// 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 "third_party/blink/renderer/platform/theme/web_theme_engine_helper.h"

#include "base/command_line.h"
#include "build/build_config.h"
#include "third_party/blink/public/common/switches.h"
#include "third_party/blink/renderer/platform/graphics/scrollbar_theme_settings.h"
#include "third_party/blink/renderer/platform/wtf/std_lib_extras.h"
#include "ui/native_theme/overlay_scrollbar_constants.h"

#if BUILDFLAG(IS_ANDROID)
#include "third_party/blink/renderer/platform/theme/web_theme_engine_android.h"
#elif BUILDFLAG(IS_MAC)
#include "third_party/blink/renderer/platform/theme/web_theme_engine_mac.h"
#else
#include "third_party/blink/renderer/platform/theme/web_theme_engine_default.h"
#endif

namespace blink {

namespace {
std::unique_ptr<WebThemeEngine> CreateWebThemeEngine() {
#if BUILDFLAG(IS_ANDROID)
  return std::make_unique<WebThemeEngineAndroid>();
#elif BUILDFLAG(IS_MAC)
  return std::make_unique<WebThemeEngineMac>();
#else
  return std::make_unique<WebThemeEngineDefault>();
#endif
}

std::unique_ptr<WebThemeEngine>& ThemeEngine() {
  DEFINE_STATIC_LOCAL(std::unique_ptr<WebThemeEngine>, theme_engine,
                      {CreateWebThemeEngine()});
  return theme_engine;
}

}  // namespace

WebThemeEngine* WebThemeEngineHelper::GetNativeThemeEngine() {
  return ThemeEngine().get();
}

std::unique_ptr<WebThemeEngine>
WebThemeEngineHelper::SwapNativeThemeEngineForTesting(
    std::unique_ptr<WebThemeEngine> new_theme) {
  ThemeEngine().swap(new_theme);
  return new_theme;
}

const WebThemeEngine::ScrollbarStyle&
WebThemeEngineHelper::AndroidScrollbarStyle() {
  if (ScrollbarThemeSettings::DesktopAndroidScrollbarsEnabled()) {
    DEFINE_STATIC_LOCAL(
        WebThemeEngine::ScrollbarStyle, desktop_style,
        ({/*thumb_thickness=*/8,
          /*scrollbar_margin=*/4,
          /*color=*/{0.5f, 0.5f, 0.5f, 0.5f},
          /*fade_out_delay=*/ui::GetOverlayScrollbarFadeDelay(),
          /*fade_out_duration=*/ui::GetOverlayScrollbarFadeDuration(),
          /*idle_thickness_scale=*/ui::kOverlayScrollbarIdleThicknessScale}));
    return desktop_style;
  }
  DEFINE_STATIC_LOCAL(WebThemeEngine::ScrollbarStyle, style,
                      ({/*thumb_thickness=*/4,
                        /*scrollbar_margin=*/0,
                        /*color=*/{0.5f, 0.5f, 0.5f, 0.5f}}));
  return style;
}

}  // namespace blink