Add uploads rewriter and use it when moving issue

1 files changed, 56 insertions, 0 deletions

diff --git a/lib/gitlab/gfm/uploads_rewriter.rb b/lib/gitlab/gfm/uploads_rewriter.rb
new file mode 100644
index 00000000000..778b6fe9f9d
--- /dev/null
+++ b/lib/gitlab/gfm/uploads_rewriter.rb
@@ -0,0 +1,56 @@
+module Gitlab
+  module Gfm
+    ##
+    # Class that rewrites markdown links for uploads
+    #
+    # Using a pattern defined in `FileUploader` copies files to a new project
+    # and rewrites all links to uploads in ain a given text.
+    #
+    class UploadsRewriter
+      def initialize(text, source_project, _current_user)
+        @text = text
+        @source_project = source_project
+        @pattern = FileUploader::MARKDOWN_PATTERN
+      end
+
+      def rewrite(target_project)
+        return unless @text
+
+        new_uploader = file_uploader(target_project)
+        @text.gsub(@pattern) do |markdown_link|
+          old_file = find_file(@source_project, $~[:secret], $~[:file])
+          return markdown_link unless old_file.exists?
+
+          new_uploader.store!(old_file)
+          new_uploader.to_h[:markdown]
+        end
+      end
+
+      def has_uploads?
+        !(@text =~ @pattern).nil?
+      end
+
+      def files
+        referenced_files = @text.scan(@pattern).map do
+          find_file(@source_project, $~[:secret], $~[:file])
+        end
+
+        referenced_files.compact.select(&:exists?)
+      end
+
+      private
+
+      def find_file(project, secret, file)
+        uploader = file_uploader(project, secret)
+        uploader.retrieve_from_store!(file)
+        uploader.file
+      end
+
+      def file_uploader(*args)
+        uploader = FileUploader.new(*args)
+        uploader.define_singleton_method(:move_to_store) { false }
+        uploader
+      end
+    end
+  end
+end