/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

#include "uv.h"

#include "internal.h"

static int uv__dlerror(uv_lib_t* lib, const char* filename, DWORD errorno);

int uv_dlopen(const char* filename, uv_lib_t* lib) {

  WCHAR filename_w[32768];

  lib->handle = NULL;

  lib->errmsg = NULL;

  if (!MultiByteToWideChar(CP_UTF8,

                           0,

                           filename,

                           -1,

                           filename_w,

                           ARRAY_SIZE(filename_w))) {

    return uv__dlerror(lib, filename, GetLastError());

  }

  lib->handle = LoadLibraryExW(filename_w, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);

  if (lib->handle == NULL) {

    return uv__dlerror(lib, filename, GetLastError());

  }

  return 0;

}

void uv_dlclose(uv_lib_t* lib) {

  if (lib->errmsg) {

    LocalFree((void*)lib->errmsg);

    lib->errmsg = NULL;

  }

  if (lib->handle) {

    /* Ignore errors. No good way to signal them without leaking memory. */

    FreeLibrary(lib->handle);

    lib->handle = NULL;

  }

}

int uv_dlsym(uv_lib_t* lib, const char* name, void** ptr) {

  /* Cast though integer to suppress pedantic warning about forbidden cast. */

  *ptr = (void*)(uintptr_t) GetProcAddress(lib->handle, name);

  return uv__dlerror(lib, "", *ptr ? 0 : GetLastError());

}

const char* uv_dlerror(const uv_lib_t* lib) {

  return lib->errmsg ? lib->errmsg : "no error";

}

static void uv__format_fallback_error(uv_lib_t* lib, int errorno){

  static const CHAR fallback_error[] = "error: %1!d!";

  DWORD_PTR args[1];

  args[0] = (DWORD_PTR) errorno;

  FormatMessageA(FORMAT_MESSAGE_FROM_STRING |

                 FORMAT_MESSAGE_ARGUMENT_ARRAY |

                 FORMAT_MESSAGE_ALLOCATE_BUFFER,

                 fallback_error, 0, 0,

                 (LPSTR) &lib->errmsg,

                 0, (va_list*) args);

}

static int uv__dlerror(uv_lib_t* lib, const char* filename, DWORD errorno) {

  DWORD_PTR arg;

  DWORD res;

  char* msg;

  if (lib->errmsg) {

    LocalFree(lib->errmsg);

    lib->errmsg = NULL;

  }

  if (errorno == 0)

    return 0;

  res = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |

                       FORMAT_MESSAGE_FROM_SYSTEM |

                       FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorno,

                       MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),

                       (LPSTR) &lib->errmsg, 0, NULL);

  if (!res && (GetLastError() == ERROR_MUI_FILE_NOT_FOUND ||

               GetLastError() == ERROR_RESOURCE_TYPE_NOT_FOUND)) {

    res = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |

                         FORMAT_MESSAGE_FROM_SYSTEM |

                         FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorno,

                         0, (LPSTR) &lib->errmsg, 0, NULL);

  }

  if (res && errorno == ERROR_BAD_EXE_FORMAT && strstr(lib->errmsg, "%1")) {

    msg = lib->errmsg;

    lib->errmsg = NULL;

    arg = (DWORD_PTR) filename;

    res = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |

                         FORMAT_MESSAGE_ARGUMENT_ARRAY |

                         FORMAT_MESSAGE_FROM_STRING,

                         msg,

                         0, 0, (LPSTR) &lib->errmsg, 0, (va_list*) &arg;;

    LocalFree(msg);

  }

  if (!res)

    uv__format_fallback_error(lib, errorno);

  return -1;

}