// Copyright 2015 The Chromium Embedded Framework 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 "libcef/browser/native/browser_platform_delegate_native_win.h"

#include <shellapi.h>
#include <wininet.h>
#include <winspool.h>

#include "libcef/browser/browser_host_impl.h"
#include "libcef/browser/context.h"
#include "libcef/browser/native/file_dialog_runner_win.h"
#include "libcef/browser/native/javascript_dialog_runner_win.h"
#include "libcef/browser/native/menu_runner_win.h"
#include "libcef/browser/native/window_delegate_view.h"
#include "libcef/browser/thread_util.h"

#include "base/files/file_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/registry.h"
#include "content/public/browser/native_web_keyboard_event.h"
#include "ui/aura/window.h"
#include "ui/base/win/shell.h"
#include "ui/gfx/screen.h"
#include "ui/gfx/win/hwnd_util.h"
#include "ui/views/widget/desktop_aura/desktop_window_tree_host_win.h"
#include "ui/views/widget/widget.h"
#include "ui/views/win/hwnd_util.h"

#pragma comment(lib, "dwmapi.lib")

namespace {

void WriteTempFileAndView(scoped_refptr<base::RefCountedString> str) {
  CEF_REQUIRE_FILET();

  base::FilePath tmp_file;
  if (!base::CreateTemporaryFile(&tmp_file))
    return;

  // The shell command will look at the file extension to identify the correct
  // program to open.
  tmp_file = tmp_file.AddExtension(L"txt");

  const std::string& data = str->data();
  int write_ct = base::WriteFile(tmp_file, data.c_str(), data.size());
  DCHECK_EQ(static_cast<int>(data.size()), write_ct);

  ui::win::OpenFileViaShell(tmp_file);
}

// According to Mozilla in uriloader/exthandler/win/nsOSHelperAppService.cpp:
// "Some versions of windows (Win2k before SP3, Win XP before SP1) crash in
// ShellExecute on long URLs (bug 161357 on bugzilla.mozilla.org). IE 5 and 6
// support URLS of 2083 chars in length, 2K is safe."
const int kMaxAddressLengthChars = 2048;

bool HasExternalHandler(const std::string& scheme) {
  base::win::RegKey key;
  const std::wstring registry_path =
      base::ASCIIToUTF16(scheme + "\\shell\\open\\command");
  key.Open(HKEY_CLASSES_ROOT, registry_path.c_str(), KEY_READ);
  if (key.Valid()) {
    DWORD size = 0;
    key.ReadValue(NULL, NULL, &size, NULL);
    if (size > 2) {
       // ShellExecute crashes the process when the command is empty.
       // We check for "2" because it always returns the trailing NULL.
       return true;
    }
  }

  return false;
}

void ExecuteExternalProtocol(const GURL& url) {
  CEF_REQUIRE_FILET();

  if (!HasExternalHandler(url.scheme()))
    return;

  const std::string& address = url.spec();
  if (address.length() > kMaxAddressLengthChars)
    return;

  ShellExecuteA(NULL, "open", address.c_str(), NULL, NULL, SW_SHOWNORMAL);
}

WORD KeyStatesToWord() {
  static const USHORT kHighBitMaskShort = 0x8000;
  WORD result = 0;

  if (GetKeyState(VK_CONTROL) & kHighBitMaskShort)
    result |= MK_CONTROL;
  if (GetKeyState(VK_SHIFT) & kHighBitMaskShort)
    result |= MK_SHIFT;
  if (GetKeyState(VK_LBUTTON) & kHighBitMaskShort)
    result |= MK_LBUTTON;
  if (GetKeyState(VK_MBUTTON) & kHighBitMaskShort)
    result |= MK_MBUTTON;
  if (GetKeyState(VK_RBUTTON) & kHighBitMaskShort)
    result |= MK_RBUTTON;
  return result;
}

}  // namespace

CefBrowserPlatformDelegateNativeWin::CefBrowserPlatformDelegateNativeWin(
    const CefWindowInfo& window_info)
    : CefBrowserPlatformDelegateNative(window_info),
      host_window_created_(false),
      window_widget_(nullptr) {
}

void CefBrowserPlatformDelegateNativeWin::BrowserDestroyed(
    CefBrowserHostImpl* browser) {
  CefBrowserPlatformDelegate::BrowserDestroyed(browser);

  if (host_window_created_) {
    // Release the reference added in CreateHostWindow().
    browser->Release();
  }
}

bool CefBrowserPlatformDelegateNativeWin::CreateHostWindow() {
  RegisterWindowClass();

  std::wstring windowName(CefString(&window_info_.window_name));

  // Create the new browser window.
  window_info_.window = CreateWindowEx(window_info_.ex_style,
      GetWndClass(), windowName.c_str(), window_info_.style,
      window_info_.x, window_info_.y, window_info_.width,
      window_info_.height, window_info_.parent_window, window_info_.menu,
      ::GetModuleHandle(NULL), NULL);

  // It's possible for CreateWindowEx to fail if the parent window was
  // destroyed between the call to CreateBrowser and the above one.
  DCHECK(window_info_.window != NULL);
  if (!window_info_.window)
    return false;

  host_window_created_ = true;

  // Set window user data to this object for future reference from the window
  // procedure.
  gfx::SetWindowUserData(window_info_.window, this);

  // Add a reference that will later be released in DestroyBrowser().
  browser_->AddRef();

  RECT cr;
  GetClientRect(window_info_.window, &cr);

  DCHECK(!window_widget_);

  SkColor background_color = SK_ColorWHITE;
  const CefSettings& settings = CefContext::Get()->settings();
  if (CefColorGetA(settings.background_color) > 0) {
    background_color = SkColorSetRGB(
        CefColorGetR(settings.background_color),
        CefColorGetG(settings.background_color),
        CefColorGetB(settings.background_color));
  }

  // Adjust for potential display scaling.
  gfx::Point point = gfx::Point(cr.right, cr.bottom);
  float scale = gfx::Screen::GetScreen()->
      GetDisplayNearestPoint(point).device_scale_factor();
  point = gfx::ToFlooredPoint(
      gfx::ScalePoint(gfx::PointF(point), 1.0f / scale));

  CefWindowDelegateView* delegate_view =
      new CefWindowDelegateView(background_color);
  delegate_view->Init(window_info_.window,
                      browser_->web_contents(),
                      gfx::Rect(0, 0, point.x(), point.y()));

  window_widget_ = delegate_view->GetWidget();
  window_widget_->Show();

  return true;
}

void CefBrowserPlatformDelegateNativeWin::CloseHostWindow() {
  if (window_info_.window != NULL) {
    HWND frameWnd = GetAncestor(window_info_.window, GA_ROOT);
    PostMessage(frameWnd, WM_CLOSE, 0, 0);
  }
}

CefWindowHandle
    CefBrowserPlatformDelegateNativeWin::GetHostWindowHandle() const {
  if (windowless_handler_)
    return windowless_handler_->GetParentWindowHandle();
  return window_info_.window;
}

views::Widget* CefBrowserPlatformDelegateNativeWin::GetWindowWidget() const {
  return window_widget_;
}

void CefBrowserPlatformDelegateNativeWin::SendFocusEvent(bool setFocus) {
  if (!setFocus)
    return;

  if (browser_->web_contents()) {
    // Give logical focus to the RenderWidgetHostViewAura in the views
    // hierarchy. This does not change the native keyboard focus.
    browser_->web_contents()->Focus();
  }

  if (window_widget_) {
    // Give native focus to the DesktopWindowTreeHostWin associated with the
    // root window.
    //
    // The DesktopWindowTreeHostWin HandleNativeFocus/HandleNativeBlur methods
    // are called in response to WM_SETFOCUS/WM_KILLFOCUS respectively. The
    // implementation has been patched to call HandleActivationChanged which
    // results in the following behaviors:
    // 1. Update focus/activation state of the aura::Window indirectly via
    //    wm::FocusController. This allows focus-related behaviors (e.g. focus
    //    rings, flashing caret, onFocus/onBlur JS events, etc.) to work as
    //    expected (see issue #1677).
    // 2. Update focus state of the ui::InputMethod. If this does not occur
    //    then InputMethodBase::GetTextInputClient will return NULL and
    //    InputMethodWin::OnChar will fail to sent character events to the
    //    renderer (see issue #1700).
    //
    // This differs from activation in Chrome which is handled via
    // HWNDMessageHandler::PostProcessActivateMessage (Widget::Show indirectly
    // calls HWNDMessageHandler::Activate which calls ::SetForegroundWindow
    // resulting in a WM_ACTIVATE message being sent to the window). The Chrome
    // code path doesn't work for CEF because IsTopLevelWindow in
    // hwnd_message_handler.cc will return false and consequently
    // HWNDMessageHandler::PostProcessActivateMessage will not be called.
    //
    // Activation events are usually reserved for the top-level window so
    // triggering activation based on focus events may be incorrect in some
    // circumstances. Revisit this implementation if additional problems are
    // discovered.
    ::SetFocus(HWNDForWidget(window_widget_));
  }
}

void CefBrowserPlatformDelegateNativeWin::NotifyMoveOrResizeStarted() {
  // Call the parent method to dismiss any existing popups.
  CefBrowserPlatformDelegate::NotifyMoveOrResizeStarted();

  if (!window_widget_)
    return;

  // Notify DesktopWindowTreeHostWin of move events so that screen rectangle
  // information is communicated to the renderer process and popups are
  // displayed in the correct location.
  views::DesktopWindowTreeHostWin* tree_host =
      static_cast<views::DesktopWindowTreeHostWin*>(
          aura::WindowTreeHost::GetForAcceleratedWidget(
              HWNDForWidget(window_widget_)));
  DCHECK(tree_host);
  if (tree_host) {
    // Cast to HWNDMessageHandlerDelegate so we can access HandleMove().
    static_cast<views::HWNDMessageHandlerDelegate*>(tree_host)->HandleMove();
  }
}

void CefBrowserPlatformDelegateNativeWin::SizeTo(int width, int height) {
  HWND window = window_info_.window;

  RECT rect = {0, 0, width, height};
  DWORD style = GetWindowLong(window, GWL_STYLE);
  DWORD ex_style = GetWindowLong(window, GWL_EXSTYLE);
  bool has_menu = !(style & WS_CHILD) && (GetMenu(window) != NULL);

  // The size value is for the client area. Calculate the whole window size
  // based on the current style.
  AdjustWindowRectEx(&rect, style, has_menu, ex_style);

  // Size the window.
  SetWindowPos(window, NULL, 0, 0, rect.right,
               rect.bottom, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
}

gfx::Point CefBrowserPlatformDelegateNativeWin::GetScreenPoint(
    const gfx::Point& view) const {
  if (windowless_handler_)
    return windowless_handler_->GetParentScreenPoint(view);

  if (!window_widget_)
    return view;

  aura::Window* window = window_widget_->GetNativeView();
  const gfx::Rect& bounds_in_screen = window->GetBoundsInScreen();
  const gfx::Point& screen_point = gfx::Point(bounds_in_screen.x() + view.x(),
                                              bounds_in_screen.y() + view.y());

  // Adjust for potential display scaling.
  float scale = gfx::Screen::GetScreen()->
      GetDisplayNearestPoint(screen_point).device_scale_factor();
  return gfx::ToFlooredPoint(
      gfx::ScalePoint(gfx::PointF(screen_point), scale));
}

void CefBrowserPlatformDelegateNativeWin::ViewText(const std::string& text) {
  std::string str = text;
  scoped_refptr<base::RefCountedString> str_ref =
      base::RefCountedString::TakeString(&str);
  CEF_POST_TASK(CEF_FILET, base::Bind(WriteTempFileAndView, str_ref));
}

void CefBrowserPlatformDelegateNativeWin::HandleKeyboardEvent(
    const content::NativeWebKeyboardEvent& event) {
  // Any unhandled keyboard/character messages are sent to DefWindowProc so that
  // shortcut keys work correctly.
  if (event.os_event) {
    const MSG& msg = event.os_event->native_event();
    DefWindowProc(msg.hwnd, msg.message, msg.wParam, msg.lParam);
  } else {
    MSG msg = {};

    msg.hwnd = GetHostWindowHandle();
    if (!msg.hwnd)
      return;

    switch (event.type) {
      case blink::WebInputEvent::RawKeyDown:
        msg.message = event.isSystemKey ? WM_SYSKEYDOWN : WM_KEYDOWN;
        break;
      case blink::WebInputEvent::KeyUp:
        msg.message = event.isSystemKey ? WM_SYSKEYUP : WM_KEYUP;
        break;
      case blink::WebInputEvent::Char:
        msg.message = event.isSystemKey ? WM_SYSCHAR: WM_CHAR;
        break;
      default:
        NOTREACHED();
        return;
    }

    msg.wParam = event.windowsKeyCode;

    UINT scan_code = ::MapVirtualKeyW(event.windowsKeyCode, MAPVK_VK_TO_VSC);
    msg.lParam = (scan_code << 16) |  // key scan code
                                  1;  // key repeat count
    if (event.modifiers & content::NativeWebKeyboardEvent::AltKey)
      msg.lParam |= (1 << 29);

    DefWindowProc(msg.hwnd, msg.message, msg.wParam, msg.lParam);
  }
}

void CefBrowserPlatformDelegateNativeWin::HandleExternalProtocol(
    const GURL& url) {
  // Execute on the FILE thread.
  CEF_POST_TASK(CEF_FILET,
      base::Bind(ExecuteExternalProtocol, url));
}

void CefBrowserPlatformDelegateNativeWin::TranslateKeyEvent(
    content::NativeWebKeyboardEvent& result,
    const CefKeyEvent& key_event) const {
  result.timeStampSeconds = GetMessageTime() / 1000.0;

  result.windowsKeyCode = key_event.windows_key_code;
  result.nativeKeyCode = key_event.native_key_code;
  result.isSystemKey = key_event.is_system_key ? 1 : 0;
  switch (key_event.type) {
  case KEYEVENT_RAWKEYDOWN:
  case KEYEVENT_KEYDOWN:
    result.type = blink::WebInputEvent::RawKeyDown;
    break;
  case KEYEVENT_KEYUP:
    result.type = blink::WebInputEvent::KeyUp;
    break;
  case KEYEVENT_CHAR:
    result.type = blink::WebInputEvent::Char;
    break;
  default:
    NOTREACHED();
  }

  if (result.type == blink::WebInputEvent::Char ||
      result.type == blink::WebInputEvent::RawKeyDown) {
    result.text[0] = result.windowsKeyCode;
    result.unmodifiedText[0] = result.windowsKeyCode;
  }
  if (result.type != blink::WebInputEvent::Char)
    result.setKeyIdentifierFromWindowsKeyCode();

  result.modifiers |= TranslateModifiers(key_event.modifiers);
}

void CefBrowserPlatformDelegateNativeWin::TranslateClickEvent(
    blink::WebMouseEvent& result,
    const CefMouseEvent& mouse_event,
    CefBrowserHost::MouseButtonType type,
    bool mouseUp, int clickCount) const {
  TranslateMouseEvent(result, mouse_event);

  switch (type) {
  case MBT_LEFT:
    result.type = mouseUp ? blink::WebInputEvent::MouseUp :
                            blink::WebInputEvent::MouseDown;
    result.button = blink::WebMouseEvent::ButtonLeft;
    break;
  case MBT_MIDDLE:
    result.type = mouseUp ? blink::WebInputEvent::MouseUp :
                            blink::WebInputEvent::MouseDown;
    result.button = blink::WebMouseEvent::ButtonMiddle;
    break;
  case MBT_RIGHT:
    result.type = mouseUp ? blink::WebInputEvent::MouseUp :
                            blink::WebInputEvent::MouseDown;
    result.button = blink::WebMouseEvent::ButtonRight;
    break;
  default:
    NOTREACHED();
  }

  result.clickCount = clickCount;
}

void CefBrowserPlatformDelegateNativeWin::TranslateMoveEvent(
    blink::WebMouseEvent& result,
    const CefMouseEvent& mouse_event,
    bool mouseLeave) const {
  TranslateMouseEvent(result, mouse_event);

  if (!mouseLeave) {
    result.type = blink::WebInputEvent::MouseMove;
    if (mouse_event.modifiers & EVENTFLAG_LEFT_MOUSE_BUTTON)
      result.button = blink::WebMouseEvent::ButtonLeft;
    else if (mouse_event.modifiers & EVENTFLAG_MIDDLE_MOUSE_BUTTON)
      result.button = blink::WebMouseEvent::ButtonMiddle;
    else if (mouse_event.modifiers & EVENTFLAG_RIGHT_MOUSE_BUTTON)
      result.button = blink::WebMouseEvent::ButtonRight;
    else
      result.button = blink::WebMouseEvent::ButtonNone;
  } else {
    result.type = blink::WebInputEvent::MouseLeave;
    result.button = blink::WebMouseEvent::ButtonNone;
  }

  result.clickCount = 0;
}

void CefBrowserPlatformDelegateNativeWin::TranslateWheelEvent(
    blink::WebMouseWheelEvent& result,
    const CefMouseEvent& mouse_event,
    int deltaX, int deltaY) const {
  TranslateMouseEvent(result, mouse_event);

  result.type = blink::WebInputEvent::MouseWheel;
  result.button = blink::WebMouseEvent::ButtonNone;

  float wheelDelta;
  bool horizontalScroll = false;

  wheelDelta = static_cast<float>(deltaY ? deltaY : deltaX);

  horizontalScroll = (deltaY == 0);

  static const ULONG defaultScrollCharsPerWheelDelta = 1;
  static const FLOAT scrollbarPixelsPerLine = 100.0f / 3.0f;
  static const ULONG defaultScrollLinesPerWheelDelta = 3;
  wheelDelta /= WHEEL_DELTA;
  float scrollDelta = wheelDelta;
  if (horizontalScroll) {
    ULONG scrollChars = defaultScrollCharsPerWheelDelta;
    SystemParametersInfo(SPI_GETWHEELSCROLLCHARS, 0, &scrollChars, 0);
    scrollDelta *= static_cast<FLOAT>(scrollChars) * scrollbarPixelsPerLine;
  } else {
    ULONG scrollLines = defaultScrollLinesPerWheelDelta;
    SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &scrollLines, 0);
    if (scrollLines == WHEEL_PAGESCROLL)
      result.scrollByPage = true;
    if (!result.scrollByPage)
      scrollDelta *= static_cast<FLOAT>(scrollLines) * scrollbarPixelsPerLine;
  }

  // Set scroll amount based on above calculations.  WebKit expects positive
  // deltaY to mean "scroll up" and positive deltaX to mean "scroll left".
  if (horizontalScroll) {
    result.deltaX = scrollDelta;
    result.wheelTicksX = wheelDelta;
  } else {
    result.deltaY = scrollDelta;
    result.wheelTicksY = wheelDelta;
  }
}

CefEventHandle CefBrowserPlatformDelegateNativeWin::GetEventHandle(
    const content::NativeWebKeyboardEvent& event) const {
  if (!event.os_event)
    return NULL;
  return const_cast<CefEventHandle>(&event.os_event->native_event());
}

scoped_ptr<CefFileDialogRunner>
    CefBrowserPlatformDelegateNativeWin::CreateFileDialogRunner() {
  return make_scoped_ptr(new CefFileDialogRunnerWin);
}

scoped_ptr<CefJavaScriptDialogRunner>
    CefBrowserPlatformDelegateNativeWin::CreateJavaScriptDialogRunner() {
  return make_scoped_ptr(new CefJavaScriptDialogRunnerWin);
}

scoped_ptr<CefMenuRunner>
    CefBrowserPlatformDelegateNativeWin::CreateMenuRunner() {
  return make_scoped_ptr(new CefMenuRunnerWin);
}

void CefBrowserPlatformDelegateNativeWin::TranslateMouseEvent(
    blink::WebMouseEvent& result,
    const CefMouseEvent& mouse_event) const {
  // position
  result.x = mouse_event.x;
  result.y = mouse_event.y;
  result.windowX = result.x;
  result.windowY = result.y;

  const gfx::Point& screen_pt = GetScreenPoint(gfx::Point(result.x, result.y));
  result.globalX = screen_pt.x();
  result.globalY = screen_pt.y();

  // modifiers
  result.modifiers |= TranslateModifiers(mouse_event.modifiers);

  // timestamp
  result.timeStampSeconds = GetMessageTime() / 1000.0;
}

// static
void CefBrowserPlatformDelegateNativeWin::RegisterWindowClass() {
  static bool registered = false;
  if (registered)
    return;

  // Register the window class
  WNDCLASSEX wcex = {
    /* cbSize = */ sizeof(WNDCLASSEX),
    /* style = */ CS_HREDRAW | CS_VREDRAW,
    /* lpfnWndProc = */ CefBrowserPlatformDelegateNativeWin::WndProc,
    /* cbClsExtra = */ 0,
    /* cbWndExtra = */ 0,
    /* hInstance = */ ::GetModuleHandle(NULL),
    /* hIcon = */ NULL,
    /* hCursor = */ LoadCursor(NULL, IDC_ARROW),
    /* hbrBackground = */ 0,
    /* lpszMenuName = */ NULL,
    /* lpszClassName = */ CefBrowserPlatformDelegateNativeWin::GetWndClass(),
    /* hIconSm = */ NULL,
  };
  RegisterClassEx(&wcex);

  registered = true;
}

// static
LPCTSTR CefBrowserPlatformDelegateNativeWin::GetWndClass() {
  return L"CefBrowserWindow";
}

// static
LRESULT CALLBACK CefBrowserPlatformDelegateNativeWin::WndProc(
    HWND hwnd, UINT message,
    WPARAM wParam, LPARAM lParam) {
  CefBrowserPlatformDelegateNativeWin* platform_delegate =
      static_cast<CefBrowserPlatformDelegateNativeWin*>(
          gfx::GetWindowUserData(hwnd));
  CefBrowserHostImpl* browser = nullptr;
  if (platform_delegate)
      browser = platform_delegate->browser_;

  switch (message) {
  case WM_CLOSE:
    // Protect against multiple requests to close while the close is pending.
    if (browser &&
        browser->destruction_state() <=
            CefBrowserHostImpl::DESTRUCTION_STATE_PENDING) {
      if (browser->destruction_state() ==
              CefBrowserHostImpl::DESTRUCTION_STATE_NONE) {
        // Request that the browser close.
        browser->CloseBrowser(false);
      }

      // Cancel the close.
      return 0;
    }

    // Allow the close.
    break;

  case WM_DESTROY:
    if (platform_delegate) {
      // Clear the user data pointer.
      gfx::SetWindowUserData(hwnd, NULL);

      // Force the browser to be destroyed. This will result in a call to
      // BrowserDestroyed() that will release the reference added in
      // CreateHostWindow().
      browser->WindowDestroyed();
    }
    return 0;

  case WM_SIZE:
    if (platform_delegate && platform_delegate->window_widget_) {
      // Pass window resize events to the HWND for the DesktopNativeWidgetAura
      // root window. Passing size 0x0 (wParam == SIZE_MINIMIZED, for example)
      // will cause the widget to be hidden which reduces resource usage.
      RECT rc;
      GetClientRect(hwnd, &rc);
      SetWindowPos(HWNDForWidget(platform_delegate->window_widget_), NULL,
            rc.left, rc.top, rc.right - rc.left, rc.bottom - rc.top,
            SWP_NOZORDER);
    }
    return 0;

  case WM_MOVING:
  case WM_MOVE:
    if (browser)
      browser->NotifyMoveOrResizeStarted();
    return 0;

  case WM_SETFOCUS:
    if (browser)
      browser->SetFocus(true);
    return 0;

  case WM_ERASEBKGND:
    return 0;
  }

  return DefWindowProc(hwnd, message, wParam, lParam);
}