require 'rflow/daemon_process'
require 'rflow/pid_file'
require 'rflow/shard'

class RFlow
  class Master < DaemonProcess
    attr_reader :shards

    def initialize(config)
      super(config['rflow.application_name'], 'Master')
      @pid_file = PIDFile.new(config['rflow.pid_file_path'])
      @shards = config.shards.map {|config| Shard.new(config) }
    end

    def run!
      write_pid_file
      super
    ensure
      remove_pid_file
    end

    def spawn_subprocesses
      shards.each(&:run!)
    end

    def subprocesses
      shards.flat_map(&:workers)
    end

    def run_process
      EM.run do
        # TODO: Monitor the workers
      end
    end

    def shutdown!(reason)
      remove_pid_file
      super
    end

    private
    def write_pid_file; @pid_file.write; end
    def remove_pid_file; @pid_file.safe_unlink; end
  end
end