/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 */

/** \file
 * \ingroup GHOST
 */

#include "GHOST_DisplayManagerWin32.h"
#include "GHOST_Debug.h"

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

// We do not support multiple monitors at the moment
#define COMPILE_MULTIMON_STUBS
#include <multimon.h>

GHOST_DisplayManagerWin32::GHOST_DisplayManagerWin32(void)
{
}

GHOST_TSuccess GHOST_DisplayManagerWin32::getNumDisplays(GHOST_TUns8 &numDisplays) const
{
  numDisplays = ::GetSystemMetrics(SM_CMONITORS);
  return numDisplays > 0 ? GHOST_kSuccess : GHOST_kFailure;
}

static BOOL get_dd(DWORD d, DISPLAY_DEVICE *dd)
{
  dd->cb = sizeof(DISPLAY_DEVICE);
  return ::EnumDisplayDevices(NULL, d, dd, 0);
}

/*
 * When you call EnumDisplaySettings with iModeNum set to zero, the operating system
 * initializes and caches information about the display device. When you call
 * EnumDisplaySettings with iModeNum set to a non-zero value, the function returns
 * the information that was cached the last time the function was called with iModeNum
 * set to zero.
 */
GHOST_TSuccess GHOST_DisplayManagerWin32::getNumDisplaySettings(GHOST_TUns8 display,
                                                                GHOST_TInt32 &numSettings) const
{
  DISPLAY_DEVICE display_device;
  if (!get_dd(display, &display_device))
    return GHOST_kFailure;

  numSettings = 0;
  DEVMODE dm;
  while (::EnumDisplaySettings(display_device.DeviceName, numSettings, &dm)) {
    numSettings++;
  }
  return GHOST_kSuccess;
}

GHOST_TSuccess GHOST_DisplayManagerWin32::getDisplaySetting(GHOST_TUns8 display,
                                                            GHOST_TInt32 index,
                                                            GHOST_DisplaySetting &setting) const
{
  DISPLAY_DEVICE display_device;
  if (!get_dd(display, &display_device))
    return GHOST_kFailure;

  GHOST_TSuccess success;
  DEVMODE dm;
  if (::EnumDisplaySettings(display_device.DeviceName, index, &dm)) {
#ifdef GHOST_DEBUG
    printf("display mode: width=%d, height=%d, bpp=%d, frequency=%d\n",
           dm.dmPelsWidth,
           dm.dmPelsHeight,
           dm.dmBitsPerPel,
           dm.dmDisplayFrequency);
#endif  // GHOST_DEBUG
    setting.xPixels = dm.dmPelsWidth;
    setting.yPixels = dm.dmPelsHeight;
    setting.bpp = dm.dmBitsPerPel;
    /* When you call the EnumDisplaySettings function, the dmDisplayFrequency member
     * may return with the value 0 or 1. These values represent the display hardware's
     * default refresh rate. This default rate is typically set by switches on a display
     * card or computer motherboard, or by a configuration program that does not use
     * Win32 display functions such as ChangeDisplaySettings.
     */
    /* First, we tried to explicitly set the frequency to 60 if EnumDisplaySettings
     * returned 0 or 1 but this doesn't work since later on an exact match will
     * be searched. And this will never happen if we change it to 60. Now we rely
     * on the default h/w setting.
     */
    setting.frequency = dm.dmDisplayFrequency;
    success = GHOST_kSuccess;
  }
  else {
    success = GHOST_kFailure;
  }
  return success;
}

GHOST_TSuccess GHOST_DisplayManagerWin32::getCurrentDisplaySetting(
    GHOST_TUns8 display, GHOST_DisplaySetting &setting) const
{
  return getDisplaySetting(display, ENUM_CURRENT_SETTINGS, setting);
}

GHOST_TSuccess GHOST_DisplayManagerWin32::setCurrentDisplaySetting(
    GHOST_TUns8 display, const GHOST_DisplaySetting &setting)
{
  DISPLAY_DEVICE display_device;
  if (!get_dd(display, &display_device))
    return GHOST_kFailure;

  GHOST_DisplaySetting match;
  findMatch(display, setting, match);
  DEVMODE dm;
  int i = 0;
  while (::EnumDisplaySettings(display_device.DeviceName, i++, &dm)) {
    if ((dm.dmBitsPerPel == match.bpp) && (dm.dmPelsWidth == match.xPixels) &&
        (dm.dmPelsHeight == match.yPixels) && (dm.dmDisplayFrequency == match.frequency)) {
      break;
    }
  }
  /*
   * dm.dmBitsPerPel = match.bpp;
   * dm.dmPelsWidth = match.xPixels;
   * dm.dmPelsHeight = match.yPixels;
   * dm.dmDisplayFrequency = match.frequency;
   * dm.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT | DM_DISPLAYFREQUENCY;
   * dm.dmSize = sizeof(DEVMODE);
   * dm.dmDriverExtra = 0;
   */
#ifdef GHOST_DEBUG
  printf("display change: Requested settings:\n");
  printf("  dmBitsPerPel=%d\n", dm.dmBitsPerPel);
  printf("  dmPelsWidth=%d\n", dm.dmPelsWidth);
  printf("  dmPelsHeight=%d\n", dm.dmPelsHeight);
  printf("  dmDisplayFrequency=%d\n", dm.dmDisplayFrequency);
#endif  // GHOST_DEBUG

  LONG status = ::ChangeDisplaySettings(&dm, CDS_FULLSCREEN);
#ifdef GHOST_DEBUG
  switch (status) {
    case DISP_CHANGE_SUCCESSFUL:
      printf("display change: The settings change was successful.\n");
      break;
    case DISP_CHANGE_RESTART:
      printf(
          "display change: The computer must be restarted in order for the graphics mode to "
          "work.\n");
      break;
    case DISP_CHANGE_BADFLAGS:
      printf("display change: An invalid set of flags was passed in.\n");
      break;
    case DISP_CHANGE_BADPARAM:
      printf(
          "display change: An invalid parameter was passed in. "
          "This can include an invalid flag or combination of flags.\n");
      break;
    case DISP_CHANGE_FAILED:
      printf("display change: The display driver failed the specified graphics mode.\n");
      break;
    case DISP_CHANGE_BADMODE:
      printf("display change: The graphics mode is not supported.\n");
      break;
    case DISP_CHANGE_NOTUPDATED:
      printf("display change: Windows NT: Unable to write settings to the registry.\n");
      break;
    default:
      printf("display change: Return value invalid\n");
      break;
  }
#endif  // GHOST_DEBUG
  return status == DISP_CHANGE_SUCCESSFUL ? GHOST_kSuccess : GHOST_kFailure;
}
