/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include "common.h"

#include "error.h"

#include "utf-conv.h"

#ifdef GIT_WINHTTP

# include <winhttp.h>

#endif

char *git_win32_get_error_message(DWORD error_code)

{

	LPWSTR lpMsgBuf = NULL;

	HMODULE hModule = NULL;

	char *utf8_msg = NULL;

	DWORD dwFlags =

		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS;

	if (!error_code)

		return NULL;

#ifdef GIT_WINHTTP

	/* Errors raised by WinHTTP are not in the system resource table */

	if (error_code >= WINHTTP_ERROR_BASE &&

		error_code <= WINHTTP_ERROR_LAST)

		hModule = GetModuleHandleW(L"winhttp");

#endif

	GIT_UNUSED(hModule);

	if (hModule)

		dwFlags |= FORMAT_MESSAGE_FROM_HMODULE;

	else

		dwFlags |= FORMAT_MESSAGE_FROM_SYSTEM;

	if (FormatMessageW(dwFlags, hModule, error_code,

		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

		(LPWSTR)&lpMsgBuf, 0, NULL)) {

		/* Convert the message to UTF-8. If this fails, we will

		 * return NULL, which is a condition expected by the caller */

		if (git__utf16_to_8_alloc(&utf8_msg, lpMsgBuf) < 0)

			utf8_msg = NULL;

		LocalFree(lpMsgBuf);

	}

	return utf8_msg;

}