/*
 *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

package org.webrtc;

import javax.annotation.Nullable;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.List;

/**
 * Helper class that combines HW and SW decoders.
 */
public class DefaultVideoDecoderFactory implements VideoDecoderFactory {
  private final VideoDecoderFactory hardwareVideoDecoderFactory;
  private final VideoDecoderFactory softwareVideoDecoderFactory = new SoftwareVideoDecoderFactory();
  private final @Nullable VideoDecoderFactory platformSoftwareVideoDecoderFactory;

  /**
   * Create decoder factory using default hardware decoder factory.
   */
  public DefaultVideoDecoderFactory(@Nullable EglBase.Context eglContext) {
    this.hardwareVideoDecoderFactory = new HardwareVideoDecoderFactory(eglContext);
    this.platformSoftwareVideoDecoderFactory = new PlatformSoftwareVideoDecoderFactory(eglContext);
  }

  /**
   * Create decoder factory using explicit hardware decoder factory.
   */
  DefaultVideoDecoderFactory(VideoDecoderFactory hardwareVideoDecoderFactory) {
    this.hardwareVideoDecoderFactory = hardwareVideoDecoderFactory;
    this.platformSoftwareVideoDecoderFactory = null;
  }

  @Override
  public @Nullable VideoDecoder createDecoder(VideoCodecInfo codecType) {
    VideoDecoder softwareDecoder = softwareVideoDecoderFactory.createDecoder(codecType);
    final VideoDecoder hardwareDecoder = hardwareVideoDecoderFactory.createDecoder(codecType);
    if (softwareDecoder == null && platformSoftwareVideoDecoderFactory != null) {
      softwareDecoder = platformSoftwareVideoDecoderFactory.createDecoder(codecType);
    }
    if (hardwareDecoder != null && softwareDecoder != null) {
      // Both hardware and software supported, wrap it in a software fallback
      return new VideoDecoderFallback(
          /* fallback= */ softwareDecoder, /* primary= */ hardwareDecoder);
    }
    return hardwareDecoder != null ? hardwareDecoder : softwareDecoder;
  }

  @Override
  public VideoCodecInfo[] getSupportedCodecs() {
    LinkedHashSet<VideoCodecInfo> supportedCodecInfos = new LinkedHashSet<VideoCodecInfo>();

    supportedCodecInfos.addAll(Arrays.asList(softwareVideoDecoderFactory.getSupportedCodecs()));
    supportedCodecInfos.addAll(Arrays.asList(hardwareVideoDecoderFactory.getSupportedCodecs()));
    if (platformSoftwareVideoDecoderFactory != null) {
      supportedCodecInfos.addAll(
          Arrays.asList(platformSoftwareVideoDecoderFactory.getSupportedCodecs()));
    }

    return supportedCodecInfos.toArray(new VideoCodecInfo[supportedCodecInfos.size()]);
  }
}