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`

config/locales/en.yml

@@ -483,13 +483,14 @@ en:
       title: Account statuses
       with_media: With media
     tags:
-      accounts: Accounts
-      hidden: Hidden
-      hide: Hide from directory
-      name: Hashtag
+      context: Context
+      directory: In directory
+      in_directory: "%{count} in directory"
+      review: Review status
+      reviewed: Reviewed
       title: Hashtags
-      unhide: Show in directory
-      visible: Visible
+      trending_right_now: Trending right now
+      unique_uses_today: "%{count} posting today"
     title: Administration
     warning_presets:
       add_new: Add new
@@ -505,6 +506,9 @@ 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})
   appearance:
     advanced_web_interface: Advanced web interface
     advanced_web_interface_hint: 'If you want to make use of your entire screen width, the advanced web interface allows you to configure many different columns to see as much information at the same time as you want: Home, notifications, federated timeline, any number of lists and hashtags.'
@@ -939,6 +943,8 @@ en:
     pinned: Pinned toot
     reblogged: boosted
     sensitive_content: Sensitive content
+  tags:
+    does_not_match_previous_name: does not match the previous name
   terms:
     body_html: |
       <h2>Privacy Policy</h2>

config/locales/simple_form.en.yml

@@ -48,6 +48,8 @@ en:
         text: This will help us review your application
       sessions:
         otp: 'Enter the two-factor code generated by your phone app or use one of your recovery codes:'
+      tag:
+        name: You can only change the casing of the letters, for example, to make it more readable
       user:
         chosen_languages: When checked, only toots in selected languages will be displayed in public timelines
     labels:
@@ -137,6 +139,11 @@ en:
         pending_account: Send e-mail when a new account needs review
         reblog: Send e-mail when someone boosts your status
         report: Send e-mail when a new report is submitted
+        trending_tag: Send e-mail when an unreviewed hashtag is trending
+      tag:
+        listable: Allow this hashtag to appear on the profile directory
+        trendable: Allow this hashtag to appear under trends
+        usable: Allow toots to use this hashtag
     'no': 'No'
     recommended: Recommended
     required:

config/navigation.rb

@@ -38,7 +38,7 @@ SimpleNavigation::Configuration.run do |navigation|
       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('tag fw'), t('admin.tags.title')]), admin_tags_path
+      s.item :tags, safe_join([fa_icon('hashtag fw'), t('admin.tags.title')]), admin_tags_path, highlights_on: %r{/admin/tags}
       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? }
     end

config/routes.rb

@@ -243,13 +243,7 @@ Rails.application.routes.draw do
     end
 
     resources :account_moderation_notes, only: [:create, :destroy]
-
-    resources :tags, only: [:index] do
-      member do
-        post :hide
-        post :unhide
-      end
-    end
+    resources :tags, only: [:index, :show, :update]
   end
 
   get '/admin', to: redirect('/admin/dashboard', status: 302)
@@ -311,6 +305,7 @@ Rails.application.routes.draw do
       resources :mutes,        only: [:index]
       resources :favourites,   only: [:index]
       resources :reports,      only: [:create]
+      resources :trends,       only: [:index]
       resources :filters,      only: [:index, :create, :show, :update, :destroy]
       resources :endorsements, only: [:index]
 

config/settings.yml

@@ -43,6 +43,7 @@ defaults: &defaults
     digest: true
     report: true
     pending_account: true
+    trending_tag: true
   interactions:
     must_be_follower: false
     must_be_following: false