// Copyright 2013 The Flutter 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 <dlfcn.h>
#include <filesystem>
#include <memory>

#include "flutter/impeller/golden_tests/golden_playground_test.h"

#include "flutter/impeller/aiks/picture.h"
#include "flutter/impeller/golden_tests/golden_digest.h"
#include "flutter/impeller/golden_tests/metal_screenshotter.h"
#include "flutter/impeller/golden_tests/vulkan_screenshotter.h"
#include "impeller/typographer/backends/skia/typographer_context_skia.h"
#include "impeller/typographer/typographer_context.h"

#define GLFW_INCLUDE_NONE
#include "third_party/glfw/include/GLFW/glfw3.h"

#include "third_party/abseil-cpp/absl/base/no_destructor.h"

namespace impeller {

namespace {
std::unique_ptr<PlaygroundImpl> MakeVulkanPlayground(bool enable_validations) {
  FML_CHECK(::glfwInit() == GLFW_TRUE);
  PlaygroundSwitches playground_switches;
  playground_switches.enable_vulkan_validation = enable_validations;
  return PlaygroundImpl::Create(PlaygroundBackend::kVulkan,
                                playground_switches);
}

// Returns a static instance to a playground that can be used across tests.
const std::unique_ptr<PlaygroundImpl>& GetSharedVulkanPlayground(
    bool enable_validations) {
  if (enable_validations) {
    static absl::NoDestructor<std::unique_ptr<PlaygroundImpl>>
        vulkan_validation_playground(
            MakeVulkanPlayground(/*enable_validations=*/true));
    // TODO(https://github.com/flutter/flutter/issues/142237): This can be
    // removed when the thread local storage is removed.
    static fml::ScopedCleanupClosure context_cleanup(
        [&] { (*vulkan_validation_playground)->GetContext()->Shutdown(); });
    return *vulkan_validation_playground;
  } else {
    static absl::NoDestructor<std::unique_ptr<PlaygroundImpl>>
        vulkan_playground(MakeVulkanPlayground(/*enable_validations=*/false));
    // TODO(https://github.com/flutter/flutter/issues/142237): This can be
    // removed when the thread local storage is removed.
    static fml::ScopedCleanupClosure context_cleanup(
        [&] { (*vulkan_playground)->GetContext()->Shutdown(); });
    return *vulkan_playground;
  }
}
}  // namespace

#define IMP_AIKSTEST(name)                         \
  "impeller_Play_AiksTest_" #name "_Metal",        \
      "impeller_Play_AiksTest_" #name "_OpenGLES", \
      "impeller_Play_AiksTest_" #name "_Vulkan"

// If you add a new playground test to the aiks unittests and you do not want it
// to also be a golden test, then add the test name here.
static const std::vector<std::string> kSkipTests = {
    // TextRotated is flakey and we can't seem to get it to stabilize on Skia
    // Gold.
    IMP_AIKSTEST(TextRotated),
    // Runtime stage based tests get confused with a Metal context.
    "impeller_Play_AiksTest_CanRenderClippedRuntimeEffects_Vulkan",
};

static const std::vector<std::string> kVulkanDenyValidationTests = {};

namespace {
std::string GetTestName() {
  std::string suite_name =
      ::testing::UnitTest::GetInstance()->current_test_suite()->name();
  std::string test_name =
      ::testing::UnitTest::GetInstance()->current_test_info()->name();
  std::stringstream ss;
  ss << "impeller_" << suite_name << "_" << test_name;
  std::string result = ss.str();
  // Make sure there are no slashes in the test name.
  std::replace(result.begin(), result.end(), '/', '_');
  return result;
}

std::string GetGoldenFilename() {
  return GetTestName() + ".png";
}

bool SaveScreenshot(std::unique_ptr<testing::Screenshot> screenshot) {
  if (!screenshot || !screenshot->GetBytes()) {
    FML_LOG(ERROR) << "Failed to collect screenshot for test " << GetTestName();
    return false;
  }
  std::string test_name = GetTestName();
  std::string filename = GetGoldenFilename();
  testing::GoldenDigest::Instance()->AddImage(
      test_name, filename, screenshot->GetWidth(), screenshot->GetHeight());
  if (!screenshot->WriteToPNG(
          testing::WorkingDirectory::Instance()->GetFilenamePath(filename))) {
    FML_LOG(ERROR) << "Failed to write screenshot to " << filename;
    return false;
  }
  return true;
}

bool ShouldTestHaveVulkanValidations() {
  std::string test_name = GetTestName();
  return std::find(kVulkanDenyValidationTests.begin(),
                   kVulkanDenyValidationTests.end(),
                   test_name) == kVulkanDenyValidationTests.end();
}
}  // namespace

struct GoldenPlaygroundTest::GoldenPlaygroundTestImpl {
  std::unique_ptr<PlaygroundImpl> test_vulkan_playground;
  std::unique_ptr<PlaygroundImpl> test_opengl_playground;
  std::unique_ptr<testing::Screenshotter> screenshotter;
  ISize window_size = ISize{1024, 768};
};

GoldenPlaygroundTest::GoldenPlaygroundTest()
    : typographer_context_(TypographerContextSkia::Make()),
      pimpl_(new GoldenPlaygroundTest::GoldenPlaygroundTestImpl()) {}

GoldenPlaygroundTest::~GoldenPlaygroundTest() = default;

void GoldenPlaygroundTest::SetTypographerContext(
    std::shared_ptr<TypographerContext> typographer_context) {
  typographer_context_ = std::move(typographer_context);
};

void GoldenPlaygroundTest::TearDown() {
  ASSERT_FALSE(dlopen("/usr/local/lib/libMoltenVK.dylib", RTLD_NOLOAD));
}

void GoldenPlaygroundTest::SetUp() {
  std::filesystem::path testing_assets_path =
      flutter::testing::GetTestingAssetsPath();
  std::filesystem::path target_path = testing_assets_path.parent_path()
                                          .parent_path()
                                          .parent_path()
                                          .parent_path();
  std::filesystem::path icd_path = target_path / "vk_swiftshader_icd.json";
  setenv("VK_ICD_FILENAMES", icd_path.c_str(), 1);

  bool enable_vulkan_validations = ShouldTestHaveVulkanValidations();
  switch (GetParam()) {
    case PlaygroundBackend::kMetal:
      pimpl_->screenshotter = std::make_unique<testing::MetalScreenshotter>();
      break;
    case PlaygroundBackend::kVulkan: {
      const std::unique_ptr<PlaygroundImpl>& playground =
          GetSharedVulkanPlayground(enable_vulkan_validations);
      pimpl_->screenshotter =
          std::make_unique<testing::VulkanScreenshotter>(playground);
      break;
    }
    case PlaygroundBackend::kOpenGLES: {
      FML_CHECK(::glfwInit() == GLFW_TRUE);
      PlaygroundSwitches playground_switches;
      playground_switches.use_angle = true;
      pimpl_->test_opengl_playground = PlaygroundImpl::Create(
          PlaygroundBackend::kOpenGLES, playground_switches);
      pimpl_->screenshotter = std::make_unique<testing::VulkanScreenshotter>(
          pimpl_->test_opengl_playground);
      break;
    }
  }
  if (GetParam() == PlaygroundBackend::kMetal) {
    pimpl_->screenshotter = std::make_unique<testing::MetalScreenshotter>();
  } else if (GetParam() == PlaygroundBackend::kVulkan) {
    const std::unique_ptr<PlaygroundImpl>& playground =
        GetSharedVulkanPlayground(enable_vulkan_validations);
    pimpl_->screenshotter =
        std::make_unique<testing::VulkanScreenshotter>(playground);
  }

  std::string test_name = GetTestName();
  if (std::find(kSkipTests.begin(), kSkipTests.end(), test_name) !=
      kSkipTests.end()) {
    GTEST_SKIP_(
        "GoldenPlaygroundTest doesn't support interactive playground tests "
        "yet.");
  }

  testing::GoldenDigest::Instance()->AddDimension(
      "gpu_string", GetContext()->DescribeGpuModel());
}

PlaygroundBackend GoldenPlaygroundTest::GetBackend() const {
  return GetParam();
}

bool GoldenPlaygroundTest::OpenPlaygroundHere(Picture picture) {
  AiksContext renderer(GetContext(), typographer_context_);

  auto screenshot = pimpl_->screenshotter->MakeScreenshot(renderer, picture,
                                                          pimpl_->window_size);
  return SaveScreenshot(std::move(screenshot));
}

bool GoldenPlaygroundTest::OpenPlaygroundHere(
    AiksPlaygroundCallback
        callback) {  // NOLINT(performance-unnecessary-value-param)
  AiksContext renderer(GetContext(), typographer_context_);

  std::optional<Picture> picture;
  std::unique_ptr<testing::Screenshot> screenshot;
  for (int i = 0; i < 2; ++i) {
    picture = callback(renderer);
    if (!picture.has_value()) {
      return false;
    }
    screenshot = pimpl_->screenshotter->MakeScreenshot(
        renderer, picture.value(), pimpl_->window_size);
  }

  return SaveScreenshot(std::move(screenshot));
}

bool GoldenPlaygroundTest::ImGuiBegin(const char* name,
                                      bool* p_open,
                                      ImGuiWindowFlags flags) {
  return false;
}

std::shared_ptr<Texture> GoldenPlaygroundTest::CreateTextureForFixture(
    const char* fixture_name,
    bool enable_mipmapping) const {
  std::shared_ptr<fml::Mapping> mapping =
      flutter::testing::OpenFixtureAsMapping(fixture_name);
  auto result = Playground::CreateTextureForMapping(GetContext(), mapping,
                                                    enable_mipmapping);
  if (result) {
    result->SetLabel(fixture_name);
  }
  return result;
}

RuntimeStage::Map GoldenPlaygroundTest::OpenAssetAsRuntimeStage(
    const char* asset_name) const {
  const std::shared_ptr<fml::Mapping> fixture =
      flutter::testing::OpenFixtureAsMapping(asset_name);
  if (!fixture || fixture->GetSize() == 0) {
    return {};
  }
  return RuntimeStage::DecodeRuntimeStages(fixture);
}

std::shared_ptr<Context> GoldenPlaygroundTest::GetContext() const {
  return pimpl_->screenshotter->GetPlayground().GetContext();
}

std::shared_ptr<Context> GoldenPlaygroundTest::MakeContext() const {
  if (GetParam() == PlaygroundBackend::kMetal) {
    /// On Metal we create a context for each test.
    return GetContext();
  } else if (GetParam() == PlaygroundBackend::kVulkan) {
    bool enable_vulkan_validations = ShouldTestHaveVulkanValidations();
    FML_CHECK(!pimpl_->test_vulkan_playground)
        << "We don't support creating multiple contexts for one test";
    pimpl_->test_vulkan_playground =
        MakeVulkanPlayground(enable_vulkan_validations);
    pimpl_->screenshotter = std::make_unique<testing::VulkanScreenshotter>(
        pimpl_->test_vulkan_playground);
    return pimpl_->test_vulkan_playground->GetContext();
  } else {
    /// On OpenGL we create a context for each test.
    return GetContext();
  }
}

Point GoldenPlaygroundTest::GetContentScale() const {
  return pimpl_->screenshotter->GetPlayground().GetContentScale();
}

Scalar GoldenPlaygroundTest::GetSecondsElapsed() const {
  return 0.0f;
}

ISize GoldenPlaygroundTest::GetWindowSize() const {
  return pimpl_->window_size;
}

void GoldenPlaygroundTest::GoldenPlaygroundTest::SetWindowSize(ISize size) {
  pimpl_->window_size = size;
}

fml::Status GoldenPlaygroundTest::SetCapabilities(
    const std::shared_ptr<Capabilities>& capabilities) {
  return pimpl_->screenshotter->GetPlayground().SetCapabilities(capabilities);
}

}  // namespace impeller