1 files changed, 69 insertions, 0 deletions
diff --git a/app/lib/activitypub/tag_manager.rb b/app/lib/activitypub/tag_manager.rb
new file mode 100644
index 000000000..ec42bcad3
--- /dev/null
+++ b/app/lib/activitypub/tag_manager.rb
@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+require 'singleton'
+
+class ActivityPub::TagManager
+  include Singleton
+  include RoutingHelper
+
+  COLLECTIONS = {
+    public: 'https://www.w3.org/ns/activitystreams#Public',
+  }.freeze
+
+  def url_for(target)
+    return target.url if target.respond_to?(:local?) && !target.local?
+
+    case target.object_type
+    when :person
+      short_account_url(target)
+    when :note, :comment, :activity
+      short_account_status_url(target.account, target)
+    end
+  end
+
+  def uri_for(target)
+    return target.uri if target.respond_to?(:local?) && !target.local?
+
+    case target.object_type
+    when :person
+      account_url(target)
+    when :note, :comment, :activity
+      account_status_url(target.account, target)
+    end
+  end
+
+  # Primary audience of a status
+  # Public statuses go out to primarily the public collection
+  # Unlisted and private statuses go out primarily to the followers collection
+  # Others go out only to the people they mention
+  def to(status)
+    case status.visibility
+    when 'public'
+      [COLLECTIONS[:public]]
+    when 'unlisted', 'private'
+      [account_followers_url(status.account)]
+    when 'direct'
+      status.mentions.map { |mention| uri_for(mention.account) }
+    end
+  end
+
+  # Secondary audience of a status
+  # Public statuses go out to followers as well
+  # Unlisted statuses go to the public as well
+  # Both of those and private statuses also go to the people mentioned in them
+  # Direct ones don't have a secondary audience
+  def cc(status)
+    cc = []
+
+    case status.visibility
+    when 'public'
+      cc << account_followers_url(status.account)
+    when 'unlisted'
+      cc << COLLECTIONS[:public]
+    end
+
+    cc.concat(status.mentions.map { |mention| uri_for(mention.account) }) unless status.direct_visibility?
+
+    cc
+  end
+end