acuppy/daemons

module Daemons
  class Optparse
    attr_reader :usage

    def initialize(controller)
      @controller = controller
      @options = {}

      @opts = OptionParser.new do |opts|
        opts.banner = ''

        opts.on('-t', '--ontop', 'Stay on top (does not daemonize)') do |t|
          @options[:ontop] = t
        end

        opts.on('-f', '--force', 'Force operation') do |t|
          @options[:force] = t
        end

        opts.on('-n', '--no_wait', 'Do not wait for processes to stop') do |t|
          @options[:no_wait] = t
        end

        opts.separator ''
        opts.separator 'Common options:'

        # No argument, shows at tail.  This will print an options summary
        opts.on_tail('-h', '--help', 'Show this message') do
          controller.print_usage

          exit
        end

        # Switch to print the version.
        opts.on_tail('--version', 'Show version') do
          puts "daemons version #{Daemons::VERSION}"
          exit
        end
      end

      begin
        @usage = @opts.to_s
      rescue ::Exception # work around a bug in ruby 1.9
        @usage = <<END
            -t, --ontop                      Stay on top (does not daemonize)
            -f, --force                      Force operation
            -n, --no_wait                    Do not wait for processes to stop

        Common options:
            -h, --help                       Show this message
                --version                    Show version
END
      end
    end

    # Return a hash describing the options.
    #
    def parse(args)
      # The options specified on the command line will be collected in *options*.
      # We set default values here.
      
      @opts.parse(args)

      @options
    end
  end

  class Controller
    def print_usage
      puts "Usage: #{@app_name} <command> <options> -- <application options>"
      puts
      puts '* where <command> is one of:'
      puts '  start         start an instance of the application'
      puts '  stop          stop all instances of the application'
      puts '  restart       stop all instances and restart them afterwards'
      puts '  reload        send a SIGHUP to all instances of the application'
      puts '  run           start the application and stay on top'
      puts '  zap           set the application to a stopped state'
      puts '  status        show status (PID) of application instances'
      puts
      puts '* and where <options> may contain several of the following:'

      puts @optparse.usage
    end

    def catch_exceptions(&block)
      begin
        block.call
      rescue CmdException, OptionParser::ParseError => e
        puts "ERROR: #{e}"
        puts
        print_usage
      rescue RuntimeException => e
        puts "ERROR: #{e}"
      end
    end
  end
end