text: # Copyright 2017 Mycroft AI Inc.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  """Mycroft audio service.
  
      This handles playback of audio and speech
  """
  from mycroft.configuration import Configuration
  from mycroft.messagebus.client import MessageBusClient
  from mycroft.util import reset_sigint_handler, wait_for_exit_signal, \
      create_daemon, create_echo_function, check_for_signal
  from mycroft.util.log import LOG
  
  import mycroft.audio.speech as speech
  from .audioservice import AudioService
  
  
  def on_ready():
      LOG.info('Audio service is ready.')
  
  
  def on_error(e='Unknown'):
      LOG.error('Audio service failed to launch ({}).'.format(repr(e)))
  
  
  def on_stopping():
      LOG.info('Audio service is shutting down...')
  
  
  def main(ready_hook=on_ready, error_hook=on_error, stopping_hook=on_stopping):
      """ Main function. Run when file is invoked. """
      try:
          reset_sigint_handler()
          check_for_signal("isSpeaking")
          bus = MessageBusClient()  # Connect to the Mycroft Messagebus
          Configuration.set_config_update_handlers(bus)
          speech.init(bus)
  
          LOG.info("Starting Audio Services")
          bus.on('message', create_echo_function('AUDIO',
                                                 ['mycroft.audio.service']))
  
          # Connect audio service instance to message bus
          audio = AudioService(bus)
      except Exception as e:
          error_hook(e)
      else:
          create_daemon(bus.run_forever)
          if audio.wait_for_load() and len(audio.service) > 0:
              # If at least one service exists, report ready
              ready_hook()
              wait_for_exit_signal()
              stopping_hook()
          else:
              error_hook('No audio services loaded')
  
          speech.shutdown()
          audio.shutdown()
  
  
  if __name__ == '__main__':
      main()
  