Add trending links (#16917)

* Add trending links * Add overriding specific links trendability * Add link type to preview cards and only trend articles Change trends review notifications from being sent every 5 minutes to being sent every 2 hours Change threshold from 5 unique accounts to 15 unique accounts * Fix tests
2021-11-25 13:07:38 +01:00 · 2021-11-25 13:07:38 +01:00 · 6e50134a42
parent 46e62fc4b3
commit 6e50134a42
97 changed files with 2071 additions and 722 deletions
--- a/app/chewy/tags_index.rb
+++ b/app/chewy/tags_index.rb
@ -31,7 +31,7 @@ class TagsIndex < Chewy::Index
    end

    field :reviewed, type: 'boolean', value: ->(tag) { tag.reviewed? }
-    field :usage, type: 'long', value: ->(tag) { tag.history.reduce(0) { |total, day| total + day[:accounts].to_i } }
+    field :usage, type: 'long', value: ->(tag) { tag.history.reduce(0) { |total, day| total + day.accounts } }
    field :last_status_at, type: 'date', value: ->(tag) { tag.last_status_at || tag.created_at }
  end
 end
--- a/app/controllers/admin/dashboard_controller.rb
+++ b/app/controllers/admin/dashboard_controller.rb
@ -4,7 +4,7 @@ module Admin
  class DashboardController < BaseController
    def index
      @system_checks         = Admin::SystemCheck.perform
-      @time_period           = (1.month.ago.to_date...Time.now.utc.to_date)
+      @time_period           = (29.days.ago.to_date...Time.now.utc.to_date)
      @pending_users_count   = User.pending.count
      @pending_reports_count = Report.unresolved.count
      @pending_tags_count    = Tag.pending_review.count
--- a/app/controllers/admin/tags_controller.rb
+++ b/app/controllers/admin/tags_controller.rb
@ -2,38 +2,12 @@

 module Admin
  class TagsController < BaseController
-    before_action :set_tag, except: [:index, :batch, :approve_all, :reject_all]
-    before_action :set_usage_by_domain, except: [:index, :batch, :approve_all, :reject_all]
-    before_action :set_counters, except: [:index, :batch, :approve_all, :reject_all]
-
-    def index
-      authorize :tag, :index?
-
-      @tags = filtered_tags.page(params[:page])
-      @form = Form::TagBatch.new
-    end
-
-    def batch
-      @form = Form::TagBatch.new(form_tag_batch_params.merge(current_account: current_account, action: action_from_button))
-      @form.save
-    rescue ActionController::ParameterMissing
-      flash[:alert] = I18n.t('admin.accounts.no_account_selected')
-    ensure
-      redirect_to admin_tags_path(filter_params)
-    end
-
-    def approve_all
-      Form::TagBatch.new(current_account: current_account, tag_ids: Tag.pending_review.pluck(:id), action: 'approve').save
-      redirect_to admin_tags_path(filter_params)
-    end
-
-    def reject_all
-      Form::TagBatch.new(current_account: current_account, tag_ids: Tag.pending_review.pluck(:id), action: 'reject').save
-      redirect_to admin_tags_path(filter_params)
-    end
+    before_action :set_tag

    def show
      authorize @tag, :show?
+
+      @time_period = (6.days.ago.to_date...Time.now.utc.to_date)
    end

    def update
@ -52,52 +26,8 @@ module Admin
      @tag = Tag.find(params[:id])
    end

-    def set_usage_by_domain
-      @usage_by_domain = @tag.statuses
-                             .with_public_visibility
-                             .excluding_silenced_accounts
-                             .where(Status.arel_table[:id].gteq(Mastodon::Snowflake.id_at(Time.now.utc.beginning_of_day)))
-                             .joins(:account)
-                             .group('accounts.domain')
-                             .reorder(statuses_count: :desc)
-                             .pluck(Arel.sql('accounts.domain, count(*) AS statuses_count'))
-    end
-
-    def set_counters
-      @accounts_today = @tag.history.first[:accounts]
-      @accounts_week  = Redis.current.pfcount(*current_week_days.map { |day| "activity:tags:#{@tag.id}:#{day}:accounts" })
-    end
-
-    def filtered_tags
-      TagFilter.new(filter_params).results
-    end
-
-    def filter_params
-      params.slice(:page, *TagFilter::KEYS).permit(:page, *TagFilter::KEYS)
-    end
-
    def tag_params
      params.require(:tag).permit(:name, :trendable, :usable, :listable)
    end
-
-    def current_week_days
-      now = Time.now.utc.beginning_of_day.to_date
-
-      (Date.commercial(now.cwyear, now.cweek)..now).map do |date|
-        date.to_time(:utc).beginning_of_day.to_i
-      end
-    end
-
-    def form_tag_batch_params
-      params.require(:form_tag_batch).permit(:action, tag_ids: [])
-    end
-
-    def action_from_button
-      if params[:approve]
-        'approve'
-      elsif params[:reject]
-        'reject'
-      end
-    end
  end
 end
--- a/app/controllers/admin/trends/links/preview_card_providers_controller.rb
+++ b/app/controllers/admin/trends/links/preview_card_providers_controller.rb
@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class Admin::Trends::Links::PreviewCardProvidersController < Admin::BaseController
+  def index
+    authorize :preview_card_provider, :index?
+
+    @preview_card_providers = filtered_preview_card_providers.page(params[:page])
+    @form = Form::PreviewCardProviderBatch.new
+  end
+
+  def batch
+    @form = Form::PreviewCardProviderBatch.new(form_preview_card_provider_batch_params.merge(current_account: current_account, action: action_from_button))
+    @form.save
+  rescue ActionController::ParameterMissing
+    flash[:alert] = I18n.t('admin.accounts.no_account_selected')
+  ensure
+    redirect_to admin_trends_links_preview_card_providers_path(filter_params)
+  end
+
+  private
+
+  def filtered_preview_card_providers
+    PreviewCardProviderFilter.new(filter_params).results
+  end
+
+  def filter_params
+    params.slice(:page, *PreviewCardProviderFilter::KEYS).permit(:page, *PreviewCardProviderFilter::KEYS)
+  end
+
+  def form_preview_card_provider_batch_params
+    params.require(:form_preview_card_provider_batch).permit(:action, preview_card_provider_ids: [])
+  end
+
+  def action_from_button
+    if params[:approve]
+      'approve'
+    elsif params[:reject]
+      'reject'
+    end
+  end
+end
--- a/app/controllers/admin/trends/links_controller.rb
+++ b/app/controllers/admin/trends/links_controller.rb
@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class Admin::Trends::LinksController < Admin::BaseController
+  def index
+    authorize :preview_card, :index?
+
+    @preview_cards = filtered_preview_cards.page(params[:page])
+    @form          = Form::PreviewCardBatch.new
+  end
+
+  def batch
+    @form = Form::PreviewCardBatch.new(form_preview_card_batch_params.merge(current_account: current_account, action: action_from_button))
+    @form.save
+  rescue ActionController::ParameterMissing
+    flash[:alert] = I18n.t('admin.accounts.no_account_selected')
+  ensure
+    redirect_to admin_trends_links_path(filter_params)
+  end
+
+  private
+
+  def filtered_preview_cards
+    PreviewCardFilter.new(filter_params.with_defaults(trending: 'all')).results
+  end
+
+  def filter_params
+    params.slice(:page, *PreviewCardFilter::KEYS).permit(:page, *PreviewCardFilter::KEYS)
+  end
+
+  def form_preview_card_batch_params
+    params.require(:form_preview_card_batch).permit(:action, preview_card_ids: [])
+  end
+
+  def action_from_button
+    if params[:approve]
+      'approve'
+    elsif params[:approve_all]
+      'approve_all'
+    elsif params[:reject]
+      'reject'
+    elsif params[:reject_all]
+      'reject_all'
+    end
+  end
+end
--- a/app/controllers/admin/trends/tags_controller.rb
+++ b/app/controllers/admin/trends/tags_controller.rb
@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class Admin::Trends::TagsController < Admin::BaseController
+  def index
+    authorize :tag, :index?
+
+    @tags = filtered_tags.page(params[:page])
+    @form = Form::TagBatch.new
+  end
+
+  def batch
+    @form = Form::TagBatch.new(form_tag_batch_params.merge(current_account: current_account, action: action_from_button))
+    @form.save
+  rescue ActionController::ParameterMissing
+    flash[:alert] = I18n.t('admin.accounts.no_account_selected')
+  ensure
+    redirect_to admin_trends_tags_path(filter_params)
+  end
+
+  private
+
+  def filtered_tags
+    TagFilter.new(filter_params).results
+  end
+
+  def filter_params
+    params.slice(:page, *TagFilter::KEYS).permit(:page, *TagFilter::KEYS)
+  end
+
+  def form_tag_batch_params
+    params.require(:form_tag_batch).permit(:action, tag_ids: [])
+  end
+
+  def action_from_button
+    if params[:approve]
+      'approve'
+    elsif params[:reject]
+      'reject'
+    end
+  end
+end
--- a/app/controllers/api/v1/admin/dimensions_controller.rb
+++ b/app/controllers/api/v1/admin/dimensions_controller.rb
@ -17,7 +17,8 @@ class Api::V1::Admin::DimensionsController < Api::BaseController
      params[:keys],
      params[:start_at],
      params[:end_at],
-      params[:limit]
+      params[:limit],
+      params
    )
  end
 end
--- a/app/controllers/api/v1/admin/measures_controller.rb
+++ b/app/controllers/api/v1/admin/measures_controller.rb
@ -16,7 +16,8 @@ class Api::V1::Admin::MeasuresController < Api::BaseController
    @measures = Admin::Metrics::Measure.retrieve(
      params[:keys],
      params[:start_at],
-      params[:end_at]
+      params[:end_at],
+      params
    )
  end
 end
--- a/app/controllers/api/v1/admin/trends/tags_controller.rb
+++ b/app/controllers/api/v1/admin/trends/tags_controller.rb
@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+class Api::V1::Admin::Trends::TagsController < Api::BaseController
+  before_action :require_staff!
+  before_action :set_tags
+
+  def index
+    render json: @tags, each_serializer: REST::Admin::TagSerializer
+  end
+
+  private
+
+  def set_tags
+    @tags = Trends.tags.get(false, limit_param(10))
+  end
+end
--- a/app/controllers/api/v1/admin/trends_controller.rb
+++ b/app/controllers/api/v1/admin/trends_controller.rb
@ -1,16 +0,0 @@
-# frozen_string_literal: true
-
-class Api::V1::Admin::TrendsController < Api::BaseController
-  before_action :require_staff!
-  before_action :set_trends
-
-  def index
-    render json: @trends, each_serializer: REST::Admin::TagSerializer
-  end
-
-  private
-
-  def set_trends
-    @trends = TrendingTags.get(10, filtered: false)
-  end
-end
--- a/app/controllers/api/v1/trends/links_controller.rb
+++ b/app/controllers/api/v1/trends/links_controller.rb
@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class Api::V1::Trends::LinksController < Api::BaseController
+  before_action :set_links
+
+  def index
+    render json: @links, each_serializer: REST::Trends::LinkSerializer
+  end
+
+  private
+
+  def set_links
+    @links = begin
+      if Setting.trends
+        Trends.links.get(true, limit_param(10))
+      else
+        []
+      end
+    end
+  end
+end
--- a/app/controllers/api/v1/trends/tags_controller.rb
+++ b/app/controllers/api/v1/trends/tags_controller.rb
@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class Api::V1::Trends::TagsController < Api::BaseController
+  before_action :set_tags
+
+  def index
+    render json: @tags, each_serializer: REST::TagSerializer
+  end
+
+  private
+
+  def set_tags
+    @tags = begin
+      if Setting.trends
+        Trends.tags.get(true, limit_param(10))
+      else
+        []
+      end
+    end
+  end
+end
--- a/app/controllers/api/v1/trends_controller.rb
+++ b/app/controllers/api/v1/trends_controller.rb
@ -1,15 +0,0 @@
-# frozen_string_literal: true
-
-class Api::V1::TrendsController < Api::BaseController
-  before_action :set_tags
-
-  def index
-    render json: @tags, each_serializer: REST::TagSerializer
-  end
-
-  private
-
-  def set_tags
-    @tags = TrendingTags.get(limit_param(10))
-  end
-end
--- a/app/helpers/admin/filter_helper.rb
+++ b/app/helpers/admin/filter_helper.rb
@ -6,6 +6,8 @@ module Admin::FilterHelper
    CustomEmojiFilter::KEYS,
    ReportFilter::KEYS,
    TagFilter::KEYS,
+    PreviewCardProviderFilter::KEYS,
+    PreviewCardFilter::KEYS,
    InstanceFilter::KEYS,
    InviteFilter::KEYS,
    RelationshipFilter::KEYS,
--- a/app/helpers/languages_helper.rb
+++ b/app/helpers/languages_helper.rb
@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+module LanguagesHelper
+  HUMAN_LOCALES = {
+    af: 'Afrikaans',
+    ar: 'العربية',
+    ast: 'Asturianu',
+    bg: 'Български',
+    bn: 'বাংলা',
+    br: 'Breton',
+    ca: 'Català',
+    co: 'Corsu',
+    cs: 'Čeština',
+    cy: 'Cymraeg',
+    da: 'Dansk',
+    de: 'Deutsch',
+    el: 'Ελληνικά',
+    en: 'English',
+    eo: 'Esperanto',
+    'es-AR': 'Español (Argentina)',
+    'es-MX': 'Español (México)',
+    es: 'Español',
+    et: 'Eesti',
+    eu: 'Euskara',
+    fa: 'فارسی',
+    fi: 'Suomi',
+    fr: 'Français',
+    ga: 'Gaeilge',
+    gd: 'Gàidhlig',
+    gl: 'Galego',
+    he: 'עברית',
+    hi: 'हिन्दी',
+    hr: 'Hrvatski',
+    hu: 'Magyar',
+    hy: 'Հայերեն',
+    id: 'Bahasa Indonesia',
+    io: 'Ido',
+    is: 'Íslenska',
+    it: 'Italiano',
+    ja: '日本語',
+    ka: 'ქართული',
+    kab: 'Taqbaylit',
+    kk: 'Қазақша',
+    kmr: 'Kurmancî',
+    kn: 'ಕನ್ನಡ',
+    ko: '한국어',
+    ku: 'سۆرانی',
+    lt: 'Lietuvių',
+    lv: 'Latviešu',
+    mk: 'Македонски',
+    ml: 'മലയാളം',
+    mr: 'मराठी',
+    ms: 'Bahasa Melayu',
+    nl: 'Nederlands',
+    nn: 'Nynorsk',
+    no: 'Norsk',
+    oc: 'Occitan',
+    pl: 'Polski',
+    'pt-BR': 'Português (Brasil)',
+    'pt-PT': 'Português (Portugal)',
+    pt: 'Português',
+    ro: 'Română',
+    ru: 'Русский',
+    sa: 'संस्कृतम्',
+    sc: 'Sardu',
+    si: 'සිංහල',
+    sk: 'Slovenčina',
+    sl: 'Slovenščina',
+    sq: 'Shqip',
+    'sr-Latn': 'Srpski (latinica)',
+    sr: 'Српски',
+    sv: 'Svenska',
+    ta: 'தமிழ்',
+    te: 'తెలుగు',
+    th: 'ไทย',
+    tr: 'Türkçe',
+    uk: 'Українська',
+    ur: 'اُردُو',
+    vi: 'Tiếng Việt',
+    zgh: 'ⵜⴰⵎⴰⵣⵉⵖⵜ',
+    'zh-CN': '简体中文',
+    'zh-HK': '繁體中文（香港）',
+    'zh-TW': '繁體中文（臺灣）',
+    zh: '中文',
+  }.freeze
+
+  def human_locale(locale)
+    if locale == 'und'
+      I18n.t('generic.none')
+    else
+      HUMAN_LOCALES[locale.to_sym] || locale
+    end
+  end
+end
--- a/app/helpers/settings_helper.rb
+++ b/app/helpers/settings_helper.rb
@ -1,95 +1,8 @@
 # frozen_string_literal: true

 module SettingsHelper
-  HUMAN_LOCALES = {
-    af: 'Afrikaans',
-    ar: 'العربية',
-    ast: 'Asturianu',
-    bg: 'Български',
-    bn: 'বাংলা',
-    br: 'Breton',
-    ca: 'Català',
-    co: 'Corsu',
-    cs: 'Čeština',
-    cy: 'Cymraeg',
-    da: 'Dansk',
-    de: 'Deutsch',
-    el: 'Ελληνικά',
-    en: 'English',
-    eo: 'Esperanto',
-    'es-AR': 'Español (Argentina)',
-    'es-MX': 'Español (México)',
-    es: 'Español',
-    et: 'Eesti',
-    eu: 'Euskara',
-    fa: 'فارسی',
-    fi: 'Suomi',
-    fr: 'Français',
-    ga: 'Gaeilge',
-    gd: 'Gàidhlig',
-    gl: 'Galego',
-    he: 'עברית',
-    hi: 'हिन्दी',
-    hr: 'Hrvatski',
-    hu: 'Magyar',
-    hy: 'Հայերեն',
-    id: 'Bahasa Indonesia',
-    io: 'Ido',
-    is: 'Íslenska',
-    it: 'Italiano',
-    ja: '日本語',
-    ka: 'ქართული',
-    kab: 'Taqbaylit',
-    kk: 'Қазақша',
-    kmr: 'Kurmancî',
-    kn: 'ಕನ್ನಡ',
-    ko: '한국어',
-    ku: 'سۆرانی',
-    lt: 'Lietuvių',
-    lv: 'Latviešu',
-    mk: 'Македонски',
-    ml: 'മലയാളം',
-    mr: 'मराठी',
-    ms: 'Bahasa Melayu',
-    nl: 'Nederlands',
-    nn: 'Nynorsk',
-    no: 'Norsk',
-    oc: 'Occitan',
-    pl: 'Polski',
-    'pt-BR': 'Português (Brasil)',
-    'pt-PT': 'Português (Portugal)',
-    pt: 'Português',
-    ro: 'Română',
-    ru: 'Русский',
-    sa: 'संस्कृतम्',
-    sc: 'Sardu',
-    si: 'සිංහල',
-    sk: 'Slovenčina',
-    sl: 'Slovenščina',
-    sq: 'Shqip',
-    'sr-Latn': 'Srpski (latinica)',
-    sr: 'Српски',
-    sv: 'Svenska',
-    ta: 'தமிழ்',
-    te: 'తెలుగు',
-    th: 'ไทย',
-    tr: 'Türkçe',
-    uk: 'Українська',
-    ur: 'اُردُو',
-    vi: 'Tiếng Việt',
-    zgh: 'ⵜⴰⵎⴰⵣⵉⵖⵜ',
-    'zh-CN': '简体中文',
-    'zh-HK': '繁體中文（香港）',
-    'zh-TW': '繁體中文（臺灣）',
-    zh: '中文',
-  }.freeze
-
-  def human_locale(locale)
-    HUMAN_LOCALES[locale]
-  end
-
  def filterable_languages
-    LanguageDetector.instance.language_names.select(&HUMAN_LOCALES.method(:key?))
+    LanguageDetector.instance.language_names.select(&LanguagesHelper::HUMAN_LOCALES.method(:key?))
  end

  def hash_to_object(hash)
--- a/app/javascript/mastodon/components/admin/Counter.js
+++ b/app/javascript/mastodon/components/admin/Counter.js
@ -32,6 +32,7 @@ export default class Counter extends React.PureComponent {
    end_at: PropTypes.string.isRequired,
    label: PropTypes.string.isRequired,
    href: PropTypes.string,
+    params: PropTypes.object,
  };

  state = {
@ -40,9 +41,9 @@ export default class Counter extends React.PureComponent {
  };

  componentDidMount () {
-    const { measure, start_at, end_at } = this.props;
+    const { measure, start_at, end_at, params } = this.props;

-    api().post('/api/v1/admin/measures', { keys: [measure], start_at, end_at }).then(res => {
+    api().post('/api/v1/admin/measures', { keys: [measure], start_at, end_at, [measure]: params }).then(res => {
      this.setState({
        loading: false,
        data: res.data,
--- a/app/javascript/mastodon/components/admin/Dimension.js
+++ b/app/javascript/mastodon/components/admin/Dimension.js
@ -13,6 +13,7 @@ export default class Dimension extends React.PureComponent {
    end_at: PropTypes.string.isRequired,
    limit: PropTypes.number.isRequired,
    label: PropTypes.string.isRequired,
+    params: PropTypes.object,
  };

  state = {
@ -21,9 +22,9 @@ export default class Dimension extends React.PureComponent {
  };

  componentDidMount () {
-    const { start_at, end_at, dimension, limit } = this.props;
+    const { start_at, end_at, dimension, limit, params } = this.props;

-    api().post('/api/v1/admin/dimensions', { keys: [dimension], start_at, end_at, limit }).then(res => {
+    api().post('/api/v1/admin/dimensions', { keys: [dimension], start_at, end_at, limit, [dimension]: params }).then(res => {
      this.setState({
        loading: false,
        data: res.data,
--- a/app/javascript/mastodon/components/admin/Trends.js
+++ b/app/javascript/mastodon/components/admin/Trends.js
@ -19,7 +19,7 @@ export default class Trends extends React.PureComponent {
  componentDidMount () {
    const { limit } = this.props;

-    api().get('/api/v1/admin/trends', { params: { limit } }).then(res => {
+    api().get('/api/v1/admin/trends/tags', { params: { limit } }).then(res => {
      this.setState({
        loading: false,
        data: res.data,
--- a/app/javascript/styles/mastodon/accounts.scss
+++ b/app/javascript/styles/mastodon/accounts.scss
@ -325,3 +325,19 @@
    margin-top: 10px;
  }
 }
+
+.batch-table__row--muted .pending-account__header {
+  &,
+  a,
+  strong {
+    color: lighten($ui-base-color, 26%);
+  }
+}
+
+.batch-table__row--attention .pending-account__header {
+  &,
+  a,
+  strong {
+    color: $gold-star;
+  }
+}
--- a/app/javascript/styles/mastodon/dashboard.scss
+++ b/app/javascript/styles/mastodon/dashboard.scss
@ -100,6 +100,16 @@
      transition: all 200ms ease-out;
    }

+    &.positive {
+      background: lighten($ui-base-color, 4%);
+      color: $valid-value-color;
+    }
+
+    &.negative {
+      background: lighten($ui-base-color, 4%);
+      color: $error-value-color;
+    }
+
    span {
      flex: 1 1 auto;
    }
--- a/app/lib/activitypub/activity.rb
+++ b/app/lib/activitypub/activity.rb
@ -129,8 +129,6 @@ class ActivityPub::Activity
  end

  def crawl_links(status)
-    return if status.spoiler_text?
-
    # Spread out crawling randomly to avoid DDoSing the link
    LinkCrawlWorker.perform_in(rand(1..59).seconds, status.id)
  end
--- a/app/lib/activitypub/activity/announce.rb
+++ b/app/lib/activitypub/activity/announce.rb
@ -22,9 +22,8 @@ class ActivityPub::Activity::Announce < ActivityPub::Activity
        visibility: visibility_from_audience
      )

-      original_status.tags.each do |tag|
-        tag.use!(@account)
-      end
+      Trends.tags.register(@status)
+      Trends.links.register(@status)

      distribute(@status)
    end
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@ -164,9 +164,14 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
  def attach_tags(status)
    @tags.each do |tag|
      status.tags << tag
-      tag.use!(@account, status: status, at_time: status.created_at) if status.public_visibility?
+      tag.update(last_status_at: status.created_at) if tag.last_status_at.nil? || (tag.last_status_at < status.created_at && tag.last_status_at < 12.hours.ago)
    end

+    # If we're processing an old status, this may register tags as being used now
+    # as opposed to when the status was really published, but this is probably
+    # not a big deal
+    Trends.tags.register(status)
+
    @mentions.each do |mention|
      mention.status = status
      mention.save
--- a/app/lib/admin/metrics/dimension.rb
+++ b/app/lib/admin/metrics/dimension.rb
@ -7,9 +7,14 @@ class Admin::Metrics::Dimension
    servers: Admin::Metrics::Dimension::ServersDimension,
    space_usage: Admin::Metrics::Dimension::SpaceUsageDimension,
    software_versions: Admin::Metrics::Dimension::SoftwareVersionsDimension,
+    tag_servers: Admin::Metrics::Dimension::TagServersDimension,
+    tag_languages: Admin::Metrics::Dimension::TagLanguagesDimension,
  }.freeze

-  def self.retrieve(dimension_keys, start_at, end_at, limit)
-    Array(dimension_keys).map { |key| DIMENSIONS[key.to_sym]&.new(start_at, end_at, limit) }.compact
+  def self.retrieve(dimension_keys, start_at, end_at, limit, params)
+    Array(dimension_keys).map do |key|
+      klass = DIMENSIONS[key.to_sym]
+      klass&.new(start_at, end_at, limit, klass.with_params? ? params.require(key.to_sym) : nil)
+    end.compact
  end
 end
--- a/app/lib/admin/metrics/dimension/base_dimension.rb
+++ b/app/lib/admin/metrics/dimension/base_dimension.rb
@ -1,10 +1,15 @@
 # frozen_string_literal: true

 class Admin::Metrics::Dimension::BaseDimension
-  def initialize(start_at, end_at, limit)
+  def self.with_params?
+    false
+  end
+
+  def initialize(start_at, end_at, limit, params)
    @start_at = start_at&.to_datetime
    @end_at   = end_at&.to_datetime
    @limit    = limit&.to_i
+    @params   = params
  end

  def key
@ -26,6 +31,10 @@ class Admin::Metrics::Dimension::BaseDimension
  protected

  def time_period
-    (@start_at...@end_at)
+    (@start_at..@end_at)
+  end
+
+  def params
+    raise NotImplementedError
  end
 end
--- a/app/lib/admin/metrics/dimension/languages_dimension.rb
+++ b/app/lib/admin/metrics/dimension/languages_dimension.rb
@ -1,6 +1,8 @@
 # frozen_string_literal: true

 class Admin::Metrics::Dimension::LanguagesDimension < Admin::Metrics::Dimension::BaseDimension
+  include LanguagesHelper
+
  def key
    'languages'
  end
@ -18,6 +20,6 @@ class Admin::Metrics::Dimension::LanguagesDimension < Admin::Metrics::Dimension:

    rows = ActiveRecord::Base.connection.select_all(sql, nil, [[nil, @start_at], [nil, @end_at], [nil, @limit]])

-    rows.map { |row| { key: row['locale'], human_key: SettingsHelper::HUMAN_LOCALES[row['locale'].to_sym], value: row['value'].to_s } }
+    rows.map { |row| { key: row['locale'], human_key: human_locale(row['locale']), value: row['value'].to_s } }
  end
 end
--- a/app/lib/admin/metrics/dimension/tag_languages_dimension.rb
+++ b/app/lib/admin/metrics/dimension/tag_languages_dimension.rb
@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+class Admin::Metrics::Dimension::TagLanguagesDimension < Admin::Metrics::Dimension::BaseDimension
+  include LanguagesHelper
+
+  def self.with_params?
+    true
+  end
+
+  def key
+    'tag_languages'
+  end
+
+  def data
+    sql = <<-SQL.squish
+      SELECT COALESCE(statuses.language, 'und') AS language, count(*) AS value
+      FROM statuses
+      INNER JOIN statuses_tags ON statuses_tags.status_id = statuses.id
+      WHERE statuses_tags.tag_id = $1
+        AND statuses.id BETWEEN $2 AND $3
+      GROUP BY COALESCE(statuses.language, 'und')
+      ORDER BY count(*) DESC
+      LIMIT $4
+    SQL
+
+    rows = ActiveRecord::Base.connection.select_all(sql, nil, [[nil, params[:id]], [nil, Mastodon::Snowflake.id_at(@start_at, with_random: false)], [nil, Mastodon::Snowflake.id_at(@end_at, with_random: false)], [nil, @limit]])
+
+    rows.map { |row| { key: row['language'], human_key: human_locale(row['language']), value: row['value'].to_s } }
+  end
+
+  private
+
+  def params
+    @params.permit(:id)
+  end
+end
--- a/app/lib/admin/metrics/dimension/tag_servers_dimension.rb
+++ b/app/lib/admin/metrics/dimension/tag_servers_dimension.rb
@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+class Admin::Metrics::Dimension::TagServersDimension < Admin::Metrics::Dimension::BaseDimension
+  def self.with_params?
+    true
+  end
+
+  def key
+    'tag_servers'
+  end
+
+  def data
+    sql = <<-SQL.squish
+      SELECT accounts.domain, count(*) AS value
+      FROM statuses
+      INNER JOIN accounts ON accounts.id = statuses.account_id
+      INNER JOIN statuses_tags ON statuses_tags.status_id = statuses.id
+      WHERE statuses_tags.tag_id = $1
+        AND statuses.id BETWEEN $2 AND $3
+      GROUP BY accounts.domain
+      ORDER BY count(*) DESC
+      LIMIT $4
+    SQL
+
+    rows = ActiveRecord::Base.connection.select_all(sql, nil, [[nil, params[:id]], [nil, Mastodon::Snowflake.id_at(@start_at, with_random: false)], [nil, Mastodon::Snowflake.id_at(@end_at, with_random: false)], [nil, @limit]])
+
+    rows.map { |row| { key: row['domain'] || Rails.configuration.x.local_domain, human_key: row['domain'] || Rails.configuration.x.local_domain, value: row['value'].to_s } }
+  end
+
+  private
+
+  def params
+    @params.permit(:id)
+  end
+end
--- a/app/lib/admin/metrics/measure.rb
+++ b/app/lib/admin/metrics/measure.rb
@ -7,9 +7,15 @@ class Admin::Metrics::Measure
    interactions: Admin::Metrics::Measure::InteractionsMeasure,
    opened_reports: Admin::Metrics::Measure::OpenedReportsMeasure,
    resolved_reports: Admin::Metrics::Measure::ResolvedReportsMeasure,
+    tag_accounts: Admin::Metrics::Measure::TagAccountsMeasure,
+    tag_uses: Admin::Metrics::Measure::TagUsesMeasure,
+    tag_servers: Admin::Metrics::Measure::TagServersMeasure,
  }.freeze

-  def self.retrieve(measure_keys, start_at, end_at)
-    Array(measure_keys).map { |key| MEASURES[key.to_sym]&.new(start_at, end_at) }.compact
+  def self.retrieve(measure_keys, start_at, end_at, params)
+    Array(measure_keys).map do |key|
+      klass = MEASURES[key.to_sym]
+      klass&.new(start_at, end_at, klass.with_params? ? params.require(key.to_sym) : nil)
+    end.compact
  end
 end
--- a/app/lib/admin/metrics/measure/active_users_measure.rb
+++ b/app/lib/admin/metrics/measure/active_users_measure.rb
@ -24,10 +24,10 @@ class Admin::Metrics::Measure::ActiveUsersMeasure < Admin::Metrics::Measure::Bas
  end

  def time_period
-    (@start_at.to_date...@end_at.to_date)
+    (@start_at.to_date..@end_at.to_date)
  end

  def previous_time_period
-    ((@start_at.to_date - length_of_period)...(@end_at.to_date - length_of_period))
+    ((@start_at.to_date - length_of_period)..(@end_at.to_date - length_of_period))
  end
 end
--- a/app/lib/admin/metrics/measure/base_measure.rb
+++ b/app/lib/admin/metrics/measure/base_measure.rb
@ -1,9 +1,14 @@
 # frozen_string_literal: true

 class Admin::Metrics::Measure::BaseMeasure
-  def initialize(start_at, end_at)
+  def self.with_params?
+    false
+  end
+
+  def initialize(start_at, end_at, params)
    @start_at = start_at&.to_datetime
    @end_at   = end_at&.to_datetime
+    @params   = params
  end

  def key
@ -33,14 +38,18 @@ class Admin::Metrics::Measure::BaseMeasure
  protected

  def time_period
-    (@start_at...@end_at)
+    (@start_at..@end_at)
  end

  def previous_time_period
-    ((@start_at - length_of_period)...(@end_at - length_of_period))
+    ((@start_at - length_of_period)..(@end_at - length_of_period))
  end

  def length_of_period
    @length_of_period ||= @end_at - @start_at
  end
+
+  def params
+    raise NotImplementedError
+  end
 end
--- a/app/lib/admin/metrics/measure/interactions_measure.rb
+++ b/app/lib/admin/metrics/measure/interactions_measure.rb
@ -24,10 +24,10 @@ class Admin::Metrics::Measure::InteractionsMeasure < Admin::Metrics::Measure::Ba
  end

  def time_period
-    (@start_at.to_date...@end_at.to_date)
+    (@start_at.to_date..@end_at.to_date)
  end

  def previous_time_period
-    ((@start_at.to_date - length_of_period)...(@end_at.to_date - length_of_period))
+    ((@start_at.to_date - length_of_period)..(@end_at.to_date - length_of_period))
  end
 end
--- a/app/lib/admin/metrics/measure/tag_accounts_measure.rb
+++ b/app/lib/admin/metrics/measure/tag_accounts_measure.rb
@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class Admin::Metrics::Measure::TagAccountsMeasure < Admin::Metrics::Measure::BaseMeasure
+  def self.with_params?
+    true
+  end
+
+  def key
+    'tag_accounts'
+  end
+
+  def total
+    tag.history.aggregate(time_period).accounts
+  end
+
+  def previous_total
+    tag.history.aggregate(previous_time_period).accounts
+  end
+
+  def data
+    time_period.map { |date| { date: date.to_time(:utc).iso8601, value: tag.history.get(date).accounts.to_s } }
+  end
+
+  protected
+
+  def tag
+    @tag ||= Tag.find(params[:id])
+  end
+
+  def time_period
+    (@start_at.to_date..@end_at.to_date)
+  end
+
+  def previous_time_period
+    ((@start_at.to_date - length_of_period)..(@end_at.to_date - length_of_period))
+  end
+
+  def params
+    @params.permit(:id)
+  end
+end
--- a/app/lib/admin/metrics/measure/tag_servers_measure.rb
+++ b/app/lib/admin/metrics/measure/tag_servers_measure.rb
@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+class Admin::Metrics::Measure::TagServersMeasure < Admin::Metrics::Measure::BaseMeasure
+  def self.with_params?
+    true
+  end
+
+  def key
+    'tag_servers'
+  end
+
+  def total
+    tag.statuses.where('statuses.id BETWEEN ? AND ?', Mastodon::Snowflake.id_at(@start_at, with_random: false), Mastodon::Snowflake.id_at(@end_at, with_random: false)).joins(:account).count('distinct accounts.domain')
+  end
+
+  def previous_total
+    tag.statuses.where('statuses.id BETWEEN ? AND ?', Mastodon::Snowflake.id_at(@start_at - length_of_period, with_random: false), Mastodon::Snowflake.id_at(@end_at - length_of_period, with_random: false)).joins(:account).count('distinct accounts.domain')
+  end
+
+  def data
+    sql = <<-SQL.squish
+      SELECT axis.*, (
+        SELECT count(*) AS value
+        FROM statuses
+        WHERE statuses.id BETWEEN $1 AND $2
+          AND date_trunc('day', statuses.created_at)::date = axis.day
+      )
+      FROM (
+        SELECT generate_series(date_trunc('day', $3::timestamp)::date, date_trunc('day', $4::timestamp)::date, ('1 day')::interval) AS day
+      ) as axis
+    SQL
+
+    rows = ActiveRecord::Base.connection.select_all(sql, nil, [[nil, Mastodon::Snowflake.id_at(@start_at, with_random: false)], [nil, Mastodon::Snowflake.id_at(@end_at, with_random: false)], [nil, @start_at], [nil, @end_at]])
+
+    rows.map { |row| { date: row['day'], value: row['value'].to_s } }
+  end
+
+  protected
+
+  def tag
+    @tag ||= Tag.find(params[:id])
+  end
+
+  def params
+    @params.permit(:id)
+  end
+end
--- a/app/lib/admin/metrics/measure/tag_uses_measure.rb
+++ b/app/lib/admin/metrics/measure/tag_uses_measure.rb
@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class Admin::Metrics::Measure::TagUsesMeasure < Admin::Metrics::Measure::BaseMeasure
+  def self.with_params?
+    true
+  end
+
+  def key
+    'tag_uses'
+  end
+
+  def total
+    tag.history.aggregate(time_period).uses
+  end
+
+  def previous_total
+    tag.history.aggregate(previous_time_period).uses
+  end
+
+  def data
+    time_period.map { |date| { date: date.to_time(:utc).iso8601, value: tag.history.get(date).uses.to_s } }
+  end
+
+  protected
+
+  def tag
+    @tag ||= Tag.find(params[:id])
+  end
+
+  def time_period
+    (@start_at.to_date..@end_at.to_date)
+  end
+
+  def previous_time_period
+    ((@start_at.to_date - length_of_period)..(@end_at.to_date - length_of_period))
+  end
+
+  def params
+    @params.permit(:id)
+  end
+end
--- a/app/lib/link_details_extractor.rb
+++ b/app/lib/link_details_extractor.rb
@ -4,6 +4,11 @@ class LinkDetailsExtractor
  include ActionView::Helpers::TagHelper

  class StructuredData
+    SUPPORTED_TYPES = %w(
+      NewsArticle
+      WebPage
+    ).freeze
+
    def initialize(data)
      @data = data
    end
@ -16,6 +21,14 @@ class LinkDetailsExtractor
      json['description']
    end

+    def language
+      json['inLanguage']
+    end
+
+    def type
+      json['@type']
+    end
+
    def image
      obj = first_of_value(json['image'])

@ -44,6 +57,10 @@ class LinkDetailsExtractor
      publisher['name']
    end

+    def publisher_logo
+      publisher.dig('logo', 'url')
+    end
+
    private

    def author
@ -58,8 +75,12 @@ class LinkDetailsExtractor
      arr.is_a?(Array) ? arr.first : arr
    end

+    def root_array(root)
+      root.is_a?(Array) ? root : [root]
+    end
+
    def json
-      @json ||= first_of_value(Oj.load(@data))
+      @json ||= root_array(Oj.load(@data)).find { |obj| SUPPORTED_TYPES.include?(obj['@type']) } || {}
    end
  end

@ -75,6 +96,7 @@ class LinkDetailsExtractor
      description: description || '',
      image_remote_url: image,
      type: type,
+      link_type: link_type,
      width: width || 0,
      height: height || 0,
      html: html || '',
@ -83,6 +105,7 @@ class LinkDetailsExtractor
      author_name: author_name || '',
      author_url: author_url || '',
      embed_url: embed_url || '',
+      language: language,
    }
  end

@ -90,6 +113,14 @@ class LinkDetailsExtractor
    player_url.present? ? :video : :link
  end

+  def link_type
+    if structured_data&.type == 'NewsArticle' || opengraph_tag('og:type') == 'article'
+      :article
+    else
+      :unknown
+    end
+  end
+
  def html
    player_url.present? ? content_tag(:iframe, nil, src: player_url, width: width, height: height, allowtransparency: 'true', scrolling: 'no', frameborder: '0') : nil
  end
@ -138,6 +169,14 @@ class LinkDetailsExtractor
    valid_url_or_nil(opengraph_tag('twitter:player:stream'))
  end

+  def language
+    valid_locale_or_nil(structured_data&.language || opengraph_tag('og:locale') || document.xpath('//html').map { |element| element['lang'] }.first)
+  end
+
+  def icon
+    valid_url_or_nil(structured_data&.publisher_icon || link_tag('apple-touch-icon') || link_tag('shortcut icon'))
+  end
+
  private

  def player_url
@ -162,6 +201,14 @@ class LinkDetailsExtractor
    nil
  end

+  def valid_locale_or_nil(str)
+    return nil if str.blank?
+
+    code,  = str.split(/_-/) # Strip out the region from e.g. en_US or ja-JA
+    locale = ISO_639.find(code)
+    locale&.alpha2
+  end
+
  def link_tag(name)
    document.xpath("//link[@rel=\"#{name}\"]").map { |link| link['href'] }.first
  end
--- a/app/mailers/admin_mailer.rb
+++ b/app/mailers/admin_mailer.rb
@ -25,13 +25,25 @@ class AdminMailer < ApplicationMailer
    end
  end

-  def new_trending_tag(recipient, tag)
-    @tag      = tag
-    @me       = recipient
-    @instance = Rails.configuration.x.local_domain
+  def new_trending_tags(recipient, tags)
+    @tags                = tags
+    @me                  = recipient
+    @instance            = Rails.configuration.x.local_domain
+    @lowest_trending_tag = Trends.tags.get(true, Trends::Tags::REVIEW_THRESHOLD).last

    locale_for_account(@me) do
-      mail to: @me.user_email, subject: I18n.t('admin_mailer.new_trending_tag.subject', instance: @instance, name: @tag.name)
+      mail to: @me.user_email, subject: I18n.t('admin_mailer.new_trending_tags.subject', instance: @instance)
+    end
+  end
+
+  def new_trending_links(recipient, links)
+    @links                = links
+    @me                   = recipient
+    @instance             = Rails.configuration.x.local_domain
+    @lowest_trending_link = Trends.links.get(true, Trends::Links::REVIEW_THRESHOLD).last
+
+    locale_for_account(@me) do
+      mail to: @me.user_email, subject: I18n.t('admin_mailer.new_trending_links.subject', instance: @instance)
    end
  end
 end
--- a/app/models/account_statuses_cleanup_policy.rb
+++ b/app/models/account_statuses_cleanup_policy.rb
@ -4,8 +4,8 @@
 #
 # Table name: account_statuses_cleanup_policies
 #
-#  id                 :bigint           not null, primary key
-#  account_id         :bigint           not null
+#  id                 :bigint(8)        not null, primary key
+#  account_id         :bigint(8)        not null
 #  enabled            :boolean          default(TRUE), not null
 #  min_status_age     :integer          default(1209600), not null
 #  keep_direct        :boolean          default(TRUE), not null
--- a/app/models/form/preview_card_batch.rb
+++ b/app/models/form/preview_card_batch.rb
@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+class Form::PreviewCardBatch
+  include ActiveModel::Model
+  include Authorization
+
+  attr_accessor :preview_card_ids, :action, :current_account, :precision
+
+  def save
+    case action
+    when 'approve'
+      approve!
+    when 'approve_all'
+      approve_all!
+    when 'reject'
+      reject!
+    when 'reject_all'
+      reject_all!
+    end
+  end
+
+  private
+
+  def preview_cards
+    @preview_cards ||= PreviewCard.where(id: preview_card_ids)
+  end
+
+  def preview_card_providers
+    @preview_card_providers ||= preview_cards.map(&:domain).uniq.map { |domain| PreviewCardProvider.matching_domain(domain) || PreviewCardProvider.new(domain: domain) }
+  end
+
+  def approve!
+    preview_cards.each { |preview_card| authorize(preview_card, :update?) }
+    preview_cards.update_all(trendable: true)
+  end
+
+  def approve_all!
+    preview_card_providers.each do |provider|
+      authorize(provider, :update?)
+      provider.update(trendable: true, reviewed_at: action_time)
+    end
+
+    # Reset any individual overrides
+    preview_cards.update_all(trendable: nil)
+  end
+
+  def reject!
+    preview_cards.each { |preview_card| authorize(preview_card, :update?) }
+    preview_cards.update_all(trendable: false)
+  end
+
+  def reject_all!
+    preview_card_providers.each do |provider|
+      authorize(provider, :update?)
+      provider.update(trendable: false, reviewed_at: action_time)
+    end
+
+    # Reset any individual overrides
+    preview_cards.update_all(trendable: nil)
+  end
+
+  def action_time
+    @action_time ||= Time.now.utc
+  end
+end
--- a/app/models/form/preview_card_provider_batch.rb
+++ b/app/models/form/preview_card_provider_batch.rb
@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+class Form::PreviewCardProviderBatch
+  include ActiveModel::Model
+  include Authorization
+
+  attr_accessor :preview_card_provider_ids, :action, :current_account
+
+  def save
+    case action
+    when 'approve'
+      approve!
+    when 'reject'
+      reject!
+    end
+  end
+
+  private
+
+  def preview_card_providers
+    PreviewCardProvider.where(id: preview_card_provider_ids)
+  end
+
+  def approve!
+    preview_card_providers.each { |provider| authorize(provider, :update?) }
+    preview_card_providers.update_all(trendable: true, reviewed_at: Time.now.utc)
+  end
+
+  def reject!
+    preview_card_providers.each { |provider| authorize(provider, :update?) }
+    preview_card_providers.update_all(trendable: false, reviewed_at: Time.now.utc)
+  end
+end
--- a/app/models/form/tag_batch.rb
+++ b/app/models/form/tag_batch.rb
@ -23,11 +23,15 @@ class Form::TagBatch

  def approve!
    tags.each { |tag| authorize(tag, :update?) }
-    tags.update_all(trendable: true, reviewed_at: Time.now.utc)
+    tags.update_all(trendable: true, reviewed_at: action_time)
  end

  def reject!
    tags.each { |tag| authorize(tag, :update?) }
-    tags.update_all(trendable: false, reviewed_at: Time.now.utc)
+    tags.update_all(trendable: false, reviewed_at: action_time)
+  end
+
+  def action_time
+    @action_time ||= Time.now.utc
  end
 end
--- a/app/models/preview_card.rb
+++ b/app/models/preview_card.rb
@ -24,6 +24,11 @@
 #  embed_url                    :string           default(""), not null
 #  image_storage_schema_version :integer
 #  blurhash                     :string
+#  language                     :string
+#  max_score                    :float
+#  max_score_at                 :datetime
+#  trendable                    :boolean
+#  link_type                    :integer
 #

 class PreviewCard < ApplicationRecord
@ -40,6 +45,7 @@ class PreviewCard < ApplicationRecord
  self.inheritance_column = false

  enum type: [:link, :photo, :video, :rich]
+  enum link_type: [:unknown, :article]

  has_and_belongs_to_many :statuses

@ -54,6 +60,32 @@ class PreviewCard < ApplicationRecord

  before_save :extract_dimensions, if: :link?

+  def appropriate_for_trends?
+    link? && article? && title.present? && description.present? && image.present? && provider_name.present?
+  end
+
+  def domain
+    @domain ||= Addressable::URI.parse(url).normalized_host
+  end
+
+  def provider
+    @provider ||= PreviewCardProvider.matching_domain(domain)
+  end
+
+  def trendable?
+    if attributes['trendable'].nil?
+      provider&.trendable?
+    else
+      attributes['trendable']
+    end
+  end
+
+  def requires_review_notification?
+    attributes['trendable'].nil? && (provider.nil? || provider.requires_review_notification?)
+  end
+
+  attr_writer :provider
+
  def local?
    false
  end
@ -69,11 +101,14 @@ class PreviewCard < ApplicationRecord
    save!
  end

+  def history
+    @history ||= Trends::History.new('links', id)
+  end
+
  class << self
    private

-    # rubocop:disable Naming/MethodParameterName
-    def image_styles(f)
+    def image_styles(file)
      styles = {
        original: {
          geometry: '400x400>',
@ -83,10 +118,9 @@ class PreviewCard < ApplicationRecord
        },
      }

-      styles[:original][:format] = 'jpg' if f.instance.image_content_type == 'image/gif'
+      styles[:original][:format] = 'jpg' if file.instance.image_content_type == 'image/gif'
      styles
    end
-    # rubocop:enable Naming/MethodParameterName
  end

  private
--- a/app/models/preview_card_filter.rb
+++ b/app/models/preview_card_filter.rb
@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+class PreviewCardFilter
+  KEYS = %i(
+    trending
+  ).freeze
+
+  attr_reader :params
+
+  def initialize(params)
+    @params = params
+  end
+
+  def results
+    scope = PreviewCard.unscoped
+
+    params.each do |key, value|
+      next if key.to_s == 'page'
+
+      scope.merge!(scope_for(key, value.to_s.strip)) if value.present?
+    end
+
+    scope
+  end
+
+  private
+
+  def scope_for(key, value)
+    case key.to_s
+    when 'trending'
+      trending_scope(value)
+    else
+      raise "Unknown filter: #{key}"
+    end
+  end
+
+  def trending_scope(value)
+    ids = begin
+      case value.to_s
+      when 'allowed'
+        Trends.links.currently_trending_ids(true, -1)
+      else
+        Trends.links.currently_trending_ids(false, -1)
+      end
+    end
+
+    if ids.empty?
+      PreviewCard.none
+    else
+      PreviewCard.joins("join unnest(array[#{ids.map(&:to_i).join(',')}]::integer[]) with ordinality as x (id, ordering) on preview_cards.id = x.id").order('x.ordering')
+    end
+  end
+end
--- a/app/models/preview_card_provider.rb
+++ b/app/models/preview_card_provider.rb
@ -0,0 +1,57 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: preview_card_providers
+#
+#  id                  :bigint(8)        not null, primary key
+#  domain              :string           default(""), not null
+#  icon_file_name      :string
+#  icon_content_type   :string
+#  icon_file_size      :bigint(8)
+#  icon_updated_at     :datetime
+#  trendable           :boolean
+#  reviewed_at         :datetime
+#  requested_review_at :datetime
+#  created_at          :datetime         not null
+#  updated_at          :datetime         not null
+#
+
+class PreviewCardProvider < ApplicationRecord
+  include DomainNormalizable
+  include Attachmentable
+
+  ICON_MIME_TYPES = %w(image/x-icon image/vnd.microsoft.icon image/png).freeze
+  LIMIT = 1.megabyte
+
+  validates :domain, presence: true, uniqueness: true, domain: true
+
+  has_attached_file :icon, styles: { static: { format: 'png', convert_options: '-coalesce -strip' } }, validate_media_type: false
+  validates_attachment :icon, content_type: { content_type: ICON_MIME_TYPES }, size: { less_than: LIMIT }
+  remotable_attachment :icon, LIMIT
+
+  scope :trendable, -> { where(trendable: true) }
+  scope :not_trendable, -> { where(trendable: false) }
+  scope :reviewed, -> { where.not(reviewed_at: nil) }
+  scope :pending_review, -> { where(reviewed_at: nil) }
+
+  def requires_review?
+    reviewed_at.nil?
+  end
+
+  def reviewed?
+    reviewed_at.present?
+  end
+
+  def requested_review?
+    requested_review_at.present?
+  end
+
+  def requires_review_notification?
+    requires_review? && !requested_review?
+  end
+
+  def self.matching_domain(domain)
+    segments = domain.split('.')
+    where(domain: segments.map.with_index { |_, i| segments[i..-1].join('.') }).order(Arel.sql('char_length(domain) desc')).first
+  end
+end
--- a/app/models/preview_card_provider_filter.rb
+++ b/app/models/preview_card_provider_filter.rb
@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+class PreviewCardProviderFilter
+  KEYS = %i(
+    status
+  ).freeze
+
+  attr_reader :params
+
+  def initialize(params)
+    @params = params
+  end
+
+  def results
+    scope = PreviewCardProvider.unscoped
+
+    params.each do |key, value|
+      next if key.to_s == 'page'
+
+      scope.merge!(scope_for(key, value.to_s.strip)) if value.present?
+    end
+
+    scope.order(domain: :asc)
+  end
+
+  private
+
+  def scope_for(key, value)
+    case key.to_s
+    when 'status'
+      status_scope(value)
+    else
+      raise "Unknown filter: #{key}"
+    end
+  end
+
+  def status_scope(value)
+    case value.to_s
+    when 'approved'
+      PreviewCardProvider.trendable
+    when 'rejected'
+      PreviewCardProvider.not_trendable
+    when 'pending_review'
+      PreviewCardProvider.pending_review
+    else
+      raise "Unknown status: #{value}"
+    end
+  end
+end
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@ -36,6 +36,7 @@ class Tag < ApplicationRecord
  scope :usable, -> { where(usable: [true, nil]) }
  scope :listable, -> { where(listable: [true, nil]) }
  scope :trendable, -> { Setting.trendable_by_default ? where(trendable: [true, nil]) : where(trendable: true) }
+  scope :not_trendable, -> { where(trendable: false) }
  scope :recently_used, ->(account) { joins(:statuses).where(statuses: { id: account.statuses.select(:id).limit(1000) }).group(:id).order(Arel.sql('count(*) desc')) }
  scope :matches_name, ->(term) { where(arel_table[:name].lower.matches(arel_table.lower("#{sanitize_sql_like(Tag.normalize(term))}%"), nil, true)) } # Search with case-sensitive to use B-tree index

@ -75,28 +76,12 @@ class Tag < ApplicationRecord
    requested_review_at.present?
  end

-  def use!(account, status: nil, at_time: Time.now.utc)
-    TrendingTags.record_use!(self, account, status: status, at_time: at_time)
-  end
-
-  def trending?
-    TrendingTags.trending?(self)
+  def requires_review_notification?
+    requires_review? && !requested_review?
  end

  def history
-    days = []
-
-    7.times do |i|
-      day = i.days.ago.beginning_of_day.to_i
-
-      days << {
-        day: day.to_s,
-        uses: Redis.current.get("activity:tags:#{id}:#{day}") || '0',
-        accounts: Redis.current.pfcount("activity:tags:#{id}:#{day}:accounts").to_s,
-      }
-    end
-
-    days
+    @history ||= Trends::History.new('tags', id)
  end

  class << self
--- a/app/models/tag_filter.rb
+++ b/app/models/tag_filter.rb
@ -2,13 +2,8 @@

 class TagFilter
  KEYS = %i(
-    directory
-    reviewed
-    unreviewed
-    pending_review
-    popular
-    active
-    name
+    trending
+    status
  ).freeze

  attr_reader :params
@ -18,7 +13,13 @@ class TagFilter
  end

  def results
-    scope = Tag.unscoped
+    scope = begin
+      if params[:status] == 'pending_review'
+        Tag.unscoped
+      else
+        trending_scope
+      end
+    end

    params.each do |key, value|
      next if key.to_s == 'page'
@ -26,27 +27,40 @@ class TagFilter
      scope.merge!(scope_for(key, value.to_s.strip)) if value.present?
    end

-    scope.order(id: :desc)
+    scope
  end

  private

  def scope_for(key, value)
    case key.to_s
-    when 'reviewed'
-      Tag.reviewed.order(reviewed_at: :desc)
-    when 'unreviewed'
-      Tag.unreviewed
-    when 'pending_review'
-      Tag.pending_review.order(requested_review_at: :desc)
-    when 'popular'
-      Tag.order('max_score DESC NULLS LAST')
-    when 'active'
-      Tag.order('last_status_at DESC NULLS LAST')
-    when 'name'
-      Tag.matches_name(value)
+    when 'status'
+      status_scope(value)
    else
      raise "Unknown filter: #{key}"
    end
  end
+
+  def trending_scope
+    ids = Trends.tags.currently_trending_ids(false, -1)
+
+    if ids.empty?
+      Tag.none
+    else
+      Tag.joins("join unnest(array[#{ids.map(&:to_i).join(',')}]::integer[]) with ordinality as x (id, ordering) on tags.id = x.id").order('x.ordering')
+    end
+  end
+
+  def status_scope(value)
+    case value.to_s
+    when 'approved'
+      Tag.trendable
+    when 'rejected'
+      Tag.not_trendable
+    when 'pending_review'
+      Tag.pending_review
+    else
+      raise "Unknown status: #{value}"
+    end
+  end
 end
--- a/app/models/trending_tags.rb
+++ b/app/models/trending_tags.rb
@ -1,128 +0,0 @@
-# frozen_string_literal: true
-
-class TrendingTags
-  KEY                  = 'trending_tags'
-  EXPIRE_HISTORY_AFTER = 7.days.seconds
-  EXPIRE_TRENDS_AFTER  = 1.day.seconds
-  THRESHOLD            = 5
-  LIMIT                = 10
-  REVIEW_THRESHOLD     = 3
-  MAX_SCORE_COOLDOWN   = 2.days.freeze
-  MAX_SCORE_HALFLIFE   = 2.hours.freeze
-
-  class << self
-    include Redisable
-
-    def record_use!(tag, account, status: nil, at_time: Time.now.utc)
-      return unless tag.usable? && !account.silenced?
-
-      # Even if a tag is not allowed to trend, we still need to
-      # record the stats since they can be displayed in other places
-      increment_historical_use!(tag.id, at_time)
-      increment_unique_use!(tag.id, account.id, at_time)
-      increment_use!(tag.id, at_time)
-
-      # Only update when the tag was last used once every 12 hours
-      # and only if a status is given (lets use ignore reblogs)
-      tag.update(last_status_at: at_time) if status.present? && (tag.last_status_at.nil? || (tag.last_status_at < at_time && tag.last_status_at < 12.hours.ago))
-    end
-
-    def update!(at_time = Time.now.utc)
-      tag_ids = redis.smembers("#{KEY}:used:#{at_time.beginning_of_day.to_i}") + redis.zrange(KEY, 0, -1)
-      tags    = Tag.trendable.where(id: tag_ids.uniq)
-
-      # First pass to calculate scores and update the set
-
-      tags.each do |tag|
-        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
-        max_time  = tag.max_score_at
-        max_score = tag.max_score
-        max_score = 0 if max_time.nil? || max_time < (at_time - MAX_SCORE_COOLDOWN)
-
-        score = begin
-          if expected > observed || observed < THRESHOLD
-            0
-          else
-            ((observed - expected)**2) / expected
-          end
-        end
-
-        if score > max_score
-          max_score = score
-          max_time  = at_time
-
-          # Not interested in triggering any callbacks for this
-          tag.update_columns(max_score: max_score, max_score_at: max_time)
-        end
-
-        decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / MAX_SCORE_HALFLIFE.to_f))
-
-        if decaying_score.zero?
-          redis.zrem(KEY, tag.id)
-        else
-          redis.zadd(KEY, decaying_score, tag.id)
-        end
-      end
-
-      users_for_review = User.staff.includes(:account).to_a.select(&:allows_trending_tag_emails?)
-
-      # Second pass to notify about previously unreviewed trends
-
-      tags.each do |tag|
-        current_rank              = redis.zrevrank(KEY, tag.id)
-        needs_review_notification = tag.requires_review? && !tag.requested_review?
-        rank_passes_threshold     = current_rank.present? && current_rank <= REVIEW_THRESHOLD
-
-        next unless !tag.trendable? && rank_passes_threshold && needs_review_notification
-
-        tag.touch(:requested_review_at)
-
-        users_for_review.each do |user|
-          AdminMailer.new_trending_tag(user.account, tag).deliver_later!
-        end
-      end
-
-      # Trim older items
-
-      redis.zremrangebyrank(KEY, 0, -(LIMIT + 1))
-      redis.zremrangebyscore(KEY, '(0.3', '-inf')
-    end
-
-    def get(limit, filtered: true)
-      tag_ids = redis.zrevrange(KEY, 0, LIMIT - 1).map(&:to_i)
-
-      tags = Tag.where(id: tag_ids)
-      tags = tags.trendable if filtered
-      tags = tags.index_by(&:id)
-
-      tag_ids.map { |tag_id| tags[tag_id] }.compact.take(limit)
-    end
-
-    def trending?(tag)
-      rank = redis.zrevrank(KEY, tag.id)
-      rank.present? && rank < LIMIT
-    end
-
-    private
-
-    def increment_historical_use!(tag_id, at_time)
-      key = "activity:tags:#{tag_id}:#{at_time.beginning_of_day.to_i}"
-      redis.incrby(key, 1)
-      redis.expire(key, EXPIRE_HISTORY_AFTER)
-    end
-
-    def increment_unique_use!(tag_id, account_id, at_time)
-      key = "activity:tags:#{tag_id}:#{at_time.beginning_of_day.to_i}:accounts"
-      redis.pfadd(key, account_id)
-      redis.expire(key, EXPIRE_HISTORY_AFTER)
-    end
-
-    def increment_use!(tag_id, at_time)
-      key = "#{KEY}:used:#{at_time.beginning_of_day.to_i}"
-      redis.sadd(key, tag_id)
-      redis.expire(key, EXPIRE_HISTORY_AFTER)
-    end
-  end
-end
--- a/app/models/trends.rb
+++ b/app/models/trends.rb
@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module Trends
+  def self.table_name_prefix
+    'trends_'
+  end
+
+  def self.links
+    @links ||= Trends::Links.new
+  end
+
+  def self.tags
+    @tags ||= Trends::Tags.new
+  end
+
+  def self.refresh!
+    [links, tags].each(&:refresh)
+  end
+
+  def self.request_review!
+    [links, tags].each(&:request_review) if enabled?
+  end
+
+  def self.enabled?
+    Setting.trends
+  end
+end
--- a/app/models/trends/base.rb
+++ b/app/models/trends/base.rb
@ -0,0 +1,80 @@
+# frozen_string_literal: true
+
+class Trends::Base
+  include Redisable
+
+  class_attribute :default_options
+
+  attr_reader :options
+
+  # @param [Hash] options
+  # @option options [Integer] :threshold Minimum amount of uses by unique accounts to begin calculating the score
+  # @option options [Integer] :review_threshold Minimum rank (lower = better) before requesting a review
+  # @option options [ActiveSupport::Duration] :max_score_cooldown For this amount of time, the peak score (if bigger than current score) is decayed-from
+  # @option options [ActiveSupport::Duration] :max_score_halflife How quickly a peak score decays
+  def initialize(options = {})
+    @options = self.class.default_options.merge(options)
+  end
+
+  def register(_status)
+    raise NotImplementedError
+  end
+
+  def add(*)
+    raise NotImplementedError
+  end
+
+  def refresh(*)
+    raise NotImplementedError
+  end
+
+  def request_review
+    raise NotImplementedError
+  end
+
+  def get(*)
+    raise NotImplementedError
+  end
+
+  def score(id)
+    redis.zscore("#{key_prefix}:all", id) || 0
+  end
+
+  def rank(id)
+    redis.zrevrank("#{key_prefix}:allowed", id)
+  end
+
+  def currently_trending_ids(allowed, limit)
+    redis.zrevrange(allowed ? "#{key_prefix}:allowed" : "#{key_prefix}:all", 0, limit.positive? ? limit - 1 : limit).map(&:to_i)
+  end
+
+  protected
+
+  def key_prefix
+    raise NotImplementedError
+  end
+
+  def recently_used_ids(at_time = Time.now.utc)
+    redis.smembers(used_key(at_time)).map(&:to_i)
+  end
+
+  def record_used_id(id, at_time = Time.now.utc)
+    redis.sadd(used_key(at_time), id)
+    redis.expire(used_key(at_time), 1.day.seconds)
+  end
+
+  def trim_older_items
+    redis.zremrangebyscore("#{key_prefix}:all", '-inf', '(1')
+    redis.zremrangebyscore("#{key_prefix}:allowed", '-inf', '(1')
+  end
+
+  def score_at_rank(rank)
+    redis.zrevrange("#{key_prefix}:allowed", 0, rank, with_scores: true).last&.last || 0
+  end
+
+  private
+
+  def used_key(at_time)
+    "#{key_prefix}:used:#{at_time.beginning_of_day.to_i}"
+  end
+end
--- a/app/models/trends/history.rb
+++ b/app/models/trends/history.rb
@ -0,0 +1,98 @@
+# frozen_string_literal: true
+
+class Trends::History
+  include Enumerable
+
+  class Aggregate
+    include Redisable
+
+    def initialize(prefix, id, date_range)
+      @days = date_range.map { |date| Day.new(prefix, id, date.to_time(:utc)) }
+    end
+
+    def uses
+      redis.mget(*@days.map { |day| day.key_for(:uses) }).map(&:to_i).sum
+    end
+
+    def accounts
+      redis.pfcount(*@days.map { |day| day.key_for(:accounts) })
+    end
+  end
+
+  class Day
+    include Redisable
+
+    EXPIRE_AFTER = 14.days.seconds
+
+    def initialize(prefix, id, day)
+      @prefix = prefix
+      @id     = id
+      @day    = day.beginning_of_day
+    end
+
+    attr_reader :day
+
+    def accounts
+      redis.pfcount(key_for(:accounts))
+    end
+
+    def uses
+      redis.get(key_for(:uses))&.to_i || 0
+    end
+
+    def add(account_id)
+      redis.pipelined do
+        redis.incrby(key_for(:uses), 1)
+        redis.pfadd(key_for(:accounts), account_id)
+        redis.expire(key_for(:uses), EXPIRE_AFTER)
+        redis.expire(key_for(:accounts), EXPIRE_AFTER)
+      end
+    end
+
+    def as_json
+      { day: day.to_i.to_s, accounts: accounts.to_s, uses: uses.to_s }
+    end
+
+    def key_for(suffix)
+      case suffix
+      when :accounts
+        "#{key_prefix}:#{suffix}"
+      when :uses
+        key_prefix
+      end
+    end
+
+    def key_prefix
+      "activity:#{@prefix}:#{@id}:#{day.to_i}"
+    end
+  end
+
+  def initialize(prefix, id)
+    @prefix = prefix
+    @id     = id
+  end
+
+  def get(date)
+    Day.new(@prefix, @id, date)
+  end
+
+  def add(account_id, at_time = Time.now.utc)
+    Day.new(@prefix, @id, at_time).add(account_id)
+  end
+
+  def aggregate(date_range)
+    Aggregate.new(@prefix, @id, date_range)
+  end
+
+  def each(&block)
+    if block_given?
+      (0...7).map { |i| block.call(get(i.days.ago)) }
+    else
+      to_enum(:each)
+    end
+  end
+
+  def as_json(*)
+    map(&:as_json)
+  end
+end
--- a/app/models/trends/links.rb
+++ b/app/models/trends/links.rb
@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+class Trends::Links < Trends::Base
+  PREFIX = 'trending_links'
+
+  self.default_options = {
+    threshold: 15,
+    review_threshold: 10,
+    max_score_cooldown: 2.days.freeze,
+    max_score_halflife: 8.hours.freeze,
+  }
+
+  def register(status, at_time = Time.now.utc)
+    original_status = status.reblog? ? status.reblog : status
+
+    return unless original_status.public_visibility? && status.public_visibility? &&
+                  !original_status.account.silenced? && !status.account.silenced? &&
+                  !original_status.spoiler_text?
+
+    original_status.preview_cards.each do |preview_card|
+      add(preview_card, status.account_id, at_time) if preview_card.appropriate_for_trends?
+    end
+  end
+
+  def add(preview_card, account_id, at_time = Time.now.utc)
+    preview_card.history.add(account_id, at_time)
+    record_used_id(preview_card.id, at_time)
+  end
+
+  def get(allowed, limit)
+    preview_card_ids = currently_trending_ids(allowed, limit)
+    preview_cards = PreviewCard.where(id: preview_card_ids).index_by(&:id)
+    preview_card_ids.map { |id| preview_cards[id] }.compact
+  end
+
+  def refresh(at_time = Time.now.utc)
+    preview_cards = PreviewCard.where(id: (recently_used_ids(at_time) + currently_trending_ids(false, -1)).uniq)
+    calculate_scores(preview_cards, at_time)
+    trim_older_items
+  end
+
+  def request_review
+    preview_cards = PreviewCard.where(id: currently_trending_ids(false, -1))
+
+    preview_cards_requiring_review = preview_cards.filter_map do |preview_card|
+      next unless would_be_trending?(preview_card.id) && !preview_card.trendable? && preview_card.requires_review_notification?
+
+      if preview_card.provider.nil?
+        preview_card.provider = PreviewCardProvider.create(domain: preview_card.domain, requested_review_at: Time.now.utc)
+      else
+        preview_card.provider.touch(:requested_review_at)
+      end
+
+      preview_card
+    end
+
+    return if preview_cards_requiring_review.empty?
+
+    User.staff.includes(:account).find_each do |user|
+      AdminMailer.new_trending_links(user.account, preview_cards_requiring_review).deliver_later! if user.allows_trending_tag_emails?
+    end
+  end
+
+  protected
+
+  def key_prefix
+    PREFIX
+  end
+
+  private
+
+  def calculate_scores(preview_cards, at_time)
+    preview_cards.each do |preview_card|
+      expected  = preview_card.history.get(at_time - 1.day).accounts.to_f
+      expected  = 1.0 if expected.zero?
+      observed  = preview_card.history.get(at_time).accounts.to_f
+      max_time  = preview_card.max_score_at
+      max_score = preview_card.max_score
+      max_score = 0 if max_time.nil? || max_time < (at_time - options[:max_score_cooldown])
+
+      score = begin
+        if expected > observed || observed < options[:threshold]
+          0
+        else
+          ((observed - expected)**2) / expected
+        end
+      end
+
+      if score > max_score
+        max_score = score
+        max_time  = at_time
+
+        # Not interested in triggering any callbacks for this
+        preview_card.update_columns(max_score: max_score, max_score_at: max_time)
+      end
+
+      decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / options[:max_score_halflife].to_f))
+
+      if decaying_score.zero?
+        redis.zrem("#{PREFIX}:all", preview_card.id)
+        redis.zrem("#{PREFIX}:allowed", preview_card.id)
+      else
+        redis.zadd("#{PREFIX}:all", decaying_score, preview_card.id)
+
+        if preview_card.trendable?
+          redis.zadd("#{PREFIX}:allowed", decaying_score, preview_card.id)
+        else
+          redis.zrem("#{PREFIX}:allowed", preview_card.id)
+        end
+      end
+    end
+  end
+
+  def would_be_trending?(id)
+    score(id) > score_at_rank(options[:review_threshold] - 1)
+  end
+end
--- a/app/models/trends/tags.rb
+++ b/app/models/trends/tags.rb
@ -0,0 +1,111 @@
+# frozen_string_literal: true
+
+class Trends::Tags < Trends::Base
+  PREFIX = 'trending_tags'
+
+  self.default_options = {
+    threshold: 15,
+    review_threshold: 10,
+    max_score_cooldown: 2.days.freeze,
+    max_score_halflife: 4.hours.freeze,
+  }
+
+  def register(status, at_time = Time.now.utc)
+    original_status = status.reblog? ? status.reblog : status
+
+    return unless original_status.public_visibility? && status.public_visibility? &&
+                  !original_status.account.silenced? && !status.account.silenced?
+
+    original_status.tags.each do |tag|
+      add(tag, status.account_id, at_time) if tag.usable?
+    end
+  end
+
+  def add(tag, account_id, at_time = Time.now.utc)
+    tag.history.add(account_id, at_time)
+    record_used_id(tag.id, at_time)
+  end
+
+  def refresh(at_time = Time.now.utc)
+    tags = Tag.where(id: (recently_used_ids(at_time) + currently_trending_ids(false, -1)).uniq)
+    calculate_scores(tags, at_time)
+    trim_older_items
+  end
+
+  def get(allowed, limit)
+    tag_ids = currently_trending_ids(allowed, limit)
+    tags = Tag.where(id: tag_ids).index_by(&:id)
+    tag_ids.map { |id| tags[id] }.compact
+  end
+
+  def request_review
+    tags = Tag.where(id: currently_trending_ids(false, -1))
+
+    tags_requiring_review = tags.filter_map do |tag|
+      next unless would_be_trending?(tag.id) && !tag.trendable? && tag.requires_review_notification?
+
+      tag.touch(:requested_review_at)
+      tag
+    end
+
+    return if tags_requiring_review.empty?
+
+    User.staff.includes(:account).find_each do |user|
+      AdminMailer.new_trending_tags(user.account, tags_requiring_review).deliver_later! if user.allows_trending_tag_emails?
+    end
+  end
+
+  protected
+
+  def key_prefix
+    PREFIX
+  end
+
+  private
+
+  def calculate_scores(tags, at_time)
+    tags.each do |tag|
+      expected  = tag.history.get(at_time - 1.day).accounts.to_f
+      expected  = 1.0 if expected.zero?
+      observed  = tag.history.get(at_time).accounts.to_f
+      max_time  = tag.max_score_at
+      max_score = tag.max_score
+      max_score = 0 if max_time.nil? || max_time < (at_time - options[:max_score_cooldown])
+
+      score = begin
+        if expected > observed || observed < options[:threshold]
+          0
+        else
+          ((observed - expected)**2) / expected
+        end
+      end
+
+      if score > max_score
+        max_score = score
+        max_time  = at_time
+
+        # Not interested in triggering any callbacks for this
+        tag.update_columns(max_score: max_score, max_score_at: max_time)
+      end
+
+      decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / options[:max_score_halflife].to_f))
+
+      if decaying_score.zero?
+        redis.zrem("#{PREFIX}:all", tag.id)
+        redis.zrem("#{PREFIX}:allowed", tag.id)
+      else
+        redis.zadd("#{PREFIX}:all", decaying_score, tag.id)
+
+        if tag.trendable?
+          redis.zadd("#{PREFIX}:allowed", decaying_score, tag.id)
+        else
+          redis.zrem("#{PREFIX}:allowed", tag.id)
+        end
+      end
+    end
+  end
+
+  def would_be_trending?(id)
+    score(id) > score_at_rank(options[:review_threshold] - 1)
+  end
+end
--- a/app/policies/preview_card_policy.rb
+++ b/app/policies/preview_card_policy.rb
@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class PreviewCardPolicy < ApplicationPolicy
+  def index?
+    staff?
+  end
+
+  def update?
+    staff?
+  end
+end
--- a/app/policies/preview_card_provider_policy.rb
+++ b/app/policies/preview_card_provider_policy.rb
@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class PreviewCardProviderPolicy < ApplicationPolicy
+  def index?
+    staff?
+  end
+
+  def update?
+    staff?
+  end
+end
--- a/app/serializers/rest/trends/link_serializer.rb
+++ b/app/serializers/rest/trends/link_serializer.rb
@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class REST::Trends::LinkSerializer < REST::PreviewCardSerializer
+  attributes :history
+end
--- a/app/services/fetch_link_card_service.rb
+++ b/app/services/fetch_link_card_service.rb
@ -50,7 +50,7 @@ class FetchLinkCardService < BaseService
      # We follow redirects, and ideally we want to save the preview card for
      # the destination URL and not any link shortener in-between, so here
      # we set the URL to the one of the last response in the redirect chain
-      @url  = res.request.uri.to_s.to_s
+      @url  = res.request.uri.to_s
      @card = PreviewCard.find_or_initialize_by(url: @url) if @card.url != @url

      if res.code == 200 && res.mime_type == 'text/html'
@ -66,6 +66,7 @@ class FetchLinkCardService < BaseService
  def attach_card
    @status.preview_cards << @card
    Rails.cache.delete(@status)
+    Trends.links.register(@status)
  end

  def parse_urls
--- a/app/services/post_status_service.rb
+++ b/app/services/post_status_service.rb
@ -91,7 +91,8 @@ class PostStatusService < BaseService
  end

  def postprocess_status!
-    LinkCrawlWorker.perform_async(@status.id) unless @status.spoiler_text?
+    Trends.tags.register(@status)
+    LinkCrawlWorker.perform_async(@status.id)
    DistributionWorker.perform_async(@status.id)
    ActivityPub::DistributionWorker.perform_async(@status.id)
    PollExpirationNotifyWorker.perform_at(@status.poll.expires_at, @status.poll.id) if @status.poll
--- a/app/services/process_hashtags_service.rb
+++ b/app/services/process_hashtags_service.rb
@ -8,7 +8,7 @@ class ProcessHashtagsService < BaseService
    Tag.find_or_create_by_names(tags) do |tag|
      status.tags << tag
      records << tag
-      tag.use!(status.account, status: status, at_time: status.created_at) if status.public_visibility?
+      tag.update(last_status_at: status.created_at) if tag.last_status_at.nil? || (tag.last_status_at < status.created_at && tag.last_status_at < 12.hours.ago)
    end

    return unless status.distributable?
--- a/app/services/reblog_service.rb
+++ b/app/services/reblog_service.rb
@ -30,12 +30,13 @@ class ReblogService < BaseService

    reblog = account.statuses.create!(reblog: reblogged_status, text: '', visibility: visibility, rate_limit: options[:with_rate_limit])

+    Trends.tags.register(reblog)
+    Trends.links.register(reblog)
    DistributionWorker.perform_async(reblog.id)
    ActivityPub::DistributionWorker.perform_async(reblog.id)

    create_notification(reblog)
    bump_potential_friendship(account, reblog)
-    record_use(account, reblog)

    reblog
  end
@ -60,16 +61,6 @@ class ReblogService < BaseService
    PotentialFriendshipTracker.record(account.id, reblog.reblog.account_id, :reblog)
  end

-  def record_use(account, reblog)
-    return unless reblog.public_visibility?
-
-    original_status = reblog.reblog
-
-    original_status.tags.each do |tag|
-      tag.use!(account)
-    end
-  end
-
  def build_json(reblog)
    Oj.dump(serialize_payload(ActivityPub::ActivityPresenter.from_status(reblog), ActivityPub::ActivitySerializer, signer: reblog.account))
  end
--- a/app/views/admin/dashboard/index.html.haml
+++ b/app/views/admin/dashboard/index.html.haml
@ -42,7 +42,7 @@
      %span= t('admin.dashboard.pending_users_html', count: @pending_users_count)
      = fa_icon 'chevron-right fw'

-    = link_to admin_tags_path(pending_review: '1'), class: 'dashboard__quick-access' do
+    = link_to admin_trends_tags_path(status: 'pending_review'), class: 'dashboard__quick-access' do
      %span= t('admin.dashboard.pending_tags_html', count: @pending_tags_count)
      = fa_icon 'chevron-right fw'

--- a/app/views/admin/tags/_tag.html.haml
+++ b/app/views/admin/tags/_tag.html.haml
@ -1,19 +0,0 @@
-.batch-table__row
-  - if batch_available
-    %label.batch-table__row__select.batch-table__row__select--aligned.batch-checkbox
-      = f.check_box :tag_ids, { multiple: true, include_hidden: false }, tag.id
-
-  .directory__tag
-    = link_to admin_tag_path(tag.id) do
-      %h4
-        = fa_icon 'hashtag'
-        = tag.name
-
-        %small
-          = t('admin.tags.unique_uses_today', count: tag.history.first[:accounts])
-
-          - if tag.trending?
-            = fa_icon 'fire fw'
-            = t('admin.tags.trending_right_now')
-
-      .trends__item__current= friendly_number_to_human tag.history.first[:uses]
--- a/app/views/admin/tags/index.html.haml
+++ b/app/views/admin/tags/index.html.haml
@ -1,74 +0,0 @@
- content_for :page_title do
-  = t('admin.tags.title')
-
- content_for :header_tags do
-  = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
-
-.filters
-  .filter-subset
-    %strong= t('admin.tags.review')
-    %ul
-      %li= filter_link_to t('generic.all'), reviewed: nil, unreviewed: nil, pending_review: nil
-      %li= filter_link_to t('admin.tags.unreviewed'), unreviewed: '1', reviewed: nil, pending_review: nil
-      %li= filter_link_to t('admin.tags.reviewed'), reviewed: '1', unreviewed: nil, pending_review: nil
-      %li= filter_link_to safe_join([t('admin.accounts.moderation.pending'), "(#{Tag.pending_review.count})"], ' '), pending_review: '1', reviewed: nil, unreviewed: nil
-
-  .filter-subset
-    %strong= t('generic.order_by')
-    %ul
-      %li= filter_link_to t('admin.tags.most_recent'), popular: nil, active: nil
-      %li= filter_link_to t('admin.tags.last_active'), active: '1', popular: nil
-      %li= filter_link_to t('admin.tags.most_popular'), popular: '1', active: nil
-
-
-= form_tag admin_tags_url, method: 'GET', class: 'simple_form' do
-  .fields-group
-    - TagFilter::KEYS.each do |key|
-      = hidden_field_tag key, params[key] if params[key].present?
-
-    - %i(name).each do |key|
-      .input.string.optional
-        = text_field_tag key, params[key], class: 'string optional', placeholder: I18n.t("admin.tags.#{key}")
-
-    .actions
-      %button.button= t('admin.accounts.search')
-      = link_to t('admin.accounts.reset'), admin_tags_path, class: 'button negative'
-
-%hr.spacer/
-
-= form_for(@form, url: batch_admin_tags_path) do |f|
-  = hidden_field_tag :page, params[:page] || 1
-
-  - TagFilter::KEYS.each do |key|
-    = hidden_field_tag key, params[key] if params[key].present?
-
-  .batch-table.optional
-    .batch-table__toolbar
-      - if params[:pending_review] == '1' || params[:unreviewed] == '1'
-        %label.batch-table__toolbar__select.batch-checkbox-all
-          = check_box_tag :batch_checkbox_all, nil, false
-        .batch-table__toolbar__actions
-          = f.button safe_join([fa_icon('check'), t('admin.accounts.approve')]), name: :approve, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
-
-          = f.button safe_join([fa_icon('times'), t('admin.accounts.reject')]), name: :reject, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
-      - else
-        .batch-table__toolbar__actions
-          %span.neutral-hint= t('generic.no_batch_actions_available')
-
-    .batch-table__body
-      - if @tags.empty?
-        = nothing_here 'nothing-here--under-tabs'
-      - else
-        = render partial: 'tag', collection: @tags, locals: { f: f, batch_available: params[:pending_review] == '1' || params[:unreviewed] == '1' }
-
-= paginate @tags
-
- if params[:pending_review] == '1' || params[:unreviewed] == '1'
-  %hr.spacer/
-
-  %div.action-buttons
-    %div
-      = link_to t('admin.accounts.approve_all'), approve_all_admin_tags_path, method: :post, data: { confirm: t('admin.accounts.are_you_sure') }, class: 'button'
-
-    %div
-      = link_to t('admin.accounts.reject_all'), reject_all_admin_tags_path, method: :post, data: { confirm: t('admin.accounts.are_you_sure') }, class: 'button button--destructive'
--- a/app/views/admin/tags/show.html.haml
+++ b/app/views/admin/tags/show.html.haml
@ -1,15 +1,50 @@
+- content_for :header_tags do
+  = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
+
 - content_for :page_title do
  = "##{@tag.name}"

-.dashboard__counters
-  %div
-    = link_to tag_url(@tag), target: '_blank', rel: 'noopener noreferrer' do
-      .dashboard__counters__num= number_with_delimiter @accounts_today
-      .dashboard__counters__label= t 'admin.tags.accounts_today'
-  %div
-    %div
-      .dashboard__counters__num= number_with_delimiter @accounts_week
-      .dashboard__counters__label= t 'admin.tags.accounts_week'
+- content_for :heading_actions do
+  = l(@time_period.first)
+  = ' - '
+  = l(@time_period.last)
+
+.dashboard
+  .dashboard__item
+    = react_admin_component :counter, measure: 'tag_accounts', start_at: @time_period.first, end_at: @time_period.last, params: { id: @tag.id }, label: t('admin.trends.tags.dashboard.tag_accounts_measure')
+  .dashboard__item
+    = react_admin_component :counter, measure: 'tag_uses', start_at: @time_period.first, end_at: @time_period.last, params: { id: @tag.id }, label: t('admin.trends.tags.dashboard.tag_uses_measure')
+  .dashboard__item
+    = react_admin_component :counter, measure: 'tag_servers', start_at: @time_period.first, end_at: @time_period.last, params: { id: @tag.id }, label: t('admin.trends.tags.dashboard.tag_servers_measure')
+  .dashboard__item
+    = react_admin_component :dimension, dimension: 'tag_servers', start_at: @time_period.first, end_at: @time_period.last, params: { id: @tag.id }, limit: 8, label: t('admin.trends.tags.dashboard.tag_servers_dimension')
+  .dashboard__item
+    = react_admin_component :dimension, dimension: 'tag_languages', start_at: @time_period.first, end_at: @time_period.last, params: { id: @tag.id }, limit: 8, label: t('admin.trends.tags.dashboard.tag_languages_dimension')
+  .dashboard__item
+    = link_to admin_tag_path(@tag.id), class: ['dashboard__quick-access', @tag.usable? ? 'positive' : 'negative'] do
+      - if @tag.usable?
+        %span= t('admin.trends.tags.usable')
+        = fa_icon 'check fw'
+      - else
+        %span= t('admin.trends.tags.not_usable')
+        = fa_icon 'lock fw'
+
+    = link_to admin_tag_path(@tag.id), class: ['dashboard__quick-access', @tag.trendable? ? 'positive' : 'negative'] do
+      - if @tag.trendable?
+        %span= t('admin.trends.tags.trendable')
+        = fa_icon 'check fw'
+      - else
+        %span= t('admin.trends.tags.not_trendable')
+        = fa_icon 'lock fw'
+
+
+    = link_to admin_tag_path(@tag.id), class: ['dashboard__quick-access', @tag.listable? ? 'positive' : 'negative'] do
+      - if @tag.listable?
+        %span= t('admin.trends.tags.listable')
+        = fa_icon 'check fw'
+      - else
+        %span= t('admin.trends.tags.not_listable')
+        = fa_icon 'lock fw'

 %hr.spacer/

@ -26,18 +61,3 @@

  .actions
    = f.button :button, t('generic.save_changes'), type: :submit
-
-%hr.spacer/
-
-%h3= t 'admin.tags.breakdown'
-
-.table-wrapper
-  %table.table
-    %tbody
-      - total = @usage_by_domain.sum(&:last).to_f
-
-      - @usage_by_domain.each do |(domain, count)|
-        %tr
-          %th= domain || site_hostname
-          %td= number_to_percentage((count / total) * 100, precision: 1)
-          %td= number_with_delimiter count
--- a/app/views/admin/trends/links/_preview_card.html.haml
+++ b/app/views/admin/trends/links/_preview_card.html.haml
@ -0,0 +1,30 @@
+.batch-table__row{ class: [preview_card.provider&.requires_review? && 'batch-table__row--attention', !preview_card.provider&.requires_review? && !preview_card.trendable? && 'batch-table__row--muted'] }
+  %label.batch-table__row__select.batch-table__row__select--aligned.batch-checkbox
+    = f.check_box :preview_card_ids, { multiple: true, include_hidden: false }, preview_card.id
+
+  .batch-table__row__content.pending-account
+    .pending-account__header
+      = link_to preview_card.title, preview_card.url
+
+      %br/
+
+      - if preview_card.provider_name.present?
+        = preview_card.provider_name
+        •
+
+      - if preview_card.language.present?
+        = human_locale(preview_card.language)
+        •
+
+      = t('admin.trends.links.shared_by_over_week', count: preview_card.history.reduce(0) { |sum, day| sum + day.accounts })
+
+      - if preview_card.trendable? && (rank = Trends.links.rank(preview_card.id))
+        •
+        %abbr{ title: t('admin.trends.tags.current_score', score: Trends.links.score(preview_card.id)) }= t('admin.trends.tags.trending_rank', rank: rank + 1)
+
+        - if preview_card.max_score_at && preview_card.max_score_at >= Trends::Links::MAX_SCORE_COOLDOWN.ago && preview_card.max_score_at < 1.day.ago
+          •
+          = t('admin.trends.tags.peaked_on_and_decaying', date: l(preview_card.max_score_at.to_date, format: :short))
+      - elsif preview_card.provider&.requires_review?
+        •
+        = t('admin.trends.pending_review')
--- a/app/views/admin/trends/links/index.html.haml
+++ b/app/views/admin/trends/links/index.html.haml
@ -0,0 +1,41 @@
+- content_for :page_title do
+  = t('admin.trends.links.title')
+
+- content_for :header_tags do
+  = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
+
+.filters
+  .filter-subset
+    %strong= t('admin.trends.trending')
+    %ul
+      %li= filter_link_to t('generic.all'), trending: nil
+      %li= filter_link_to t('admin.trends.only_allowed'), trending: 'allowed'
+  .back-link
+    = link_to admin_trends_links_preview_card_providers_path do
+      = t('admin.trends.preview_card_providers.title')
+      = fa_icon 'chevron-right fw'
+
+%hr.spacer/
+
+= form_for(@form, url: batch_admin_trends_links_path) do |f|
+  = hidden_field_tag :page, params[:page] || 1
+
+  - PreviewCardFilter::KEYS.each do |key|
+    = hidden_field_tag key, params[key] if params[key].present?
+
+  .batch-table
+    .batch-table__toolbar
+      %label.batch-table__toolbar__select.batch-checkbox-all
+        = check_box_tag :batch_checkbox_all, nil, false
+      .batch-table__toolbar__actions
+        = f.button safe_join([fa_icon('check'), t('admin.trends.links.allow')]), name: :approve, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+        = f.button safe_join([fa_icon('check'), t('admin.trends.links.allow_provider')]), name: :approve_all, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+        = f.button safe_join([fa_icon('times'), t('admin.trends.links.disallow')]), name: :reject, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+        = f.button safe_join([fa_icon('times'), t('admin.trends.links.disallow_provider')]), name: :reject_all, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+    .batch-table__body
+      - if @preview_cards.empty?
+        = nothing_here 'nothing-here--under-tabs'
+      - else
+        = render partial: 'preview_card', collection: @preview_cards, locals: { f: f }
+
+= paginate @preview_cards
--- a/app/views/admin/trends/links/preview_card_providers/_preview_card_provider.html.haml
+++ b/app/views/admin/trends/links/preview_card_providers/_preview_card_provider.html.haml
@ -0,0 +1,16 @@
+.batch-table__row{ class: [preview_card_provider.requires_review? && 'batch-table__row--attention', !preview_card_provider.requires_review? && !preview_card_provider.trendable? && 'batch-table__row--muted'] }
+  %label.batch-table__row__select.batch-table__row__select--aligned.batch-checkbox
+    = f.check_box :preview_card_provider_ids, { multiple: true, include_hidden: false }, preview_card_provider.id
+
+  .batch-table__row__content.pending-account
+    .pending-account__header
+      %strong= preview_card_provider.domain
+
+      %br/
+
+      - if preview_card_provider.requires_review?
+        = t('admin.trends.pending_review')
+      - elsif preview_card_provider.trendable?
+        = t('admin.trends.preview_card_providers.allowed')
+      - else
+        = t('admin.trends.preview_card_providers.rejected')
--- a/app/views/admin/trends/links/preview_card_providers/index.html.haml
+++ b/app/views/admin/trends/links/preview_card_providers/index.html.haml
@ -0,0 +1,43 @@
+- content_for :page_title do
+  = t('admin.trends.preview_card_providers.title')
+
+- content_for :header_tags do
+  = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
+
+.filters
+  .filter-subset
+    %strong= t('admin.tags.review')
+    %ul
+      %li= filter_link_to t('generic.all'), status: nil
+      %li= filter_link_to t('admin.trends.approved'), status: 'approved'
+      %li= filter_link_to t('admin.trends.rejected'), status: 'rejected'
+      %li= filter_link_to safe_join([t('admin.accounts.moderation.pending'), "(#{PreviewCardProvider.pending_review.count})"], ' '), status: 'pending_review'
+  .back-link
+    = link_to admin_trends_links_path do
+      = fa_icon 'chevron-left fw'
+      = t('admin.trends.links.title')
+
+
+%hr.spacer/
+
+= form_for(@form, url: batch_admin_trends_links_preview_card_providers_path) do |f|
+  = hidden_field_tag :page, params[:page] || 1
+
+  - PreviewCardProviderFilter::KEYS.each do |key|
+    = hidden_field_tag key, params[key] if params[key].present?
+
+  .batch-table.optional
+    .batch-table__toolbar
+      %label.batch-table__toolbar__select.batch-checkbox-all
+        = check_box_tag :batch_checkbox_all, nil, false
+      .batch-table__toolbar__actions
+        = f.button safe_join([fa_icon('check'), t('admin.trends.allow')]), name: :approve, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+        = f.button safe_join([fa_icon('times'), t('admin.trends.disallow')]), name: :reject, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+
+    .batch-table__body
+      - if @preview_card_providers.empty?
+        = nothing_here 'nothing-here--under-tabs'
+      - else
+        = render partial: 'preview_card_provider', collection: @preview_card_providers, locals: { f: f }
+
+= paginate @preview_card_providers
--- a/app/views/admin/trends/tags/_tag.html.haml
+++ b/app/views/admin/trends/tags/_tag.html.haml
@ -0,0 +1,24 @@
+.batch-table__row{ class: [tag.requires_review? && 'batch-table__row--attention', !tag.requires_review? && !tag.trendable? && 'batch-table__row--muted'] }
+  %label.batch-table__row__select.batch-table__row__select--aligned.batch-checkbox
+    = f.check_box :tag_ids, { multiple: true, include_hidden: false }, tag.id
+
+  .batch-table__row__content.pending-account
+    .pending-account__header
+      = link_to admin_tag_path(tag.id) do
+        = fa_icon 'hashtag'
+        = tag.name
+
+      %br/
+
+      = t('admin.trends.tags.used_by_over_week', count: tag.history.reduce(0) { |sum, day| sum + day.accounts })
+
+      - if tag.trendable? && (rank = Trends.tags.rank(tag.id))
+        •
+        %abbr{ title: t('admin.trends.tags.current_score', score: Trends.tags.score(tag.id)) }= t('admin.trends.tags.trending_rank', rank: rank + 1)
+
+        - if tag.max_score_at && tag.max_score_at >= Trends::Tags::MAX_SCORE_COOLDOWN.ago && tag.max_score_at < 1.day.ago
+          •
+          = t('admin.trends.tags.peaked_on_and_decaying', date: l(tag.max_score_at.to_date, format: :short))
+      - elsif tag.requires_review?
+        •
+        = t('admin.trends.pending_review')
--- a/app/views/admin/trends/tags/index.html.haml
+++ b/app/views/admin/trends/tags/index.html.haml
@ -0,0 +1,38 @@
+- content_for :page_title do
+  = t('admin.trends.tags.title')
+
+- content_for :header_tags do
+  = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
+
+.filters
+  .filter-subset
+    %strong= t('admin.tags.review')
+    %ul
+      %li= filter_link_to t('generic.all'), status: nil
+      %li= filter_link_to t('admin.trends.approved'), status: 'approved'
+      %li= filter_link_to t('admin.trends.rejected'), status: 'rejected'
+      %li= filter_link_to safe_join([t('admin.accounts.moderation.pending'), "(#{Tag.pending_review.count})"], ' '), status: 'pending_review'
+
+%hr.spacer/
+
+= form_for(@form, url: batch_admin_trends_tags_path) do |f|
+  = hidden_field_tag :page, params[:page] || 1
+
+  - TagFilter::KEYS.each do |key|
+    = hidden_field_tag key, params[key] if params[key].present?
+
+  .batch-table.optional
+    .batch-table__toolbar
+      %label.batch-table__toolbar__select.batch-checkbox-all
+        = check_box_tag :batch_checkbox_all, nil, false
+      .batch-table__toolbar__actions
+        = f.button safe_join([fa_icon('check'), t('admin.trends.allow')]), name: :approve, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+        = f.button safe_join([fa_icon('times'), t('admin.trends.disallow')]), name: :reject, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+
+    .batch-table__body
+      - if @tags.empty?
+        = nothing_here 'nothing-here--under-tabs'
+      - else
+        = render partial: 'tag', collection: @tags, locals: { f: f }
+
+= paginate @tags
--- a/app/views/admin_mailer/new_trending_links.text.erb
+++ b/app/views/admin_mailer/new_trending_links.text.erb
@ -0,0 +1,16 @@
+<%= raw t('application_mailer.salutation', name: display_name(@me)) %>
+
+<%= raw t('admin_mailer.new_trending_links.body') %>
+
+<% @links.each do |link| %>
+- <%= link.title %> • <%= link.url %>
+  <%= t('admin.trends.links.usage_comparison', today: link.history.get(Time.now.utc).accounts, yesterday: link.history.get(Time.now.utc - 1.day).accounts) %> • <%= t('admin.trends.tags.current_score', score: Trends.links.score(link.id).round(2)) %>
+<% end %>
+
+<% if @lowest_trending_link %>
+<%= t('admin_mailer.new_trending_links.requirements', lowest_link_title: @lowest_trending_link.title, lowest_link_score: Trends.links.score(@lowest_trending_link.id).round(2)) %>
+<% else %>
+<%= t('admin_mailer.new_trending_links.no_approved_links') %>
+<% end %>
+
+<%= raw t('application_mailer.view')%> <%= admin_trends_links_url %>
--- a/app/views/admin_mailer/new_trending_tag.text.erb
+++ b/app/views/admin_mailer/new_trending_tag.text.erb
@ -1,5 +0,0 @@
-<%= raw t('application_mailer.salutation', name: display_name(@me)) %>
-
-<%= raw t('admin_mailer.new_trending_tag.body', name: @tag.name) %>
-
-<%= raw t('application_mailer.view')%> <%= admin_tags_url(pending_review: '1') %>
--- a/app/views/admin_mailer/new_trending_tags.text.erb
+++ b/app/views/admin_mailer/new_trending_tags.text.erb
@ -0,0 +1,16 @@
+<%= raw t('application_mailer.salutation', name: display_name(@me)) %>
+
+<%= raw t('admin_mailer.new_trending_tags.body') %>
+
+<% @tags.each do |tag| %>
+- #<%= tag.name %>
+  <%= t('admin.trends.tags.usage_comparison', today: tag.history.get(Time.now.utc).accounts, yesterday: tag.history.get(Time.now.utc - 1.day).accounts) %> • <%= t('admin.trends.tags.current_score', score: Trends.tags.score(tag.id).round(2)) %>
+<% end %>
+
+<% if @lowest_trending_tag %>
+<%= t('admin_mailer.new_trending_tags.requirements', lowest_tag_name: @lowest_trending_tag.name, lowest_tag_score: Trends.tags.score(@lowest_trending_tag.id).round(2)) %>
+<% else %>
+<%= t('admin_mailer.new_trending_tags.no_approved_tags') %>
+<% end %>
+
+<%= raw t('application_mailer.view')%> <%= admin_trends_tags_url(pending_review: '1') %>
--- a/app/views/application/_sidebar.html.haml
+++ b/app/views/application/_sidebar.html.haml
@ -6,7 +6,7 @@
    %p= @instance_presenter.site_short_description.html_safe.presence || t('about.about_mastodon_html')

 - if Setting.trends && !(user_signed_in? && !current_user.setting_trends)
-  - trends = TrendingTags.get(3)
+  - trends = Trends.tags.get(true, 3)

  - unless trends.empty?
    .endorsements-widget.trends-widget
--- a/app/workers/scheduler/trends/refresh_scheduler.rb
+++ b/app/workers/scheduler/trends/refresh_scheduler.rb
@ -1,11 +1,11 @@
 # frozen_string_literal: true

-class Scheduler::TrendingTagsScheduler
+class Scheduler::Trends::RefreshScheduler
  include Sidekiq::Worker

  sidekiq_options retry: 0

  def perform
-    TrendingTags.update! if Setting.trends
+    Trends.refresh!
  end
 end
--- a/app/workers/scheduler/trends/review_notifications_scheduler.rb
+++ b/app/workers/scheduler/trends/review_notifications_scheduler.rb
@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class Scheduler::Trends::ReviewNotificationsScheduler
+  include Sidekiq::Worker
+
+  sidekiq_options retry: 0
+
+  def perform
+    Trends.request_review!
+  end
+end
--- a/config/brakeman.ignore
+++ b/config/brakeman.ignore
@ -67,7 +67,7 @@
      "check_name": "SQL",
      "message": "Possible SQL injection",
      "file": "app/models/account.rb",
-      "line": 479,
+      "line": 484,
      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
      "code": "find_by_sql([\"          WITH first_degree AS (\\n            SELECT target_account_id\\n            FROM follows\\n            WHERE account_id = ?\\n            UNION ALL\\n            SELECT ?\\n          )\\n          SELECT\\n            accounts.*,\\n            (count(f.id) + 1) * ts_rank_cd(#{textsearch}, #{query}, 32) AS rank\\n          FROM accounts\\n          LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = ?)\\n          WHERE accounts.id IN (SELECT * FROM first_degree)\\n            AND #{query} @@ #{textsearch}\\n            AND accounts.suspended_at IS NULL\\n            AND accounts.moved_to_account_id IS NULL\\n          GROUP BY accounts.id\\n          ORDER BY rank DESC\\n          LIMIT ? OFFSET ?\\n\".squish, account.id, account.id, account.id, limit, offset])",
      "render_path": null,
@ -100,6 +100,26 @@
      "confidence": "Weak",
      "note": ""
    },
+    {
+      "warning_type": "SQL Injection",
+      "warning_code": 0,
+      "fingerprint": "75fcd147b7611763ab6915faf8c5b0709e612b460f27c05c72d8b9bd0a6a77f8",
+      "check_name": "SQL",
+      "message": "Possible SQL injection",
+      "file": "lib/mastodon/snowflake.rb",
+      "line": 87,
+      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
+      "code": "connection.execute(\"CREATE OR REPLACE FUNCTION timestamp_id(table_name text)\\nRETURNS bigint AS\\n$$\\n  DECLARE\\n    time_part bigint;\\n    sequence_base bigint;\\n    tail bigint;\\n  BEGIN\\n    time_part := (\\n      -- Get the time in milliseconds\\n      ((date_part('epoch', now()) * 1000))::bigint\\n      -- And shift it over two bytes\\n      << 16);\\n\\n    sequence_base := (\\n      'x' ||\\n      -- Take the first two bytes (four hex characters)\\n      substr(\\n        -- Of the MD5 hash of the data we documented\\n        md5(table_name || '#{SecureRandom.hex(16)}' || time_part::text),\\n        1, 4\\n      )\\n    -- And turn it into a bigint\\n    )::bit(16)::bigint;\\n\\n    -- Finally, add our sequence number to our base, and chop\\n    -- it to the last two bytes\\n    tail := (\\n      (sequence_base + nextval(table_name || '_id_seq'))\\n      & 65535);\\n\\n    -- Return the time part and the sequence part. OR appears\\n    -- faster here than addition, but they're equivalent:\\n    -- time_part has no trailing two bytes, and tail is only\\n    -- the last two bytes.\\n    RETURN time_part | tail;\\n  END\\n$$ LANGUAGE plpgsql VOLATILE;\\n\")",
+      "render_path": null,
+      "location": {
+        "type": "method",
+        "class": "Mastodon::Snowflake",
+        "method": "define_timestamp_id"
+      },
+      "user_input": "SecureRandom.hex(16)",
+      "confidence": "Medium",
+      "note": ""
+    },
    {
      "warning_type": "Mass Assignment",
      "warning_code": 105,
@ -140,6 +160,26 @@
      "confidence": "High",
      "note": ""
    },
+    {
+      "warning_type": "SQL Injection",
+      "warning_code": 0,
+      "fingerprint": "8c1d8c4b76c1cd3960e90dff999f854a6ff742fcfd8de6c7184ac5a1b1a4d7dd",
+      "check_name": "SQL",
+      "message": "Possible SQL injection",
+      "file": "app/models/preview_card_filter.rb",
+      "line": 50,
+      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
+      "code": "PreviewCard.joins(\"join unnest(array[#{(Trends.links.currently_trending_ids(true, -1) or Trends.links.currently_trending_ids(false, -1)).map(&:to_i).join(\",\")}]::integer[]) with ordinality as x (id, ordering) on preview_cards.id = x.id\")",
+      "render_path": null,
+      "location": {
+        "type": "method",
+        "class": "PreviewCardFilter",
+        "method": "trending_scope"
+      },
+      "user_input": "(Trends.links.currently_trending_ids(true, -1) or Trends.links.currently_trending_ids(false, -1)).map(&:to_i).join(\",\")",
+      "confidence": "Medium",
+      "note": ""
+    },
    {
      "warning_type": "SQL Injection",
      "warning_code": 0,
@ -147,7 +187,7 @@
      "check_name": "SQL",
      "message": "Possible SQL injection",
      "file": "app/models/account.rb",
-      "line": 448,
+      "line": 453,
      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
      "code": "find_by_sql([\"        SELECT\\n          accounts.*,\\n          ts_rank_cd(#{textsearch}, #{query}, 32) AS rank\\n        FROM accounts\\n        WHERE #{query} @@ #{textsearch}\\n          AND accounts.suspended_at IS NULL\\n          AND accounts.moved_to_account_id IS NULL\\n        ORDER BY rank DESC\\n        LIMIT ? OFFSET ?\\n\".squish, limit, offset])",
      "render_path": null,
@ -160,26 +200,6 @@
      "confidence": "Medium",
      "note": ""
    },
-    {
-      "warning_type": "SQL Injection",
-      "warning_code": 0,
-      "fingerprint": "9ccb9ba6a6947400e187d515e0bf719d22993d37cfc123c824d7fafa6caa9ac3",
-      "check_name": "SQL",
-      "message": "Possible SQL injection",
-      "file": "lib/mastodon/snowflake.rb",
-      "line": 87,
-      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
-      "code": "connection.execute(\"        CREATE OR REPLACE FUNCTION timestamp_id(table_name text)\\n        RETURNS bigint AS\\n        $$\\n          DECLARE\\n            time_part bigint;\\n            sequence_base bigint;\\n            tail bigint;\\n          BEGIN\\n            time_part := (\\n              -- Get the time in milliseconds\\n              ((date_part('epoch', now()) * 1000))::bigint\\n              -- And shift it over two bytes\\n              << 16);\\n\\n            sequence_base := (\\n              'x' ||\\n              -- Take the first two bytes (four hex characters)\\n              substr(\\n                -- Of the MD5 hash of the data we documented\\n                md5(table_name ||\\n                  '#{SecureRandom.hex(16)}' ||\\n                  time_part::text\\n                ),\\n                1, 4\\n              )\\n            -- And turn it into a bigint\\n            )::bit(16)::bigint;\\n\\n            -- Finally, add our sequence number to our base, and chop\\n            -- it to the last two bytes\\n            tail := (\\n              (sequence_base + nextval(table_name || '_id_seq'))\\n              & 65535);\\n\\n            -- Return the time part and the sequence part. OR appears\\n            -- faster here than addition, but they're equivalent:\\n            -- time_part has no trailing two bytes, and tail is only\\n            -- the last two bytes.\\n            RETURN time_part | tail;\\n          END\\n        $$ LANGUAGE plpgsql VOLATILE;\\n\")",
-      "render_path": null,
-      "location": {
-        "type": "method",
-        "class": "Mastodon::Snowflake",
-        "method": "define_timestamp_id"
-      },
-      "user_input": "SecureRandom.hex(16)",
-      "confidence": "Medium",
-      "note": ""
-    },
    {
      "warning_type": "Redirect",
      "warning_code": 18,
@ -201,23 +221,53 @@
      "note": ""
    },
    {
-      "warning_type": "Redirect",
-      "warning_code": 18,
-      "fingerprint": "ba699ddcc6552c422c4ecd50d2cd217f616a2446659e185a50b05a0f2dad8d33",
-      "check_name": "Redirect",
-      "message": "Possible unprotected redirect",
-      "file": "app/controllers/media_controller.rb",
-      "line": 20,
-      "link": "https://brakemanscanner.org/docs/warning_types/redirect/",
-      "code": "redirect_to(MediaAttachment.attached.find_by!(:shortcode => ((params[:id] or params[:medium_id]))).file.url(:original))",
+      "warning_type": "SQL Injection",
+      "warning_code": 0,
+      "fingerprint": "c32a484ccd9da46abd3bc93d08b72029d7dbc0576ccf4e878a9627e9a83cad2e",
+      "check_name": "SQL",
+      "message": "Possible SQL injection",
+      "file": "app/models/tag_filter.rb",
+      "line": 50,
+      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
+      "code": "Tag.joins(\"join unnest(array[#{Trends.tags.currently_trending_ids(false, -1).map(&:to_i).join(\",\")}]::integer[]) with ordinality as x (id, ordering) on tags.id = x.id\")",
      "render_path": null,
      "location": {
        "type": "method",
-        "class": "MediaController",
-        "method": "show"
+        "class": "TagFilter",
+        "method": "trending_scope"
      },
-      "user_input": "MediaAttachment.attached.find_by!(:shortcode => ((params[:id] or params[:medium_id]))).file.url(:original)",
-      "confidence": "High",
+      "user_input": "Trends.tags.currently_trending_ids(false, -1).map(&:to_i).join(\",\")",
+      "confidence": "Medium",
+      "note": ""
+    },
+    {
+      "warning_type": "Cross-Site Scripting",
+      "warning_code": 4,
+      "fingerprint": "cd5cfd7f40037fbfa753e494d7129df16e358bfc43ef0da3febafbf4ee1ed3ac",
+      "check_name": "LinkToHref",
+      "message": "Potentially unsafe model attribute in `link_to` href",
+      "file": "app/views/admin/trends/links/_preview_card.html.haml",
+      "line": 7,
+      "link": "https://brakemanscanner.org/docs/warning_types/link_to_href",
+      "code": "link_to((Unresolved Model).new.title, (Unresolved Model).new.url)",
+      "render_path": [
+        {
+          "type": "template",
+          "name": "admin/trends/links/index",
+          "line": 37,
+          "file": "app/views/admin/trends/links/index.html.haml",
+          "rendered": {
+            "name": "admin/trends/links/_preview_card",
+            "file": "app/views/admin/trends/links/_preview_card.html.haml"
+          }
+        }
+      ],
+      "location": {
+        "type": "template",
+        "template": "admin/trends/links/_preview_card"
+      },
+      "user_input": "(Unresolved Model).new.url",
+      "confidence": "Weak",
      "note": ""
    },
    {
@ -227,7 +277,7 @@
      "check_name": "SQL",
      "message": "Possible SQL injection",
      "file": "app/models/account.rb",
-      "line": 495,
+      "line": 500,
      "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
      "code": "find_by_sql([\"          SELECT\\n            accounts.*,\\n            (count(f.id) + 1) * ts_rank_cd(#{textsearch}, #{query}, 32) AS rank\\n          FROM accounts\\n          LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = ?) OR (accounts.id = f.target_account_id AND f.account_id = ?)\\n          WHERE #{query} @@ #{textsearch}\\n            AND accounts.suspended_at IS NULL\\n            AND accounts.moved_to_account_id IS NULL\\n          GROUP BY accounts.id\\n          ORDER BY rank DESC\\n          LIMIT ? OFFSET ?\\n\".squish, account.id, account.id, limit, offset])",
      "render_path": null,
@ -261,6 +311,6 @@
      "note": ""
    }
  ],
-  "updated": "2021-05-11 20:22:27 +0900",
-  "brakeman_version": "5.0.1"
+  "updated": "2021-11-14 05:26:09 +0100",
+  "brakeman_version": "5.1.2"
 }
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@ -674,8 +674,8 @@ en:
        desc_html: Affects hashtags that have not been previously disallowed
        title: Allow hashtags to trend without prior review
      trends:
-        desc_html: Publicly display previously reviewed hashtags that are currently trending
-        title: Trending hashtags
+        desc_html: Publicly display previously reviewed content that is currently trending
+        title: Trends
    site_uploads:
      delete: Delete uploaded file
      destroyed_msg: Site upload successfully deleted!
@ -702,21 +702,51 @@ en:
      sidekiq_process_check:
        message_html: No Sidekiq process running for the %{value} queue(s). Please review your Sidekiq configuration
    tags:
-      accounts_today: Unique uses today
-      accounts_week: Unique uses this week
-      breakdown: Breakdown of today's usage by source
-      last_active: Recently used
-      most_popular: Most popular
-      most_recent: Recently created
-      name: Hashtag
      review: Review status
-      reviewed: Reviewed
-      title: Hashtags
-      trending_right_now: Trending right now
-      unique_uses_today: "%{count} posting today"
-      unreviewed: Not reviewed
      updated_msg: Hashtag settings updated successfully
    title: Administration
+    trends:
+      allow: Allow
+      approved: Approved
+      disallow: Disallow
+      links:
+        allow: Allow link
+        allow_provider: Allow publisher
+        disallow: Disallow link
+        disallow_provider: Disallow publisher
+        shared_by_over_week:
+          one: Shared by one person over the last week
+          other: Shared by %{count} people over the last week
+        title: Trending links
+        usage_comparison: Shared %{today} times today, compared to %{yesterday} yesterday
+      pending_review: Pending review
+      preview_card_providers:
+        allowed: Links from this publisher can trend
+        rejected: Links from this publisher won't trend
+        title: Publishers
+      rejected: Rejected
+      tags:
+        current_score: Current score %{score}
+        dashboard:
+          tag_accounts_measure: unique uses
+          tag_languages_dimension: Top languages
+          tag_servers_dimension: Top servers
+          tag_servers_measure: different servers
+          tag_uses_measure: total uses
+        listable: Can be suggested
+        not_listable: Won't be suggested
+        not_trendable: Won't appear under trends
+        not_usable: Cannot be used
+        peaked_on_and_decaying: Peaked on %{date}, now decaying
+        title: Trending hashtags
+        trendable: Can appear under trends
+        trending_rank: 'Trending #%{rank}'
+        usable: Can be used
+        usage_comparison: Used %{today} times today, compared to %{yesterday} yesterday
+        used_by_over_week:
+          one: Used by one person over the last week
+          other: Used by %{count} people over the last week
+      title: Trends
    warning_presets:
      add_new: Add new
      delete: Delete
@ -731,9 +761,16 @@ en:
      body: "%{reporter} has reported %{target}"
      body_remote: Someone from %{domain} has reported %{target}
      subject: New report for %{instance} (#%{id})
-    new_trending_tag:
-      body: 'The hashtag #%{name} is trending today, but has not been previously reviewed. It will not be displayed publicly unless you allow it to, or just save the form as it is to never hear about it again.'
-      subject: New hashtag up for review on %{instance} (#%{name})
+    new_trending_links:
+      body: The following links are trending today, but their publishers have not been previously reviewed. They will not be displayed publicly unless you approve them. Further notifications from the same publishers will not be generated.
+      no_approved_links: There are currently no approved trending links.
+      requirements: The lowest approved trending link is currently "%{lowest_link_title}" with a score of %{lowest_link_score}.
+      subject: New trending links up for review on %{instance}
+    new_trending_tags:
+      body: 'The following hashtags are trending today, but they have not been previously reviewed. They will not be displayed publicly unless you approve them:'
+      no_approved_tags: There are currently no approved trending hashtags.
+      requirements: 'The lowest approved trending hashtag is currently #%{lowest_tag_name} with a score of %{lowest_tag_score}.'
+      subject: New trending hashtags up for review on %{instance}
  aliases:
    add_new: Create alias
    created_msg: Successfully created a new alias. You can now initiate the move from the old account.
@ -940,7 +977,7 @@ en:
    changes_saved_msg: Changes successfully saved!
    copy: Copy
    delete: Delete
-    no_batch_actions_available: No batch actions available on this page
+    none: None
    order_by: Order by
    save_changes: Save changes
    validation_errors:
--- a/config/locales/simple_form.en.yml
+++ b/config/locales/simple_form.en.yml
@ -204,8 +204,8 @@ en:
        mention: Someone mentioned you
        pending_account: New account needs review
        reblog: Someone boosted your post
-        report: New report is submitted
-        trending_tag: An unreviewed hashtag is trending
+        report: A new report is submitted
+        trending_tag: A new trend requires approval
      rule:
        text: Rule
      tag:
--- a/config/navigation.rb
+++ b/config/navigation.rb
@ -34,12 +34,16 @@ SimpleNavigation::Configuration.run do |navigation|
    n.item :invites, safe_join([fa_icon('user-plus fw'), t('invites.title')]), invites_path, if: proc { Setting.min_invite_role == 'user' && current_user.functional? }
    n.item :development, safe_join([fa_icon('code fw'), t('settings.development')]), settings_applications_url, if: -> { current_user.functional? }

+    n.item :trends, safe_join([fa_icon('fire fw'), t('admin.trends.title')]), admin_trends_tags_path, if: proc { current_user.staff? } do |s|
+      s.item :tags, safe_join([fa_icon('hashtag fw'), t('admin.trends.tags.title')]), admin_trends_tags_path, highlights_on: %r{/admin/tags|/admin/trends/tags}
+      s.item :links, safe_join([fa_icon('newspaper-o fw'), t('admin.trends.links.title')]), admin_trends_links_path, highlights_on: %r{/admin/trends/links}
+    end
+
    n.item :moderation, safe_join([fa_icon('gavel fw'), t('moderation.title')]), admin_reports_url, if: proc { current_user.staff? } do |s|
      s.item :action_logs, safe_join([fa_icon('bars fw'), t('admin.action_logs.title')]), admin_action_logs_url
      s.item :reports, safe_join([fa_icon('flag fw'), t('admin.reports.title')]), admin_reports_url, highlights_on: %r{/admin/reports}
      s.item :accounts, safe_join([fa_icon('users fw'), t('admin.accounts.title')]), admin_accounts_url, highlights_on: %r{/admin/accounts|/admin/pending_accounts}
      s.item :invites, safe_join([fa_icon('user-plus fw'), t('admin.invites.title')]), admin_invites_path
-      s.item :tags, safe_join([fa_icon('hashtag fw'), t('admin.tags.title')]), admin_tags_path, highlights_on: %r{/admin/tags}
      s.item :follow_recommendations, safe_join([fa_icon('user-plus fw'), t('admin.follow_recommendations.title')]), admin_follow_recommendations_path, highlights_on: %r{/admin/follow_recommendations}
      s.item :instances, safe_join([fa_icon('cloud fw'), t('admin.instances.title')]), admin_instances_url(limited: whitelist_mode? ? nil : '1'), highlights_on: %r{/admin/instances|/admin/domain_blocks|/admin/domain_allows}, if: -> { current_user.admin? }
      s.item :email_domain_blocks, safe_join([fa_icon('envelope fw'), t('admin.email_domain_blocks.title')]), admin_email_domain_blocks_url, highlights_on: %r{/admin/email_domain_blocks}, if: -> { current_user.admin? }
--- a/config/routes.rb
+++ b/config/routes.rb
@ -301,12 +301,27 @@ Rails.application.routes.draw do

    resources :account_moderation_notes, only: [:create, :destroy]
    resource :follow_recommendations, only: [:show, :update]
+    resources :tags, only: [:show, :update]

-    resources :tags, only: [:index, :show, :update] do
-      collection do
-        post :approve_all
-        post :reject_all
-        post :batch
+    namespace :trends do
+      resources :links, only: [:index] do
+        collection do
+          post :batch
+        end
+      end
+
+      resources :tags, only: [:index] do
+        collection do
+          post :batch
+        end
+      end
+
+      namespace :links do
+        resources :preview_card_providers, only: [:index], path: :publishers do
+          collection do
+            post :batch
+          end
+        end
      end
    end
  end
@ -399,7 +414,7 @@ Rails.application.routes.draw do
      resources :favourites,   only: [:index]
      resources :bookmarks,    only: [:index]
      resources :reports,      only: [:create]
-      resources :trends,       only: [:index]
+      resources :trends,       only: [:index], controller: 'trends/tags'
      resources :filters,      only: [:index, :create, :show, :update, :destroy]
      resources :endorsements, only: [:index]
      resources :markers,      only: [:index, :create]
@ -410,6 +425,11 @@ Rails.application.routes.draw do

      resources :apps, only: [:create]

+      namespace :trends do
+        resources :links, only: [:index]
+        resources :tags, only: [:index]
+      end
+
      namespace :emails do
        resources :confirmations, only: [:create]
      end
@ -512,7 +532,9 @@ Rails.application.routes.draw do
          end
        end

-        resources :trends, only: [:index]
+        namespace :trends do
+          resources :tags, only: [:index]
+        end

        post :measures, to: 'measures#create'
        post :dimensions, to: 'dimensions#create'
--- a/config/sidekiq.yml
+++ b/config/sidekiq.yml
@ -13,9 +13,13 @@
    every: '5m'
    class: Scheduler::ScheduledStatusesScheduler
    queue: scheduler
-  trending_tags_scheduler:
+  trends_refresh_scheduler:
    every: '5m'
-    class: Scheduler::TrendingTagsScheduler
+    class: Scheduler::Trends::RefreshScheduler
+    queue: scheduler
+  trends_review_notifications_scheduler:
+    every: '2h'
+    class: Scheduler::Trends::ReviewNotificationsScheduler
    queue: scheduler
  media_cleanup_scheduler:
    cron: '<%= Random.rand(0..59) %> <%= Random.rand(3..5) %> * * *'
--- a/db/migrate/20211031031021_create_preview_card_providers.rb
+++ b/db/migrate/20211031031021_create_preview_card_providers.rb
@ -0,0 +1,12 @@
+class CreatePreviewCardProviders < ActiveRecord::Migration[6.1]
+  def change
+    create_table :preview_card_providers do |t|
+      t.string :domain, null: false, default: '', index: { unique: true }
+      t.attachment :icon
+      t.boolean :trendable
+      t.datetime :reviewed_at
+      t.datetime :requested_review_at
+      t.timestamps
+    end
+  end
+end
--- a/db/migrate/20211112011713_add_language_to_preview_cards.rb
+++ b/db/migrate/20211112011713_add_language_to_preview_cards.rb
@ -0,0 +1,7 @@
+class AddLanguageToPreviewCards < ActiveRecord::Migration[6.1]
+  def change
+    add_column :preview_cards, :language, :string
+    add_column :preview_cards, :max_score, :float
+    add_column :preview_cards, :max_score_at, :datetime
+  end
+end
--- a/db/migrate/20211115032527_add_trendable_to_preview_cards.rb
+++ b/db/migrate/20211115032527_add_trendable_to_preview_cards.rb
@ -0,0 +1,5 @@
+class AddTrendableToPreviewCards < ActiveRecord::Migration[6.1]
+  def change
+    add_column :preview_cards, :trendable, :boolean
+  end
+end
--- a/db/migrate/20211123212714_add_link_type_to_preview_cards.rb
+++ b/db/migrate/20211123212714_add_link_type_to_preview_cards.rb
@ -0,0 +1,5 @@
+class AddLinkTypeToPreviewCards < ActiveRecord::Migration[6.1]
+  def change
+    add_column :preview_cards, :link_type, :int
+  end
+end
--- a/db/schema.rb
+++ b/db/schema.rb
@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.

-ActiveRecord::Schema.define(version: 2021_08_08_071221) do
+ActiveRecord::Schema.define(version: 2021_11_23_212714) do

  # These are extensions that must be enabled in order to support this database
  enable_extension "plpgsql"
@ -689,6 +689,20 @@ ActiveRecord::Schema.define(version: 2021_08_08_071221) do
    t.index ["status_id"], name: "index_polls_on_status_id"
  end

+  create_table "preview_card_providers", force: :cascade do |t|
+    t.string "domain", default: "", null: false
+    t.string "icon_file_name"
+    t.string "icon_content_type"
+    t.bigint "icon_file_size"
+    t.datetime "icon_updated_at"
+    t.boolean "trendable"
+    t.datetime "reviewed_at"
+    t.datetime "requested_review_at"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["domain"], name: "index_preview_card_providers_on_domain", unique: true
+  end
+
  create_table "preview_cards", force: :cascade do |t|
    t.string "url", default: "", null: false
    t.string "title", default: "", null: false
@ -710,6 +724,11 @@ ActiveRecord::Schema.define(version: 2021_08_08_071221) do
    t.string "embed_url", default: "", null: false
    t.integer "image_storage_schema_version"
    t.string "blurhash"
+    t.string "language"
+    t.float "max_score"
+    t.datetime "max_score_at"
+    t.boolean "trendable"
+    t.integer "link_type"
    t.index ["url"], name: "index_preview_cards_on_url", unique: true
  end

--- a/lib/mastodon/snowflake.rb
+++ b/lib/mastodon/snowflake.rb
@ -84,10 +84,7 @@ module Mastodon::Snowflake
              -- Take the first two bytes (four hex characters)
              substr(
                -- Of the MD5 hash of the data we documented
-                md5(table_name ||
-                  '#{SecureRandom.hex(16)}' ||
-                  time_part::text
-                ),
+                md5(table_name || '#{SecureRandom.hex(16)}' || time_part::text),
                1, 4
              )
            -- And turn it into a bigint
--- a/lib/tasks/repo.rake
+++ b/lib/tasks/repo.rake
@ -96,7 +96,7 @@ namespace :repo do
    end.uniq.compact

    missing_available_locales = locales_in_files - I18n.available_locales
-    missing_locale_names = I18n.available_locales.reject { |locale| SettingsHelper::HUMAN_LOCALES.key?(locale) }
+    missing_locale_names = I18n.available_locales.reject { |locale| LanguagesHelper::HUMAN_LOCALES.key?(locale) }

    critical = false

--- a/spec/controllers/admin/tags_controller_spec.rb
+++ b/spec/controllers/admin/tags_controller_spec.rb
@ -9,18 +9,6 @@ RSpec.describe Admin::TagsController, type: :controller do
    sign_in Fabricate(:user, admin: true)
  end

-  describe 'GET #index' do
-    let!(:tag) { Fabricate(:tag) }
-
-    before do
-      get :index
-    end
-
-    it 'returns status 200' do
-      expect(response).to have_http_status(200)
-    end
-  end
-
  describe 'GET #show' do
    let!(:tag) { Fabricate(:tag) }

--- a/spec/controllers/api/v1/trends/tags_controller_spec.rb
+++ b/spec/controllers/api/v1/trends/tags_controller_spec.rb
@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Api::V1::Trends::TagsController, type: :controller do
+  render_views
+
+  describe 'GET #index' do
+    before do
+      trending_tags = double()
+
+      allow(trending_tags).to receive(:get).and_return(Fabricate.times(10, :tag))
+      allow(Trends).to receive(:tags).and_return(trending_tags)
+
+      get :index
+    end
+
+    it 'returns http success' do
+      expect(response).to have_http_status(200)
+    end
+  end
+end
--- a/spec/controllers/api/v1/trends_controller_spec.rb
+++ b/spec/controllers/api/v1/trends_controller_spec.rb
@ -1,18 +0,0 @@
-# frozen_string_literal: true
-
-require 'rails_helper'
-
-RSpec.describe Api::V1::TrendsController, type: :controller do
-  render_views
-
-  describe 'GET #index' do
-    before do
-      allow(TrendingTags).to receive(:get).and_return(Fabricate.times(10, :tag))
-      get :index
-    end
-
-    it 'returns http success' do
-      expect(response).to have_http_status(200)
-    end
-  end
-end
--- a/spec/helpers/languages_helper_spec.rb
+++ b/spec/helpers/languages_helper_spec.rb
@ -2,20 +2,15 @@

 require 'rails_helper'

-describe SettingsHelper do
+describe LanguagesHelper do
  describe 'the HUMAN_LOCALES constant' do
    it 'includes all I18n locales' do
-      options = I18n.available_locales
-
-      expect(described_class::HUMAN_LOCALES.keys).to include(*options)
+      expect(described_class::HUMAN_LOCALES.keys).to include(*I18n.available_locales)
    end
  end

  describe 'human_locale' do
    it 'finds the human readable local description from a key' do
-      # Ensure the value is as we expect
-      expect(described_class::HUMAN_LOCALES[:en]).to eq('English')
-
      expect(helper.human_locale(:en)).to eq('English')
    end
  end
--- a/spec/mailers/previews/admin_mailer_preview.rb
+++ b/spec/mailers/previews/admin_mailer_preview.rb
@ -5,4 +5,14 @@ class AdminMailerPreview < ActionMailer::Preview
  def new_pending_account
    AdminMailer.new_pending_account(Account.first, User.pending.first)
  end
+
+  # Preview this email at http://localhost:3000/rails/mailers/admin_mailer/new_trending_tags
+  def new_trending_tags
+    AdminMailer.new_trending_tags(Account.first, Tag.limit(3))
+  end
+
+  # Preview this email at http://localhost:3000/rails/mailers/admin_mailer/new_trending_links
+  def new_trending_links
+    AdminMailer.new_trending_links(Account.first, PreviewCard.limit(3))
+  end
 end
--- a/spec/models/trending_tags_spec.rb
+++ b/spec/models/trending_tags_spec.rb
@ -1,68 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe TrendingTags do
-  describe '.record_use!' do
-    pending
-  end
-
-  describe '.update!' do
-    let!(:at_time) { Time.now.utc }
-    let!(:tag1) { Fabricate(:tag, name: 'Catstodon', trendable: true) }
-    let!(:tag2) { Fabricate(:tag, name: 'DogsOfMastodon', trendable: true) }
-    let!(:tag3) { Fabricate(:tag, name: 'OCs', trendable: true) }
-
-    before do
-      allow(Redis.current).to receive(:pfcount) do |key|
-        case key
-        when "activity:tags:#{tag1.id}:#{(at_time - 1.day).beginning_of_day.to_i}:accounts"
-          2
-        when "activity:tags:#{tag1.id}:#{at_time.beginning_of_day.to_i}:accounts"
-          16
-        when "activity:tags:#{tag2.id}:#{(at_time - 1.day).beginning_of_day.to_i}:accounts"
-          0
-        when "activity:tags:#{tag2.id}:#{at_time.beginning_of_day.to_i}:accounts"
-          4
-        when "activity:tags:#{tag3.id}:#{(at_time - 1.day).beginning_of_day.to_i}:accounts"
-          13
-        end
-      end
-
-      Redis.current.zadd('trending_tags', 0.9, tag3.id)
-      Redis.current.sadd("trending_tags:used:#{at_time.beginning_of_day.to_i}", [tag1.id, tag2.id])
-
-      tag3.update(max_score: 0.9, max_score_at: (at_time - 1.day).beginning_of_day + 12.hours)
-
-      described_class.update!(at_time)
-    end
-
-    it 'calculates and re-calculates scores' do
-      expect(described_class.get(10, filtered: false)).to eq [tag1, tag3]
-    end
-
-    it 'omits hashtags below threshold' do
-      expect(described_class.get(10, filtered: false)).to_not include(tag2)
-    end
-
-    it 'decays scores' do
-      expect(Redis.current.zscore('trending_tags', tag3.id)).to be < 0.9
-    end
-  end
-
-  describe '.trending?' do
-    let(:tag) { Fabricate(:tag) }
-
-    before do
-      10.times { |i| Redis.current.zadd('trending_tags', i + 1, Fabricate(:tag).id) }
-    end
-
-    it 'returns true if the hashtag is within limit' do
-      Redis.current.zadd('trending_tags', 11, tag.id)
-      expect(described_class.trending?(tag)).to be true
-    end
-
-    it 'returns false if the hashtag is outside the limit' do
-      Redis.current.zadd('trending_tags', 0, tag.id)
-      expect(described_class.trending?(tag)).to be false
-    end
-  end
-end
--- a/spec/models/trends/tags_spec.rb
+++ b/spec/models/trends/tags_spec.rb
@ -0,0 +1,67 @@
+require 'rails_helper'
+
+RSpec.describe Trends::Tags do
+  subject { described_class.new(threshold: 5, review_threshold: 10) }
+
+  let!(:at_time) { DateTime.new(2021, 11, 14, 10, 15, 0) }
+
+  describe '#add' do
+    let(:tag) { Fabricate(:tag) }
+
+    before do
+      subject.add(tag, 1, at_time)
+    end
+
+    it 'records history' do
+      expect(tag.history.get(at_time).accounts).to eq 1
+    end
+
+    it 'records use' do
+      expect(subject.send(:recently_used_ids, at_time)).to eq [tag.id]
+    end
+  end
+
+  describe '#get' do
+    pending
+  end
+
+  describe '#refresh' do
+    let!(:today) { at_time }
+    let!(:yesterday) { today - 1.day }
+
+    let!(:tag1) { Fabricate(:tag, name: 'Catstodon', trendable: true) }
+    let!(:tag2) { Fabricate(:tag, name: 'DogsOfMastodon', trendable: true) }
+    let!(:tag3) { Fabricate(:tag, name: 'OCs', trendable: true) }
+
+    before do
+      2.times  { |i| subject.add(tag1, i, yesterday) }
+      13.times { |i| subject.add(tag3, i, yesterday) }
+      16.times { |i| subject.add(tag1, i, today) }
+      4.times  { |i| subject.add(tag2, i, today) }
+    end
+
+    context do
+      before do
+        subject.refresh(yesterday + 12.hours)
+        subject.refresh(at_time)
+      end
+
+      it 'calculates and re-calculates scores' do
+        expect(subject.get(false, 10)).to eq [tag1, tag3]
+      end
+
+      it 'omits hashtags below threshold' do
+        expect(subject.get(false, 10)).to_not include(tag2)
+      end
+    end
+
+    it 'decays scores' do
+      subject.refresh(yesterday + 12.hours)
+      original_score = subject.score(tag3.id)
+      expect(original_score).to eq 144.0
+      subject.refresh(yesterday + 12.hours + subject.options[:max_score_halflife])
+      decayed_score = subject.score(tag3.id)
+      expect(decayed_score).to be <= original_score / 2
+    end
+  end
+end