/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 2016 - 2021, Steve Holme, <steve_holme@hotmail.com>.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#if defined(WIN32)

#include <curl/curl.h>
#include "version_win32.h"
#include "warnless.h"

/* The last #include files should be: */
#include "curl_memory.h"
#include "memdebug.h"

/* This Unicode version struct works for VerifyVersionInfoW (OSVERSIONINFOEXW)
   and RtlVerifyVersionInfo (RTLOSVERSIONINFOEXW) */
struct OUR_OSVERSIONINFOEXW {
  ULONG  dwOSVersionInfoSize;
  ULONG  dwMajorVersion;
  ULONG  dwMinorVersion;
  ULONG  dwBuildNumber;
  ULONG  dwPlatformId;
  WCHAR  szCSDVersion[128];
  USHORT wServicePackMajor;
  USHORT wServicePackMinor;
  USHORT wSuiteMask;
  UCHAR  wProductType;
  UCHAR  wReserved;
};

/*
 * curlx_verify_windows_version()
 *
 * This is used to verify if we are running on a specific windows version.
 *
 * Parameters:
 *
 * majorVersion [in] - The major version number.
 * minorVersion [in] - The minor version number.
 * platform     [in] - The optional platform identifier.
 * condition    [in] - The test condition used to specifier whether we are
 *                     checking a version less then, equal to or greater than
 *                     what is specified in the major and minor version
 *                     numbers.
 *
 * Returns TRUE if matched; otherwise FALSE.
 */
bool curlx_verify_windows_version(const unsigned int majorVersion,
                                  const unsigned int minorVersion,
                                  const PlatformIdentifier platform,
                                  const VersionCondition condition)
{
  bool matched = FALSE;

#if defined(CURL_WINDOWS_APP)
  /* We have no way to determine the Windows version from Windows apps,
     so let's assume we're running on the target Windows version. */
  const WORD fullVersion = MAKEWORD(minorVersion, majorVersion);
  const WORD targetVersion = (WORD)_WIN32_WINNT;

  switch(condition) {
  case VERSION_LESS_THAN:
    matched = targetVersion < fullVersion;
    break;

  case VERSION_LESS_THAN_EQUAL:
    matched = targetVersion <= fullVersion;
    break;

  case VERSION_EQUAL:
    matched = targetVersion == fullVersion;
    break;

  case VERSION_GREATER_THAN_EQUAL:
    matched = targetVersion >= fullVersion;
    break;

  case VERSION_GREATER_THAN:
    matched = targetVersion > fullVersion;
    break;
  }

  if(matched && (platform == PLATFORM_WINDOWS)) {
    /* we're always running on PLATFORM_WINNT */
    matched = FALSE;
  }
#elif !defined(_WIN32_WINNT) || !defined(_WIN32_WINNT_WIN2K) || \
    (_WIN32_WINNT < _WIN32_WINNT_WIN2K)
  OSVERSIONINFO osver;

  memset(&osver, 0, sizeof(osver));
  osver.dwOSVersionInfoSize = sizeof(osver);

  /* Find out Windows version */
  if(GetVersionEx(&osver)) {
    /* Verify the Operating System version number */
    switch(condition) {
    case VERSION_LESS_THAN:
      if(osver.dwMajorVersion < majorVersion ||
        (osver.dwMajorVersion == majorVersion &&
         osver.dwMinorVersion < minorVersion))
        matched = TRUE;
      break;

    case VERSION_LESS_THAN_EQUAL:
      if(osver.dwMajorVersion < majorVersion ||
        (osver.dwMajorVersion == majorVersion &&
         osver.dwMinorVersion <= minorVersion))
        matched = TRUE;
      break;

    case VERSION_EQUAL:
      if(osver.dwMajorVersion == majorVersion &&
         osver.dwMinorVersion == minorVersion)
        matched = TRUE;
      break;

    case VERSION_GREATER_THAN_EQUAL:
      if(osver.dwMajorVersion > majorVersion ||
        (osver.dwMajorVersion == majorVersion &&
         osver.dwMinorVersion >= minorVersion))
        matched = TRUE;
      break;

    case VERSION_GREATER_THAN:
      if(osver.dwMajorVersion > majorVersion ||
        (osver.dwMajorVersion == majorVersion &&
         osver.dwMinorVersion > minorVersion))
        matched = TRUE;
      break;
    }

    /* Verify the platform identifier (if necessary) */
    if(matched) {
      switch(platform) {
      case PLATFORM_WINDOWS:
        if(osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS)
          matched = FALSE;
        break;

      case PLATFORM_WINNT:
        if(osver.dwPlatformId != VER_PLATFORM_WIN32_NT)
          matched = FALSE;

      default: /* like platform == PLATFORM_DONT_CARE */
        break;
      }
    }
  }
#else
  ULONGLONG cm = 0;
  struct OUR_OSVERSIONINFOEXW osver;
  BYTE majorCondition;
  BYTE minorCondition;
  BYTE spMajorCondition;
  BYTE spMinorCondition;

  typedef LONG (APIENTRY *RTLVERIFYVERSIONINFO_FN)
    (struct OUR_OSVERSIONINFOEXW *, ULONG, ULONGLONG);
  static RTLVERIFYVERSIONINFO_FN pRtlVerifyVersionInfo;
  static bool onetime = true; /* safe because first call is during init */

  if(onetime) {
    pRtlVerifyVersionInfo = CURLX_FUNCTION_CAST(RTLVERIFYVERSIONINFO_FN,
      (GetProcAddress(GetModuleHandleA("ntdll"), "RtlVerifyVersionInfo")));
    onetime = false;
  }

  switch(condition) {
  case VERSION_LESS_THAN:
    majorCondition = VER_LESS;
    minorCondition = VER_LESS;
    spMajorCondition = VER_LESS_EQUAL;
    spMinorCondition = VER_LESS_EQUAL;
    break;

  case VERSION_LESS_THAN_EQUAL:
    majorCondition = VER_LESS_EQUAL;
    minorCondition = VER_LESS_EQUAL;
    spMajorCondition = VER_LESS_EQUAL;
    spMinorCondition = VER_LESS_EQUAL;
    break;

  case VERSION_EQUAL:
    majorCondition = VER_EQUAL;
    minorCondition = VER_EQUAL;
    spMajorCondition = VER_GREATER_EQUAL;
    spMinorCondition = VER_GREATER_EQUAL;
    break;

  case VERSION_GREATER_THAN_EQUAL:
    majorCondition = VER_GREATER_EQUAL;
    minorCondition = VER_GREATER_EQUAL;
    spMajorCondition = VER_GREATER_EQUAL;
    spMinorCondition = VER_GREATER_EQUAL;
    break;

  case VERSION_GREATER_THAN:
    majorCondition = VER_GREATER;
    minorCondition = VER_GREATER;
    spMajorCondition = VER_GREATER_EQUAL;
    spMinorCondition = VER_GREATER_EQUAL;
    break;

  default:
    return FALSE;
  }

  memset(&osver, 0, sizeof(osver));
  osver.dwOSVersionInfoSize = sizeof(osver);
  osver.dwMajorVersion = majorVersion;
  osver.dwMinorVersion = minorVersion;
  if(platform == PLATFORM_WINDOWS)
    osver.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS;
  else if(platform == PLATFORM_WINNT)
    osver.dwPlatformId = VER_PLATFORM_WIN32_NT;

  cm = VerSetConditionMask(cm, VER_MAJORVERSION, majorCondition);
  cm = VerSetConditionMask(cm, VER_MINORVERSION, minorCondition);
  cm = VerSetConditionMask(cm, VER_SERVICEPACKMAJOR, spMajorCondition);
  cm = VerSetConditionMask(cm, VER_SERVICEPACKMINOR, spMinorCondition);
  if(platform != PLATFORM_DONT_CARE)
    cm = VerSetConditionMask(cm, VER_PLATFORMID, VER_EQUAL);

  /* Later versions of Windows have version functions that may not return the
     real version of Windows unless the application is so manifested. We prefer
     the real version always, so we use the Rtl variant of the function when
     possible. Note though the function signatures have underlying fundamental
     types that are the same, the return values are different. */
  if(pRtlVerifyVersionInfo) {
    matched = !pRtlVerifyVersionInfo(&osver,
      (VER_MAJORVERSION | VER_MINORVERSION |
       VER_SERVICEPACKMAJOR | VER_SERVICEPACKMINOR),
      cm);
  }
  else {
    matched = !!VerifyVersionInfoW((OSVERSIONINFOEXW *)&osver,
      (VER_MAJORVERSION | VER_MINORVERSION |
       VER_SERVICEPACKMAJOR | VER_SERVICEPACKMINOR),
      cm);
  }
#endif

  return matched;
}

#endif /* WIN32 */