/*
 *  Copyright (c) 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.
 */

#include "media/engine/convert_legacy_video_factory.h"

#include <utility>
#include <vector>

#include "api/video_codecs/video_decoder_factory.h"
#include "api/video_codecs/video_encoder_factory.h"
#include "media/engine/internaldecoderfactory.h"
#include "media/engine/internalencoderfactory.h"
#include "media/engine/scopedvideodecoder.h"
#include "media/engine/scopedvideoencoder.h"
#include "media/engine/simulcast_encoder_adapter.h"
#include "media/engine/videodecodersoftwarefallbackwrapper.h"
#include "media/engine/videoencodersoftwarefallbackwrapper.h"
#include "media/engine/vp8_encoder_simulcast_proxy.h"
#include "media/engine/webrtcvideodecoderfactory.h"
#include "media/engine/webrtcvideoencoderfactory.h"
#include "rtc_base/checks.h"

namespace cricket {

namespace {

class EncoderAdapter : public webrtc::VideoEncoderFactory {
 public:
  explicit EncoderAdapter(
      std::unique_ptr<WebRtcVideoEncoderFactory> external_encoder_factory)
      : internal_encoder_factory_(new InternalEncoderFactory()),
        external_encoder_factory_(std::move(external_encoder_factory)) {}

  webrtc::VideoEncoderFactory::CodecInfo QueryVideoEncoder(
      const webrtc::SdpVideoFormat& format) const {
    const VideoCodec codec(format);
    if (external_encoder_factory_ != nullptr &&
        FindMatchingCodec(external_encoder_factory_->supported_codecs(),
                          codec)) {
      // Format is supported by the external factory.
      const webrtc::VideoCodecType codec_type =
          webrtc::PayloadStringToCodecType(codec.name);
      webrtc::VideoEncoderFactory::CodecInfo info;
      info.has_internal_source =
          external_encoder_factory_->EncoderTypeHasInternalSource(codec_type);
      info.is_hardware_accelerated = true;
      return info;
    }

    // Format must be one of the internal formats.
    RTC_DCHECK(FindMatchingCodec(internal_encoder_factory_->supported_codecs(),
                                 codec));
    webrtc::VideoEncoderFactory::CodecInfo info;
    info.has_internal_source = false;
    info.is_hardware_accelerated = false;
    return info;
  }

  std::unique_ptr<webrtc::VideoEncoder> CreateVideoEncoder(
      const webrtc::SdpVideoFormat& format) {
    const VideoCodec codec(format);
    // Try creating external encoder.
    if (external_encoder_factory_ != nullptr &&
        FindMatchingCodec(external_encoder_factory_->supported_codecs(),
                          codec)) {
      std::unique_ptr<webrtc::VideoEncoder> external_encoder;
      if (CodecNamesEq(codec.name.c_str(), kVp8CodecName)) {
        // If it's a codec type we can simulcast, create a wrapped encoder.
        external_encoder = std::unique_ptr<webrtc::VideoEncoder>(
            new webrtc::SimulcastEncoderAdapter(
                external_encoder_factory_.get()));
      } else {
        external_encoder =
            CreateScopedVideoEncoder(external_encoder_factory_.get(), codec);
      }
      if (external_encoder) {
        return std::unique_ptr<webrtc::VideoEncoder>(
            new webrtc::VideoEncoderSoftwareFallbackWrapper(
                codec, std::move(external_encoder)));
      }
    }

    // Try creating internal encoder.
    if (FindMatchingCodec(internal_encoder_factory_->supported_codecs(),
                          codec)) {
      if (CodecNamesEq(codec.name.c_str(), kVp8CodecName)) {
        return std::unique_ptr<webrtc::VideoEncoder>(
            new webrtc::VP8EncoderSimulcastProxy(
                internal_encoder_factory_.get()));
      } else {
        return std::unique_ptr<webrtc::VideoEncoder>(
            internal_encoder_factory_->CreateVideoEncoder(codec));
      }
    }

    // This shouldn't happen, we should not be trying to create something we
    // don't support.
    RTC_NOTREACHED();
    return nullptr;
  }

  std::vector<webrtc::SdpVideoFormat> GetSupportedFormats() const {
    std::vector<VideoCodec> codecs =
        InternalEncoderFactory().supported_codecs();

    // Add external codecs.
    if (external_encoder_factory_ != nullptr) {
      const std::vector<VideoCodec>& external_codecs =
          external_encoder_factory_->supported_codecs();
      for (const VideoCodec& codec : external_codecs) {
        // Don't add same codec twice.
        if (!FindMatchingCodec(codecs, codec))
          codecs.push_back(codec);
      }
    }

    std::vector<webrtc::SdpVideoFormat> formats;
    for (const VideoCodec& codec : codecs) {
      formats.push_back(webrtc::SdpVideoFormat(codec.name, codec.params));
    }

    return formats;
  }

 private:
  const std::unique_ptr<WebRtcVideoEncoderFactory> internal_encoder_factory_;
  const std::unique_ptr<WebRtcVideoEncoderFactory> external_encoder_factory_;
};

class DecoderAdapter : public webrtc::VideoDecoderFactory {
 public:
  explicit DecoderAdapter(
      std::unique_ptr<WebRtcVideoDecoderFactory> external_decoder_factory)
      : internal_decoder_factory_(new InternalDecoderFactory()),
        external_decoder_factory_(std::move(external_decoder_factory)) {}

  std::unique_ptr<webrtc::VideoDecoder> CreateVideoDecoder(
      const webrtc::SdpVideoFormat& format) override {
    const VideoCodec codec(format);
    const VideoDecoderParams params = {};
    if (external_decoder_factory_ != nullptr) {
      std::unique_ptr<webrtc::VideoDecoder> external_decoder =
          CreateScopedVideoDecoder(external_decoder_factory_.get(), codec,
                                   params);
      if (external_decoder) {
        webrtc::VideoCodecType type =
            webrtc::PayloadStringToCodecType(codec.name);
        std::unique_ptr<webrtc::VideoDecoder> internal_decoder(
            new webrtc::VideoDecoderSoftwareFallbackWrapper(
                type, std::move(external_decoder)));
        return internal_decoder;
      }
    }
    std::unique_ptr<webrtc::VideoDecoder> internal_decoder(
        internal_decoder_factory_->CreateVideoDecoderWithParams(codec, params));
    return internal_decoder;
  }

  std::vector<webrtc::SdpVideoFormat> GetSupportedFormats() const override {
    // This is not implemented for the legacy decoder factory.
    RTC_NOTREACHED();
    return std::vector<webrtc::SdpVideoFormat>();
  }

 private:
  const std::unique_ptr<WebRtcVideoDecoderFactory> internal_decoder_factory_;
  const std::unique_ptr<WebRtcVideoDecoderFactory> external_decoder_factory_;
};

}  // namespace

std::unique_ptr<webrtc::VideoEncoderFactory> ConvertVideoEncoderFactory(
    std::unique_ptr<WebRtcVideoEncoderFactory> external_encoder_factory) {
  return std::unique_ptr<webrtc::VideoEncoderFactory>(
      new EncoderAdapter(std::move(external_encoder_factory)));
}

std::unique_ptr<webrtc::VideoDecoderFactory> ConvertVideoDecoderFactory(
    std::unique_ptr<WebRtcVideoDecoderFactory> external_decoder_factory) {
  return std::unique_ptr<webrtc::VideoDecoderFactory>(
      new DecoderAdapter(std::move(external_decoder_factory)));
}

}  // namespace cricket