// 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 <memory>

#include "flutter/flow/layers/container_layer.h"
#include "flutter/flow/layers/layer.h"
#include "flutter/flow/layers/physical_shape_layer.h"
#include "flutter/flow/layers/picture_layer.h"
#include "flutter/fml/command_line.h"
#include "flutter/fml/file.h"
#include "flutter/fml/unique_fd.h"
#include "flutter/shell/common/persistent_cache.h"
#include "flutter/shell/common/shell_test.h"
#include "flutter/shell/common/switches.h"
#include "flutter/testing/testing.h"
#include "include/core/SkPicture.h"

namespace flutter {
namespace testing {

static void WaitForIO(Shell* shell) {
  std::promise<bool> io_task_finished;
  shell->GetTaskRunners().GetIOTaskRunner()->PostTask(
      [&io_task_finished]() { io_task_finished.set_value(true); });
  io_task_finished.get_future().wait();
}

TEST_F(ShellTest, CacheSkSLWorks) {
  // Create a temp dir to store the persistent cache
  fml::ScopedTemporaryDirectory dir;
  PersistentCache::SetCacheDirectoryPath(dir.path());
  PersistentCache::ResetCacheForProcess();

  auto settings = CreateSettingsForFixture();
  settings.cache_sksl = true;
  settings.dump_skp_on_shader_compilation = true;

  fml::AutoResetWaitableEvent firstFrameLatch;
  settings.frame_rasterized_callback =
      [&firstFrameLatch](const FrameTiming& t) { firstFrameLatch.Signal(); };

  auto sksl_config = RunConfiguration::InferFromSettings(settings);
  sksl_config.SetEntrypoint("emptyMain");
  std::unique_ptr<Shell> shell = CreateShell(settings);
  PlatformViewNotifyCreated(shell.get());
  RunEngine(shell.get(), std::move(sksl_config));

  // Initially, we should have no SkSL cache
  auto cache = PersistentCache::GetCacheForProcess()->LoadSkSLs();
  ASSERT_EQ(cache.size(), 0u);

  // Draw something to trigger shader compilations.
  LayerTreeBuilder builder = [](std::shared_ptr<ContainerLayer> root) {
    SkPath path;
    path.addCircle(50, 50, 20);
    auto physical_shape_layer = std::make_shared<PhysicalShapeLayer>(
        SK_ColorRED, SK_ColorBLUE, 1.0f, path, Clip::antiAlias);
    root->Add(physical_shape_layer);
  };
  PumpOneFrame(shell.get(), 100, 100, builder);
  firstFrameLatch.Wait();
  WaitForIO(shell.get());

  // Some skp should be dumped due to shader compilations.
  int skp_count = 0;
  fml::FileVisitor skp_visitor = [&skp_count](const fml::UniqueFD& directory,
                                              const std::string& filename) {
    if (filename.size() >= 4 &&
        filename.substr(filename.size() - 4, 4) == ".skp") {
      skp_count += 1;
    }
    return true;
  };
  fml::VisitFilesRecursively(dir.fd(), skp_visitor);
  ASSERT_GT(skp_count, 0);

  // SkSL cache should be generated by the last run.
  cache = PersistentCache::GetCacheForProcess()->LoadSkSLs();
  ASSERT_GT(cache.size(), 0u);

  // Run the engine again with cache_sksl = false and check that the previously
  // generated SkSL cache is used for precompile.
  PersistentCache::ResetCacheForProcess();
  settings.cache_sksl = false;
  settings.dump_skp_on_shader_compilation = true;
  auto normal_config = RunConfiguration::InferFromSettings(settings);
  normal_config.SetEntrypoint("emptyMain");
  DestroyShell(std::move(shell));
  shell = CreateShell(settings);
  PlatformViewNotifyCreated(shell.get());
  RunEngine(shell.get(), std::move(normal_config));
  firstFrameLatch.Reset();
  PumpOneFrame(shell.get(), 100, 100, builder);
  firstFrameLatch.Wait();
  WaitForIO(shell.get());

  // To check that all shaders are precompiled, verify that no new skp is dumped
  // due to shader compilations.
  int old_skp_count = skp_count;
  skp_count = 0;
  fml::VisitFilesRecursively(dir.fd(), skp_visitor);
  ASSERT_EQ(skp_count, old_skp_count);

  // Remove all files generated
  fml::FileVisitor remove_visitor = [&remove_visitor](
                                        const fml::UniqueFD& directory,
                                        const std::string& filename) {
    if (fml::IsDirectory(directory, filename.c_str())) {
      {  // To trigger fml::~UniqueFD before fml::UnlinkDirectory
        fml::UniqueFD sub_dir =
            fml::OpenDirectoryReadOnly(directory, filename.c_str());
        fml::VisitFiles(sub_dir, remove_visitor);
      }
      fml::UnlinkDirectory(directory, filename.c_str());
    } else {
      fml::UnlinkFile(directory, filename.c_str());
    }
    return true;
  };
  fml::VisitFiles(dir.fd(), remove_visitor);
  DestroyShell(std::move(shell));
}

}  // namespace testing
}  // namespace flutter