// 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 "content/browser/renderer_host/web_input_event_aura.h"

#include "content/browser/renderer_host/input/web_input_event_util.h"
#include "content/browser/renderer_host/ui_events_helper.h"
#include "ui/aura/client/screen_position_client.h"
#include "ui/aura/window.h"
#include "ui/events/blink/blink_event_util.h"
#include "ui/events/event.h"
#include "ui/events/event_utils.h"
#include "ui/events/keycodes/dom4/keycode_converter.h"

namespace content {

namespace {

gfx::Point GetScreenLocationFromEvent(const ui::LocatedEvent& event) {
  if (!event.target())
    return event.root_location();

  aura::Window* root =
      static_cast<aura::Window*>(event.target())->GetRootWindow();
  aura::client::ScreenPositionClient* spc =
      aura::client::GetScreenPositionClient(root);
  if (!spc)
    return event.root_location();

  gfx::Point screen_location(event.root_location());
  spc->ConvertPointToScreen(root, &screen_location);
  return screen_location;
}

}  // namespace

#if defined(OS_WIN)
blink::WebMouseEvent MakeUntranslatedWebMouseEventFromNativeEvent(
    const base::NativeEvent& native_event);
blink::WebMouseWheelEvent MakeUntranslatedWebMouseWheelEventFromNativeEvent(
    const base::NativeEvent& native_event);
blink::WebKeyboardEvent MakeWebKeyboardEventFromNativeEvent(
    const base::NativeEvent& native_event);
blink::WebGestureEvent MakeWebGestureEventFromNativeEvent(
    const base::NativeEvent& native_event);
#endif

blink::WebKeyboardEvent MakeWebKeyboardEventFromAuraEvent(
    const ui::KeyEvent& event) {
  blink::WebKeyboardEvent webkit_event;

  webkit_event.timeStampSeconds = event.time_stamp().InSecondsF();
  webkit_event.modifiers = ui::EventFlagsToWebEventModifiers(event.flags());
  switch (ui::KeycodeConverter::DomCodeToLocation(event.code())) {
    case ui::DomKeyLocation::LEFT:
      webkit_event.modifiers |= blink::WebInputEvent::IsLeft;
      break;
    case ui::DomKeyLocation::RIGHT:
      webkit_event.modifiers |= blink::WebInputEvent::IsRight;
      break;
    case ui::DomKeyLocation::NUMPAD:
      webkit_event.modifiers |= blink::WebInputEvent::IsKeyPad;
      break;
    case ui::DomKeyLocation::STANDARD:
      break;
  }

  switch (event.type()) {
    case ui::ET_KEY_PRESSED:
      webkit_event.type = event.is_char() ? blink::WebInputEvent::Char :
          blink::WebInputEvent::RawKeyDown;
      break;
    case ui::ET_KEY_RELEASED:
      webkit_event.type = blink::WebInputEvent::KeyUp;
      break;
    default:
      NOTREACHED();
  }

  if (webkit_event.modifiers & blink::WebInputEvent::AltKey)
    webkit_event.isSystemKey = true;

  webkit_event.windowsKeyCode = event.GetLocatedWindowsKeyboardCode();
  webkit_event.nativeKeyCode =
    ui::KeycodeConverter::DomCodeToNativeKeycode(event.code());
  webkit_event.domCode = static_cast<int>(event.code());
  webkit_event.unmodifiedText[0] = event.GetUnmodifiedText();
  webkit_event.text[0] = event.GetText();

  webkit_event.setKeyIdentifierFromWindowsKeyCode();

  return webkit_event;
}

blink::WebMouseWheelEvent MakeWebMouseWheelEventFromAuraEvent(
    const ui::ScrollEvent& event) {
  blink::WebMouseWheelEvent webkit_event;

  webkit_event.type = blink::WebInputEvent::MouseWheel;
  webkit_event.button = blink::WebMouseEvent::ButtonNone;
  webkit_event.modifiers = ui::EventFlagsToWebEventModifiers(event.flags());
  webkit_event.timeStampSeconds = event.time_stamp().InSecondsF();
  webkit_event.hasPreciseScrollingDeltas = true;

  float offset_ordinal_x = 0.f;
  float offset_ordinal_y = 0.f;
  if ((event.flags() & ui::EF_SHIFT_DOWN) != 0 && event.x_offset() == 0) {
    webkit_event.deltaX = event.y_offset();
    webkit_event.deltaY = 0;
    offset_ordinal_x = event.y_offset_ordinal();
    offset_ordinal_y = event.x_offset_ordinal();
  } else {
    webkit_event.deltaX = event.x_offset();
    webkit_event.deltaY = event.y_offset();
    offset_ordinal_x = event.x_offset_ordinal();
    offset_ordinal_y = event.y_offset_ordinal();
  }

  if (offset_ordinal_x != 0.f && webkit_event.deltaX != 0.f)
    webkit_event.accelerationRatioX = offset_ordinal_x / webkit_event.deltaX;
  webkit_event.wheelTicksX = webkit_event.deltaX / kPixelsPerTick;
  webkit_event.wheelTicksY = webkit_event.deltaY / kPixelsPerTick;
  if (offset_ordinal_y != 0.f && webkit_event.deltaY != 0.f)
    webkit_event.accelerationRatioY = offset_ordinal_y / webkit_event.deltaY;
  return webkit_event;
}

blink::WebGestureEvent MakeWebGestureEventFromAuraEvent(
    const ui::ScrollEvent& event) {
  blink::WebGestureEvent webkit_event;

  switch (event.type()) {
    case ui::ET_SCROLL_FLING_START:
      webkit_event.type = blink::WebInputEvent::GestureFlingStart;
      webkit_event.data.flingStart.velocityX = event.x_offset();
      webkit_event.data.flingStart.velocityY = event.y_offset();
      break;
    case ui::ET_SCROLL_FLING_CANCEL:
      webkit_event.type = blink::WebInputEvent::GestureFlingCancel;
      break;
    case ui::ET_SCROLL:
      NOTREACHED() << "Invalid gesture type: " << event.type();
      break;
    default:
      NOTREACHED() << "Unknown gesture type: " << event.type();
  }

  webkit_event.sourceDevice = blink::WebGestureDeviceTouchpad;
  webkit_event.modifiers = ui::EventFlagsToWebEventModifiers(event.flags());
  webkit_event.timeStampSeconds = event.time_stamp().InSecondsF();
  return webkit_event;
}

blink::WebMouseEvent MakeWebMouseEventFromAuraEvent(
    const ui::MouseEvent& event);
blink::WebMouseWheelEvent MakeWebMouseWheelEventFromAuraEvent(
    const ui::MouseWheelEvent& event);

// General approach:
//
// ui::Event only carries a subset of possible event data provided to Aura by
// the host platform. WebKit utilizes a larger subset of that information than
// Aura itself. WebKit includes some built in cracking functionality that we
// rely on to obtain this information cleanly and consistently.
//
// The only place where an ui::Event's data differs from what the underlying
// base::NativeEvent would provide is position data, since we would like to
// provide coordinates relative to the aura::Window that is hosting the
// renderer, not the top level platform window.
//
// The approach is to fully construct a blink::WebInputEvent from the
// ui::Event's base::NativeEvent, and then replace the coordinate fields with
// the translated values from the ui::Event.
//
// The exception is mouse events on linux. The ui::MouseEvent contains enough
// necessary information to construct a WebMouseEvent. So instead of extracting
// the information from the XEvent, which can be tricky when supporting both
// XInput2 and XInput, the WebMouseEvent is constructed from the
// ui::MouseEvent. This will not be necessary once only XInput2 is supported.
//

blink::WebMouseEvent MakeWebMouseEvent(const ui::MouseEvent& event) {
  // Construct an untranslated event from the platform event data.
  blink::WebMouseEvent webkit_event =
#if defined(OS_WIN)
  // On Windows we have WM_ events comming from desktop and pure aura
  // events comming from metro mode.
  event.native_event().message ?
      MakeUntranslatedWebMouseEventFromNativeEvent(event.native_event()) :
      MakeWebMouseEventFromAuraEvent(event);
#else
  MakeWebMouseEventFromAuraEvent(event);
#endif
  // Replace the event's coordinate fields with translated position data from
  // |event|.
  webkit_event.windowX = webkit_event.x = event.x();
  webkit_event.windowY = webkit_event.y = event.y();

#if defined(OS_WIN)
  if (event.native_event().message)
    return webkit_event;
#endif
  const gfx::Point screen_point = GetScreenLocationFromEvent(event);
  webkit_event.globalX = screen_point.x();
  webkit_event.globalY = screen_point.y();

  return webkit_event;
}

blink::WebMouseWheelEvent MakeWebMouseWheelEvent(
    const ui::MouseWheelEvent& event) {
#if defined(OS_WIN)
  // Construct an untranslated event from the platform event data.
  blink::WebMouseWheelEvent webkit_event = event.native_event().message ?
      MakeUntranslatedWebMouseWheelEventFromNativeEvent(event.native_event()) :
      MakeWebMouseWheelEventFromAuraEvent(event);
#else
  blink::WebMouseWheelEvent webkit_event =
      MakeWebMouseWheelEventFromAuraEvent(event);
#endif

  // Replace the event's coordinate fields with translated position data from
  // |event|.
  webkit_event.windowX = webkit_event.x = event.x();
  webkit_event.windowY = webkit_event.y = event.y();

  const gfx::Point screen_point = GetScreenLocationFromEvent(event);
  webkit_event.globalX = screen_point.x();
  webkit_event.globalY = screen_point.y();

  // Scroll events generated from the mouse wheel when the control key is held
  // don't trigger scrolling. Instead, they may cause zooming.
  bool from_mouse_wheel = !webkit_event.hasPreciseScrollingDeltas;
  if ((webkit_event.modifiers & blink::WebInputEvent::ControlKey) &&
      from_mouse_wheel) {
    webkit_event.canScroll = false;
  }

  return webkit_event;
}

blink::WebMouseWheelEvent MakeWebMouseWheelEvent(const ui::ScrollEvent& event) {
#if defined(OS_WIN)
  // Construct an untranslated event from the platform event data.
  blink::WebMouseWheelEvent webkit_event = event.native_event().message ?
      MakeUntranslatedWebMouseWheelEventFromNativeEvent(event.native_event()) :
      MakeWebMouseWheelEventFromAuraEvent(event);
#else
  blink::WebMouseWheelEvent webkit_event =
      MakeWebMouseWheelEventFromAuraEvent(event);
#endif

  // Replace the event's coordinate fields with translated position data from
  // |event|.
  webkit_event.windowX = webkit_event.x = event.x();
  webkit_event.windowY = webkit_event.y = event.y();

  const gfx::Point screen_point = GetScreenLocationFromEvent(event);
  webkit_event.globalX = screen_point.x();
  webkit_event.globalY = screen_point.y();

  return webkit_event;
}

blink::WebKeyboardEvent MakeWebKeyboardEvent(const ui::KeyEvent& event) {
  // Windows can figure out whether or not to construct a RawKeyDown or a Char
  // WebInputEvent based on the type of message carried in
  // event.native_event(). X11 is not so fortunate, there is no separate
  // translated event type, so DesktopHostLinux sends an extra KeyEvent with
  // is_char() == true. We need to pass the ui::KeyEvent to the X11 function
  // to detect this case so the right event type can be constructed.
#if defined(OS_WIN)
  if (event.HasNativeEvent()) {
    // Key events require no translation by the aura system.
    return MakeWebKeyboardEventFromNativeEvent(event.native_event());
  }
#endif
  return MakeWebKeyboardEventFromAuraEvent(event);
}

blink::WebGestureEvent MakeWebGestureEvent(const ui::GestureEvent& event) {
  blink::WebGestureEvent gesture_event;
#if defined(OS_WIN)
  if (event.HasNativeEvent())
    gesture_event = MakeWebGestureEventFromNativeEvent(event.native_event());
  else
    gesture_event = MakeWebGestureEventFromUIEvent(event);
#else
  gesture_event = MakeWebGestureEventFromUIEvent(event);
#endif

  gesture_event.x = event.x();
  gesture_event.y = event.y();

  const gfx::Point screen_point = GetScreenLocationFromEvent(event);
  gesture_event.globalX = screen_point.x();
  gesture_event.globalY = screen_point.y();

  return gesture_event;
}

blink::WebGestureEvent MakeWebGestureEvent(const ui::ScrollEvent& event) {
  blink::WebGestureEvent gesture_event;

#if defined(OS_WIN)
  gesture_event = MakeWebGestureEventFromNativeEvent(event.native_event());
#else
  gesture_event = MakeWebGestureEventFromAuraEvent(event);
#endif

  gesture_event.x = event.x();
  gesture_event.y = event.y();

  const gfx::Point screen_point = GetScreenLocationFromEvent(event);
  gesture_event.globalX = screen_point.x();
  gesture_event.globalY = screen_point.y();

  return gesture_event;
}

blink::WebGestureEvent MakeWebGestureEventFlingCancel() {
  blink::WebGestureEvent gesture_event;

  // All other fields are ignored on a GestureFlingCancel event.
  gesture_event.type = blink::WebInputEvent::GestureFlingCancel;
  gesture_event.sourceDevice = blink::WebGestureDeviceTouchpad;
  return gesture_event;
}

blink::WebMouseEvent MakeWebMouseEventFromAuraEvent(
    const ui::MouseEvent& event) {
  blink::WebMouseEvent webkit_event;

  webkit_event.modifiers = ui::EventFlagsToWebEventModifiers(event.flags());
  webkit_event.timeStampSeconds = event.time_stamp().InSecondsF();

  webkit_event.button = blink::WebMouseEvent::ButtonNone;
  int button_flags = event.flags();
  if (event.type() == ui::ET_MOUSE_PRESSED ||
      event.type() == ui::ET_MOUSE_RELEASED) {
    // We want to use changed_button_flags() for mouse pressed & released.
    // These flags can be used only if they are set which is not always the case
    // (see e.g. GetChangedMouseButtonFlagsFromNative() in events_win.cc).
    if (event.changed_button_flags())
      button_flags = event.changed_button_flags();
  }
  if (button_flags & ui::EF_LEFT_MOUSE_BUTTON)
    webkit_event.button = blink::WebMouseEvent::ButtonLeft;
  if (button_flags & ui::EF_MIDDLE_MOUSE_BUTTON)
    webkit_event.button = blink::WebMouseEvent::ButtonMiddle;
  if (button_flags & ui::EF_RIGHT_MOUSE_BUTTON)
    webkit_event.button = blink::WebMouseEvent::ButtonRight;

  switch (event.type()) {
    case ui::ET_MOUSE_PRESSED:
      webkit_event.type = blink::WebInputEvent::MouseDown;
      webkit_event.clickCount = event.GetClickCount();
      break;
    case ui::ET_MOUSE_RELEASED:
      webkit_event.type = blink::WebInputEvent::MouseUp;
      webkit_event.clickCount = event.GetClickCount();
      break;
    case ui::ET_MOUSE_ENTERED:
    case ui::ET_MOUSE_EXITED:
    case ui::ET_MOUSE_MOVED:
    case ui::ET_MOUSE_DRAGGED:
      webkit_event.type = blink::WebInputEvent::MouseMove;
      break;
    default:
      NOTIMPLEMENTED() << "Received unexpected event: " << event.type();
      break;
  }

  return webkit_event;
}

blink::WebMouseWheelEvent MakeWebMouseWheelEventFromAuraEvent(
    const ui::MouseWheelEvent& event) {
  blink::WebMouseWheelEvent webkit_event;

  webkit_event.type = blink::WebInputEvent::MouseWheel;
  webkit_event.button = blink::WebMouseEvent::ButtonNone;
  webkit_event.modifiers = ui::EventFlagsToWebEventModifiers(event.flags());
  webkit_event.timeStampSeconds = event.time_stamp().InSecondsF();

  if ((event.flags() & ui::EF_SHIFT_DOWN) != 0 && event.x_offset() == 0) {
    webkit_event.deltaX = event.y_offset();
    webkit_event.deltaY = 0;
  } else {
    webkit_event.deltaX = event.x_offset();
    webkit_event.deltaY = event.y_offset();
  }

  webkit_event.wheelTicksX = webkit_event.deltaX / kPixelsPerTick;
  webkit_event.wheelTicksY = webkit_event.deltaY / kPixelsPerTick;

  return webkit_event;
}

}  // namespace content