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

Fix #271

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

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

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

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

4 files changed, 41 insertions, 16 deletions

diff --git a/app/controllers/admin/dashboard_controller.rb b/app/controllers/admin/dashboard_controller.rb
index e74e4755f..70afdedd7 100644
--- a/app/controllers/admin/dashboard_controller.rb
+++ b/app/controllers/admin/dashboard_controller.rb
@@ -27,7 +27,7 @@ module Admin
       @saml_enabled          = ENV['SAML_ENABLED'] == 'true'
       @pam_enabled           = ENV['PAM_ENABLED'] == 'true'
       @hidden_service        = ENV['ALLOW_ACCESS_TO_HIDDEN_SERVICE'] == 'true'
-      @trending_hashtags     = TrendingTags.get(7)
+      @trending_hashtags     = TrendingTags.get(10, filtered: false)
       @profile_directory     = Setting.profile_directory
       @timeline_preview      = Setting.timeline_preview
       @spam_check_enabled    = Setting.spam_check_enabled
diff --git a/app/controllers/admin/tags_controller.rb b/app/controllers/admin/tags_controller.rb
index e9f4f2cfa..0e9dda302 100644
--- a/app/controllers/admin/tags_controller.rb
+++ b/app/controllers/admin/tags_controller.rb
@@ -4,41 +4,49 @@ module Admin
   class TagsController < BaseController
     before_action :set_tags, only: :index
     before_action :set_tag, except: :index
-    before_action :set_filter_params
 
     def index
       authorize :tag, :index?
     end
 
-    def hide
-      authorize @tag, :hide?
-      @tag.account_tag_stat.update!(hidden: true)
-      redirect_to admin_tags_path(@filter_params)
+    def show
+      authorize @tag, :show?
     end
 
-    def unhide
-      authorize @tag, :unhide?
-      @tag.account_tag_stat.update!(hidden: false)
-      redirect_to admin_tags_path(@filter_params)
+    def update
+      authorize @tag, :update?
+
+      if @tag.update(tag_params.merge(reviewed_at: Time.now.utc))
+        redirect_to admin_tag_path(@tag.id)
+      else
+        render :show
+      end
     end
 
     private
 
     def set_tags
-      @tags = Tag.discoverable
-      @tags.merge!(Tag.hidden) if filter_params[:hidden]
+      @tags = filtered_tags.page(params[:page])
     end
 
     def set_tag
       @tag = Tag.find(params[:id])
     end
 
-    def set_filter_params
-      @filter_params = filter_params.to_hash.symbolize_keys
+    def filtered_tags
+      scope = Tag
+      scope = scope.discoverable if filter_params[:context] == 'directory'
+      scope = scope.reviewed if filter_params[:review] == 'reviewed'
+      scope = scope.pending_review if filter_params[:review] == 'pending_review'
+      scope.reorder(score: :desc)
     end
 
     def filter_params
-      params.permit(:hidden)
+      params.slice(:context, :review).permit(:context, :review)
+    end
+
+    def tag_params
+      params.require(:tag).permit(:name, :trendable, :usable, :listable)
     end
   end
 end
diff --git a/app/controllers/api/v1/trends_controller.rb b/app/controllers/api/v1/trends_controller.rb
new file mode 100644
index 000000000..bcea9857e
--- /dev/null
+++ b/app/controllers/api/v1/trends_controller.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class Api::V1::TrendsController < Api::BaseController
+  before_action :set_tags
+
+  respond_to :json
+
+  def index
+    render json: @tags, each_serializer: REST::TagSerializer
+  end
+
+  private
+
+  def set_tags
+    @tags = TrendingTags.get(limit_param(10))
+  end
+end
diff --git a/app/controllers/settings/preferences_controller.rb b/app/controllers/settings/preferences_controller.rb
index 742c97cdb..d548072a8 100644
--- a/app/controllers/settings/preferences_controller.rb
+++ b/app/controllers/settings/preferences_controller.rb
@@ -56,7 +56,7 @@ class Settings::PreferencesController < Settings::BaseController
       :setting_advanced_layout,
       :setting_use_blurhash,
       :setting_use_pending_items,
-      notification_emails: %i(follow follow_request reblog favourite mention digest report pending_account),
+      notification_emails: %i(follow follow_request reblog favourite mention digest report pending_account trending_tag),
       interactions: %i(must_be_follower must_be_following must_be_following_dm)
     )
   end