import logging
import platform
import sys
import threading

import aiy.assistant.auth_helpers
from aiy.assistant.library import Assistant
import aiy.voicehat
from google.assistant.library.event import EventType

logging.basicConfig(
    level=logging.INFO,
    format="[%(asctime)s] %(levelname)s:%(name)s:%(message)s"
)

class MyAssistant(object):
    
    def __init__(self):
        self._task = threading.Thread(target=self._run_task)
        self._can_start_conversation = False
        self._assistant = None

    def start(self):
        self._task.start()

    def _run_task(self):
        credentials = aiy.assistant.auth_helpers.get_assistant_credentials()
        with Assistant(credentials) as assistant:
            self._assistant = assistant
            for event in assistant.start():
                self._process_event(event)

    def _process_event(self, event):
        status_ui = aiy.voicehat.get_status_ui()
        if event.type == EventType.ON_START_FINISHED:
            status_ui.status('ready')
            self._can_start_conversation = True
            # Start the voicehat button trigger.
            aiy.voicehat.get_button().on_press(self._on_button_pressed)
            if sys.stdout.isatty():
                print('Say "OK, Google" or press the button, then speak. '
                      'Press Ctrl+C to quit...')

        elif event.type == EventType.ON_CONVERSATION_TURN_STARTED:
            self._can_start_conversation = False
            status_ui.status('listening')

        elif event.type == EventType.ON_END_OF_UTTERANCE:
            status_ui.status('thinking')

        elif (event.type == EventType.ON_CONVERSATION_TURN_FINISHED
              or event.type == EventType.ON_CONVERSATION_TURN_TIMEOUT
              or event.type == EventType.ON_NO_RESPONSE):
            status_ui.status('ready')
            self._can_start_conversation = True

        elif event.type == EventType.ON_ASSISTANT_ERROR and event.args and event.args['is_fatal']:
            sys.exit(1)

    def _on_button_pressed(self):
        if self._can_start_conversation:
            self._assistant.start_conversation()

def main():
    if platform.machine() == 'armv6l':
        print('Cannot run hotword demo on Pi Zero!')
        exit(-1)
    MyAssistant().start()

if __name__ == '__main__':
    main()