// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/gpu/android/codec_output_buffer_renderer.h"

#include <string.h>

#include <optional>

#include "base/android/scoped_hardware_buffer_fence_sync.h"
#include "base/functional/callback_helpers.h"
#include "gpu/command_buffer/service/gles2_cmd_decoder.h"
#include "gpu/command_buffer/service/texture_manager.h"
#include "ui/gl/gl_context.h"
#include "ui/gl/scoped_make_current.h"

namespace media {
namespace {
BASE_FEATURE(kHandleUpdateTexImageFailures, base::FEATURE_ENABLED_BY_DEFAULT);
}

CodecOutputBufferRenderer::CodecOutputBufferRenderer(
    std::unique_ptr<CodecOutputBuffer> output_buffer,
    scoped_refptr<CodecBufferWaitCoordinator> codec_buffer_wait_coordinator,
    scoped_refptr<gpu::RefCountedLock> drdc_lock)
    : RefCountedLockHelperDrDc(std::move(drdc_lock)),
      output_buffer_(std::move(output_buffer)),
      codec_buffer_wait_coordinator_(std::move(codec_buffer_wait_coordinator)) {
}

CodecOutputBufferRenderer::~CodecOutputBufferRenderer() {
  Invalidate();
}

bool CodecOutputBufferRenderer::RenderToTextureOwnerBackBuffer() {
  AssertAcquiredDrDcLock();
  DCHECK_NE(phase_, Phase::kInFrontBuffer);
  if (phase_ == Phase::kInBackBuffer)
    return true;
  if (phase_ == Phase::kInvalidated)
    return false;

  // Normally, we should have a wait coordinator if we're called.  However, if
  // the renderer is torn down (either VideoFrameSubmitter or the whole process)
  // before we get returns back from viz, then we can be notified that we're
  // no longer in use (erroneously) when the VideoFrame is destroyed.  So, if
  // we don't have a wait coordinator, then just fail.
  if (!codec_buffer_wait_coordinator_)
    return false;

  // Don't render frame if one is already pending.
  // RenderToTextureOwnerFrontBuffer will wait before calling this.
  if (codec_buffer_wait_coordinator_->IsExpectingFrameAvailable()) {
    return false;
  }
  if (!output_buffer_->ReleaseToSurface()) {
    Invalidate();
    return false;
  }
  phase_ = Phase::kInBackBuffer;
  codec_buffer_wait_coordinator_->SetReleaseTimeToNow();
  return true;
}

bool CodecOutputBufferRenderer::RenderToTextureOwnerFrontBuffer() {
  AssertAcquiredDrDcLock();
  // Normally, we should have a wait coordinator if we're called.  However, if
  // the renderer is torn down (either VideoFrameSubmitter or the whole process)
  // before we get returns back from viz, then we can be notified that we're
  // no longer in use (erroneously) when the VideoFrame is destroyed.  So, if
  // we don't have a wait coordinator, then just fail.
  if (!codec_buffer_wait_coordinator_)
    return false;

  if (phase_ == Phase::kInFrontBuffer) {
    return true;
  }
  if (phase_ == Phase::kInvalidated)
    return false;

  // Render it to the back buffer if it's not already there.
  if (phase_ != Phase::kInBackBuffer) {
    // Wait for a previous frame available so we don't confuse it with the one
    // we're about to render.
    if (codec_buffer_wait_coordinator_->IsExpectingFrameAvailable()) {
      codec_buffer_wait_coordinator_->WaitForFrameAvailable();

      // We must call update tex image if we did get OnFrameAvailable, otherwise
      // we will stop receiving callbacks (see https://crbug.com/c/1113203).
      // Note, that we don't early out here if this didn't succeed, as we only
      // need to attempt getting the buffer for callbacks to work.
      codec_buffer_wait_coordinator_->texture_owner()->UpdateTexImage(
          /*discard=*/true);
    }
    if (!RenderToTextureOwnerBackBuffer()) {
      // RenderTotextureOwnerBackBuffer can fail now only if ReleaseToSurface
      // failed.
      DCHECK_EQ(phase_, Phase::kInvalidated);
      return false;
    }
  }

  // The image is now in the back buffer, so promote it to the front buffer.
  phase_ = Phase::kInFrontBuffer;
  if (codec_buffer_wait_coordinator_->IsExpectingFrameAvailable())
    codec_buffer_wait_coordinator_->WaitForFrameAvailable();

  if (!codec_buffer_wait_coordinator_->texture_owner()->UpdateTexImage(
          /*discard=*/false)) {
    if (base::FeatureList::IsEnabled(kHandleUpdateTexImageFailures)) {
      return false;
    }
  }

  if (frame_info_callback_) {
    gfx::Size coded_size;
    gfx::Rect visible_rect;
    if (texture_owner() && texture_owner()->GetCodedSizeAndVisibleRect(
                               size(), &coded_size, &visible_rect)) {
      std::move(frame_info_callback_).Run(coded_size, visible_rect);
    } else {
      std::move(frame_info_callback_).Run(std::nullopt, std::nullopt);
    }
  }

  return true;
}

bool CodecOutputBufferRenderer::RenderToOverlay() {
  AssertAcquiredDrDcLock();
  if (phase_ == Phase::kInFrontBuffer)
    return true;
  if (phase_ == Phase::kInvalidated)
    return false;

  if (!output_buffer_->ReleaseToSurface()) {
    Invalidate();
    return false;
  }
  phase_ = Phase::kInFrontBuffer;
  return true;
}

bool CodecOutputBufferRenderer::RenderToFrontBuffer() {
  AssertAcquiredDrDcLock();

  // Trigger early rendering of the image before it is used for compositing.
  return codec_buffer_wait_coordinator_ ? RenderToTextureOwnerFrontBuffer()
                                        : RenderToOverlay();
}

void CodecOutputBufferRenderer::Invalidate() {
  phase_ = Phase::kInvalidated;
  if (frame_info_callback_) {
    std::move(frame_info_callback_).Run(std::nullopt, std::nullopt);
  }
}

}  // namespace media