#include <stdio.h>

#include <windows.h>

#include <windns.h>

#include "lua.h"

#include "lauxlib.h"

static int Lget_nameservers(lua_State *L) {

	char stack_buffer[1024]; // stack allocated buffer

	IP4_ARRAY* ips = (IP4_ARRAY*) stack_buffer;

	DWORD len = sizeof(stack_buffer);

	DNS_STATUS status;

	status = DnsQueryConfig(DnsConfigDnsServerList, FALSE, NULL, NULL, ips, &len);

	if (status == 0) {

		DWORD i;

		lua_createtable(L, ips->AddrCount, 0);

		for (i = 0; i < ips->AddrCount; i++) {

			DWORD ip = ips->AddrArray[i];

			char ip_str[16] = "";

			sprintf_s(ip_str, sizeof(ip_str), "%d.%d.%d.%d", (ip >> 0) & 255, (ip >> 8) & 255, (ip >> 16) & 255, (ip >> 24) & 255);

			lua_pushstring(L, ip_str);

			lua_rawseti(L, -2, i+1);

		}

		return 1;

	} else {

		luaL_error(L, "DnsQueryConfig returned %d", status);

		return 0; // unreachable, but prevents a compiler warning

	}

}

static const luaL_Reg Reg[] =

{

	{ "get_nameservers",	Lget_nameservers	},

	{ NULL,		NULL	}

};

LUALIB_API int luaopen_util_windows(lua_State *L) {

	luaL_register(L, "windows", Reg);

	lua_pushliteral(L, "version");			/** version */

	lua_pushliteral(L, "-3.14");

	lua_settable(L,-3);

	return 1;

}