/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
#define CAML_NAME_SPACE

#include <stdio.h>
#include <caml/mlvalues.h>
#include <caml/memory.h>
#include <caml/fail.h>

#ifdef _WIN32
#include <windows.h>

// In mingw environments this is not defined, and it is also likely not defined
// in older windows versions too.  If it's not defined in older windows
// versions, then SetConsoleMode will likely fail anyways.
#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#endif

#endif

CAMLprim value enable_windows_console_ansi_sequences()
{
  CAMLparam0();

#ifdef _WIN32
  int success = 0;

  HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
  DWORD dwMode = 0;
  // GetConsoleMode returns 6 "invalid handle" when running in cygwin build /
  // dev shell. You don't need to enable ansi sequences anyways in that case.
  // So if GetConsoleMode returns false, just give up.
  if (hOut != INVALID_HANDLE_VALUE && GetConsoleMode(hOut, &dwMode))
  {
    dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    success = SetConsoleMode(hOut, dwMode) ? 1 : 0;
    if (success != 1) {
      caml_failwith( "error in enable_windows_console_ansi_seqences");
    }
  }

#endif

  CAMLreturn(Val_unit);
}