/*
 * Copyright 2020 The Android Open Source Project
 *
 * 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.
 */
package androidx.media3.exoplayer.hls;

import static androidx.media3.test.utils.robolectric.RobolectricUtil.runMainLooperUntil;
import static com.google.common.truth.Truth.assertThat;

import android.net.Uri;
import android.os.SystemClock;
import androidx.media3.common.C;
import androidx.media3.common.MediaItem;
import androidx.media3.common.ParserException;
import androidx.media3.common.Timeline;
import androidx.media3.common.util.Util;
import androidx.media3.exoplayer.analytics.PlayerId;
import androidx.media3.exoplayer.hls.playlist.HlsMediaPlaylist;
import androidx.media3.exoplayer.hls.playlist.HlsPlaylistParser;
import androidx.media3.exoplayer.source.MediaSource;
import androidx.media3.test.utils.FakeDataSet;
import androidx.media3.test.utils.FakeDataSource;
import androidx.test.ext.junit.runners.AndroidJUnit4;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.Test;
import org.junit.runner.RunWith;

/** Unit test for {@link HlsMediaSource}. */
@RunWith(AndroidJUnit4.class)
public class HlsMediaSourceTest {

  @Test
  public void loadLivePlaylist_noTargetLiveOffsetDefined_fallbackToThreeTargetDuration()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds but not hold back or part hold back.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:CAN-SKIP-UNTIL=24";
    // The playlist finishes 1 second before the current time, therefore there's a live edge
    // offset of 1 second.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from target duration (3 * 4 = 12 seconds) and then expressed
    // in relation to the live edge (12 + 1 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(13000);
    assertThat(window.liveConfiguration.minPlaybackSpeed).isEqualTo(1f);
    assertThat(window.liveConfiguration.maxPlaybackSpeed).isEqualTo(1f);
    assertThat(window.defaultPositionUs).isEqualTo(4000000);
  }

  @Test
  public void loadLivePlaylist_holdBackInPlaylist_targetLiveOffsetFromHoldBack()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds and a hold back of 12 seconds.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12";
    // The playlist finishes 1 second before the current time, therefore there's a live edge
    // offset of 1 second.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from hold back and then expressed in relation to the live
    // edge (+1 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(13000);
    assertThat(window.liveConfiguration.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
    assertThat(window.liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
    assertThat(window.defaultPositionUs).isEqualTo(4000000);
  }

  @Test
  public void
      loadLivePlaylist_partHoldBackWithoutPartInformationInPlaylist_targetLiveOffsetFromHoldBack()
          throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a part hold back but not EXT-X-PART-INF. We should pick up the hold back.
    // The duration of the playlist is 16 seconds so that the defined hold back is within the live
    // window.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from hold back and then expressed in relation to the live
    // edge (+1 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(13000);
    assertThat(window.liveConfiguration.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
    assertThat(window.liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
    assertThat(window.defaultPositionUs).isEqualTo(4000000);
  }

  @Test
  public void
      loadLivePlaylist_partHoldBackWithPartInformationInPlaylist_targetLiveOffsetFromPartHoldBack()
          throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 4 seconds, part hold back and EXT-X-PART-INF defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXT-X-PART-INF:PART-TARGET=0.5\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:05.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from part hold back and then expressed in relation to the
    // live edge (+1 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(4000);
    assertThat(window.liveConfiguration.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
    assertThat(window.liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
    assertThat(window.defaultPositionUs).isEqualTo(0);
  }

  @Test
  public void loadLivePlaylist_withParts_defaultPositionPointsAtClosestIndependentPart()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 7 seconds, part hold back and EXT-X-PART-INF defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=2\n"
            + "#EXT-X-PART-INF:PART-TARGET=0.5\n"
            + "#EXT-X-PART:DURATION=0.5000,URI=\"fileSequence1.0.ts\",INDEPENDENT=YES\n"
            + "#EXT-X-PART:DURATION=0.5000,URI=\"fileSequence1.1.ts\"\n"
            + "#EXT-X-PART:DURATION=0.5000,URI=\"fileSequence1.2.ts\",INDEPENDENT=YES\n"
            + "#EXT-X-PART:DURATION=0.5000,URI=\"fileSequence1.3.ts\"\n"
            + "#EXT-X-PART:DURATION=0.5000,URI=\"fileSequence1.4.ts\",INDEPENDENT=YES\n"
            + "#EXT-X-PART:DURATION=0.5000,URI=\"fileSequence1.5.ts\"";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:08.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from part hold back and then expressed in relation to the
    // live edge (+1 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(3000);
    // The default position points the closest preceding independent part.
    assertThat(window.defaultPositionUs).isEqualTo(5000000);
  }

  @Test
  public void loadLivePlaylist_withNonPreciseStartTime_targetLiveOffsetFromStartTime()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds, and part hold back, hold back and start time
    // defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-START:TIME-OFFSET=-10\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3\n";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from start time (16 - 10 = 6) and then expressed in relation
    // to the live edge (17 - 6 = 11 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(11000);
    // The default position points to the segment containing the start time.
    assertThat(window.defaultPositionUs).isEqualTo(4000000);
  }

  @Test
  public void
      loadLivePlaylist_withNonPreciseStartTimeAndUserDefinedLiveOffset_startsFromPrecedingSegment()
          throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds, and part hold back, hold back and start time
    // defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-START:TIME-OFFSET=-10\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3\n";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem =
        new MediaItem.Builder()
            .setUri(playlistUri)
            .setLiveConfiguration(
                new MediaItem.LiveConfiguration.Builder().setTargetOffsetMs(3000).build())
            .build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(3000);
    // The default position points to the segment containing the start time.
    assertThat(window.defaultPositionUs).isEqualTo(4000000);
  }

  @Test
  public void loadLivePlaylist_withPreciseStartTime_targetLiveOffsetFromStartTime()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds, and part hold back, hold back and start time
    // defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-START:TIME-OFFSET=-10,PRECISE=YES\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = MediaItem.fromUri(playlistUri);
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from start time (16 - 10 = 6) and then expressed in relation
    // to the live edge (17 - 7 = 11 seconds).
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(11000);
    // The default position points to the start time.
    assertThat(window.defaultPositionUs).isEqualTo(6000000);
  }

  @Test
  public void loadLivePlaylist_withPreciseStartTimeAndUserDefinedLiveOffset_startsFromStartTime()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds, and part hold back, hold back and start time
    // defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-START:TIME-OFFSET=-10,PRECISE=YES\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3";
    // The playlist finishes 1 second before the current time.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:17.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem =
        new MediaItem.Builder()
            .setUri(playlistUri)
            .setLiveConfiguration(
                new MediaItem.LiveConfiguration.Builder().setTargetOffsetMs(3000).build())
            .build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(3000);
    // The default position points to the start time.
    assertThat(window.defaultPositionUs).isEqualTo(6000000);
  }

  @Test
  public void loadLivePlaylist_targetLiveOffsetInMediaItem_targetLiveOffsetPickedFromMediaItem()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a hold back of 12 seconds and a part hold back of 3 seconds.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12,PART-HOLD-BACK=3";
    // The playlist finishes 1 second before the current time. This should not affect the target
    // live offset set in the media item.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:05.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem =
        new MediaItem.Builder()
            .setUri(playlistUri)
            .setLiveConfiguration(
                new MediaItem.LiveConfiguration.Builder().setTargetOffsetMs(1000).build())
            .build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is picked from the media item and not adjusted.
    assertThat(window.liveConfiguration).isEqualTo(mediaItem.liveConfiguration);
    assertThat(window.defaultPositionUs).isEqualTo(0);
  }

  @Test
  public void loadLivePlaylist_noHoldBackInPlaylistAndNoPlaybackSpeedInMediaItem_usesUnitSpeed()
      throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has no hold back defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts";
    // The playlist finishes 1 second before the current time. This should not affect the target
    // live offset set in the media item.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:05.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem =
        new MediaItem.Builder()
            .setUri(playlistUri)
            .setLiveConfiguration(
                new MediaItem.LiveConfiguration.Builder().setTargetOffsetMs(1000).build())
            .build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(window.liveConfiguration.minPlaybackSpeed).isEqualTo(1f);
    assertThat(window.liveConfiguration.maxPlaybackSpeed).isEqualTo(1f);
    assertThat(window.defaultPositionUs).isEqualTo(0);
  }

  @Test
  public void
      loadLivePlaylist_noHoldBackInPlaylistAndPlaybackSpeedInMediaItem_usesMediaItemConfiguration()
          throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has no hold back defined.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts";
    // The playlist finishes 1 second before the current time. This should not affect the target
    // live offset set in the media item.
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:05.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem =
        new MediaItem.Builder()
            .setUri(playlistUri)
            .setLiveConfiguration(
                new MediaItem.LiveConfiguration.Builder()
                    .setTargetOffsetMs(1000)
                    .setMinPlaybackSpeed(0.94f)
                    .setMaxPlaybackSpeed(1.02f)
                    .build())
            .build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(window.liveConfiguration).isEqualTo(mediaItem.liveConfiguration);
    assertThat(window.defaultPositionUs).isEqualTo(0);
  }

  @Test
  public void
      loadLivePlaylist_targetLiveOffsetLargerThanLiveWindow_targetLiveOffsetIsWithinLiveWindow()
          throws TimeoutException, ParserException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 8 seconds and a hold back of 12 seconds.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PROGRAM-DATE-TIME:2020-01-01T00:00:00.0+00:00\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXT-X-SERVER-CONTROL:CAN-SKIP-UNTIL=24";
    // The playlist finishes 1 second before the live edge, therefore the live window duration is
    // 9 seconds (8 + 1).
    SystemClock.setCurrentTimeMillis(Util.parseXsDateTime("2020-01-01T00:00:09.0+00:00"));
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem =
        new MediaItem.Builder()
            .setUri(playlistUri)
            .setLiveConfiguration(
                new MediaItem.LiveConfiguration.Builder().setTargetOffsetMs(20_000).build())
            .build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(mediaItem.liveConfiguration.targetOffsetMs)
        .isGreaterThan(Util.usToMs(window.durationUs));
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(9000);
  }

  @Test
  public void
      loadLivePlaylist_withoutProgramDateTime_targetLiveOffsetFromPlaylistNotAdjustedToLiveEdge()
          throws TimeoutException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    // The playlist has a duration of 16 seconds and a hold back of 12 seconds.
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK=12";
    // The playlist finishes 8 seconds before the current time.
    SystemClock.setCurrentTimeMillis(20000);
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = new MediaItem.Builder().setUri(playlistUri).build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is not adjusted to the live edge because the list does not have
    // program date time.
    assertThat(window.liveConfiguration.targetOffsetMs).isEqualTo(12000);
    assertThat(window.defaultPositionUs).isEqualTo(4000000);
  }

  @Test
  public void loadOnDemandPlaylist_withPreciseStartTime_setsDefaultPosition()
      throws TimeoutException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PLAYLIST-TYPE:VOD\n"
            + "#EXT-X-TARGETDURATION:10\n"
            + "#EXT-X-VERSION:4\n"
            + "#EXT-X-START:TIME-OFFSET=15.000,PRECISE=YES"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence2.ts\n"
            + "#EXT-X-ENDLIST";
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = new MediaItem.Builder().setUri(playlistUri).build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is not adjusted to the live edge because the list does not have
    // program date time.
    assertThat(window.liveConfiguration).isNull();
    assertThat(window.defaultPositionUs).isEqualTo(15000000);
  }

  @Test
  public void loadOnDemandPlaylist_withNonPreciseStartTime_setsDefaultPosition()
      throws TimeoutException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PLAYLIST-TYPE:VOD\n"
            + "#EXT-X-TARGETDURATION:10\n"
            + "#EXT-X-VERSION:4\n"
            + "#EXT-X-START:TIME-OFFSET=15.000"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence2.ts\n"
            + "#EXT-X-ENDLIST";
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = new MediaItem.Builder().setUri(playlistUri).build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    // The target live offset is not adjusted to the live edge because the list does not have
    // program date time.
    assertThat(window.liveConfiguration).isNull();
    assertThat(window.defaultPositionUs).isEqualTo(10000000);
  }

  @Test
  public void
      loadOnDemandPlaylist_withStartTimeBeforeTheBeginning_setsDefaultPositionToTheBeginning()
          throws TimeoutException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PLAYLIST-TYPE:VOD\n"
            + "#EXT-X-TARGETDURATION:10\n"
            + "#EXT-X-VERSION:4\n"
            + "#EXT-X-START:TIME-OFFSET=-35.000"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence2.ts\n"
            + "#EXT-X-ENDLIST";
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = new MediaItem.Builder().setUri(playlistUri).build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(window.liveConfiguration).isNull();
    assertThat(window.defaultPositionUs).isEqualTo(0);
  }

  @Test
  public void loadOnDemandPlaylist_withStartTimeAfterTheNed_setsDefaultPositionToTheEnd()
      throws TimeoutException {
    String playlistUri = "fake://foo.bar/media0/playlist.m3u8";
    String playlist =
        "#EXTM3U\n"
            + "#EXT-X-PLAYLIST-TYPE:VOD\n"
            + "#EXT-X-TARGETDURATION:10\n"
            + "#EXT-X-VERSION:4\n"
            + "#EXT-X-START:TIME-OFFSET=35.000"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:10.0,\n"
            + "fileSequence2.ts\n"
            + "#EXT-X-ENDLIST";
    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri, playlist);
    MediaItem mediaItem = new MediaItem.Builder().setUri(playlistUri).build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);

    Timeline timeline = prepareAndWaitForTimeline(mediaSource);

    Timeline.Window window = timeline.getWindow(0, new Timeline.Window());
    assertThat(window.liveConfiguration).isNull();
    assertThat(window.defaultPositionUs).isEqualTo(20000000);
  }

  @Test
  public void refreshPlaylist_targetLiveOffsetRemainsInWindow()
      throws TimeoutException, IOException {
    String playlistUri1 = "fake://foo.bar/media0/playlist1.m3u8";
    // The playlist has a duration of 16 seconds and a hold back of 12 seconds.
    String playlist1 =
        "#EXTM3U\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:0\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence0.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence1.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence2.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence3.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK:12";
    // The second playlist defines a different hold back.
    String playlistUri2 = "fake://foo.bar/media0/playlist2.m3u8";
    String playlist2 =
        "#EXTM3U\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:4\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence4.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence5.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence6.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence7.ts\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK:14";
    // The third playlist has a duration of 8 seconds.
    String playlistUri3 = "fake://foo.bar/media0/playlist3.m3u8";
    String playlist3 =
        "#EXTM3U\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:4\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence8.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence9.ts\n"
            + "#EXTINF:4.00000,\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK:12";
    // The third playlist has a duration of 16 seconds but the target live offset should remain at
    // 8 seconds.
    String playlistUri4 = "fake://foo.bar/media0/playlist4.m3u8";
    String playlist4 =
        "#EXTM3U\n"
            + "#EXT-X-TARGETDURATION:4\n"
            + "#EXT-X-VERSION:3\n"
            + "#EXT-X-MEDIA-SEQUENCE:4\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence10.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence11.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence12.ts\n"
            + "#EXTINF:4.00000,\n"
            + "fileSequence13.ts\n"
            + "#EXTINF:4.00000,\n"
            + "#EXT-X-SERVER-CONTROL:HOLD-BACK:12";

    HlsMediaSource.Factory factory = createHlsMediaSourceFactory(playlistUri1, playlist1);
    MediaItem mediaItem = new MediaItem.Builder().setUri(playlistUri1).build();
    HlsMediaSource mediaSource = factory.createMediaSource(mediaItem);
    HlsMediaPlaylist secondPlaylist = parseHlsMediaPlaylist(playlistUri2, playlist2);
    HlsMediaPlaylist thirdPlaylist = parseHlsMediaPlaylist(playlistUri3, playlist3);
    HlsMediaPlaylist fourthPlaylist = parseHlsMediaPlaylist(playlistUri4, playlist4);
    List<Timeline> timelines = new ArrayList<>();
    MediaSource.MediaSourceCaller mediaSourceCaller = (source, timeline) -> timelines.add(timeline);

    mediaSource.prepareSource(mediaSourceCaller, /* mediaTransferListener= */ null, PlayerId.UNSET);
    runMainLooperUntil(() -> timelines.size() == 1);
    mediaSource.onPrimaryPlaylistRefreshed(secondPlaylist);
    runMainLooperUntil(() -> timelines.size() == 2);
    mediaSource.onPrimaryPlaylistRefreshed(thirdPlaylist);
    runMainLooperUntil(() -> timelines.size() == 3);
    mediaSource.onPrimaryPlaylistRefreshed(fourthPlaylist);
    runMainLooperUntil(() -> timelines.size() == 4);

    Timeline.Window window = new Timeline.Window();
    assertThat(timelines.get(0).getWindow(0, window).liveConfiguration.targetOffsetMs)
        .isEqualTo(12000);
    assertThat(timelines.get(1).getWindow(0, window).liveConfiguration.targetOffsetMs)
        .isEqualTo(12000);
    assertThat(timelines.get(2).getWindow(0, window).liveConfiguration.targetOffsetMs)
        .isEqualTo(8000);
    assertThat(timelines.get(3).getWindow(0, window).liveConfiguration.targetOffsetMs)
        .isEqualTo(8000);
  }

  private static HlsMediaSource.Factory createHlsMediaSourceFactory(
      String playlistUri, String playlist) {
    FakeDataSet fakeDataSet = new FakeDataSet().setData(playlistUri, Util.getUtf8Bytes(playlist));
    return new HlsMediaSource.Factory(
            dataType -> new FakeDataSource.Factory().setFakeDataSet(fakeDataSet).createDataSource())
        .setElapsedRealTimeOffsetMs(0);
  }

  /** Prepares the media source and waits until the timeline is updated. */
  private static Timeline prepareAndWaitForTimeline(HlsMediaSource mediaSource)
      throws TimeoutException {
    AtomicReference<Timeline> receivedTimeline = new AtomicReference<>();
    mediaSource.prepareSource(
        (source, timeline) -> receivedTimeline.set(timeline),
        /* mediaTransferListener= */ null,
        PlayerId.UNSET);
    runMainLooperUntil(() -> receivedTimeline.get() != null);
    return receivedTimeline.get();
  }

  private static HlsMediaPlaylist parseHlsMediaPlaylist(String playlistUri, String playlist)
      throws IOException {
    return (HlsMediaPlaylist)
        new HlsPlaylistParser()
            .parse(Uri.parse(playlistUri), new ByteArrayInputStream(Util.getUtf8Bytes(playlist)));
  }
}
