content: /*
   * Copyright (C) 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 com.google.android.exoplayer2.metadata;
  
  import static com.google.common.truth.Truth.assertThat;
  import static org.junit.Assert.assertThrows;
  
  import androidx.annotation.Nullable;
  import androidx.test.ext.junit.runners.AndroidJUnit4;
  import com.google.android.exoplayer2.C;
  import java.nio.ByteBuffer;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  
  /** Tests for {@link SimpleMetadataDecoder}. */
  @RunWith(AndroidJUnit4.class)
  public class SimpleMetadataDecoderTest {
  
    @Test
    public void decode_nullDataInputBuffer_throwsNullPointerException() {
      TestSimpleMetadataDecoder decoder = new TestSimpleMetadataDecoder();
      MetadataInputBuffer nullDataInputBuffer = new MetadataInputBuffer();
      nullDataInputBuffer.data = null;
  
      assertThrows(NullPointerException.class, () -> decoder.decode(nullDataInputBuffer));
      assertThat(decoder.decodeWasCalled).isFalse();
    }
  
    @Test
    public void decode_directDataInputBuffer_throwsIllegalArgumentException() {
      TestSimpleMetadataDecoder decoder = new TestSimpleMetadataDecoder();
      MetadataInputBuffer directDataInputBuffer = new MetadataInputBuffer();
      directDataInputBuffer.data = ByteBuffer.allocateDirect(8);
  
      assertThrows(IllegalArgumentException.class, () -> decoder.decode(directDataInputBuffer));
      assertThat(decoder.decodeWasCalled).isFalse();
    }
  
    @Test
    public void decode_nonZeroPositionDataInputBuffer_throwsIllegalArgumentException() {
      TestSimpleMetadataDecoder decoder = new TestSimpleMetadataDecoder();
      MetadataInputBuffer nonZeroPositionDataInputBuffer = new MetadataInputBuffer();
      nonZeroPositionDataInputBuffer.data = ByteBuffer.wrap(new byte[8]);
      nonZeroPositionDataInputBuffer.data.position(1);
  
      assertThrows(
          IllegalArgumentException.class, () -> decoder.decode(nonZeroPositionDataInputBuffer));
      assertThat(decoder.decodeWasCalled).isFalse();
    }
  
    @Test
    public void decode_nonZeroOffsetDataInputBuffer_throwsIllegalArgumentException() {
      TestSimpleMetadataDecoder decoder = new TestSimpleMetadataDecoder();
      MetadataInputBuffer directDataInputBuffer = new MetadataInputBuffer();
      directDataInputBuffer.data = ByteBuffer.wrap(new byte[8], /* offset= */ 4, /* length= */ 4);
  
      assertThrows(IllegalArgumentException.class, () -> decoder.decode(directDataInputBuffer));
      assertThat(decoder.decodeWasCalled).isFalse();
    }
  
    @Test
    public void decode_decodeOnlyBuffer_notPassedToDecodeInternal() {
      TestSimpleMetadataDecoder decoder = new TestSimpleMetadataDecoder();
      MetadataInputBuffer decodeOnlyBuffer = new MetadataInputBuffer();
      decodeOnlyBuffer.data = ByteBuffer.wrap(new byte[8]);
      decodeOnlyBuffer.setFlags(C.BUFFER_FLAG_DECODE_ONLY);
  
      assertThat(decoder.decode(decodeOnlyBuffer)).isNull();
      assertThat(decoder.decodeWasCalled).isFalse();
    }
  
    @Test
    public void decode_returnsDecodeInternalResult() {
      TestSimpleMetadataDecoder decoder = new TestSimpleMetadataDecoder();
      MetadataInputBuffer buffer = new MetadataInputBuffer();
      buffer.data = ByteBuffer.wrap(new byte[8]);
  
      assertThat(decoder.decode(buffer)).isSameInstanceAs(decoder.result);
      assertThat(decoder.decodeWasCalled).isTrue();
    }
  
    private static final class TestSimpleMetadataDecoder extends SimpleMetadataDecoder {
  
      public final Metadata result;
  
      public boolean decodeWasCalled;
  
      public TestSimpleMetadataDecoder() {
        result = new Metadata();
      }
  
      @Nullable
      @Override
      protected Metadata decode(MetadataInputBuffer inputBuffer, ByteBuffer buffer) {
        decodeWasCalled = true;
        return result;
      }
    }
  }
  