Change admin UI for hashtags and add back whitelisted trends (mastodon#11490)

Fix mastodon#271

Add back the `GET /api/v1/trends` API with the caveat that it does
not return tags that have not been allowed to trend by the staff.

When a hashtag begins to trend (internally) and that hashtag has
not been previously reviewed by the staff, the staff is notified.

The new admin UI for hashtags allows filtering hashtags by where
they are used (e.g. in the profile directory), whether they have
been reviewed or are pending reviewal, they show by how many people
the hashtag is used in the directory, how many people used it
today, how many statuses with it have been created today, and it
allows fixing the name of the hashtag to make it more readable.

The disallowed hashtags feature has been reworked. It is now
controlled from the admin UI for hashtags instead of from
the file `config/settings.yml`

Author: Gargron

app/controllers/admin/dashboard_controller.rb

@@ -27,7 +27,7 @@ def index
       @saml_enabled          = ENV['SAML_ENABLED'] == 'true'
       @pam_enabled           = ENV['PAM_ENABLED'] == 'true'
       @hidden_service        = ENV['ALLOW_ACCESS_TO_HIDDEN_SERVICE'] == 'true'
-      @trending_hashtags     = TrendingTags.get(7)
+      @trending_hashtags     = TrendingTags.get(10, filtered: false)
       @profile_directory     = Setting.profile_directory
       @timeline_preview      = Setting.timeline_preview
       @spam_check_enabled    = Setting.spam_check_enabled

app/controllers/admin/tags_controller.rb

@@ -4,41 +4,49 @@ module Admin
   class TagsController < BaseController
     before_action :set_tags, only: :index
     before_action :set_tag, except: :index
-    before_action :set_filter_params
 
     def index
       authorize :tag, :index?
     end
 
-    def hide
-      authorize @tag, :hide?
-      @tag.account_tag_stat.update!(hidden: true)
-      redirect_to admin_tags_path(@filter_params)
+    def show
+      authorize @tag, :show?
     end
 
-    def unhide
-      authorize @tag, :unhide?
-      @tag.account_tag_stat.update!(hidden: false)
-      redirect_to admin_tags_path(@filter_params)
+    def update
+      authorize @tag, :update?
+
+      if @tag.update(tag_params.merge(reviewed_at: Time.now.utc))
+        redirect_to admin_tag_path(@tag.id)
+      else
+        render :show
+      end
     end
 
     private
 
     def set_tags
-      @tags = Tag.discoverable
-      @tags.merge!(Tag.hidden) if filter_params[:hidden]
+      @tags = filtered_tags.page(params[:page])
     end
 
     def set_tag
       @tag = Tag.find(params[:id])
     end
 
-    def set_filter_params
-      @filter_params = filter_params.to_hash.symbolize_keys
+    def filtered_tags
+      scope = Tag
+      scope = scope.discoverable if filter_params[:context] == 'directory'
+      scope = scope.reviewed if filter_params[:review] == 'reviewed'
+      scope = scope.pending_review if filter_params[:review] == 'pending_review'
+      scope.reorder(score: :desc)
     end
 
     def filter_params
-      params.permit(:hidden)
+      params.slice(:context, :review).permit(:context, :review)
+    end
+
+    def tag_params
+      params.require(:tag).permit(:name, :trendable, :usable, :listable)
     end
   end
 end

app/controllers/api/v1/trends_controller.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class Api::V1::TrendsController < Api::BaseController
+  before_action :set_tags
+
+  respond_to :json
+
+  def index
+    render json: @tags, each_serializer: REST::TagSerializer
+  end
+
+  private
+
+  def set_tags
+    @tags = TrendingTags.get(limit_param(10))
+  end
+end

app/controllers/settings/preferences_controller.rb

@@ -56,7 +56,7 @@ def user_settings_params
       :setting_advanced_layout,
       :setting_use_blurhash,
       :setting_use_pending_items,
-      notification_emails: %i(follow follow_request reblog favourite mention digest report pending_account),
+      notification_emails: %i(follow follow_request reblog favourite mention digest report pending_account trending_tag),
       interactions: %i(must_be_follower must_be_following must_be_following_dm)
     )
   end

app/helpers/admin/filter_helper.rb

@@ -5,15 +5,16 @@ module Admin::FilterHelper
   REPORT_FILTERS       = %i(resolved account_id target_account_id).freeze
   INVITE_FILTER        = %i(available expired).freeze
   CUSTOM_EMOJI_FILTERS = %i(local remote by_domain shortcode).freeze
-  TAGS_FILTERS         = %i(hidden).freeze
+  TAGS_FILTERS         = %i(context review).freeze
   INSTANCES_FILTERS    = %i(limited by_domain).freeze
   FOLLOWERS_FILTERS    = %i(relationship status by_domain activity order).freeze
 
   FILTERS = ACCOUNT_FILTERS + REPORT_FILTERS + INVITE_FILTER + CUSTOM_EMOJI_FILTERS + TAGS_FILTERS + INSTANCES_FILTERS + FOLLOWERS_FILTERS
 
   def filter_link_to(text, link_to_params, link_class_params = link_to_params)
-    new_url = filtered_url_for(link_to_params)
+    new_url   = filtered_url_for(link_to_params)
     new_class = filtered_url_for(link_class_params)
+
     link_to text, new_url, class: filter_link_class(new_class)
   end
 

app/mailers/admin_mailer.rb

@@ -24,4 +24,14 @@ def new_pending_account(recipient, user)
       mail to: @me.user_email, subject: I18n.t('admin_mailer.new_pending_account.subject', instance: @instance, username: @account.username)
     end
   end
+
+  def new_trending_tag(recipient, tag)
+    @tag      = tag
+    @me       = recipient
+    @instance = Rails.configuration.x.local_domain
+
+    locale_for_account(@me) do
+      mail to: @me.user_email, subject: I18n.t('admin_mailer.new_trending_tag.subject', instance: @instance, name: @tag.name)
+    end
+  end
 end

app/models/application_record.rb

@@ -2,5 +2,16 @@
 
 class ApplicationRecord < ActiveRecord::Base
   self.abstract_class = true
+
   include Remotable
+
+  def boolean_with_default(key, default_value)
+    value = attributes[key]
+
+    if value.nil?
+      default_value
+    else
+      value
+    end
+  end
 end

app/models/tag.rb

@@ -3,11 +3,16 @@
 #
 # Table name: tags
 #
-#  id         :bigint(8)        not null, primary key
-#  name       :string           default(""), not null
-#  created_at :datetime         not null
-#  updated_at :datetime         not null
-#  score      :integer
+#  id                  :bigint(8)        not null, primary key
+#  name                :string           default(""), not null
+#  created_at          :datetime         not null
+#  updated_at          :datetime         not null
+#  score               :integer
+#  usable              :boolean
+#  trendable           :boolean
+#  listable            :boolean
+#  reviewed_at         :datetime
+#  requested_review_at :datetime
 #
 
 class Tag < ApplicationRecord
@@ -22,16 +27,17 @@ class Tag < ApplicationRecord
   HASHTAG_RE = /(?:^|[^\/\)\w])#(#{HASHTAG_NAME_RE})/i
 
   validates :name, presence: true, format: { with: /\A(#{HASHTAG_NAME_RE})\z/i }
+  validate :validate_name_change, if: -> { !new_record? && name_changed? }
 
-  scope :discoverable, -> { joins(:account_tag_stat).where(AccountTagStat.arel_table[:accounts_count].gt(0)).where(account_tag_stats: { hidden: false }).order(Arel.sql('account_tag_stats.accounts_count desc')) }
-  scope :hidden, -> { where(account_tag_stats: { hidden: true }) }
+  scope :reviewed, -> { where.not(reviewed_at: nil) }
+  scope :pending_review, -> { where(reviewed_at: nil).where.not(requested_review_at: nil) }
+  scope :discoverable, -> { where.not(listable: false).joins(:account_tag_stat).where(AccountTagStat.arel_table[:accounts_count].gt(0)).order(Arel.sql('account_tag_stats.accounts_count desc')) }
   scope :most_used, ->(account) { joins(:statuses).where(statuses: { account: account }).group(:id).order(Arel.sql('count(*) desc')) }
 
   delegate :accounts_count,
            :accounts_count=,
            :increment_count!,
            :decrement_count!,
-           :hidden?,
            to: :account_tag_stat
 
   after_save :save_account_tag_stat
@@ -48,6 +54,40 @@ def to_param
     name
   end
 
+  def usable
+    boolean_with_default('usable', true)
+  end
+
+  alias usable? usable
+
+  def listable
+    boolean_with_default('listable', true)
+  end
+
+  alias listable? listable
+
+  def trendable
+    boolean_with_default('trendable', false)
+  end
+
+  alias trendable? trendable
+
+  def requires_review?
+    reviewed_at.nil?
+  end
+
+  def reviewed?
+    reviewed_at.present?
+  end
+
+  def requested_review?
+    requested_review_at.present?
+  end
+
+  def trending?
+    TrendingTags.trending?(self)
+  end
+
   def history
     days = []
 
@@ -117,4 +157,8 @@ def save_account_tag_stat
     return unless account_tag_stat&.changed?
     account_tag_stat.save
   end
+
+  def validate_name_change
+    errors.add(:name, I18n.t('tags.does_not_match_previous_name')) unless name_was.mb_chars.casecmp(name.mb_chars).zero?
+  end
 end

app/models/trending_tags.rb

@@ -10,20 +10,28 @@ class << self
     include Redisable
 
     def record_use!(tag, account, at_time = Time.now.utc)
-      return if disallowed_hashtags.include?(tag.name) || account.silenced? || account.bot?
+      return if account.silenced? || account.bot? || !tag.usable? || !(tag.trendable? || tag.requires_review?)
 
       increment_historical_use!(tag.id, at_time)
       increment_unique_use!(tag.id, account.id, at_time)
-      increment_vote!(tag.id, at_time)
+      increment_vote!(tag, at_time)
     end
 
-    def get(limit)
-      key     = "#{KEY}:#{Time.now.utc.beginning_of_day.to_i}"
-      tag_ids = redis.zrevrange(key, 0, limit - 1).map(&:to_i)
-      tags    = Tag.where(id: tag_ids).to_a.each_with_object({}) { |tag, h| h[tag.id] = tag }
+    def get(limit, filtered: true)
+      tag_ids = redis.zrevrange("#{KEY}:#{Time.now.utc.beginning_of_day.to_i}", 0, limit - 1).map(&:to_i)
+
+      tags = Tag.where(id: tag_ids)
+      tags = tags.where(trendable: true) if filtered
+      tags = tags.each_with_object({}) { |tag, h| h[tag.id] = tag }
+
       tag_ids.map { |tag_id| tags[tag_id] }.compact
     end
 
+    def trending?(tag)
+      rank = redis.zrevrank("#{KEY}:#{Time.now.utc.beginning_of_day.to_i}", tag.id)
+      rank.present? && rank <= 10
+    end
+
     private
 
     def increment_historical_use!(tag_id, at_time)
@@ -38,33 +46,27 @@ def increment_unique_use!(tag_id, account_id, at_time)
       redis.expire(key, EXPIRE_HISTORY_AFTER)
     end
 
-    def increment_vote!(tag_id, at_time)
+    def increment_vote!(tag, at_time)
       key      = "#{KEY}:#{at_time.beginning_of_day.to_i}"
-      expected = redis.pfcount("activity:tags:#{tag_id}:#{(at_time - 1.day).beginning_of_day.to_i}:accounts").to_f
+      expected = redis.pfcount("activity:tags:#{tag.id}:#{(at_time - 1.day).beginning_of_day.to_i}:accounts").to_f
       expected = 1.0 if expected.zero?
-      observed = redis.pfcount("activity:tags:#{tag_id}:#{at_time.beginning_of_day.to_i}:accounts").to_f
+      observed = redis.pfcount("activity:tags:#{tag.id}:#{at_time.beginning_of_day.to_i}:accounts").to_f
 
       if expected > observed || observed < THRESHOLD
-        redis.zrem(key, tag_id.to_s)
+        redis.zrem(key, tag.id)
       else
-        score = ((observed - expected)**2) / expected
-        added = redis.zadd(key, score, tag_id.to_s)
-        bump_tag_score!(tag_id) if added
+        score    = ((observed - expected)**2) / expected
+        old_rank = redis.zrevrank(key, tag.id)
+
+        redis.zadd(key, score, tag.id)
+        request_review!(tag) if (old_rank.nil? || old_rank > 10) && redis.zrevrank(key, tag.id) <= 10 && !tag.trendable? && tag.requires_review? && !tag.requested_review?
       end
 
       redis.expire(key, EXPIRE_TRENDS_AFTER)
     end
 
-    def bump_tag_score!(tag_id)
-      Tag.where(id: tag_id).update_all('score = COALESCE(score, 0) + 1')
-    end
-
-    def disallowed_hashtags
-      return @disallowed_hashtags if defined?(@disallowed_hashtags)
-
-      @disallowed_hashtags = Setting.disallowed_hashtags.nil? ? [] : Setting.disallowed_hashtags
-      @disallowed_hashtags = @disallowed_hashtags.split(' ') if @disallowed_hashtags.is_a? String
-      @disallowed_hashtags = @disallowed_hashtags.map(&:downcase)
+    def request_review!(tag)
+      User.staff.includes(:account).find_each { |u| AdminMailer.new_trending_tag(u.account, tag).deliver_later! if u.allows_trending_tag_emails? }
     end
   end
 end

app/models/user.rb

@@ -207,6 +207,10 @@ def allows_pending_account_emails?
     settings.notification_emails['pending_account']
   end
 
+  def allows_trending_tag_emails?
+    settings.notification_emails['trending_tag']
+  end
+
   def hides_network?
     @hides_network ||= settings.hide_network
   end