Add interface for moderation subscriptions and suggestions

app/controllers/admin/moderation_subscriptions_controller.rb

@@ -0,0 +1,96 @@
+# frozen_string_literal: true
+
+class Admin::ModerationSubscriptionsController < Admin::BaseController
+  before_action :set_moderation_subscriptions, only: :index
+  before_action :set_moderation_subscription, only: [:show, :edit, :update, :destroy]
+  before_action :set_subscribed_advisories, only: :show
+
+  def index
+    authorize :moderation_subscription, :index?
+  end
+
+  def show
+    authorize @moderation_subscription, :show?
+  end
+
+  def new
+    authorize :moderation_subscription, :create?
+    @moderation_subscription = ModerationSubscription.new
+  end
+
+  def edit
+    authorize @moderation_subscription, :update?
+  end
+
+  def create
+    authorize :moderation_subscription, :create?
+
+    # TODO: require confirmation for dangerous subscriptions
+
+    @moderation_subscription = ModerationSubscription.new(resource_params.merge('type' => 'csv_list'))
+
+    if @moderation_subscription.save
+      log_action :create, @moderation_subscription
+      redirect_to admin_moderation_subscriptions_path
+    else
+      render :new
+    end
+  end
+
+  def update
+    authorize @moderation_subscription, :update?
+
+    # TODO: require confirmation for dangerous subscriptions
+
+    if @moderation_subscription.update(resource_params)
+      log_action :update, @moderation_subscription
+      redirect_to admin_moderation_subscription_path(@moderation_subscription)
+    else
+      render :edit
+    end
+  end
+
+  def destroy
+    authorize @moderation_subscription, :destroy?
+
+    ModerationSubscription.transaction do
+      # Re-run moderation list service with empty list to ensure
+      # Retractions are handled properly
+      @moderation_subscription.advisories.delete_all
+      ProcessModerationListsService.new.call
+
+      @moderation_subscription.destroy!
+      log_action :destroy, @moderation_subscription
+    end
+
+    redirect_to admin_moderation_subscriptions_path, notice: I18n.t('admin.moderation_subscriptions.destroyed_msg')
+  end
+
+  def logs
+    authorize :moderation_subscription, :index?
+
+    @action_logs = Admin::ActionLog.latest.where.not(moderation_subscription_id: nil).page(params[:page])
+  end
+
+  private
+
+  def resource_params
+    params.expect(
+      moderation_subscription: [
+        :name, :url, :priority, :list_action, :apply_conditions, :retract_automatically
+      ]
+    )
+  end
+
+  def set_moderation_subscriptions
+    @moderation_subscriptions = ModerationSubscription.order(priority: :asc)
+  end
+
+  def set_moderation_subscription
+    @moderation_subscription = ModerationSubscription.find(params[:id])
+  end
+
+  def set_subscribed_advisories
+    @subscribed_advisories = @moderation_subscription.advisories.order(id: :asc).page(params[:page])
+  end
+end

app/controllers/admin/moderation_suggestions_controller.rb

@@ -0,0 +1,159 @@
+# frozen_string_literal: true
+
+class Admin::ModerationSuggestionsController < Admin::BaseController
+  before_action :set_moderation_suggestion_targets, only: :index
+  before_action :set_moderation_suggestions_by_target, only: :index
+  before_action :set_moderation_advisories_by_target, only: :index
+  before_action :set_current_state_by_target, only: :index
+  before_action :set_moderation_suggestion, only: [:destroy, :apply]
+
+  def index
+    authorize :moderation_suggestion, :index?
+  end
+
+  def destroy
+    authorize @moderation_suggestion, :dismiss?
+
+    # TODO: log?
+
+    # Actually dismiss all of the suggestions for the same target
+    ModerationSuggestion.where(target_type: @moderation_suggestion.target_type, target_key: @moderation_suggestion.target_key).update_all(state: :dismissed)
+
+    redirect_to admin_moderation_suggestions_path, notice: I18n.t('admin.moderation_suggestions.destroyed_msg', target_key: @moderation_suggestion.target_key)
+  end
+
+  def apply
+    authorize @moderation_suggestion, :apply?
+
+    case [@moderation_suggestion.target_type, @moderation_suggestion.action]
+    when ['domain', 'accept']
+      domain_allow = @moderation_suggestion.to_domain_allow
+
+      ApplicationRecord.transaction do
+        # TODO: log
+        domain_allow.save!
+        @moderation_suggestion.mark_as_applied!
+      end
+
+      redirect_to admin_moderation_suggestions_path, notice: I18n.t('admin.moderation_suggestions.applied_msg', target_key: @moderation_suggestion.target_key)
+    when ['domain', 'reject'], ['domain', 'limit']
+      domain_block = @moderation_suggestion.to_domain_block
+
+      # TODO: factor with `DomainBlocksController#create`?
+      existing_domain_block = DomainBlock.rule_for(domain_block.domain)
+
+      # We can't create a laxer block for a subdomain than we have for a domain
+      if existing_domain_block.present? && existing_domain_block.domain != TagManager.instance.normalize_domain(domain_block.domain) && !domain_block.stricter_than?(existing_domain_block)
+        return redirect_to admin_moderation_suggestions_path,
+                           alert: I18n.t('admin.moderation_suggestions.unable_to_apply_msg',
+                                         target_key: @moderation_suggestion.target_key)
+      end
+
+      update = false
+
+      # Allow transparently upgrading a domain block
+      if existing_domain_block.present? && existing_domain_block.domain == TagManager.instance.normalize_domain(domain_block.domain)
+        # Downgrading requires confirmation
+        return render :confirm_downgrade unless domain_block.stricter_than?(existing_domain_block) || params[:confirm_downgrade]
+
+        # Transparent upgrading is allowed
+        existing_domain_block.assign_attributes(domain_block.attributes.without('id', 'created_at', 'updated_at'))
+        domain_block = existing_domain_block
+
+        update = domain_block.severity_changed?
+      end
+
+      # Require explicit confirmation on block
+      return render :confirm_reject if requires_confirmation?(domain_block)
+
+      domain_block.save!
+      # TODO: is this the way we want to log it?
+      log_action (update ? :update : :create), domain_block, moderation_subscription_id: domain_block.moderation_subscription_id
+      DomainBlockWorker.perform_async(domain_block.id, update)
+      @moderation_suggestion.mark_as_applied!
+
+      redirect_to admin_moderation_suggestions_path, notice: I18n.t('admin.moderation_suggestions.applied_msg', target_key: @moderation_suggestion.target_key)
+    when ['domain', 'retract']
+      ApplicationRecord.transaction do
+        if Rails.configuration.x.mastodon.limited_federation_mode
+          domain_allow = DomainAllow.find_by(domain: @moderation_suggestion.target_key)
+          UnallowDomainService.new.call(domain_allow)
+          # TODO: is this the way we want to log it?
+          log_action :destroy, domain_allow, moderation_subscription_id: domain_block.moderation_subscription_id
+        else
+          domain_block = DomainBlock.find_by(domain: @moderation_suggestion.target_key)
+          UnblockDomainService.new.call(domain_block)
+          # TODO: is this the way we want to log it?
+          log_action :destroy, domain_block, moderation_subscription_id: domain_block.moderation_subscription_id
+        end
+
+        @moderation_suggestion.mark_as_applied!
+      end
+
+      redirect_to admin_moderation_suggestions_path, notice: I18n.t('admin.moderation_suggestions.retracted_msg', target_key: @moderation_suggestion.target_key)
+    end
+  end
+
+  private
+
+  def requires_confirmation?(domain_block)
+    domain_block.valid? && (domain_block.new_record? || domain_block.severity_changed?) && domain_block.suspend? && !params[:confirm]
+  end
+
+  def set_moderation_suggestion_targets
+    @moderation_suggestion_targets = ModerationSuggestion.where(state: ['new', 'mailed']).reorder([target_type: :asc, target_key: :asc]).distinct.pluck(:target_type, :target_key)
+  end
+
+  def set_moderation_suggestions_by_target
+    @moderation_suggestions_by_target = begin
+      @moderation_suggestion_targets.group_by(&:first).reduce(ModerationSuggestion.none) do |scope, (target_type, target_pairs)|
+        scope.or(ModerationSuggestion.where(target_type: target_type, target_key: target_pairs.map(&:second)))
+      end
+    end.group_by { |suggestion| [suggestion.target_type, suggestion.target_key] }
+  end
+
+  def set_moderation_advisories_by_target
+    @moderation_advisories_by_target = begin
+      @moderation_suggestion_targets.group_by(&:first).reduce(SubscribedAdvisory.none) do |scope, (target_type, target_pairs)|
+        scope.or(SubscribedAdvisory.joins(:moderation_subscription).where(target_type: target_type, target_key: target_pairs.map(&:second)))
+      end
+    end.group_by { |advisory| [advisory.target_type, advisory.target_key] }
+
+    @moderation_advisories_by_target.each_value do |advisories|
+      advisories.sort_by! { |advisory| advisory.moderation_subscription.priority }
+    end
+
+    @moderation_advisories_by_target
+  end
+
+  def set_current_state_by_target
+    # TODO: handle other target types
+
+    if Rails.configuration.x.mastodon.limited_federation_mode
+      @current_state_by_target = DomainAllow.where(domain: @moderation_suggestion_targets.filter_map { |type, key| key if type == 'domain' }).pluck(:domain).to_h { |domain| [['domain', domain], 'accept'] }
+      @current_state_by_target.default = 'reject'
+    else
+      @current_state_by_target = DomainBlock.where(domain: @moderation_suggestion_targets.filter_map { |type, key| key if type == 'domain' }).to_h do |domain_block|
+        action = begin
+          case domain_block.severity
+          when 'suspend'
+            'reject'
+          when 'silence'
+            'limit'
+          else
+            'accept'
+          end
+        end
+
+        [['domain', domain_block.domain], action]
+      end
+
+      @current_state_by_target.default = 'accept'
+    end
+    @current_state_by_target
+  end
+
+  def set_moderation_suggestion
+    @moderation_suggestion = ModerationSuggestion.find(params[:id])
+  end
+end

app/controllers/concerns/accountable_concern.rb

@@ -3,9 +3,9 @@
 module AccountableConcern
   extend ActiveSupport::Concern
 
-  def log_action(action, target)
+  def log_action(action, target, **)
     current_account
       .action_logs
-      .create(action:, target:)
+      .create(action:, target:, **)
   end
 end

app/helpers/admin/action_logs_helper.rb

@@ -39,6 +39,8 @@ module Admin::ActionLogsHelper
       link_to log.human_identifier, admin_relays_path
     when 'Tag'
       link_to log.human_identifier, admin_tag_path(log.target_id)
+    when 'ModerationSubscription'
+      link_to log.human_identifier, admin_moderation_subscription_path(log.target_id)
     end
   end
 

app/helpers/admin/content_policies_helper.rb

@@ -7,4 +7,18 @@ module Admin::ContentPoliciesHelper
       .map { |policy| I18n.t("admin.instances.content_policies.policies.#{policy}") }
       .join(' · ')
   end
+
+  def moderation_subscription_policy_list(moderation_subscription)
+    policies = []
+
+    if moderation_subscription.apply_automatically?
+      policies << (moderation_subscription.preserve_relationships? ? :apply_advisories_safely : :apply_advisories)
+    end
+
+    policies << :apply_retractions if moderation_subscription.retract_automatically?
+
+    policies
+      .map { |policy| I18n.t("admin.moderation_subscriptions.policies.#{policy}") }
+      .join(' · ')
+  end
 end

app/helpers/admin/moderation_subscriptions_helper.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Admin::ModerationSubscriptionsHelper
+  def moderation_subscription_action_label(type)
+    safe_join(
+      [
+        t("admin.moderation_subscriptions.list_actions.#{type}"),
+        content_tag(:span, t("admin.moderation_subscriptions.list_actions_hint.#{type}"), class: 'hint'),
+      ]
+    )
+  end
+
+  def moderation_subscription_apply_conditions_label(type)
+    safe_join(
+      [
+        t("admin.moderation_subscriptions.apply_conditions.#{type}"),
+        content_tag(:span, t("admin.moderation_subscriptions.apply_conditions_hint.#{type}"), class: 'hint'),
+      ]
+    )
+  end
+
+  def moderation_subscription_badge(subscription)
+    action = subscription.list_action || 'default'
+    return unless %w(accept reject default).include?(action)
+
+    content_tag(
+      :span,
+      I18n.t("admin.moderation_subscriptions.list_actions_short.#{action}"),
+      class: ['information-badge', action]
+    )
+  end
+end

app/helpers/admin/moderation_suggestions_helper.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Admin::ModerationSuggestionsHelper
+  ACTION_ICON_NAMES = {
+    accept: 'check',
+    reject: 'block',
+    limit: 'do_not_disturb_on',
+    retract: 'backspace',
+  }.freeze
+
+  def advisory_action_icon(action)
+    material_symbol(ACTION_ICON_NAMES.fetch(action.to_sym))
+  end
+
+  def advisory_action_link(action, suggestion)
+    link_to(
+      safe_join([advisory_action_icon(action), t("admin.moderation_suggestions.apply_#{action}")]),
+      suggestion ? apply_admin_moderation_suggestion_path(suggestion) : nil,
+      { class: ['button', 'button-secondary', disabled: !suggestion], method: :post }
+    )
+  end
+
+  def suggestion_status_badge(current_state)
+    return unless %w(accept limit reject).include?(current_state)
+
+    content_tag(
+      :span,
+      t("admin.moderation_suggestions.current_states.#{current_state}"),
+      class: ['information-badge', current_state]
+    )
+  end
+end

app/javascript/material-icons/400-24px/backspace.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24" viewBox="0 -960 960 960" width="24"><path d="m456-320 104-104 104 104 56-56-104-104 104-104-56-56-104 104-104-104-56 56 104 104-104 104 56 56Zm-96 160q-19 0-36-8.5T296-192L80-480l216-288q11-15 28-23.5t36-8.5h440q33 0 56.5 23.5T880-720v480q0 33-23.5 56.5T800-160H360ZM180-480l180 240h440v-480H360L180-480Zm400 0Z"/></svg>

app/javascript/material-icons/400-24px/do_not_disturb_on.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24" viewBox="0 -960 960 960" width="24"><path d="M280-440h400v-80H280v80ZM480-80q-83 0-156-31.5T197-197q-54-54-85.5-127T80-480q0-83 31.5-156T197-763q54-54 127-85.5T480-880q83 0 156 31.5T763-763q54 54 85.5 127T880-480q0 83-31.5 156T763-197q-54 54-127 85.5T480-80Zm0-80q134 0 227-93t93-227q0-134-93-227t-227-93q-134 0-227 93t-93 227q0 134 93 227t227 93Zm0-320Z"/></svg>

app/javascript/styles/mastodon/admin.scss

@@ -2511,3 +2511,45 @@ a.sparkline {
     }
   }
 }
+
+// TODO: Temporary hacks for moderation subscriptions interface, rework after design pass
+
+.information-badge {
+  &.accept {
+    color: var(--color-text-success);
+    background-color: var(--color-bg-success-softest);
+    border-color: var(--color-border-success-soft);
+  }
+
+  &.reject {
+    color: var(--color-text-error);
+    background-color: var(--color-bg-error-softest);
+    border-color: var(--color-border-error-soft);
+  }
+
+  &.limit {
+    color: var(--color-text-warning);
+    background-color: var(--color-bg-warning-softest);
+    border-color: var(--color-border-warning-soft);
+  }
+}
+
+.permissions-list__item__text__type a {
+  color: inherit;
+}
+
+.moderation_suggestion-retract {
+  color: inherit;
+}
+
+.moderation_suggestion-limit {
+  color: var(--color-text-warning);
+}
+
+.moderation_suggestion-reject {
+  color: var(--color-text-error);
+}
+
+.permissions-list__item .table-action-link {
+  padding: 0;
+}

app/models/moderation_subscription.rb

@@ -40,4 +40,31 @@ class ModerationSubscription < ApplicationRecord
     accept: 0,
     reject: 1,
   }, suffix: :action
+
+  def to_log_human_identifier
+    name
+  end
+
+  def apply_conditions
+    if apply_automatically?
+      preserve_relationships? ? :safely : :always
+    else
+      :never
+    end
+  end
+
+  def apply_conditions=(conditions)
+    case conditions.to_s
+    when 'never'
+      self.apply_automatically = false
+    when 'always'
+      self.apply_automatically = true
+      self.preserve_relationships = false
+    when 'safely'
+      self.apply_automatically = true
+      self.preserve_relationships = true
+    else
+      raise ArgumentError
+    end
+  end
 end

app/models/moderation_suggestion.rb

@@ -36,6 +36,23 @@ class ModerationSuggestion < ApplicationRecord
 
   before_validation :normalize_target_key
 
+  def mark_as_applied!
+    update!(state: :applied)
+    ModerationSuggestion.where(target_type: target_type, target_key: target_key).where.not(id: id).update_all(state: :dismissed)
+  end
+
+  def to_domain_allow
+    raise ArgumentError unless target_type == 'domain' && action == 'accept'
+
+    DomainAllow.new(domain: target_key, moderation_subscription_id: moderation_subscription_id)
+  end
+
+  def to_domain_block
+    raise ArgumentError unless target_type == 'domain' && %w(limit reject).include?(action)
+
+    DomainBlock.new(domain: target_key, moderation_subscription_id: moderation_subscription_id, severity: action == 'reject' ? :suspend : :silence)
+  end
+
   private
 
   def normalize_target_key

app/policies/moderation_subscription_policy.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class ModerationSubscriptionPolicy < ApplicationPolicy
+  def index?
+    role.can?(:manage_federation)
+  end
+
+  def show?
+    role.can?(:manage_federation)
+  end
+
+  def create?
+    role.can?(:manage_federation)
+  end
+
+  def update?
+    role.can?(:manage_federation)
+  end
+
+  def destroy?
+    role.can?(:manage_federation)
+  end
+end

app/policies/moderation_suggestion_policy.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class ModerationSuggestionPolicy < ApplicationPolicy
+  def index?
+    role.can?(:manage_federation)
+  end
+
+  def show?
+    role.can?(:manage_federation)
+  end
+
+  def dismiss?
+    role.can?(:manage_federation)
+  end
+
+  def apply?
+    role.can?(:manage_federation)
+  end
+end

app/views/admin/moderation_subscriptions/_advisory.html.haml

@@ -0,0 +1,6 @@
+.directory__tag
+  = link_to admin_instance_path(advisory.target_key) do
+    %h4
+      = advisory.target_key
+
+      %small= t('admin.moderation_subscriptions.advisory_action', action: t("admin.moderation_subscriptions.advisory_actions.#{advisory.action}"))

app/views/admin/moderation_subscriptions/_form.html.haml

@@ -0,0 +1,50 @@
+.fields-group
+  = form.input :name,
+               label: t('admin.moderation_subscriptions.name'),
+               wrapper: :with_label
+
+.fields-group
+  = form.input :url,
+               label: t('admin.moderation_subscriptions.url'),
+               wrapper: :with_label
+
+.fields-group
+  = form.input :priority,
+               label: t('admin.moderation_subscriptions.priority'),
+               hint: t('admin.moderation_subscriptions.priority_hint'),
+               wrapper: :with_label
+
+.fields-group
+  = form.input :list_action,
+               as: :radio_buttons,
+               collection: [nil, 'accept', 'reject'],
+               collection_wrapper_tag: 'ul',
+               item_wrapper_tag: 'li',
+               label_method: ->(type) { moderation_subscription_action_label(type || 'default') },
+               label: t('admin.moderation_subscriptions.list_action'),
+               wrapper: :with_label
+
+.fields-group
+  = form.input :apply_conditions,
+               as: :radio_buttons,
+               collection: %w(never safely always),
+               collection_wrapper_tag: 'ul',
+               item_wrapper_tag: 'li',
+               include_blank: false,
+               label_method: ->(type) { moderation_subscription_apply_conditions_label(type) },
+               label: t('admin.moderation_subscriptions.apply_automatically'),
+               wrapper: :with_label
+
+.fields-group
+  = form.input :override_unattributed,
+               as: :boolean,
+               wrapper: :with_label,
+               label: t('admin.moderation_subscriptions.override_unattributed'),
+               hint: t('admin.moderation_subscriptions.override_unattributed_hint')
+
+.fields-group
+  = form.input :retract_automatically,
+               as: :boolean,
+               wrapper: :with_label,
+               label: t('admin.moderation_subscriptions.retract_automatically'),
+               hint: t('admin.moderation_subscriptions.retract_automatically_hint')

app/views/admin/moderation_subscriptions/_moderation_subscription.html.haml

@@ -0,0 +1,10 @@
+.applications-list__item
+  = link_to admin_moderation_subscription_path(moderation_subscription), class: 'announcements-list__item__title' do
+    = moderation_subscription.name
+    = moderation_subscription_badge(moderation_subscription)
+
+  .announcements-list__item__permissions
+    .announcements-list__item__meta
+      = moderation_subscription.url
+    .announcements-list__item__meta
+      = moderation_subscription_policy_list(moderation_subscription)

app/views/admin/moderation_subscriptions/edit.html.haml

@@ -0,0 +1,12 @@
+- content_for :page_title do
+  = I18n.t('admin.moderation_subscriptions.show.title', name: @moderation_subscription.name)
+
+= simple_form_for [:admin, @moderation_subscription] do |form|
+  = render 'shared/error_messages', object: @moderation_subscription
+
+  = render form
+
+  .actions
+    = form.button :button,
+                  t('generic.save_changes'),
+                  type: :submit

app/views/admin/moderation_subscriptions/index.html.haml

@@ -0,0 +1,20 @@
+- content_for(:page_title) do
+  = t('admin.moderation_subscriptions.title')
+
+- content_for(:heading) do
+  .content__heading__row
+    %h1= yield :page_title
+
+    .content__heading__actions
+      = link_to t('admin.moderation_subscriptions.add_new'), new_admin_moderation_subscription_path, class: 'button', id: 'add-subscription-button' if can?(:create, :moderation_subscription)
+
+  = render 'admin/moderation_subscriptions/shared/links'
+
+%hr.spacer/
+
+- if @moderation_subscriptions.empty?
+  .muted-hint.center-text
+    = t 'admin.moderation_subscriptions.empty'
+- else
+  .applications-list
+    = render partial: 'moderation_subscription', collection: @moderation_subscriptions

app/views/admin/moderation_subscriptions/logs.html.haml

@@ -0,0 +1,16 @@
+- content_for(:heading) do
+  .content__heading__row
+    %h1= t('admin.moderation_subscriptions_logs.title')
+
+  = render 'admin/moderation_subscriptions/shared/links'
+
+%hr.spacer/
+
+- if @action_logs.empty?
+  .muted-hint.center-text
+    = t 'admin.action_logs.empty'
+- else
+  .report-notes
+    = render partial: 'admin/action_logs/action_log', collection: @action_logs
+
+= paginate @action_logs

app/views/admin/moderation_subscriptions/new.html.haml

@@ -0,0 +1,12 @@
+- content_for :page_title do
+  = t('admin.moderation_subscriptions.new.title')
+
+= simple_form_for [:admin, @moderation_subscription] do |form|
+  = render 'shared/error_messages', object: @moderation_subscription
+
+  = render form
+
+  .actions
+    = form.button :button,
+                  t('.create'),
+                  type: :submit

app/views/admin/moderation_subscriptions/shared/_links.html.haml

@@ -0,0 +1,6 @@
+.content__heading__tabs
+  = render_navigation renderer: :links do |primary|
+    :ruby
+      primary.item :suggestions, safe_join([material_symbol('flag'), t('admin.moderation_subscriptions.tabs.suggestions')]), admin_moderation_suggestions_path
+      primary.item :subscriptions, safe_join([material_symbol('edit'), t('admin.moderation_subscriptions.tabs.subscriptions')]), admin_moderation_subscriptions_path
+      primary.item :logs, safe_join([material_symbol('list'), t('admin.moderation_subscriptions.tabs.logs')]), logs_admin_moderation_subscriptions_path

app/views/admin/moderation_subscriptions/show.html.haml

@@ -0,0 +1,53 @@
+- content_for :page_title do
+  = I18n.t('admin.moderation_subscriptions.show.title', name: @moderation_subscription.name)
+
+- content_for :heading_actions do
+  - if can?(:destroy, @moderation_subscription)
+    = link_to t('admin.moderation_subscriptions.delete'),
+              admin_moderation_subscription_path(@moderation_subscription),
+              method: :delete,
+              data: { confirm: t('admin.moderation_subscriptions.show.delete_confirm') },
+              class: 'button button--destructive'
+
+.table-wrapper
+  %table.table.inline-table
+    %tbody
+      %tr
+        %th= t('admin.moderation_subscriptions.priority')
+        %td= @moderation_subscription.priority
+      %tr
+        %th= t('admin.moderation_subscriptions.type')
+        %td= t("admin.moderation_subscriptions.types.#{@moderation_subscription.type}")
+      %tr
+        %th= t('admin.moderation_subscriptions.url')
+        %td= @moderation_subscription.url
+      %tr
+        %th= t('admin.moderation_subscriptions.list_action')
+        %td= t("admin.moderation_subscriptions.list_actions.#{@moderation_subscription.list_action || 'default'}")
+      %tr
+        %th= t('admin.moderation_subscriptions.apply_automatically')
+        %td= t("admin.moderation_subscriptions.apply_conditions.#{@moderation_subscription.apply_conditions}")
+      %tr
+        %th= t('admin.moderation_subscriptions.override_unattributed')
+        %td= @moderation_subscription.override_unattributed? ? t('simple_form.yes') : t('simple_form.no')
+      %tr
+        %th= t('admin.moderation_subscriptions.retract_automatically')
+        %td= @moderation_subscription.retract_automatically? ? t('admin.moderation_subscriptions.apply_conditions.always') : t('admin.moderation_subscriptions.apply_conditions.never')
+      - if @moderation_subscription.last_synced_at.present?
+        %tr
+          %th= t('admin.moderation_subscriptions.last_synced_at')
+          %td
+            %time.formatted{ datetime: @moderation_subscription.last_synced_at.iso8601 }= @moderation_subscription.last_synced_at
+
+.action-buttons
+  = link_to t('admin.moderation_subscriptions.show.edit'), edit_admin_moderation_subscription_path(@moderation_subscription), class: 'button' if can?(:update, @moderation_subscription)
+
+%hr.spacer/
+
+- if @subscribed_advisories.empty?
+  .muted-hint.center-text
+    = t('admin.moderation_subscriptions.show.empty')
+- else
+  = render partial: 'advisory', collection: @subscribed_advisories
+
+= paginate @subscribed_advisories

app/views/admin/moderation_suggestions/_moderation_suggestion_target.html.haml

@@ -0,0 +1,38 @@
+.applications-list__item
+  - target_type, target_key = moderation_suggestion_target
+  - suggestions = moderation_suggestions_by_target[[target_type, target_key]]
+
+  = link_to admin_instance_path(target_key), class: 'announcements-list__item__title' do
+    = target_key
+    = suggestion_status_badge(current_state_by_target[[target_type, target_key]])
+
+  .announcements-list__item__action-bar
+    .announcements-list__item__meta
+      = t('admin.moderation_suggestions.description')
+
+    .announcements-list__item__actions
+      = table_link_to 'close', t('admin.moderation_suggestions.dismiss'), admin_moderation_suggestion_path(suggestions.first), method: :delete
+
+  .announcements-list__item__permissions
+    %ul.permissions-list
+      - actions = (moderation_advisories_by_target[[target_type, target_key]] || []).pluck(:action).uniq
+      - actions = ['retract'] + actions if suggestions&.any? { |suggestion| suggestion.action == 'retract' }
+      - actions.map do |action|
+        :ruby
+          advisories = moderation_advisories_by_target.fetch([target_type, target_key], []).filter { |advisory| advisory.action == action }
+          moderation_suggestion = suggestions&.find { |suggestion| suggestion.action == action }
+          subscriptions = (advisories.map(&:moderation_subscription) + [moderation_suggestion&.moderation_subscription]).compact.uniq
+
+        %li.permissions-list__item
+          .permissions-list__item__icon{ class: "moderation_suggestion-#{action}" }
+            = advisory_action_icon(action)
+          .permissions-list__item__text
+            .permissions-list__item__text__title
+              = t(action, scope: 'admin.moderation_suggestions.actions')
+            .permissions-list__item__text__type
+              = t('admin.moderation_suggestions.suggested_from_html', link: to_sentence(subscriptions.map { |subscription| link_to(subscription.name, admin_moderation_subscription_path(subscription)) }))
+          - if moderation_suggestion && can?(:apply, moderation_suggestion)
+            = table_link_to 'check',
+                            t("admin.moderation_suggestions.apply_#{moderation_suggestion.action}"),
+                            apply_admin_moderation_suggestion_path(moderation_suggestion),
+                            method: :post

app/views/admin/moderation_suggestions/confirm_downgrade.html.haml

@@ -0,0 +1,13 @@
+- content_for :page_title do
+  = t('admin.domain_blocks.confirm_downgrade.title', domain: Addressable::IDNA.to_unicode(@moderation_suggestion.target_key))
+
+= simple_form_for @moderation_suggestion, url: apply_admin_moderation_suggestion_path, method: :post do |f|
+  %p.hint= t('admin.domain_blocks.confirm_downgrade.preamble_html', domain: Addressable::IDNA.to_unicode(@moderation_suggestion.target_key))
+
+  = f.hidden_field :id
+
+  %hr.spacer
+
+  .actions
+    = link_to t('admin.domain_blocks.confirm_downgrade.cancel'), admin_moderation_suggestions_path, class: 'button button-secondary'
+    = f.button :submit, t('admin.domain_blocks.confirm_downgrade.confirm'), class: 'button button--dangerous', name: :confirm_downgrade

app/views/admin/moderation_suggestions/confirm_reject.html.haml

@@ -0,0 +1,21 @@
+- content_for :page_title do
+  = t('admin.domain_blocks.confirm_suspension.title', domain: Addressable::IDNA.to_unicode(@moderation_suggestion.target_key))
+
+= simple_form_for @moderation_suggestion, url: apply_admin_moderation_suggestion_path, method: :post do |f|
+  %p.hint= t('admin.domain_blocks.confirm_suspension.preamble_html', domain: Addressable::IDNA.to_unicode(@moderation_suggestion.target_key))
+  %ul.hint
+    %li= t('admin.domain_blocks.confirm_suspension.stop_communication')
+    %li= t('admin.domain_blocks.confirm_suspension.remove_all_data')
+    %li= t('admin.domain_blocks.confirm_suspension.undo_relationships')
+    %li.negative-hint= t('admin.domain_blocks.confirm_suspension.permanent_action')
+
+  = f.hidden_field :id
+
+  %hr.spacer
+
+  = react_admin_component :impact_report,
+                          domain: @moderation_suggestion.target_key
+
+  .actions
+    = link_to t('admin.domain_blocks.confirm_suspension.cancel'), admin_moderation_suggestions_path, class: 'button button-secondary'
+    = f.button :submit, t('admin.domain_blocks.confirm_suspension.confirm'), class: 'button button--dangerous', name: :confirm

app/views/admin/moderation_suggestions/index.html.haml

@@ -0,0 +1,19 @@
+- content_for :page_title do
+  = t('admin.moderation_suggestions.title')
+
+- content_for(:heading) do
+  .content__heading__row
+    %h1= yield :page_title
+
+  = render 'admin/moderation_subscriptions/shared/links'
+
+%hr.spacer/
+
+- if @moderation_suggestion_targets.empty?
+  .muted-hint.center-text
+    = t 'admin.moderation_suggestions.empty'
+- else
+  .applications-list
+    = render partial: 'moderation_suggestion_target',
+             collection: @moderation_suggestion_targets,
+             locals: { moderation_advisories_by_target: @moderation_advisories_by_target, moderation_suggestions_by_target: @moderation_suggestions_by_target, current_state_by_target: @current_state_by_target }

config/locales/en.yml

@@ -279,6 +279,7 @@ en:
         create_domain_block_html: "%{name} blocked domain %{target}"
         create_email_domain_block_html: "%{name} blocked email domain %{target}"
         create_ip_block_html: "%{name} created rule for IP %{target}"
+        create_moderation_subscription_html: "%{name} created moderation subscription %{target}"
         create_relay_html: "%{name} created a relay %{target}"
         create_unavailable_domain_html: "%{name} stopped delivery to domain %{target}"
         create_user_role_html: "%{name} created %{target} role"
@@ -293,6 +294,7 @@ en:
         destroy_email_domain_block_html: "%{name} unblocked email domain %{target}"
         destroy_instance_html: "%{name} purged domain %{target}"
         destroy_ip_block_html: "%{name} deleted rule for IP %{target}"
+        destroy_moderation_subscription_html: "%{name} deleted moderation subscription %{target}"
         destroy_relay_html: "%{name} deleted the relay %{target}"
         destroy_status_html: "%{name} removed post by %{target}"
         destroy_unavailable_domain_html: "%{name} resumed delivery to domain %{target}"
@@ -342,6 +344,7 @@ en:
         update_username_block_html: "%{name} updated rule for usernames containing %{target}"
         usable_tag_html: can be used;
       deleted_account: deleted account
+      deleted_suggestion: a deleted moderation subscription
       empty: No logs found.
       filter_by_action: Filter by action
       filter_by_user: Filter by user
@@ -460,6 +463,11 @@ en:
       undo: Disallow federation with domain
     domain_blocks:
       add_new: Add new domain block
+      confirm_downgrade:
+        cancel: Cancel
+        confirm: Downgrade
+        preamble_html: You are about to downgrade the existing block on <strong>%{domain}</strong> and its subdomains.
+        title: Confirm domain block downgrade for %{domain}
       confirm_suspension:
         cancel: Cancel
         confirm: Suspend
@@ -758,6 +766,92 @@ en:
       reset: Reset
       search: Search
       title: IP rules
+    moderation_subscriptions:
+      add_new: Add subscription
+      advisory_action: 'Action: %{action}'
+      advisory_actions:
+        accept: allow
+        limit: silence
+        reject: suspend
+      apply_automatically: Apply advisories automatically
+      apply_conditions:
+        always: Always
+        never: Never
+        safely: Only if it does not break relationships
+      apply_conditions_hint:
+        always: Always apply recommended actions automatically. Only use this option for lists you fully trust.
+        never: Never apply recommended actions automatically. Always generate a suggestion instead.
+        safely: Apply recommended actions unless they would break existing follow relationships with local users. In such cases, a suggestion will be generated instead.
+      delete: Delete
+      destroyed_msg: Successfully deleted moderation subscription
+      empty: No moderation list has been subscribed to yet.
+      last_synced_at: Last synced at
+      list_action: Subscription type
+      list_actions:
+        accept: Allow-list
+        default: Mixed (Allow & Deny)
+        reject: Block-list
+      list_actions_hint:
+        accept: Items with no specified action will be treated as allowed. Blocks will be ignored.
+        default: Items with no specified action will be treated as blocks. Blocks and allows will both be treated as such.
+        reject: Items with no specified action will be treated as blocks. Allows will be ignored.
+      list_actions_short:
+        accept: Allow-list
+        default: Mixed
+        reject: Block-list
+      name: Name
+      new:
+        create: Subscribe
+        title: New moderation subscription
+      override_unattributed: Override manual blocks
+      override_unattributed_hint: Allow this subscription to automatically upgrade or take over existing manual blocks when automatically applying advisories.
+      policies:
+        apply_advisories: Automatically applies advisories
+        apply_advisories_safely: Automatically applies advisories that do not break relationships
+        apply_retractions: Automatically applies retractions
+      priority: Priority
+      priority_hint: Moderation subscriptions are evaluated in order of priority, subscriptions with a lower number override subscriptions with a higher one.
+      retract_automatically: Retract advisories automatically
+      retract_automatically_hint: Whether to allow retracting or downgrading policy changes when the subscription removes a corresponding item. When automatic retraction is enabled and an equivalent advisory exists in a lower-priority list, it will be adopted. When automatic retraction is disabled, a suggestion will be generated instead.
+      show:
+        delete_confirm: Are you sure you want to delete this moderation subscription?
+        edit: Edit subscription
+        empty: This subscription has no advisory yet.
+        title: 'Moderation subscription: %{name}'
+      tabs:
+        logs: Logs
+        subscriptions: Subscriptions
+        suggestions: Suggestions
+      title: Moderation subscriptions
+      type: Type
+      types:
+        csv_list: CSV list
+      url: URL
+    moderation_subscriptions_logs:
+      title: Moderation subscriptions logs
+    moderation_suggestions:
+      actions:
+        accept: Allow
+        limit: Limit
+        reject: Suspend
+        retract: Retract current policy
+      applied_msg: Successfully applied suggestion for %{target_key}
+      apply_accept: Allow
+      apply_limit: Limit
+      apply_reject: Suspend
+      apply_retract: Retract
+      current_states:
+        accept: currently allowed
+        limit: currently limited
+        reject: currently suspended
+      description: Below are suggestions from your moderation subscriptions, ordered by priority.
+      destroyed_msg: Successfully dismissed suggestion for %{target_key}
+      dismiss: Dismiss suggestions
+      empty: There is no moderation suggestion at this time.
+      retracted_msg: Successfully retracted policy for %{target_key}
+      suggested_from_html: Suggested by %{link}
+      title: Moderation suggestions
+      unable_to_apply_msg: Unable to apply suggestion for %{target_key}
     relationships:
       title: "%{acct}'s relationships"
     relays:

config/navigation.rb

@@ -62,6 +62,7 @@ SimpleNavigation::Configuration.run do |navigation|
       s.item :instances, safe_join([material_symbol('cloud'), t('admin.instances.title')]), admin_instances_path(limited: limited_federation_mode? ? nil : '1'), highlights_on: %r{/admin/instances|/admin/domain_blocks|/admin/domain_allows|/admin/export_domain_blocks}, if: lambda {
         current_user.can?(:manage_federation)
       }
+      s.item :moderation_subscriptions, safe_join([material_symbol('cloud_download'), t('admin.moderation_subscriptions.title')]), admin_moderation_suggestions_path, highlights_on: %r{/admin/moderation_subscriptions|/admin/moderation_suggestions}, if: -> { current_user.can?(:manage_federation) }
       s.item :email_domain_blocks, safe_join([material_symbol('mail'), t('admin.email_domain_blocks.title')]), admin_email_domain_blocks_path, highlights_on: %r{/admin/email_domain_blocks}, if: -> { current_user.can?(:manage_blocks) }
       s.item :username_blocks, safe_join([material_symbol('supervised_user_circle_off'), t('admin.username_blocks.title')]), admin_username_blocks_path, highlights_on: %r{/admin/username_blocks}, if: -> { current_user.can?(:manage_blocks) }
       s.item :ip_blocks, safe_join([material_symbol('hide_source'), t('admin.ip_blocks.title')]), admin_ip_blocks_path, highlights_on: %r{/admin/ip_blocks}, if: -> { current_user.can?(:manage_blocks) }

config/routes/admin.rb

@@ -110,6 +110,18 @@ namespace :admin do
     resources :moderation_notes, module: :instances, only: [:create, :destroy]
   end
 
+  resources :moderation_subscriptions do
+    collection do
+      get :logs
+    end
+  end
+
+  resources :moderation_suggestions do
+    member do
+      post :apply
+    end
+  end
+
   resources :rules, only: [:index, :new, :create, :edit, :update, :destroy] do
     member do
       post :move_up

spec/system/admin/moderation_subscriptions_spec.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'using the moderation subscription interface' do
+  before do
+    sign_in Fabricate(:admin_user), scope: :user
+  end
+
+  context 'with a new subscription' do
+    it 'allows saving it, editing it and deleting it' do
+      visit admin_moderation_subscriptions_path
+      expect(page)
+        .to have_title(I18n.t('admin.moderation_subscriptions.title'))
+
+      # Navigate to new subscription form
+      click_on I18n.t('admin.moderation_subscriptions.add_new')
+      expect(page)
+        .to have_title(I18n.t('admin.moderation_subscriptions.new.title'))
+
+      # Submitting while leaving out some required fields
+      fill_in 'moderation_subscription_name', with: 'My first blocklist'
+      expect { click_on I18n.t('admin.moderation_subscriptions.new.create') }
+        .to_not change(ModerationSubscription, :count)
+      expect(page)
+        .to have_text(/errors below/)
+
+      # Filling in the missing fields and submitting
+      fill_in 'moderation_subscription_url', with: 'https://example.org/blocklist.csv'
+      fill_in 'moderation_subscription_priority', with: 0
+      expect { click_on I18n.t('admin.moderation_subscriptions.new.create') }
+        .to change(ModerationSubscription, :count).by(1)
+
+      expect(page)
+        .to have_title(I18n.t('admin.moderation_subscriptions.title'))
+
+      expect(ModerationSubscription.find_by(name: 'My first blocklist'))
+        .to have_attributes(url: 'https://example.org/blocklist.csv')
+
+      # The new subscription is displayed and can be visited
+      click_on 'My first blocklist'
+      expect(page)
+        .to have_title(I18n.t('admin.moderation_subscriptions.show.title', name: 'My first blocklist'))
+
+      # The subscription can be edited
+      click_on I18n.t('admin.moderation_subscriptions.show.edit')
+      fill_in 'moderation_subscription_priority', with: 10
+      expect { click_on I18n.t('generic.save_changes') }
+        .to change { ModerationSubscription.find_by(name: 'My first blocklist').priority }.from(0).to(10)
+
+      # The subscription can be deleted
+      expect { click_on I18n.t('admin.moderation_subscriptions.delete') }
+        .to change(ModerationSubscription, :count).by(-1)
+    end
+  end
+end