    [setting_date, @user.user_stat.new_since, Time.at(SiteSetting.min_new_topics_time).to_datetime].max
+  end
+end