module Eye::Cli::Server
private

  def server_started?
    _cmd(:ping) == :pong
  end

  def loader_path
    filename = File.expand_path(File.join(File.dirname(__FILE__), %w[.. .. .. bin loader_eye]))
    File.exists?(filename) ? filename : nil
  end

  def ruby_path
    require 'rbconfig'
    RbConfig::CONFIG['bindir'] + '/ruby'
  end

  def ensure_loader_path
    unless loader_path
      error! "start monitoring needs to run under ruby with installed gem 'eye'"
    end
  end

  def server_start_foreground(conf = nil)
    ensure_loader_path
    Eye::Local.ensure_eye_dir

    if server_started?
      _cmd(:quit) && sleep(1) # stop previous server
    end

    args = []
    args += ['--config', conf] if conf
    args += ['--logger', 'stdout']
    if Eye::Local.local_runner
      args += ['--stop_all']
      args += ['--dir', Eye::Local.dir]
      args += ['--config', Eye::Local.eyefile] unless conf
    end

    Process.exec(ruby_path, loader_path, *args)
  end

  def server_start(configs)
    ensure_loader_path
    Eye::Local.ensure_eye_dir

    ensure_stop_previous_server

    args = []
    args += ['--dir', Eye::Local.dir] if Eye::Local.local_runner

    opts = {:out => '/dev/null', :err => '/dev/null', :in => '/dev/null',
            :chdir => '/', :pgroup => true}

    pid = Process.spawn(ruby_path, loader_path, *args, opts)
    Process.detach(pid)
    File.open(Eye::Local.pid_path, 'w'){|f| f.write(pid) }

    unless wait_server
      error! 'server has not started in 15 seconds, something is very wrong'
    end

    configs.unshift(Eye::Local.eyeconfig) if File.exists?(Eye::Local.eyeconfig)
    configs << Eye::Local.eyefile if Eye::Local.local_runner

    say 'Eye started!', :green

    if !configs.empty?
      say_load_result cmd(:load, *configs)
    end
  end

  def ensure_stop_previous_server
    Eye::Local.ensure_eye_dir
    pid = File.read(Eye::Local.pid_path).to_i rescue nil
    if pid
      Process.kill(9, pid) rescue nil
    end
    File.delete(Eye::Local.pid_path) rescue nil
    true
  end

  def wait_server(timeout = 15)
    Timeout.timeout(timeout) do
      sleep 0.3 while !server_started?
    end
    true
  rescue Timeout::Error
    false
  end

end