// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "remoting/host/video_frame_recorder.h"

#include <stddef.h>
#include <stdint.h>

#include <utility>

#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/stl_util.h"
#include "remoting/codec/video_encoder_verbatim.h"
#include "remoting/proto/video.pb.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_region.h"

namespace webrtc {

// Define equality operator for DesktopFrame to allow use of EXPECT_EQ().
static bool operator==(const DesktopFrame& a,
                       const DesktopFrame& b) {
  if ((!a.size().equals(b.size())) ||
      (!a.updated_region().Equals(b.updated_region())) ||
      (!a.dpi().equals(b.dpi()))) {
    return false;
  }

  for (int i = 0; i < a.size().height(); ++i) {
    if (memcmp(a.data() + a.stride() * i,
               b.data() + b.stride() * i,
               a.size().width() * DesktopFrame::kBytesPerPixel) != 0) {
      return false;
    }
  }

  return true;
}

} // namespace

namespace remoting {

namespace {
const int kFrameWidth = 640;
const int kFrameHeight = 480;
const size_t kTestFrameCount = 6;
const int64_t kTestFrameBytes =
    kFrameWidth * kFrameHeight * webrtc::DesktopFrame::kBytesPerPixel;
} // namespace

class VideoFrameRecorderTest : public testing::Test {
 public:
  VideoFrameRecorderTest();

  void SetUp() override;
  void TearDown() override;

  // Creates a new VideoEncoder, wraps it using |recorder_|, and stores the
  // newly wrapped encoder in |encoder_|.
  void CreateAndWrapEncoder();

  // Creates the next test frame to pass to |encoder_|. Each test frame's pixel
  // values are set uniquely, so that tests can verify that the correct set of
  // frames were recorded.
  scoped_ptr<webrtc::DesktopFrame> CreateNextFrame();

  // Calls CreateNextFrame() to create kTextFrameCount test frames, and stores
  // them to |test_frames_|.
  void CreateTestFrames();

  // Passes the frames in |test_frames_| to |encoder_|, in order, to encode.
  void EncodeTestFrames();

  // Creates a frame and passes it to |encoder_| without adding it to
  // |test_frames_|.
  void EncodeDummyFrame();

  // Configures |recorder_| to start recording, and pumps events to ensure that
  // |encoder_| is ready to record frames.
  void StartRecording();

  // Reads frames from |recorder_| and compares them to the |test_frames_|.
  void VerifyTestFrames();

 protected:
  typedef std::list<webrtc::DesktopFrame*> DesktopFrames;

  base::MessageLoop message_loop_;

  scoped_ptr<VideoFrameRecorder> recorder_;
  scoped_ptr<VideoEncoder> encoder_;

  DesktopFrames test_frames_;
  int frame_count_;

  DISALLOW_COPY_AND_ASSIGN(VideoFrameRecorderTest);
};

VideoFrameRecorderTest::VideoFrameRecorderTest() : frame_count_(0) {}

void VideoFrameRecorderTest::SetUp() {
  const int64_t kMaxContentBytes = 10 * 1024 * 1024;
  recorder_.reset(new VideoFrameRecorder());
  recorder_->SetMaxContentBytes(kMaxContentBytes);
}

void VideoFrameRecorderTest::TearDown() {
  ASSERT_TRUE(test_frames_.empty());

  // Allow events posted to the recorder_, if still valid, to be processed.
  base::RunLoop().RunUntilIdle();

  // Tear down the recorder, if necessary.
  recorder_.reset();

  // Process any events resulting from recorder teardown.
  base::RunLoop().RunUntilIdle();
}

void VideoFrameRecorderTest::CreateAndWrapEncoder() {
  scoped_ptr<VideoEncoder> encoder(new VideoEncoderVerbatim());
  encoder_ = recorder_->WrapVideoEncoder(std::move(encoder));

  // Encode a dummy frame to bind the wrapper to the TaskRunner.
  EncodeDummyFrame();
}

scoped_ptr<webrtc::DesktopFrame> VideoFrameRecorderTest::CreateNextFrame() {
  scoped_ptr<webrtc::DesktopFrame> frame(new webrtc::BasicDesktopFrame(
      webrtc::DesktopSize(kFrameWidth, kFrameHeight)));

  // Fill content, DPI and updated-region based on |frame_count_| so that each
  // generated frame is different.
  ++frame_count_;
  memset(frame->data(), frame_count_, frame->stride() * kFrameHeight);
  frame->set_dpi(webrtc::DesktopVector(frame_count_, frame_count_));
  frame->mutable_updated_region()->SetRect(
      webrtc::DesktopRect::MakeWH(frame_count_, frame_count_));

  return frame;
}

void VideoFrameRecorderTest::CreateTestFrames() {
  for (size_t i = 0; i < kTestFrameCount; ++i) {
    test_frames_.push_back(CreateNextFrame().release());
  }
}

void VideoFrameRecorderTest::EncodeTestFrames() {
  for (DesktopFrames::iterator i = test_frames_.begin();
       i != test_frames_.end(); ++i) {
    ASSERT_TRUE(encoder_->Encode(**i));

    // Process tasks to let the recorder pick up the frame.
    base::RunLoop().RunUntilIdle();
  }
}

void VideoFrameRecorderTest::EncodeDummyFrame() {
  webrtc::BasicDesktopFrame dummy_frame(
      webrtc::DesktopSize(kFrameWidth, kFrameHeight));
  dummy_frame.mutable_updated_region()->SetRect(
      webrtc::DesktopRect::MakeWH(kFrameWidth, kFrameHeight));
  ASSERT_TRUE(encoder_->Encode(dummy_frame));
  base::RunLoop().RunUntilIdle();
}

void VideoFrameRecorderTest::StartRecording() {
  // Start the recorder and pump events to let things initialize.
  recorder_->SetEnableRecording(true);
  base::RunLoop().RunUntilIdle();
}

void VideoFrameRecorderTest::VerifyTestFrames() {
  // Verify that the recorded frames match the ones passed to the encoder.
  while (!test_frames_.empty()) {
    scoped_ptr<webrtc::DesktopFrame> recorded_frame(recorder_->NextFrame());
    ASSERT_TRUE(recorded_frame);

    scoped_ptr<webrtc::DesktopFrame> expected_frame(test_frames_.front());
    test_frames_.pop_front();

    EXPECT_EQ(*recorded_frame, *expected_frame);
  }

  EXPECT_FALSE(recorder_->NextFrame());
}

// Basic test that creating & tearing down VideoFrameRecorder doesn't crash.
TEST_F(VideoFrameRecorderTest, CreateDestroy) {
}

// Basic test that creating, starting, stopping and destroying a
// VideoFrameRecorder succeeds (e.g. does not crash or DCHECK).
TEST_F(VideoFrameRecorderTest, StartStop) {
  StartRecording();
  recorder_->SetEnableRecording(false);
}

// Test that tearing down the VideoFrameRecorder while the VideoEncoder
// wrapper exists doesn't crash.
TEST_F(VideoFrameRecorderTest, DestroyVideoFrameRecorderFirst) {
  CreateAndWrapEncoder();

  // Start the recorder, so that the wrapper will push frames to it.
  StartRecording();

  // Tear down the recorder.
  recorder_.reset();

  // Encode a dummy frame via the wrapper to ensure we don't crash.
  EncodeDummyFrame();
}

// Test that creating & tearing down the wrapper while the
// VideoFrameRecorder still exists doesn't crash.
TEST_F(VideoFrameRecorderTest, DestroyVideoEncoderWrapperFirst) {
  CreateAndWrapEncoder();

  // Start the recorder, so that the wrapper will push frames to it.
  StartRecording();

  // Encode a dummy frame via the wrapper to ensure we don't crash.
  EncodeDummyFrame();

  // Tear down the encoder wrapper.
  encoder_.reset();

  // Test teardown will stop the recorder and process pending events.
}

// Test that when asked to encode a short sequence of frames, those frames are
// all recorded, in sequence.
TEST_F(VideoFrameRecorderTest, RecordFrames) {
  CreateAndWrapEncoder();

  // Start the recorder, so that the wrapper will push frames to it.
  StartRecording();

  // Create frames, store them and pass them to the encoder.
  CreateTestFrames();
  EncodeTestFrames();

  // Verify that the recorded frames match the ones passed to the encoder.
  VerifyTestFrames();
}

// Test that when asked to record more frames than the maximum content bytes
// limit allows, the first encoded frames are dropped.
TEST_F(VideoFrameRecorderTest, MaxContentBytesEnforced) {
  CreateAndWrapEncoder();

  // Configure a maximum content size sufficient for five and a half frames.
  recorder_->SetMaxContentBytes((kTestFrameBytes * 11) / 2);

  // Start the recorder, so that the wrapper will push frames to it.
  StartRecording();

  // Create frames, store them and pass them to the encoder.
  CreateTestFrames();
  EncodeTestFrames();

  // Only five of the supplied frames should have been recorded.
  while (test_frames_.size() > 5) {
    scoped_ptr<webrtc::DesktopFrame> frame(test_frames_.front());
    test_frames_.pop_front();
  }

  // Verify that the recorded frames match the ones passed to the encoder.
  VerifyTestFrames();
}

// Test that when frames are consumed the corresponding space is freed up in
// the content buffer, allowing subsequent frames to be recorded.
TEST_F(VideoFrameRecorderTest, ContentBytesUpdatedByNextFrame) {
  CreateAndWrapEncoder();

  // Configure a maximum content size sufficient for kTestFrameCount frames.
  recorder_->SetMaxContentBytes(kTestFrameBytes * kTestFrameCount);

  // Start the recorder, so that the wrapper will push frames to it.
  StartRecording();

  // Encode a frame, to record it, and consume it from the recorder.
  EncodeDummyFrame();
  scoped_ptr<webrtc::DesktopFrame> frame = recorder_->NextFrame();
  EXPECT_TRUE(frame);

  // Create frames, store them and pass them to the encoder.
  CreateTestFrames();
  EncodeTestFrames();

  // Verify that the recorded frames match the ones passed to the encoder.
  VerifyTestFrames();
}

// Test that when asked to encode a short sequence of frames, none are recorded
// if recording was not enabled.
TEST_F(VideoFrameRecorderTest, EncodeButDontRecord) {
  CreateAndWrapEncoder();

  // Create frames, store them and pass them to the encoder.
  CreateTestFrames();
  EncodeTestFrames();

  // Clear the list of expected test frames, since none should be recorded.
  STLDeleteElements(&test_frames_);

  // Verify that the recorded frames match the ones passed to the encoder.
  VerifyTestFrames();
}

}  // namespace remoting