// Copyright (c) 2012 The Chromium 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 <stdint.h>
#include <windowsx.h>

#include "ui/events/event_constants.h"

#include "base/logging.h"
#include "base/time/time.h"
#include "ui/events/event_utils.h"
#include "ui/events/keycodes/keyboard_code_conversion_win.h"
#include "ui/events/win/system_event_state_lookup.h"
#include "ui/gfx/geometry/point.h"

namespace ui {

namespace {

// From MSDN: "Mouse" events are flagged with 0xFF515700 if they come
// from a touch or stylus device.  In Vista or later, the eighth bit,
// masked by 0x80, is used to differentiate touch input from pen input
// (0 = pen, 1 = touch).
#define MOUSEEVENTF_FROMTOUCHPEN 0xFF515700
#define MOUSEEVENTF_FROMTOUCH (MOUSEEVENTF_FROMTOUCHPEN | 0x80)
#define SIGNATURE_MASK 0xFFFFFF00

// Get the native mouse key state from the native event message type.
int GetNativeMouseKey(const base::NativeEvent& native_event) {
  switch (native_event.message) {
    case WM_LBUTTONDBLCLK:
    case WM_LBUTTONDOWN:
    case WM_LBUTTONUP:
    case WM_NCLBUTTONDBLCLK:
    case WM_NCLBUTTONDOWN:
    case WM_NCLBUTTONUP:
      return MK_LBUTTON;
    case WM_MBUTTONDBLCLK:
    case WM_MBUTTONDOWN:
    case WM_MBUTTONUP:
    case WM_NCMBUTTONDBLCLK:
    case WM_NCMBUTTONDOWN:
    case WM_NCMBUTTONUP:
      return MK_MBUTTON;
    case WM_RBUTTONDBLCLK:
    case WM_RBUTTONDOWN:
    case WM_RBUTTONUP:
    case WM_NCRBUTTONDBLCLK:
    case WM_NCRBUTTONDOWN:
    case WM_NCRBUTTONUP:
      return MK_RBUTTON;
    case WM_NCXBUTTONDBLCLK:
    case WM_NCXBUTTONDOWN:
    case WM_NCXBUTTONUP:
    case WM_XBUTTONDBLCLK:
    case WM_XBUTTONDOWN:
    case WM_XBUTTONUP:
      return MK_XBUTTON1;
  }
  return 0;
}

bool IsButtonDown(const base::NativeEvent& native_event) {
  return ((MK_LBUTTON | MK_MBUTTON | MK_RBUTTON | MK_XBUTTON1 | MK_XBUTTON2) &
          native_event.wParam) != 0;
}

bool IsClientMouseEvent(const base::NativeEvent& native_event) {
  return native_event.message == WM_MOUSELEAVE ||
         native_event.message == WM_MOUSEHOVER ||
        (native_event.message >= WM_MOUSEFIRST &&
         native_event.message <= WM_MOUSELAST);
}

bool IsNonClientMouseEvent(const base::NativeEvent& native_event) {
  return native_event.message == WM_NCMOUSELEAVE ||
         native_event.message == WM_NCMOUSEHOVER ||
        (native_event.message >= WM_NCMOUSEMOVE &&
         native_event.message <= WM_NCXBUTTONDBLCLK);
}

bool IsMouseEvent(const base::NativeEvent& native_event) {
  return IsClientMouseEvent(native_event) ||
         IsNonClientMouseEvent(native_event);
}

bool IsMouseWheelEvent(const base::NativeEvent& native_event) {
  return native_event.message == WM_MOUSEWHEEL ||
         native_event.message == WM_MOUSEHWHEEL;
}

bool IsKeyEvent(const base::NativeEvent& native_event) {
  return native_event.message == WM_KEYDOWN ||
         native_event.message == WM_SYSKEYDOWN ||
         native_event.message == WM_CHAR ||
         native_event.message == WM_SYSCHAR ||
         native_event.message == WM_KEYUP ||
         native_event.message == WM_SYSKEYUP;
}

bool IsScrollEvent(const base::NativeEvent& native_event) {
  return native_event.message == WM_VSCROLL ||
         native_event.message == WM_HSCROLL;
}

// Returns a mask corresponding to the set of pressed modifier keys.
// Checks the current global state and the state sent by client mouse messages.
int KeyStateFlagsFromNative(const base::NativeEvent& native_event) {
  int flags = GetModifiersFromKeyState();

  // Check key messages for the extended key flag.
  if (IsKeyEvent(native_event) && (HIWORD(native_event.lParam) & KF_EXTENDED))
    flags |= EF_IS_EXTENDED_KEY;

  // Most client mouse messages include key state information.
  if (IsClientMouseEvent(native_event)) {
    int win_flags = GET_KEYSTATE_WPARAM(native_event.wParam);
    flags |= (win_flags & MK_SHIFT) ? EF_SHIFT_DOWN : 0;
    flags |= (win_flags & MK_CONTROL) ? EF_CONTROL_DOWN : 0;
  }

  return flags;
}

// Returns a mask corresponding to the set of pressed mouse buttons.
// This includes the button of the given message, even if it is being released.
int MouseStateFlagsFromNative(const base::NativeEvent& native_event) {
  int win_flags = GetNativeMouseKey(native_event);

  // Client mouse messages provide key states in their WPARAMs.
  if (IsClientMouseEvent(native_event))
    win_flags |= GET_KEYSTATE_WPARAM(native_event.wParam);

  int flags = 0;
  flags |= (win_flags & MK_LBUTTON) ? EF_LEFT_MOUSE_BUTTON : 0;
  flags |= (win_flags & MK_MBUTTON) ? EF_MIDDLE_MOUSE_BUTTON : 0;
  flags |= (win_flags & MK_RBUTTON) ? EF_RIGHT_MOUSE_BUTTON : 0;
  flags |= IsNonClientMouseEvent(native_event) ? EF_IS_NON_CLIENT : 0;
  return flags;
}

}  // namespace

EventType EventTypeFromNative(const base::NativeEvent& native_event) {
  switch (native_event.message) {
    case WM_KEYDOWN:
    case WM_SYSKEYDOWN:
    case WM_CHAR:
    case WM_SYSCHAR:
      return ET_KEY_PRESSED;
    // The WM_DEADCHAR message is posted to the window with the keyboard focus
    // when a WM_KEYUP message is translated. This happens for special keyboard
    // sequences.
    case WM_DEADCHAR:
    case WM_KEYUP:
    // The WM_SYSDEADCHAR message is posted to a window with keyboard focus
    // when the WM_SYSKEYDOWN message is translated by the TranslateMessage
    // function. It specifies the character code of the system dead key.
    case WM_SYSDEADCHAR:
    case WM_SYSKEYUP:
      return ET_KEY_RELEASED;
    case WM_LBUTTONDBLCLK:
    case WM_LBUTTONDOWN:
    case WM_MBUTTONDBLCLK:
    case WM_MBUTTONDOWN:
    case WM_NCLBUTTONDBLCLK:
    case WM_NCLBUTTONDOWN:
    case WM_NCMBUTTONDBLCLK:
    case WM_NCMBUTTONDOWN:
    case WM_NCRBUTTONDBLCLK:
    case WM_NCRBUTTONDOWN:
    case WM_NCXBUTTONDBLCLK:
    case WM_NCXBUTTONDOWN:
    case WM_RBUTTONDBLCLK:
    case WM_RBUTTONDOWN:
    case WM_XBUTTONDBLCLK:
    case WM_XBUTTONDOWN:
      return ET_MOUSE_PRESSED;
    case WM_LBUTTONUP:
    case WM_MBUTTONUP:
    case WM_NCLBUTTONUP:
    case WM_NCMBUTTONUP:
    case WM_NCRBUTTONUP:
    case WM_NCXBUTTONUP:
    case WM_RBUTTONUP:
    case WM_XBUTTONUP:
      return ET_MOUSE_RELEASED;
    case WM_MOUSEMOVE:
      return IsButtonDown(native_event) ? ET_MOUSE_DRAGGED : ET_MOUSE_MOVED;
    case WM_NCMOUSEMOVE:
      return ET_MOUSE_MOVED;
    case WM_MOUSEWHEEL:
    case WM_MOUSEHWHEEL:
      return ET_MOUSEWHEEL;
    case WM_MOUSELEAVE:
    case WM_NCMOUSELEAVE:
      return ET_MOUSE_EXITED;
    case WM_VSCROLL:
    case WM_HSCROLL:
      return ET_SCROLL;
    default:
      // We can't NOTREACHED() here, since this function can be called for any
      // message.
      break;
  }
  return ET_UNKNOWN;
}

int EventFlagsFromNative(const base::NativeEvent& native_event) {
  int flags = KeyStateFlagsFromNative(native_event);
  if (IsMouseEvent(native_event))
    flags |= MouseStateFlagsFromNative(native_event);

  return flags;
}

base::TimeTicks EventTimeFromNative(const base::NativeEvent& native_event) {
  // On Windows, the native input event timestamp (|native_event.time|) is
  // coming from |GetTickCount()| clock [1], while in platform independent code
  // path we get timestamps by calling |TimeTicks::Now()|, which, if using high-
  // resolution timer as underlying implementation, could have different time
  // origin than |GetTickCount()|. To avoid the mismatching, we use
  // |TimeTicks::Now()| for event timestamp instead of the native timestamp to
  // ensure computed input latency and web exposed timestamp is consistent with
  // other components.
  // It is unnecessary to invoke |ValidateEventTimeClock| here because of above.
  // [1] http://blogs.msdn.com/b/oldnewthing/archive/2014/01/22/10491576.aspx
  return EventTimeForNow();
}

gfx::Point EventLocationFromNative(const base::NativeEvent& native_event) {
  POINT native_point;
  if ((native_event.message == WM_MOUSELEAVE ||
       native_event.message == WM_NCMOUSELEAVE) ||
      IsScrollEvent(native_event)) {
    // These events have no coordinates. For sanity with rest of events grab
    // coordinates from the OS.
    ::GetCursorPos(&native_point);
  } else if (IsClientMouseEvent(native_event) &&
             !IsMouseWheelEvent(native_event)) {
    // Note: Wheel events are considered client, but their position is in screen
    //       coordinates.
    // Client message. The position is contained in the LPARAM.
    return gfx::Point(native_event.lParam);
  } else {
    DCHECK(IsNonClientMouseEvent(native_event) ||
           IsMouseWheelEvent(native_event) || IsScrollEvent(native_event));
    // Non-client message. The position is contained in a POINTS structure in
    // LPARAM, and is in screen coordinates so we have to convert to client.
    native_point.x = GET_X_LPARAM(native_event.lParam);
    native_point.y = GET_Y_LPARAM(native_event.lParam);
  }
  ScreenToClient(native_event.hwnd, &native_point);
  return gfx::Point(native_point);
}

gfx::Point EventSystemLocationFromNative(
    const base::NativeEvent& native_event) {
  POINT global_point = { static_cast<short>(LOWORD(native_event.lParam)),
                         static_cast<short>(HIWORD(native_event.lParam)) };
  // Wheel events have position in screen coordinates.
  if (!IsMouseWheelEvent(native_event))
    ClientToScreen(native_event.hwnd, &global_point);
  return gfx::Point(global_point);
}

KeyboardCode KeyboardCodeFromNative(const base::NativeEvent& native_event) {
  return KeyboardCodeForWindowsKeyCode(static_cast<WORD>(native_event.wParam));
}

DomCode CodeFromNative(const base::NativeEvent& native_event) {
  const uint16_t scan_code = GetScanCodeFromLParam(native_event.lParam);
  return CodeForWindowsScanCode(scan_code);
}

bool IsCharFromNative(const base::NativeEvent& native_event) {
  return native_event.message == WM_CHAR || native_event.message == WM_SYSCHAR;
}

int GetChangedMouseButtonFlagsFromNative(
    const base::NativeEvent& native_event) {
  switch (GetNativeMouseKey(native_event)) {
    case MK_LBUTTON:
      return EF_LEFT_MOUSE_BUTTON;
    case MK_MBUTTON:
      return EF_MIDDLE_MOUSE_BUTTON;
    case MK_RBUTTON:
      return EF_RIGHT_MOUSE_BUTTON;
    // TODO: add support for MK_XBUTTON1.
    default:
      break;
  }
  return 0;
}

PointerDetails GetMousePointerDetailsFromNative(
    const base::NativeEvent& native_event) {
  // We should filter out all the mouse events Synthesized from touch events.
  // TODO(lanwei): Will set the pointer ID, see https://crbug.com/616771.
  if ((GetMessageExtraInfo() & SIGNATURE_MASK) != MOUSEEVENTF_FROMTOUCHPEN)
    return PointerDetails(EventPointerType::POINTER_TYPE_MOUSE);

  return PointerDetails(EventPointerType::POINTER_TYPE_PEN);
}

gfx::Vector2d GetMouseWheelOffset(const base::NativeEvent& native_event) {
  DCHECK(native_event.message == WM_MOUSEWHEEL ||
         native_event.message == WM_MOUSEHWHEEL);
  if (native_event.message == WM_MOUSEWHEEL)
    return gfx::Vector2d(0, GET_WHEEL_DELTA_WPARAM(native_event.wParam));
  return gfx::Vector2d(GET_WHEEL_DELTA_WPARAM(native_event.wParam), 0);
}

base::NativeEvent CopyNativeEvent(const base::NativeEvent& event) {
  return event;
}

void ReleaseCopiedNativeEvent(const base::NativeEvent& event) {
}

void ClearTouchIdIfReleased(const base::NativeEvent& xev) {
  NOTIMPLEMENTED();
}

int GetTouchId(const base::NativeEvent& xev) {
  NOTIMPLEMENTED();
  return 0;
}

float GetTouchAngle(const base::NativeEvent& native_event) {
  NOTIMPLEMENTED();
  return 0.0;
}

PointerDetails GetTouchPointerDetailsFromNative(
    const base::NativeEvent& native_event) {
  NOTIMPLEMENTED();
  return PointerDetails(EventPointerType::POINTER_TYPE_TOUCH,
                        /* radius_x */ 1.0,
                        /* radius_y */ 1.0,
                        /* force */ 0.f,
                        /* tilt_x */ 0.f,
                        /* tilt_y */ 0.f);
}

bool GetScrollOffsets(const base::NativeEvent& native_event,
                      float* x_offset,
                      float* y_offset,
                      float* x_offset_ordinal,
                      float* y_offset_ordinal,
                      int* finger_count) {
  // TODO(ananta)
  // Support retrieving the scroll offsets from the scroll event.
  if (native_event.message == WM_VSCROLL || native_event.message == WM_HSCROLL)
    return true;
  return false;
}

bool GetFlingData(const base::NativeEvent& native_event,
                  float* vx,
                  float* vy,
                  float* vx_ordinal,
                  float* vy_ordinal,
                  bool* is_cancel) {
  // Not supported in Windows.
  NOTIMPLEMENTED();
  return false;
}

int GetModifiersFromKeyState() {
  int modifiers = EF_NONE;
  if (ui::win::IsShiftPressed())
    modifiers |= EF_SHIFT_DOWN;
  if (ui::win::IsCtrlPressed())
    modifiers |= EF_CONTROL_DOWN;
  if (ui::win::IsAltPressed())
    modifiers |= EF_ALT_DOWN;
  if (ui::win::IsWindowsKeyPressed())
    modifiers |= EF_COMMAND_DOWN;
  if (ui::win::IsAltGrPressed())
    modifiers |= EF_ALTGR_DOWN;
  if (ui::win::IsNumLockOn())
    modifiers |= EF_NUM_LOCK_ON;
  if (ui::win::IsCapsLockOn())
    modifiers |= EF_CAPS_LOCK_ON;
  if (ui::win::IsScrollLockOn())
    modifiers |= EF_SCROLL_LOCK_ON;
  return modifiers;
}

// Windows emulates mouse messages for touch events.
bool IsMouseEventFromTouch(UINT message) {
  return (message >= WM_MOUSEFIRST) && (message <= WM_MOUSELAST) &&
      (GetMessageExtraInfo() & MOUSEEVENTF_FROMTOUCH) ==
      MOUSEEVENTF_FROMTOUCH;
}

// Conversion scan_code and LParam each other.
// uint16_t scan_code:
//     ui/events/keycodes/dom/keycode_converter_data.inc
// 0 - 15bits: represetns the scan code.
// 28 - 30 bits (0xE000): represents whether this is an extended key or not.
//
// LPARAM lParam:
//     http://msdn.microsoft.com/en-us/library/windows/desktop/ms644984.aspx
// 16 - 23bits: represetns the scan code.
// 24bit (0x0100): represents whether this is an extended key or not.
uint16_t GetScanCodeFromLParam(LPARAM l_param) {
  uint16_t scan_code = ((l_param >> 16) & 0x00FF);
  if (l_param & (1 << 24))
    scan_code |= 0xE000;
  return scan_code;
}

LPARAM GetLParamFromScanCode(uint16_t scan_code) {
  LPARAM l_param = static_cast<LPARAM>(scan_code & 0x00FF) << 16;
  if ((scan_code & 0xE000) == 0xE000)
    l_param |= (1 << 24);
  return l_param;
}

}  // namespace ui