content: /*
   * Copyright (C) 2016 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 com.google.android.exoplayer2.extractor.ogg;
  
  import static com.google.android.exoplayer2.testutil.TestUtil.getByteArray;
  import static com.google.common.truth.Truth.assertThat;
  
  import androidx.test.core.app.ApplicationProvider;
  import androidx.test.ext.junit.runners.AndroidJUnit4;
  import com.google.android.exoplayer2.testutil.FakeExtractorInput;
  import com.google.android.exoplayer2.testutil.FakeExtractorInput.SimulatedIOException;
  import com.google.android.exoplayer2.testutil.TestUtil;
  import com.google.common.primitives.Bytes;
  import java.io.IOException;
  import java.util.Random;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  
  /** Unit test for {@link OggPageHeader}. */
  @RunWith(AndroidJUnit4.class)
  public final class OggPageHeaderTest {
  
    private final Random random;
  
    public OggPageHeaderTest() {
      this.random = new Random(/* seed= */ 0);
    }
  
    @Test
    public void skipToNextPage_success() throws Exception {
      FakeExtractorInput input =
          createInput(
              Bytes.concat(
                  TestUtil.buildTestData(20, random),
                  new byte[] {'O', 'g', 'g', 'S'},
                  TestUtil.buildTestData(20, random)),
              /* simulateUnknownLength= */ false);
      OggPageHeader oggHeader = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> oggHeader.skipToNextPage(input));
  
      assertThat(result).isTrue();
      assertThat(input.getPosition()).isEqualTo(20);
    }
  
    @Test
    public void skipToNextPage_noPage_returnsFalse() throws Exception {
      FakeExtractorInput input =
          createInput(
              Bytes.concat(TestUtil.buildTestData(20, random)), /* simulateUnknownLength= */ false);
      OggPageHeader oggHeader = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> oggHeader.skipToNextPage(input));
  
      assertThat(result).isFalse();
      assertThat(input.getPosition()).isEqualTo(20);
    }
  
    @Test
    public void skipToNextPage_respectsLimit() throws Exception {
      FakeExtractorInput input =
          createInput(
              Bytes.concat(
                  TestUtil.buildTestData(20, random),
                  new byte[] {'O', 'g', 'g', 'S'},
                  TestUtil.buildTestData(20, random)),
              /* simulateUnknownLength= */ false);
      OggPageHeader oggHeader = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> oggHeader.skipToNextPage(input, 10));
  
      assertThat(result).isFalse();
      assertThat(input.getPosition()).isEqualTo(10);
    }
  
    @Test
    public void populatePageHeader_success() throws Exception {
      byte[] data =
          getByteArray(ApplicationProvider.getApplicationContext(), "media/ogg/page_header");
  
      FakeExtractorInput input = createInput(data, /* simulateUnknownLength= */ true);
      OggPageHeader header = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> header.populate(input, /* quiet= */ false));
  
      assertThat(result).isTrue();
      assertThat(header.type).isEqualTo(0x01);
      assertThat(header.headerSize).isEqualTo(27 + 2);
      assertThat(header.bodySize).isEqualTo(4);
      assertThat(header.pageSegmentCount).isEqualTo(2);
      assertThat(header.granulePosition).isEqualTo(123456);
      assertThat(header.pageSequenceNumber).isEqualTo(4);
      assertThat(header.streamSerialNumber).isEqualTo(0x1000);
      assertThat(header.pageChecksum).isEqualTo(0x100000);
      assertThat(header.revision).isEqualTo(0);
    }
  
    @Test
    public void populatePageHeader_withLessThan27Bytes_returnFalseWithoutException()
        throws Exception {
      FakeExtractorInput input =
          createInput(TestUtil.createByteArray(2, 2), /* simulateUnknownLength= */ false);
      OggPageHeader header = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> header.populate(input, /* quiet= */ true));
  
      assertThat(result).isFalse();
    }
  
    @Test
    public void populatePageHeader_withNotOgg_returnFalseWithoutException() throws Exception {
      byte[] data =
          getByteArray(ApplicationProvider.getApplicationContext(), "media/ogg/page_header");
      // change from 'O' to 'o'
      data[0] = 'o';
      FakeExtractorInput input = createInput(data, /* simulateUnknownLength= */ false);
      OggPageHeader header = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> header.populate(input, /* quiet= */ true));
  
      assertThat(result).isFalse();
    }
  
    @Test
    public void populatePageHeader_withWrongRevision_returnFalseWithoutException() throws Exception {
      byte[] data =
          getByteArray(ApplicationProvider.getApplicationContext(), "media/ogg/page_header");
      // change revision from 0 to 1
      data[4] = 0x01;
      FakeExtractorInput input = createInput(data, /* simulateUnknownLength= */ false);
      OggPageHeader header = new OggPageHeader();
  
      boolean result = retrySimulatedIOException(() -> header.populate(input, /* quiet= */ true));
  
      assertThat(result).isFalse();
    }
  
    private static FakeExtractorInput createInput(byte[] data, boolean simulateUnknownLength) {
      return new FakeExtractorInput.Builder()
          .setData(data)
          .setSimulateIOErrors(true)
          .setSimulateUnknownLength(simulateUnknownLength)
          .setSimulatePartialReads(true)
          .build();
    }
  
    private static <T> T retrySimulatedIOException(ThrowingSupplier<T, IOException> supplier)
        throws IOException {
      while (true) {
        try {
          return supplier.get();
        } catch (SimulatedIOException e) {
          // ignored
        }
      }
    }
  
    private interface ThrowingSupplier<S, E extends Throwable> {
      S get() throws E;
    }
  }
  