/*
 * "ex" API implementation
 * http://lua-users.org/wiki/ExtensionProposal
 * Copyright 2007 Mark Edgar < medgar at gmail com >
 */
#include <stdio.h> /* sprintf() */
#include <ctype.h>
#define WIN32_LEAN_AND_MEAN 1
#define NOGDI 1
#include <windows.h>

#include "pusherror.h"

/* Push nil, followed by the Windows error message corresponding to
 * the error number, or a string giving the error value in decimal if
 * no error message is found.  If nresults is -2, always push nil and
 * the error message and return 2 even if error is NO_ERROR.  If
 * nresults is -1 and error is NO_ERROR, then push true and return 1.
 * Otherwise, if error is NO_ERROR, return nresults.
 */
int windows_pusherror(lua_State *L, DWORD error, int nresults)
{
  if (error != NO_ERROR || nresults == -2) {
    char buffer[1024];
    size_t len = sprintf(buffer, "%lu (0x%lX): ", error, error);
    size_t res = FormatMessage(
      FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
      0, error, 0, buffer + len, sizeof buffer - len, 0);
    if (res) {
      len += res;
      while (len > 0 && isspace(buffer[len - 1]))
        len--;
    }
    else {
      len += sprintf(buffer + len, "<error string not available>");
    }
    lua_pushnil(L);
    lua_pushlstring(L, buffer, len);
    nresults = 2;
  }
  else if (nresults < 0) {
    lua_pushboolean(L, 1);
    nresults = 1;
  }
  return nresults;
}