DEV: Refactor helper methods for upload markdown

Follow-up to a61ff167

lib/upload_markdown.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require_dependency "file_helper"
+
+class UploadMarkdown
+  def initialize(upload)
+    @upload = upload
+  end
+
+  def to_markdown(display_name: nil)
+    if FileHelper.is_supported_image?(@upload.original_filename)
+      image_markdown
+    else
+      attachment_markdown(display_name: display_name)
+    end
+  end
+
+  def image_markdown
+    "![#{@upload.original_filename}|#{@upload.width}x#{@upload.height}](#{@upload.short_url})"
+  end
+
+  def attachment_markdown(display_name: nil, with_filesize: true)
+    human_filesize = with_filesize ? " (#{@upload.human_filesize})" : ""
+    display_name ||= @upload.original_filename
+
+    "[#{display_name}|attachment](#{@upload.short_url})#{human_filesize}"
+  end
+end