Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `.github/dependabot.yml`:
  Updated upstream, we deleted it to not be flooded by Depandabot.
  Kept deleted.
- `Gemfile.lock`:
  Puma updated on both sides, went for the most recent version.
- `app/controllers/api/v1/mutes_controller.rb`:
  Upstream updated the serializer to support timed mutes, while
  glitch-soc added a custom API ages ago to get information that
  is already available elsewhere.
  Dropped the glitch-soc-specific API, went with upstream changes.
- `app/javascript/core/admin.js`:
  Conflict due to changing how assets are loaded. Went with upstream.
- `app/javascript/packs/public.js`:
  Conflict due to changing how assets are loaded. Went with upstream.
- `app/models/mute.rb`:
  🤷
- `app/models/user.rb`:
  New user setting added upstream while we have glitch-soc-specific
  user settings. Added upstream's user setting.
- `config/settings.yml`:
  Upstream added a new user setting close to a user setting we had
  changed the defaults for. Added the new upstream setting.
- `package.json`:
  Upstream dependency updated “too close” to a glitch-soc-specific
  dependency. No real conflict. Updated the dependency.

app/controllers/activitypub/followers_synchronizations_controller.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+class ActivityPub::FollowersSynchronizationsController < ActivityPub::BaseController
+  include SignatureVerification
+  include AccountOwnedConcern
+
+  before_action :require_signature!
+  before_action :set_items
+  before_action :set_cache_headers
+
+  def show
+    expires_in 0, public: false
+    render json: collection_presenter,
+           serializer: ActivityPub::CollectionSerializer,
+           adapter: ActivityPub::Adapter,
+           content_type: 'application/activity+json'
+  end
+
+  private
+
+  def uri_prefix
+    signed_request_account.uri[/http(s?):\/\/[^\/]+\//]
+  end
+
+  def set_items
+    @items = @account.followers.where(Account.arel_table[:uri].matches(uri_prefix + '%', false, true)).pluck(:uri)
+  end
+
+  def collection_presenter
+    ActivityPub::CollectionPresenter.new(
+      id: account_followers_synchronization_url(@account),
+      type: :ordered,
+      items: @items
+    )
+  end
+end

app/controllers/activitypub/inboxes_controller.rb

@@ -11,6 +11,7 @@ class ActivityPub::InboxesController < ActivityPub::BaseController
 
   def create
     upgrade_account
+    process_collection_synchronization
     process_payload
     head 202
   end
@@ -52,6 +53,19 @@ class ActivityPub::InboxesController < ActivityPub::BaseController
     DeliveryFailureTracker.reset!(signed_request_account.inbox_url)
   end
 
+  def process_collection_synchronization
+    raw_params = request.headers['Collection-Synchronization']
+    return if raw_params.blank? || ENV['DISABLE_FOLLOWERS_SYNCHRONIZATION'] == 'true'
+
+    # Re-using the syntax for signature parameters
+    tree   = SignatureParamsParser.new.parse(raw_params)
+    params = SignatureParamsTransformer.new.apply(tree)
+
+    ActivityPub::PrepareFollowersSynchronizationService.new.call(signed_request_account, params)
+  rescue Parslet::ParseFailed
+    Rails.logger.warn 'Error parsing Collection-Synchronization header'
+  end
+
   def process_payload
     ActivityPub::ProcessingWorker.perform_async(signed_request_account.id, body, @account&.id)
   end