module UnpackStrategy
  class Zip
    prepend Module.new {
      def extract_to_dir(unpack_dir, basename:, verbose:)
        result = super

        volumes = result.stderr.chomp
                        .split("\n")
                        .map { |l| l[/\A   skipping: (.+)  volume label\Z/, 1] }
                        .compact

        if result.stderr.lines.any? { |line| line.start_with?("._") }
          # Merge ._ files back into extended attributes.
          # ._ files inside volumes are automatically merged by ditto.
          system_command!("dot_clean",
                          args:         ["-mv", "--keep=dotbar", unpack_dir],
                          verbose:      verbose,
                          print_stderr: false)
        end

        return if volumes.empty?

        Dir.mktmpdir do |tmp_unpack_dir|
          tmp_unpack_dir = Pathname(tmp_unpack_dir)

          # `ditto` keeps Finder attributes intact and does not skip volume labels
          # like `unzip` does, which can prevent disk images from being unzipped.
          system_command! "ditto",
                          args:    ["-x", "-k", path, tmp_unpack_dir],
                          verbose: verbose

          volumes.each do |volume|
            FileUtils.mv tmp_unpack_dir/volume, unpack_dir/volume, verbose: verbose
          end
        end
      end
    }
  end
end