1 files changed, 83 insertions, 0 deletions
diff --git a/app/services/system_notes/design_management_service.rb b/app/services/system_notes/design_management_service.rb
new file mode 100644
index 00000000000..a773877e25b
--- /dev/null
+++ b/app/services/system_notes/design_management_service.rb
@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+module SystemNotes
+  class DesignManagementService < ::SystemNotes::BaseService
+    include ActionView::RecordIdentifier
+
+    # Parameters:
+    #   - version [DesignManagement::Version]
+    #
+    # Example Note text:
+    #
+    #   "added [1 designs](link-to-version)"
+    #   "changed [2 designs](link-to-version)"
+    #
+    # Returns [Array<Note>]: the created Note objects
+    def design_version_added(version)
+      events = DesignManagement::Action.events
+      link_href = designs_path(version: version.id)
+
+      version.designs_by_event.map do |(event_name, designs)|
+        note_data = self.class.design_event_note_data(events[event_name])
+        icon_name = note_data[:icon]
+        n = designs.size
+
+        body = "%s [%d %s](%s)" % [note_data[:past_tense], n, 'design'.pluralize(n), link_href]
+
+        create_note(NoteSummary.new(noteable, project, author, body, action: icon_name))
+      end
+    end
+
+    # Called when a new discussion is created on a design
+    #
+    # discussion_note - DiscussionNote
+    #
+    # Example Note text:
+    #
+    #   "started a discussion on screen.png"
+    #
+    # Returns the created Note object
+    def design_discussion_added(discussion_note)
+      design = discussion_note.noteable
+
+      body = _('started a discussion on %{design_link}') % {
+        design_link: '[%s](%s)' % [
+          design.filename,
+          designs_path(vueroute: design.filename, anchor: dom_id(discussion_note))
+        ]
+      }
+
+      action = :designs_discussion_added
+
+      create_note(NoteSummary.new(noteable, project, author, body, action: action))
+    end
+
+    # Take one of the `DesignManagement::Action.events` and
+    # return:
+    #   * an English past-tense verb.
+    #   * the name of an icon used in renderin a system note
+    #
+    # We do not currently internationalize our system notes,
+    # instead we just produce English-language descriptions.
+    # See: https://gitlab.com/gitlab-org/gitlab/issues/30408
+    # See: https://gitlab.com/gitlab-org/gitlab/issues/14056
+    def self.design_event_note_data(event)
+      case event
+      when DesignManagement::Action.events[:creation]
+        { icon: 'designs_added', past_tense: 'added' }
+      when DesignManagement::Action.events[:modification]
+        { icon: 'designs_modified', past_tense: 'updated' }
+      when DesignManagement::Action.events[:deletion]
+        { icon: 'designs_removed', past_tense: 'removed' }
+      else
+        raise "Unknown event: #{event}"
+      end
+    end
+
+    private
+
+    def designs_path(params = {})
+      url_helpers.designs_project_issue_path(project, noteable, params)
+    end
+  end
+end