# Copyright (c) 2012 The Chromium 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
import os

from autotest_lib.client.bin import utils
from autotest_lib.client.common_lib import error
from autotest_lib.client.cros.audio import audio_helper
from autotest_lib.client.cros.audio import cmd_utils
from autotest_lib.client.cros.audio import cras_utils

TEST_DURATION = 15

class audio_YoutubePlayback(audio_helper.chrome_rms_test):
    """Verifies if youtube playback can be captured."""
    version = 1

    def play_video(self, tab, video_url):
        """Plays a Youtube video to record audio samples.

           @param tab: the tab to load and play the video.
        """
        tab.Navigate(video_url)

        def player_is_ready():
            """Returns whether the player is ready."""
            return tab.EvaluateJavaScript('typeof player != "undefined"')

        utils.poll_for_condition(
            condition=player_is_ready,
            exception=error.TestError('Failed to load the Youtube player'))

        tab.ExecuteJavaScript('player.playVideo()')

        # Make sure the video is playing
        def get_current_time():
            """Returns current time."""
            return tab.EvaluateJavaScript('player.getCurrentTime()')

        old_time = get_current_time()
        utils.poll_for_condition(
            condition=lambda: get_current_time() > old_time,
            exception=error.TestError('Video is not played until timeout'))


    def run_once(self):
        """Entry point of this test."""
        self.chrome.browser.platform.SetHTTPServerDirectories(self.bindir)

        video_url = self.chrome.browser.platform.http_server.UrlOf(
                os.path.join(self.bindir, 'youtube.html'))
        logging.info('Playing back youtube media file %s.', video_url)
        noise_file = os.path.join(self.resultsdir, "noise.wav")
        recorded_file = os.path.join(self.resultsdir, "recorded.wav")
        loopback_file = os.path.join(self.resultsdir, "loopback.wav")

        # Record a sample of "silence" to use as a noise profile.
        cras_utils.capture(noise_file, duration=3)

        # Play a video and record the audio output
        self.play_video(self.chrome.browser.tabs[0], video_url)

        p1 = cmd_utils.popen(cras_utils.capture_cmd(
                recorded_file, duration=TEST_DURATION))
        p2 = cmd_utils.popen(cras_utils.loopback_cmd(
                loopback_file, duration=TEST_DURATION))

        cmd_utils.wait_and_check_returncode(p1, p2)

        # See if we recorded something
        loopback_stats = [audio_helper.get_channel_sox_stat(
                loopback_file, i) for i in (1, 2)]
        logging.info('loopback stats: %s', [str(s) for s in loopback_stats])
        rms_value = audio_helper.reduce_noise_and_get_rms(
            recorded_file, noise_file)[0]

        self.write_perf_keyval({'rms_value': rms_value})