module PluginTool
  
  PACKING_ACCEPTABLE_FILENAME = /\A(js|static|template|test|data)\/([a-z0-9_-]+\/)*[a-z0-9_-]+\.[a-z0-9]+\z/
  PACKING_ACCEPTABLE_EXCEPTIONS = ['plugin.json', 'requirements.schema', 'global.js', 'certificates-temp-http-api.pem']
  PACKING_EXCLUDE = ['developer.json']

  def self.pack_plugin(plugin_name, output_directory)
    # Get filenames and sort
    files = Dir.glob("#{plugin_name}/**/*").map do |filename|
      if File.file? filename
        filename[plugin_name.length+1, filename.length]
      else
        nil
      end
    end .select { |f| !PACKING_EXCLUDE.include?(f) }.compact.sort
    # Check each filename is acceptable
    files.each do |filename|
      unless filename =~ PACKING_ACCEPTABLE_FILENAME || PACKING_ACCEPTABLE_EXCEPTIONS.include?(filename)
        puts "File '#{filename}' has an unacceptable filename"
        exit 1
      end
    end
    # Clean output directory
    output_plugin_dir = "#{output_directory}/#{plugin_name}"
    puts "Output directory: #{output_plugin_dir}"
    if File.exist? output_plugin_dir
      puts "Removing old output directory #{output_plugin_dir}"
      FileUtils.rm_r(output_plugin_dir)
    end
    # Make file structure
    FileUtils.mkdir(output_plugin_dir)
    # Process each file, building a manifest
    puts "Processing files:"
    manifest = ''
    minimiser = PluginTool::Minimiser.new
    files.each do |filename|
      puts "  #{filename}"
      data = File.open("#{plugin_name}/#{filename}") { |f| f.read }
      # Minimise file?
      unless filename =~ /\Ajs\//
        data = minimiser.process(data, filename)
      end
      hash = Digest::SHA256.hexdigest(data)
      # Make sure output directory exists, write file
      output_pathname = "#{output_plugin_dir}/#{filename}"
      output_directory = File.dirname(output_pathname)
      FileUtils.mkdir_p(output_directory) unless File.directory?(output_directory)
      File.open(output_pathname, "w") { |f| f.write data }
      # Filename entry in Manifest
      manifest << "F #{hash} #{filename}\n"
    end
    minimiser.finish
    # Write manifest and version
    File.open("#{output_plugin_dir}/manifest", "w") { |f| f.write manifest }
    version = Digest::SHA256.hexdigest(manifest)
    File.open("#{output_plugin_dir}/version", "w") { |f| f.write "#{version}\n" }
    # All done
    puts "Version: #{version}\nPlugin packed."
  end

end