1 files changed, 49 insertions, 0 deletions
diff --git a/app/models/milestone_note.rb b/app/models/milestone_note.rb
new file mode 100644
index 00000000000..8ff0503502f
--- /dev/null
+++ b/app/models/milestone_note.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+class MilestoneNote < ::Note
+  attr_accessor :resource_parent, :event, :milestone
+
+  def self.from_event(event, resource: nil, resource_parent: nil)
+    resource ||= event.resource
+
+    attrs = {
+        system: true,
+        author: event.user,
+        created_at: event.created_at,
+        noteable: resource,
+        milestone: event.milestone,
+        event: event,
+        system_note_metadata: ::SystemNoteMetadata.new(action: 'milestone'),
+        resource_parent: resource_parent
+    }
+
+    if resource_parent.is_a?(Project)
+      attrs[:project_id] = resource_parent.id
+    end
+
+    MilestoneNote.new(attrs)
+  end
+
+  def note
+    @note ||= note_text
+  end
+
+  def note_html
+    @note_html ||= Banzai::Renderer.cacheless_render_field(self, :note, { group: group, project: project })
+  end
+
+  def project
+    resource_parent if resource_parent.is_a?(Project)
+  end
+
+  def group
+    resource_parent if resource_parent.is_a?(Group)
+  end
+
+  private
+
+  def note_text(html: false)
+    format = milestone&.group_milestone? ? :name : :iid
+    milestone.nil? ? 'removed milestone' : "changed milestone to #{milestone.to_reference(project, format: format)}"
+  end
+end