/*
  * This file is part of FFmpeg.
  *
  * FFmpeg 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 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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 FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef COMPAT_W32DLFCN_H
 #define COMPAT_W32DLFCN_H
 
 #ifdef _WIN32
 #include <windows.h>

 #include "config.h"

 #if (_WIN32_WINNT < 0x0602) || HAVE_WINRT

 #include "libavutil/wchar_filename.h"
 #endif
 /**
  * Safe function used to open dynamic libs. This attempts to improve program security
  * by removing the current directory from the dll search path. Only dll's found in the
  * executable or system directory are allowed to be loaded.
  * @param name  The dynamic lib name.
  * @return A handle to the opened lib.
  */
 static inline HMODULE win32_dlopen(const char *name)
 {
 #if _WIN32_WINNT < 0x0602
     // Need to check if KB2533623 is available
     if (!GetProcAddress(GetModuleHandleW(L"kernel32.dll"), "SetDefaultDllDirectories")) {
         HMODULE module = NULL;
         wchar_t *path = NULL, *name_w = NULL;
         DWORD pathlen;
         if (utf8towchar(name, &name_w))
             goto exit;
         path = (wchar_t *)av_mallocz_array(MAX_PATH, sizeof(wchar_t));
         // Try local directory first
         pathlen = GetModuleFileNameW(NULL, path, MAX_PATH);
         pathlen = wcsrchr(path, '\\') - path;
         if (pathlen == 0 || pathlen + wcslen(name_w) + 2 > MAX_PATH)
             goto exit;
         path[pathlen] = '\\';
         wcscpy(path + pathlen + 1, name_w);
         module = LoadLibraryExW(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
         if (module == NULL) {
             // Next try System32 directory
             pathlen = GetSystemDirectoryW(path, MAX_PATH);
             if (pathlen == 0 || pathlen + wcslen(name_w) + 2 > MAX_PATH)
                 goto exit;
             path[pathlen] = '\\';
             wcscpy(path + pathlen + 1, name_w);
             module = LoadLibraryExW(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
         }
 exit:
         av_free(path);
         av_free(name_w);
         return module;
     }
 #endif
 #ifndef LOAD_LIBRARY_SEARCH_APPLICATION_DIR
 #   define LOAD_LIBRARY_SEARCH_APPLICATION_DIR 0x00000200
 #endif
 #ifndef LOAD_LIBRARY_SEARCH_SYSTEM32
 #   define LOAD_LIBRARY_SEARCH_SYSTEM32        0x00000800
 #endif

 #if HAVE_WINRT
     wchar_t *name_w = NULL;
     int ret;
     if (utf8towchar(name, &name_w))
         return NULL;
     ret = LoadPackagedLibrary(name_w, 0);
     av_free(name_w);
     return ret;
 #else

     return LoadLibraryExA(name, NULL, LOAD_LIBRARY_SEARCH_APPLICATION_DIR | LOAD_LIBRARY_SEARCH_SYSTEM32);

 #endif

 }
 #define dlopen(name, flags) win32_dlopen(name)
 #define dlclose FreeLibrary
 #define dlsym GetProcAddress
 #else
 #include <dlfcn.h>
 #endif
 
 #endif /* COMPAT_W32DLFCN_H */