/*
 *  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 "webrtc/api/video/video_frame_buffer.h"

#include "libyuv/convert_from.h"
#include "webrtc/api/video/i420_buffer.h"
#include "webrtc/base/checks.h"

namespace webrtc {

namespace {

// TODO(magjed): Remove this class. It is only used for providing a default
// implementation of ToI420() until external clients are updated. ToI420() will
// then be made pure virtual. This adapter adapts a VideoFrameBuffer (which is
// expected to be in I420 format) to the PlanarYuvBuffer interface. The reason
// this is needed is because of the return type mismatch in NativeToI420Buffer
// (returns VideoFrameBuffer) vs ToI420 (returns PlanarYuvBuffer).
class PlanarYuvBufferAdapter : public PlanarYuvBuffer {
 public:
  explicit PlanarYuvBufferAdapter(rtc::scoped_refptr<VideoFrameBuffer> buffer)
      : buffer_(buffer) {}

  Type type() const override { return Type::kI420; }

  int width() const override { return buffer_->width(); }
  int height() const override { return buffer_->height(); }

  const uint8_t* DataY() const override { return buffer_->DataY(); }
  const uint8_t* DataU() const override { return buffer_->DataU(); }
  const uint8_t* DataV() const override { return buffer_->DataV(); }

  int StrideY() const override { return buffer_->StrideY(); }
  int StrideU() const override { return buffer_->StrideU(); }
  int StrideV() const override { return buffer_->StrideV(); }

 private:
  rtc::scoped_refptr<VideoFrameBuffer> buffer_;
};

}  // namespace

// TODO(magjed): The default implementations in VideoFrameBuffer are provided in
// order to support the deprecated interface until external clients are updated.
// Remove once done.
VideoFrameBuffer::Type VideoFrameBuffer::type() const {
  return native_handle() ? Type::kNative : Type::kI420;
}

const uint8_t* VideoFrameBuffer::DataY() const {
  return const_cast<VideoFrameBuffer*>(this)->GetI420()->DataY();
}

const uint8_t* VideoFrameBuffer::DataU() const {
  return const_cast<VideoFrameBuffer*>(this)->GetI420()->DataU();
}

const uint8_t* VideoFrameBuffer::DataV() const {
  return const_cast<VideoFrameBuffer*>(this)->GetI420()->DataV();
}

// Returns the number of bytes between successive rows for a given plane.
int VideoFrameBuffer::StrideY() const {
  return const_cast<VideoFrameBuffer*>(this)->GetI420()->StrideY();
}

int VideoFrameBuffer::StrideU() const {
  return const_cast<VideoFrameBuffer*>(this)->GetI420()->StrideU();
}

int VideoFrameBuffer::StrideV() const {
  return const_cast<VideoFrameBuffer*>(this)->GetI420()->StrideV();
}

void* VideoFrameBuffer::native_handle() const {
  RTC_DCHECK(type() != Type::kNative);
  return nullptr;
}

rtc::scoped_refptr<VideoFrameBuffer> VideoFrameBuffer::NativeToI420Buffer() {
  return ToI420();
}

rtc::scoped_refptr<PlanarYuvBuffer> VideoFrameBuffer::ToI420() {
  return new rtc::RefCountedObject<PlanarYuvBufferAdapter>(
      NativeToI420Buffer());
}

rtc::scoped_refptr<PlanarYuvBuffer> VideoFrameBuffer::GetI420() {
  RTC_CHECK(type() == Type::kI420);
  // TODO(magjed): static_cast to PlanarYuvBuffer instead once external clients
  // are updated.
  return new rtc::RefCountedObject<PlanarYuvBufferAdapter>(this);
}

rtc::scoped_refptr<PlanarYuvBuffer> VideoFrameBuffer::GetI444() {
  RTC_CHECK(type() == Type::kI444);
  return static_cast<PlanarYuvBuffer*>(this);
}

rtc::scoped_refptr<PlanarYuvBuffer> PlanarYuvBuffer::ToI420() {
  switch (type()) {
    case Type::kI420:
      return this;
    case Type::kI444: {
      rtc::scoped_refptr<I420Buffer> i420_buffer =
          I420Buffer::Create(width(), height());
      libyuv::I420ToI444(DataY(), StrideY(), DataU(), StrideU(), DataV(),
                         StrideV(), i420_buffer->MutableDataY(),
                         i420_buffer->StrideY(), i420_buffer->MutableDataU(),
                         i420_buffer->StrideU(), i420_buffer->MutableDataV(),
                         i420_buffer->StrideV(), width(), height());
      return i420_buffer;
    }
    default:
      RTC_NOTREACHED();
      return nullptr;
  }
}

int PlanarYuvBuffer::ChromaWidth() const {
  switch (type()) {
    case Type::kI420:
      return (width() + 1) / 2;
    case Type::kI444:
      return width();
    default:
      RTC_NOTREACHED();
      return 0;
  }
}

int PlanarYuvBuffer::ChromaHeight() const {
  switch (type()) {
    case Type::kI420:
      return (height() + 1) / 2;
    case Type::kI444:
      return height();
    default:
      RTC_NOTREACHED();
      return 0;
  }
}

}  // namespace webrtc