/**
 * Author......: Jens Steube <jens.steube@gmail.com>
 * License.....: MIT
 */

#include "common.h"
#include "terminal.h"

#if defined (__linux__)
static struct termios savemodes;
static int havemodes = 0;

int tty_break()
{
  struct termios modmodes;

  if (tcgetattr (fileno (stdin), &savemodes) < 0) return -1;

  havemodes = 1;

  modmodes = savemodes;
  modmodes.c_lflag &= ~ICANON;
  modmodes.c_cc[VMIN] = 1;
  modmodes.c_cc[VTIME] = 0;

  return tcsetattr (fileno (stdin), TCSANOW, &modmodes);
}

int tty_getchar()
{
  fd_set rfds;

  FD_ZERO (&rfds);

  FD_SET (fileno (stdin), &rfds);

  struct timeval tv;

  tv.tv_sec  = 1;
  tv.tv_usec = 0;

  int retval = select (1, &rfds, NULL, NULL, &tv);

  if (retval ==  0) return  0;
  if (retval == -1) return -1;

  return getchar();
}

int tty_fix()
{
  if (!havemodes) return 0;

  return tcsetattr (fileno (stdin), TCSADRAIN, &savemodes);
}
#endif

#if defined(__APPLE__) || defined(__FreeBSD__)
static struct termios savemodes;
static int havemodes = 0;

int tty_break()
{
  struct termios modmodes;

  if (ioctl (fileno (stdin), TIOCGETA, &savemodes) < 0) return -1;

  havemodes = 1;

  modmodes = savemodes;
  modmodes.c_lflag &= ~ICANON;
  modmodes.c_cc[VMIN] = 1;
  modmodes.c_cc[VTIME] = 0;

  return ioctl (fileno (stdin), TIOCSETAW, &modmodes);
}

int tty_getchar()
{
  fd_set rfds;

  FD_ZERO (&rfds);

  FD_SET (fileno (stdin), &rfds);

  struct timeval tv;

  tv.tv_sec  = 1;
  tv.tv_usec = 0;

  int retval = select (1, &rfds, NULL, NULL, &tv);

  if (retval ==  0) return  0;
  if (retval == -1) return -1;

  return getchar();
}

int tty_fix()
{
  if (!havemodes) return 0;

  return ioctl (fileno (stdin), TIOCSETAW, &savemodes);
}
#endif

#if defined (_WIN)
static DWORD saveMode = 0;

int tty_break()
{
  HANDLE stdinHandle = GetStdHandle (STD_INPUT_HANDLE);

  GetConsoleMode (stdinHandle, &saveMode);
  SetConsoleMode (stdinHandle, ENABLE_PROCESSED_INPUT);

  return 0;
}

int tty_getchar()
{
  HANDLE stdinHandle = GetStdHandle (STD_INPUT_HANDLE);

  DWORD rc = WaitForSingleObject (stdinHandle, 1000);

  if (rc == WAIT_TIMEOUT)   return  0;
  if (rc == WAIT_ABANDONED) return -1;
  if (rc == WAIT_FAILED)    return -1;

  // The whole ReadConsoleInput () part is a workaround.
  // For some unknown reason, maybe a mingw bug, a random signal
  // is sent to stdin which unblocks WaitForSingleObject () and sets rc 0.
  // Then it wants to read with getche () a keyboard input
  // which has never been made.

  INPUT_RECORD buf[100];

  DWORD num = 0;

  memset (buf, 0, sizeof (buf));

  ReadConsoleInput (stdinHandle, buf, 100, &num);

  FlushConsoleInputBuffer (stdinHandle);

  for (DWORD i = 0; i < num; i++)
  {
    if (buf[i].EventType != KEY_EVENT) continue;

    KEY_EVENT_RECORD KeyEvent = buf[i].Event.KeyEvent;

    if (KeyEvent.bKeyDown != TRUE) continue;

    return KeyEvent.uChar.AsciiChar;
  }

  return 0;
}

int tty_fix()
{
  HANDLE stdinHandle = GetStdHandle (STD_INPUT_HANDLE);

  SetConsoleMode (stdinHandle, saveMode);

  return 0;
}
#endif