module ForemanXen

  class VNCTunnel
    attr_accessor :host, :port

    def initialize(fullURL)
      @uri = URI(fullURL)
      logger.info(fullURL)
      self.host = 'localhost'
      s         = TCPServer.new('127.0.0.1', 0)
      self.port = s.addr[1]
      s.close
      @read_from_server = true
    end

    def start
      client_srv = TCPServer.new('127.0.0.1', self.port)
      Thread.new do
              req         = "CONNECT #{@uri.path}?#{@uri.query} HTTP/1.1\r\n\r\n"
              @srv_socket = TCPSocket.open(@uri.host, 80)
              @srv_socket.print req
              header = @srv_socket.readline
              if header == "HTTP/1.1 200 OK\r\n"
                @srv_socket.each_line do |line|
                  break if line == "\r\n"
                end
                listen client_srv
              else
                logger.error "Cannot connect to the console located at #{uri.to_s} reason: #{header}"
                raise "Cannot connect to the console located at #{uri.to_s} reason: #{header}"
              end
            end
    end

    def logger
      Rails.logger
    end

    private

    def listen(client_srv)
      @client_socket = client_srv.accept
      logger.debug 'VNCTunnel Client: client accepted'

      begin
        while true
          begin
            data = @client_socket.read_nonblock(1024)
            break if data == nil
            @srv_socket.write(data)
          rescue IO::WaitReadable => e
            IO.select([@client_socket])
            retry
          end
        end
      rescue EOFError
        # ignored
      rescue Exception => e
        logger.error "VNCTunnel Client: unexpected exception #{e}"
      ensure
        @read_from_server = false
        @client_socket.close
        @srv_socket.close
      end
      logger.debug 'VNCTunnel Client is stopping'
    end

    def listen_from_server
      logger.debug 'VNCTunnel Server is listening'
      begin
        while @read_from_server do
          begin
            data = @srv_socket.read_nonblock(1024)
            @client_socket.write(data)
          rescue IO::WaitReadable => e
            if IO.select([@srv_socket], nil, nil, 60) != nil
              retry
            end
          end
        end
      rescue EOFError
        # ignored
      rescue Exception => e
        logger.error "VNCTunnel Server: unexpected exception #{e}"
      end
      logger.debug('VNCTunnel Server is stopping')
    end

  end
end