/* GDK - The GIMP Drawing Kit
 * Copyright (C) 2009 Carlos Garnacho <carlosg@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <gdk/gdkwindow.h>

#include <windowsx.h>
#include <objbase.h>

#include "gdkdisplayprivate.h"
#include "gdkdevice-virtual.h"
#include "gdkwin32.h"

static gboolean gdk_device_virtual_get_history (GdkDevice      *device,
						GdkWindow      *window,
						guint32         start,
						guint32         stop,
						GdkTimeCoord ***events,
						gint           *n_events);
static void gdk_device_virtual_get_state (GdkDevice       *device,
					  GdkWindow       *window,
					  gdouble         *axes,
					  GdkModifierType *mask);
static void gdk_device_virtual_set_window_cursor (GdkDevice *device,
						  GdkWindow *window,
						  GdkCursor *cursor);
static void gdk_device_virtual_warp (GdkDevice *device,
				     GdkScreen *screen,
				     gdouble   x,
				     gdouble   y);
static void gdk_device_virtual_query_state (GdkDevice        *device,
					    GdkWindow        *window,
					    GdkWindow       **root_window,
					    GdkWindow       **child_window,
					    gdouble          *root_x,
					    gdouble          *root_y,
					    gdouble          *win_x,
					    gdouble          *win_y,
					    GdkModifierType  *mask);
static GdkGrabStatus gdk_device_virtual_grab   (GdkDevice     *device,
						GdkWindow     *window,
						gboolean       owner_events,
						GdkEventMask   event_mask,
						GdkWindow     *confine_to,
						GdkCursor     *cursor,
						guint32        time_);
static void          gdk_device_virtual_ungrab (GdkDevice     *device,
						guint32        time_);
static GdkWindow * gdk_device_virtual_window_at_position (GdkDevice       *device,
							  gdouble         *win_x,
							  gdouble         *win_y,
							  GdkModifierType *mask,
							  gboolean         get_toplevel);
static void      gdk_device_virtual_select_window_events (GdkDevice       *device,
							  GdkWindow       *window,
							  GdkEventMask     event_mask);


G_DEFINE_TYPE (GdkDeviceVirtual, gdk_device_virtual, GDK_TYPE_DEVICE)

static void
gdk_device_virtual_class_init (GdkDeviceVirtualClass *klass)
{
  GdkDeviceClass *device_class = GDK_DEVICE_CLASS (klass);

  device_class->get_history = gdk_device_virtual_get_history;
  device_class->get_state = gdk_device_virtual_get_state;
  device_class->set_window_cursor = gdk_device_virtual_set_window_cursor;
  device_class->warp = gdk_device_virtual_warp;
  device_class->query_state = gdk_device_virtual_query_state;
  device_class->grab = gdk_device_virtual_grab;
  device_class->ungrab = gdk_device_virtual_ungrab;
  device_class->window_at_position = gdk_device_virtual_window_at_position;
  device_class->select_window_events = gdk_device_virtual_select_window_events;
}

static void
gdk_device_virtual_init (GdkDeviceVirtual *device_virtual)
{
  GdkDevice *device;

  device = GDK_DEVICE (device_virtual);

}

void
_gdk_device_virtual_set_active (GdkDevice *device,
				GdkDevice *new_active)
{
  GdkDeviceVirtual *virtual = GDK_DEVICE_VIRTUAL (device);
  int n_axes, i;
  GdkAtom label_atom;
  GdkAxisUse use;
  gdouble min_value, max_value, resolution;

  if (virtual->active_device == new_active)
    return;

  virtual->active_device = new_active;
  
  if (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD)
    {
      _gdk_device_reset_axes (device);
      n_axes = gdk_device_get_n_axes (new_active);
      for (i = 0; i < n_axes; i++)
	{
	  _gdk_device_get_axis_info (new_active, i,
				     &label_atom, &use, 
				     &min_value, &max_value, &resolution);
	  _gdk_device_add_axis (device,
				label_atom, use, 
				min_value, max_value, resolution);
	}
    }

  g_signal_emit_by_name (G_OBJECT (device), "changed");
}

static gboolean
gdk_device_virtual_get_history (GdkDevice      *device,
				GdkWindow      *window,
				guint32         start,
				guint32         stop,
				GdkTimeCoord ***events,
				gint           *n_events)
{
  /* History is only per slave device */
  return FALSE;
}

static void
gdk_device_virtual_get_state (GdkDevice       *device,
			      GdkWindow       *window,
			      gdouble         *axes,
			      GdkModifierType *mask)
{
  GdkDeviceVirtual *virtual = GDK_DEVICE_VIRTUAL (device);
  GdkDevice *active = virtual->active_device;

  GDK_DEVICE_GET_CLASS (active)->get_state (active,
					    window, axes, mask);
}

static void
gdk_device_virtual_set_window_cursor (GdkDevice *device,
				      GdkWindow *window,
				      GdkCursor *cursor)
{
  GdkWin32Cursor *cursor_private;
  GdkWindow *parent_window;
  GdkWindowImplWin32 *impl;
  HCURSOR hcursor;
  HCURSOR hprevcursor;

  impl = GDK_WINDOW_IMPL_WIN32 (window->impl);
  cursor_private = (GdkWin32Cursor*) cursor;

  hprevcursor = impl->hcursor;

  if (!cursor)
    hcursor = NULL;
  else
    hcursor = cursor_private->hcursor;

  if (hcursor != NULL)
    {
      /* If the pointer is over our window, set new cursor */
      GdkWindow *curr_window = gdk_window_get_device_position (window, device, NULL, NULL, NULL);

      if (curr_window == window ||
          (curr_window && window == gdk_window_get_toplevel (curr_window)))
        SetCursor (hcursor);
      else
        {
          /* Climb up the tree and find whether our window is the
           * first ancestor that has cursor defined, and if so, set
           * new cursor.
           */
          while (curr_window && curr_window->impl &&
                 !GDK_WINDOW_IMPL_WIN32 (curr_window->impl)->hcursor)
            {
              curr_window = curr_window->parent;
              if (curr_window == GDK_WINDOW (window))
                {
                  SetCursor (hcursor);
                  break;
                }
            }
        }
    }

  /* Unset the previous cursor: Need to make sure it's no longer in
   * use before we destroy it, in case we're not over our window but
   * the cursor is still set to our old one.
   */
  if (hprevcursor != NULL &&
      GetCursor () == hprevcursor)
    {
      /* Look for a suitable cursor to use instead */
      hcursor = NULL;
      parent_window = GDK_WINDOW (window)->parent;

      while (hcursor == NULL)
        {
          if (parent_window)
            {
              impl = GDK_WINDOW_IMPL_WIN32 (parent_window->impl);
              hcursor = impl->hcursor;
              parent_window = parent_window->parent;
            }
          else
            hcursor = LoadCursor (NULL, IDC_ARROW);
        }

      SetCursor (hcursor);
    }
}

static void
gdk_device_virtual_warp (GdkDevice *device,
			 GdkScreen *screen,
			 gdouble   x,
			 gdouble   y)
{
  SetCursorPos (x - _gdk_offset_x, y - _gdk_offset_y);
}

static void
gdk_device_virtual_query_state (GdkDevice        *device,
				GdkWindow        *window,
				GdkWindow       **root_window,
				GdkWindow       **child_window,
				gdouble          *root_x,
				gdouble          *root_y,
				gdouble          *win_x,
				gdouble          *win_y,
				GdkModifierType  *mask)
{
  GdkDeviceVirtual *virtual = GDK_DEVICE_VIRTUAL (device);

  _gdk_device_query_state (virtual->active_device,
			   window, root_window, child_window,
			   root_x, root_y,
			   win_x, win_y,
			   mask);
}

static GdkGrabStatus
gdk_device_virtual_grab (GdkDevice    *device,
			 GdkWindow    *window,
			 gboolean      owner_events,
			 GdkEventMask  event_mask,
			 GdkWindow    *confine_to,
			 GdkCursor    *cursor,
			 guint32       time_)
{
  GdkWindowImplWin32 *impl = GDK_WINDOW_IMPL_WIN32 (window->impl);
  HCURSOR hcursor;
  GdkWin32Cursor *cursor_private;

  cursor_private = (GdkWin32Cursor*) cursor;

  if (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD)
    {
      if (!cursor)
	hcursor = NULL;
      else if ((hcursor = CopyCursor (cursor_private->hcursor)) == NULL)
	WIN32_API_FAILED ("CopyCursor");

      if (_gdk_win32_grab_cursor != NULL)
	{
	  if (GetCursor () == _gdk_win32_grab_cursor)
	    SetCursor (NULL);
	  DestroyCursor (_gdk_win32_grab_cursor);
	}

      _gdk_win32_grab_cursor = hcursor;

      if (_gdk_win32_grab_cursor != NULL)
	SetCursor (_gdk_win32_grab_cursor);
      else if (impl->hcursor != NULL)
	SetCursor (impl->hcursor);
      else
	SetCursor (LoadCursor (NULL, IDC_ARROW));

      SetCapture (GDK_WINDOW_HWND (window));
    }

  return GDK_GRAB_SUCCESS;
}

static void
gdk_device_virtual_ungrab (GdkDevice *device,
                         guint32    time_)
{
  GdkDeviceGrabInfo *info;
  GdkDisplay *display;

  display = gdk_device_get_display (device);
  info = _gdk_display_get_last_device_grab (display, device);

  if (info)
    info->serial_end = 0;

  if (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD)
    {
      if (_gdk_win32_grab_cursor != NULL)
	{
	  if (GetCursor () == _gdk_win32_grab_cursor)
	    SetCursor (NULL);
	  DestroyCursor (_gdk_win32_grab_cursor);
	}
      _gdk_win32_grab_cursor = NULL;

      ReleaseCapture ();
    }

  _gdk_display_device_grab_update (display, device, device, 0);
}

static void
screen_to_client (HWND hwnd, POINT screen_pt, POINT *client_pt)
{
  *client_pt = screen_pt;
  ScreenToClient (hwnd, client_pt);
}

static GdkWindow *
gdk_device_virtual_window_at_position (GdkDevice       *device,
				       gdouble         *win_x,
				       gdouble         *win_y,
				       GdkModifierType *mask,
				       gboolean         get_toplevel)
{
  GdkWindow *window = NULL;
  POINT screen_pt, client_pt;
  HWND hwnd, hwndc;
  RECT rect;

  GetCursorPos (&screen_pt);

  if (get_toplevel)
    {
      /* Only consider visible children of the desktop to avoid the various
       * non-visible windows you often find on a running Windows box. These
       * might overlap our windows and cause our walk to fail. As we assume
       * WindowFromPoint() can find our windows, we follow similar logic
       * here, and ignore invisible and disabled windows.
       */
      hwnd = GetDesktopWindow ();
      do {
        window = gdk_win32_handle_table_lookup (hwnd);

        if (window != NULL &&
            GDK_WINDOW_TYPE (window) != GDK_WINDOW_ROOT &&
            GDK_WINDOW_TYPE (window) != GDK_WINDOW_FOREIGN)
          break;

        screen_to_client (hwnd, screen_pt, &client_pt);
        hwndc = ChildWindowFromPointEx (hwnd, client_pt, CWP_SKIPDISABLED  |
                                                         CWP_SKIPINVISIBLE);

	/* Verify that we're really inside the client area of the window */
	if (hwndc != hwnd)
	  {
	    GetClientRect (hwndc, &rect);
	    screen_to_client (hwndc, screen_pt, &client_pt);
	    if (!PtInRect (&rect, client_pt))
	      hwndc = hwnd;
	  }

      } while (hwndc != hwnd && (hwnd = hwndc, 1));

    }
  else
    {
      hwnd = WindowFromPoint (screen_pt);

      /* Verify that we're really inside the client area of the window */
      GetClientRect (hwnd, &rect);
      screen_to_client (hwnd, screen_pt, &client_pt);
      if (!PtInRect (&rect, client_pt))
	hwnd = NULL;

      /* If we didn't hit any window at that point, return the desktop */
      if (hwnd == NULL)
        {
          if (win_x)
            *win_x = screen_pt.x + _gdk_offset_x;
          if (win_y)
            *win_y = screen_pt.y + _gdk_offset_y;
          return _gdk_root;
        }

      window = gdk_win32_handle_table_lookup (hwnd);
    }

  if (window && (win_x || win_y))
    {
      if (win_x)
        *win_x = client_pt.x;
      if (win_y)
        *win_y = client_pt.y;
    }

  return window;
}

static void
gdk_device_virtual_select_window_events (GdkDevice    *device,
					 GdkWindow    *window,
					 GdkEventMask  event_mask)
{
}