class Listen::Event::Loop

def _process_changes
  processor = Event::Processor.new(@config, @reasons)
  transition! :started
  processor.loop_for(@config.min_delay_between_events)
end

def _wakeup(reason)
  @reasons << reason
  @wait_thread.wakeup
end

def initialize(config)
  @config = config
  @wait_thread = nil
  @reasons = ::Queue.new
  initialize_fsm
end

def pause
  # TODO: works?
  # fail NotImplementedError
end

def start
  # TODO: use a Fiber instead?
  return unless state == :pre_start
  transition! :starting
  @wait_thread = Listen::Thread.new("wait_thread") do
    _process_changes
  end
  Listen.logger.debug("Waiting for processing to start...")
  wait_for_state(:started, timeout: MAX_STARTUP_SECONDS) or
    raise Error::NotStarted, "thread didn't start in #{MAX_STARTUP_SECONDS} seconds (in state: #{state.inspect})"
  Listen.logger.debug('Processing started.')
end

def started?
  state == :started
end

def stop
  transition! :stopped
  @wait_thread&.join
  @wait_thread = nil
end

def stopped?
  state == :stopped
end

def wakeup_on_event
  if started? && @wait_thread&.alive?
    _wakeup(:event)
  end
end