# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import logging, threading, time
from autotest_lib.client.bin import utils
from autotest_lib.client.common_lib import error
from autotest_lib.client.cros import cros_ui_test, power_utils, rtc
from autotest_lib.client.cros.audio import audio_helper

class power_AudioDetector(cros_ui_test.UITest):
    version = 1

    def run_once(self, run_time_sec=60):
        if run_time_sec < 10:
            raise error.TestFail('Must run for at least 10 seconds')

        # Start powerd if not started.  Set timeouts for quick idle events.
        run_time_ms = run_time_sec * 1000
        react_ms = min(10000, run_time_ms / 10)
        gap_ms = run_time_ms / 4
        dim_ms = min(10000, gap_ms)
        off_ms = min(20000, gap_ms * 2)
        suspend_ms = min(30000, gap_ms * 3)
        prefs = { 'disable_idle_suspend'   : 0,
                  'ignore_external_policy' : 1,
                  'plugged_dim_ms'         : dim_ms,
                  'plugged_off_ms'         : off_ms,
                  'plugged_suspend_ms'     : suspend_ms,
                  'unplugged_dim_ms'       : dim_ms,
                  'unplugged_off_ms'       : off_ms,
                  'unplugged_suspend_ms'   : suspend_ms }
        self._pref_change = power_utils.PowerPrefChanger(prefs)

        # Audio loop time should be significantly shorter than |run_time_sec|
        # time, so that the total playback time doesn't exceed it by much.
        audio_loop_time_sec = (react_ms + 500) / 1000

        self.login()

        # Set a low audio volume to avoid annoying people during tests.
        audio_helper.set_volume_levels(10, 100)

        # Start playing audio file.
        self._enable_audio_playback = True
        thread = threading.Thread(target=self._play_audio,
                                  args=(audio_loop_time_sec,))
        thread.start()

        # Set an alarm to wake up the system in case the audio detector fails
        # and the system suspends.
        alarm_time = rtc.get_seconds() + run_time_sec
        rtc.set_wake_alarm(alarm_time)

        time.sleep(run_time_sec)

        # Stop powerd to avoid suspending when the audio stops.
        utils.system_output('stop powerd')

        # Stop audio and wait for the audio thread to terminate.
        self._enable_audio_playback = False
        thread.join(timeout=(audio_loop_time_sec * 2))
        if thread.is_alive():
            logging.error('Audio thread did not terminate at end of test.')

        # Check powerd's log to make sure that no suspend took place.
        powerd_log_path = '/var/log/power_manager/powerd.LATEST'
        log = open(powerd_log_path, 'r').read()
        if log.find('Starting suspend') != -1:
            raise error.TestFail('System suspended while audio was playing.')


    def cleanup(self):
        if self.logged_in():
            self.logout()
        utils.restart_job('powerd')


    def _play_audio(self, loop_time):
        """
        Repeatedly plays audio until self._audio_playback_enabled == False.
        """
        # TODO(crosbug.com/33988): Allow for pauses in audio playback to
        # simulate delays in loading the next song.
        while self._enable_audio_playback:
            audio_helper.play_sound(duration_seconds=loop_time)
        logging.info('Done playing audio.')