// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/viz/service/transitions/transferable_resource_tracker.h"

#include <limits>
#include <memory>
#include <utility>

#include "base/functional/bind.h"
#include "base/functional/callback_helpers.h"
#include "components/viz/common/quads/compositor_frame_transition_directive.h"
#include "components/viz/service/surfaces/surface_saved_frame.h"
#include "gpu/command_buffer/client/test_shared_image_interface.h"
#include "gpu/command_buffer/common/mailbox.h"
#include "gpu/command_buffer/common/sync_token.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace viz {
namespace {
std::unique_ptr<SurfaceSavedFrame> CreateFrameWithResult(
    gpu::TestSharedImageInterface* shared_image_interface) {
  CompositorFrameTransitionDirective::SharedElement element;
  auto directive = CompositorFrameTransitionDirective::CreateSave(
      blink::ViewTransitionToken(), /*maybe_cross_frame_sink=*/false, 1,
      {element}, {}, false);
  auto frame = SurfaceSavedFrame::CreateForTesting(
      std::move(directive), shared_image_interface, base::DoNothing());
  frame->CompleteSavedFrameForTesting();
  return frame;
}
}  // namespace

class TransferableResourceTrackerTest : public testing::Test {
 public:
  TransferableResourceTrackerTest()
      : shared_image_interface_(
            base::MakeRefCounted<gpu::TestSharedImageInterface>()) {}

  void SetNextId(TransferableResourceTracker* tracker, uint32_t id) {
    tracker->id_tracker_->set_next_id_for_test(id);
  }

  // Returns if the software SharedImage for the |resource| is valid.
  bool HasSharedImageForSoftwareResource(const TransferableResource& resource) {
    DCHECK(resource.GetIsSoftware());

    return shared_image_interface()->CheckSharedImageExists(resource.mailbox());
  }

  gpu::TestSharedImageInterface* shared_image_interface() {
    return shared_image_interface_.get();
  }

 protected:
  scoped_refptr<gpu::TestSharedImageInterface> shared_image_interface_;
  ReservedResourceIdTracker id_tracker_;
};
TEST_F(TransferableResourceTrackerTest, IdInRange) {
  TransferableResourceTracker tracker(&id_tracker_);
  auto result = CreateFrameWithResult(shared_image_interface());
  auto frame1 =
      tracker.ImportResources(result->TakeResult(), result->directive());
  ASSERT_EQ(frame1.shared.size(), 1u);
  const auto& resource1 = frame1.shared.at(0);
  EXPECT_TRUE(HasSharedImageForSoftwareResource(resource1->resource));

  EXPECT_GE(resource1->resource.id, kVizReservedRangeStartId);

  result = CreateFrameWithResult(shared_image_interface());
  auto frame2 =
      tracker.ImportResources(result->TakeResult(), result->directive());
  ASSERT_EQ(frame2.shared.size(), 1u);
  const auto& resource2 = frame2.shared.at(0);
  EXPECT_TRUE(HasSharedImageForSoftwareResource(resource2->resource));

  EXPECT_GE(resource2->resource.id, resource1->resource.id);

  gpu::Mailbox mailbox1 = resource1->resource.mailbox();
  tracker.ReturnFrame(frame1);
  frame1 = TransferableResourceTracker::ResourceFrame();
  EXPECT_FALSE(shared_image_interface()->CheckSharedImageExists(mailbox1));

  gpu::Mailbox mailbox2 = resource2->resource.mailbox();
  ResourceId id2 = resource2->resource.id;
  tracker.RefResource(id2);
  tracker.ReturnFrame(frame2);
  frame2 = TransferableResourceTracker::ResourceFrame();
  EXPECT_TRUE(shared_image_interface()->CheckSharedImageExists(mailbox2));
  tracker.UnrefResource(id2, 1, gpu::SyncToken());
  EXPECT_FALSE(shared_image_interface()->CheckSharedImageExists(mailbox2));
}

TEST_F(TransferableResourceTrackerTest, ExhaustedIdLoops) {
  static_assert(std::is_same<decltype(kInvalidResourceId.GetUnsafeValue()),
                             uint32_t>::value,
                "The test only makes sense if ResourceId is uint32_t");
  uint32_t next_id = std::numeric_limits<uint32_t>::max() - 3u;
  TransferableResourceTracker tracker(&id_tracker_);
  SetNextId(&tracker, next_id);

  ResourceId last_id = kInvalidResourceId;
  std::vector<TransferableResourceTracker::ResourceFrame> frames;
  for (int i = 0; i < 10; ++i) {
    auto result = CreateFrameWithResult(shared_image_interface());
    auto frame =
        tracker.ImportResources(result->TakeResult(), result->directive());
    ASSERT_EQ(frame.shared.size(), 1u);
    const auto& resource = frame.shared.at(0);
    EXPECT_TRUE(HasSharedImageForSoftwareResource(resource->resource));

    EXPECT_GE(resource->resource.id, kVizReservedRangeStartId);
    EXPECT_NE(resource->resource.id, last_id);
    last_id = resource->resource.id;
    frames.push_back(std::move(frame));
  }
  for (auto& frame : frames) {
    gpu::Mailbox mailbox = frame.shared.at(0)->resource.mailbox();
    tracker.ReturnFrame(frame);
    frame = TransferableResourceTracker::ResourceFrame();
    EXPECT_FALSE(shared_image_interface()->CheckSharedImageExists(mailbox));
  }
}

TEST_F(TransferableResourceTrackerTest, UnrefWithCount) {
  TransferableResourceTracker tracker(&id_tracker_);
  auto result = CreateFrameWithResult(shared_image_interface());
  auto frame =
      tracker.ImportResources(result->TakeResult(), result->directive());
  ASSERT_EQ(frame.shared.size(), 1u);
  const auto& resource = frame.shared.at(0);
  for (int i = 0; i < 1000; ++i)
    tracker.RefResource(resource->resource.id);
  ASSERT_FALSE(tracker.is_empty());
  tracker.UnrefResource(resource->resource.id, 1, gpu::SyncToken());
  EXPECT_FALSE(tracker.is_empty());
  tracker.UnrefResource(resource->resource.id, 1, gpu::SyncToken());
  EXPECT_FALSE(tracker.is_empty());
  tracker.UnrefResource(resource->resource.id, 999, gpu::SyncToken());
  EXPECT_TRUE(tracker.is_empty());
}

TEST_F(TransferableResourceTrackerTest,
       ExhaustedIdLoopsButSkipsUnavailableIds) {
  static_assert(std::is_same<decltype(kInvalidResourceId.GetUnsafeValue()),
                             uint32_t>::value,
                "The test only makes sense if ResourceId is uint32_t");
  TransferableResourceTracker tracker(&id_tracker_);
  auto result = CreateFrameWithResult(shared_image_interface());
  auto reserved =
      tracker.ImportResources(result->TakeResult(), result->directive());
  ASSERT_EQ(reserved.shared.size(), 1u);
  const auto& resource = reserved.shared.at(0);
  EXPECT_GE(resource->resource.id, kVizReservedRangeStartId);

  uint32_t next_id = std::numeric_limits<uint32_t>::max() - 3u;
  SetNextId(&tracker, next_id);

  ResourceId last_id = kInvalidResourceId;
  std::vector<TransferableResourceTracker::ResourceFrame> frames;
  for (int i = 0; i < 10; ++i) {
    result = CreateFrameWithResult(shared_image_interface());
    auto frame =
        tracker.ImportResources(result->TakeResult(), result->directive());
    ASSERT_EQ(frame.shared.size(), 1u);
    const auto& new_resource = frame.shared.at(0);
    EXPECT_TRUE(HasSharedImageForSoftwareResource(new_resource->resource));

    EXPECT_GE(new_resource->resource.id, kVizReservedRangeStartId);
    EXPECT_NE(new_resource->resource.id, last_id);
    EXPECT_NE(new_resource->resource.id, resource->resource.id);
    last_id = new_resource->resource.id;
    frames.push_back(std::move(frame));
  }
  for (auto& frame : frames) {
    gpu::Mailbox mailbox = frame.shared.at(0)->resource.mailbox();
    tracker.ReturnFrame(frame);
    frame = TransferableResourceTracker::ResourceFrame();
    EXPECT_FALSE(shared_image_interface()->CheckSharedImageExists(mailbox));
  }
}

}  // namespace viz