/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * nsWinGesture - Touch input handling for tablet displays.
 */

#include "nscore.h"
#include "nsWinGesture.h"
#include "nsUXThemeData.h"
#include "nsIDOMSimpleGestureEvent.h"
#include "nsIDOMWheelEvent.h"
#include "mozilla/Logging.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/Preferences.h"
#include "mozilla/TouchEvents.h"

#include <cmath>

using namespace mozilla;
using namespace mozilla::widget;

extern mozilla::LazyLogModule gWindowsLog;


static bool gEnableSingleFingerPanEvents = false;

nsWinGesture::nsWinGesture() :
  mPanActive(false),
  mFeedbackActive(false),
  mXAxisFeedback(false),
  mYAxisFeedback(false),
  mPanInertiaActive(false)
{
  (void)InitLibrary();
  mPixelScrollOverflow = 0;
}

/* Load and shutdown */

bool nsWinGesture::InitLibrary()
{
  // Check to see if we want single finger gesture input. Only do this once
  // for the app so we don't have to look it up on every window create.
  gEnableSingleFingerPanEvents =
    Preferences::GetBool("gestures.enable_single_finger_input", false);

  return true;
}

#define GCOUNT 5

bool nsWinGesture::SetWinGestureSupport(HWND hWnd,
                     WidgetGestureNotifyEvent::PanDirection aDirection)
{
  GESTURECONFIG config[GCOUNT];

  memset(&config, 0, sizeof(config));

  config[0].dwID = GID_ZOOM;
  config[0].dwWant = GC_ZOOM;
  config[0].dwBlock = 0;

  config[1].dwID = GID_ROTATE;
  config[1].dwWant = GC_ROTATE;
  config[1].dwBlock = 0;

  config[2].dwID = GID_PAN;
  config[2].dwWant  = GC_PAN|GC_PAN_WITH_INERTIA|
                      GC_PAN_WITH_GUTTER;
  config[2].dwBlock = GC_PAN_WITH_SINGLE_FINGER_VERTICALLY|
                      GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;

  if (gEnableSingleFingerPanEvents) {

    if (aDirection == WidgetGestureNotifyEvent::ePanVertical ||
        aDirection == WidgetGestureNotifyEvent::ePanBoth)
    {
      config[2].dwWant  |= GC_PAN_WITH_SINGLE_FINGER_VERTICALLY;
      config[2].dwBlock -= GC_PAN_WITH_SINGLE_FINGER_VERTICALLY;
    }

    if (aDirection == WidgetGestureNotifyEvent::ePanHorizontal ||
        aDirection == WidgetGestureNotifyEvent::ePanBoth)
    {
      config[2].dwWant  |= GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;
      config[2].dwBlock -= GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;
    }

  }

  config[3].dwWant = GC_TWOFINGERTAP;
  config[3].dwID = GID_TWOFINGERTAP;
  config[3].dwBlock = 0;

  config[4].dwWant = GC_PRESSANDTAP;
  config[4].dwID = GID_PRESSANDTAP;
  config[4].dwBlock = 0;

  return SetGestureConfig(hWnd, 0, GCOUNT, (PGESTURECONFIG)&config,
                          sizeof(GESTURECONFIG));
}

/* Helpers */

bool nsWinGesture::IsPanEvent(LPARAM lParam)
{
  GESTUREINFO gi;

  ZeroMemory(&gi,sizeof(GESTUREINFO));
  gi.cbSize = sizeof(GESTUREINFO);

  BOOL result = GetGestureInfo((HGESTUREINFO)lParam, &gi);
  if (!result)
    return false;

  if (gi.dwID == GID_PAN)
    return true;

  return false;
}

/* Gesture event processing */

bool
nsWinGesture::ProcessGestureMessage(HWND hWnd, WPARAM wParam, LPARAM lParam,
                                    WidgetSimpleGestureEvent& evt)
{
  GESTUREINFO gi;

  ZeroMemory(&gi,sizeof(GESTUREINFO));
  gi.cbSize = sizeof(GESTUREINFO);

  BOOL result = GetGestureInfo((HGESTUREINFO)lParam, &gi);
  if (!result)
    return false;

  // The coordinates of this event
  nsPointWin coord;
  coord = gi.ptsLocation;
  coord.ScreenToClient(hWnd);

  evt.mRefPoint = LayoutDeviceIntPoint(coord.x, coord.y);

  // Multiple gesture can occur at the same time so gesture state
  // info can't be shared.
  switch(gi.dwID)
  {
    case GID_BEGIN:
    case GID_END:
      // These should always fall through to DefWndProc
      return false;
      break;

    case GID_ZOOM:
    {
      if (gi.dwFlags & GF_BEGIN) {
        // Send a zoom start event

        // The low 32 bits are the distance in pixels.
        mZoomIntermediate = (float)gi.ullArguments;

        evt.mMessage = eMagnifyGestureStart;
        evt.mDelta = 0.0;
      }
      else if (gi.dwFlags & GF_END) {
        // Send a zoom end event, the delta is the change
        // in touch points.
        evt.mMessage = eMagnifyGesture;
        // (positive for a "zoom in")
        evt.mDelta = -1.0 * (mZoomIntermediate - (float)gi.ullArguments);
        mZoomIntermediate = (float)gi.ullArguments;
      }
      else {
        // Send a zoom intermediate event, the delta is the change
        // in touch points.
        evt.mMessage = eMagnifyGestureUpdate;
        // (positive for a "zoom in")
        evt.mDelta = -1.0 * (mZoomIntermediate - (float)gi.ullArguments);
        mZoomIntermediate = (float)gi.ullArguments;
      }
    }
    break;

    case GID_ROTATE:
    {
      // Send a rotate start event
      double radians = 0.0;

      // On GF_BEGIN, ullArguments contains the absolute rotation at the
      // start of the gesture. In later events it contains the offset from
      // the start angle.
      if (gi.ullArguments != 0)
        radians = GID_ROTATE_ANGLE_FROM_ARGUMENT(gi.ullArguments);

      double degrees = -1 * radians * (180/M_PI);

      if (gi.dwFlags & GF_BEGIN) {
          // At some point we should pass the initial angle in
          // along with delta. It's useful.
          degrees = mRotateIntermediate = 0.0;
      }

      evt.mDirection = 0;
      evt.mDelta = degrees - mRotateIntermediate;
      mRotateIntermediate = degrees;

      if (evt.mDelta > 0)
        evt.mDirection = nsIDOMSimpleGestureEvent::ROTATION_COUNTERCLOCKWISE;
      else if (evt.mDelta < 0)
        evt.mDirection = nsIDOMSimpleGestureEvent::ROTATION_CLOCKWISE;

      if (gi.dwFlags & GF_BEGIN) {
        evt.mMessage = eRotateGestureStart;
      } else if (gi.dwFlags & GF_END) {
        evt.mMessage = eRotateGesture;
      } else {
        evt.mMessage = eRotateGestureUpdate;
      }
    }
    break;

    case GID_TWOFINGERTAP:
      // Normally maps to "restore" from whatever you may have recently changed.
      // A simple double click.
      evt.mMessage = eTapGesture;
      evt.mClickCount = 1;
      break;

    case GID_PRESSANDTAP:
      // Two finger right click. Defaults to right click if it falls through.
      evt.mMessage = ePressTapGesture;
      evt.mClickCount = 1;
      break;
  }

  return true;
}

bool
nsWinGesture::ProcessPanMessage(HWND hWnd, WPARAM wParam, LPARAM lParam)
{
  GESTUREINFO gi;

  ZeroMemory(&gi,sizeof(GESTUREINFO));
  gi.cbSize = sizeof(GESTUREINFO);

  BOOL result = GetGestureInfo((HGESTUREINFO)lParam, &gi);
  if (!result)
    return false;

  // The coordinates of this event
  nsPointWin coord;
  coord = mPanRefPoint = gi.ptsLocation;
  // We want screen coordinates in our local offsets as client coordinates will change
  // when feedback is taking place. Gui events though require client coordinates. 
  mPanRefPoint.ScreenToClient(hWnd);

  switch(gi.dwID)
  {
    case GID_BEGIN:
    case GID_END:
      // These should always fall through to DefWndProc
      return false;
      break;

    // Setup pixel scroll events for both axis
    case GID_PAN:
    {
      if (gi.dwFlags & GF_BEGIN) {
        mPanIntermediate = coord;
        mPixelScrollDelta = 0;
        mPanActive = true;
        mPanInertiaActive = false;
      }
      else {

#ifdef DBG_jimm
        int32_t deltaX = mPanIntermediate.x - coord.x;
        int32_t deltaY = mPanIntermediate.y - coord.y;
        MOZ_LOG(gWindowsLog, LogLevel::Info, 
               ("coordX=%d coordY=%d deltaX=%d deltaY=%d x:%d y:%d\n", coord.x,
                coord.y, deltaX, deltaY, mXAxisFeedback, mYAxisFeedback));
#endif

        mPixelScrollDelta.x = mPanIntermediate.x - coord.x;
        mPixelScrollDelta.y = mPanIntermediate.y - coord.y;
        mPanIntermediate = coord;

        if (gi.dwFlags & GF_INERTIA)
          mPanInertiaActive = true;

        if (gi.dwFlags & GF_END) {
          mPanActive = false;
          mPanInertiaActive = false;
          PanFeedbackFinalize(hWnd, true);
        }
      }
    }
    break;
  }
  return true;
}

inline bool TestTransition(int32_t a, int32_t b)
{
  // If a is zero, overflow is zero, implying the cursor has moved back to the start position.
  // If b is zero, cached overscroll is zero, implying feedback just begun. 
  if (a == 0 || b == 0) return true;
  // Test for different signs.
  return (a < 0) == (b < 0);
}

void
nsWinGesture::UpdatePanFeedbackX(HWND hWnd, int32_t scrollOverflow, bool& endFeedback)
{
  // If scroll overflow was returned indicating we panned past the bounds of
  // the scrollable view port, start feeback.
  if (scrollOverflow != 0) {
    if (!mFeedbackActive) {
      BeginPanningFeedback(hWnd);
      mFeedbackActive = true;
    }      
    endFeedback = false;
    mXAxisFeedback = true;
    return;
  }
  
  if (mXAxisFeedback) {
    int32_t newOverflow = mPixelScrollOverflow.x - mPixelScrollDelta.x;

    // Detect a reverse transition past the starting drag point. This tells us the user
    // has panned all the way back so we can stop providing feedback for this axis.
    if (!TestTransition(newOverflow, mPixelScrollOverflow.x) || newOverflow == 0)
      return;

    // Cache the total over scroll in pixels.
    mPixelScrollOverflow.x = newOverflow;
    endFeedback = false;
  }
}

void
nsWinGesture::UpdatePanFeedbackY(HWND hWnd, int32_t scrollOverflow, bool& endFeedback)
{
  // If scroll overflow was returned indicating we panned past the bounds of
  // the scrollable view port, start feeback.
  if (scrollOverflow != 0) {
    if (!mFeedbackActive) {
      BeginPanningFeedback(hWnd);
      mFeedbackActive = true;
    }
    endFeedback = false;
    mYAxisFeedback = true;
    return;
  }
  
  if (mYAxisFeedback) {
    int32_t newOverflow = mPixelScrollOverflow.y - mPixelScrollDelta.y;

    // Detect a reverse transition past the starting drag point. This tells us the user
    // has panned all the way back so we can stop providing feedback for this axis.
    if (!TestTransition(newOverflow, mPixelScrollOverflow.y) || newOverflow == 0)
      return;

    // Cache the total over scroll in pixels.
    mPixelScrollOverflow.y = newOverflow;
    endFeedback = false;
  }
}

void
nsWinGesture::PanFeedbackFinalize(HWND hWnd, bool endFeedback)
{
  if (!mFeedbackActive)
    return;

  if (endFeedback) {
    mFeedbackActive = false;
    mXAxisFeedback = false;
    mYAxisFeedback = false;
    mPixelScrollOverflow = 0;
    EndPanningFeedback(hWnd, TRUE);
    return;
  }

  UpdatePanningFeedback(hWnd, mPixelScrollOverflow.x, mPixelScrollOverflow.y, mPanInertiaActive);
}

bool
nsWinGesture::PanDeltaToPixelScroll(WidgetWheelEvent& aWheelEvent)
{
  aWheelEvent.mDeltaX = aWheelEvent.mDeltaY = aWheelEvent.mDeltaZ = 0.0;
  aWheelEvent.mLineOrPageDeltaX = aWheelEvent.mLineOrPageDeltaY = 0;

  aWheelEvent.mRefPoint = LayoutDeviceIntPoint(mPanRefPoint.x, mPanRefPoint.y);
  aWheelEvent.mDeltaMode = nsIDOMWheelEvent::DOM_DELTA_PIXEL;
  aWheelEvent.mScrollType = WidgetWheelEvent::SCROLL_SYNCHRONOUSLY;
  aWheelEvent.mIsNoLineOrPageDelta = true;

  aWheelEvent.mOverflowDeltaX = 0.0;
  aWheelEvent.mOverflowDeltaY = 0.0;

  // Don't scroll the view if we are currently at a bounds, or, if we are
  // panning back from a max feedback position. This keeps the original drag point
  // constant.
  if (!mXAxisFeedback) {
    aWheelEvent.mDeltaX = mPixelScrollDelta.x;
  }
  if (!mYAxisFeedback) {
    aWheelEvent.mDeltaY = mPixelScrollDelta.y;
  }

  return (aWheelEvent.mDeltaX != 0 || aWheelEvent.mDeltaY != 0);
}