/*
 * Copyright (C) 2019 Hertz Wang 1989wanghang@163.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see http://www.gnu.org/licenses
 *
 * Any non-GPL usage of this software or parts of this software is strictly
 * forbidden.
 *
 */

#include <assert.h>
#include <fcntl.h>
#include <poll.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <termios.h>
#include <unistd.h>

static struct termios oldtty;
static int restore_tty = 0;
// termios.h
int read_key() {
  unsigned char ch;
  int n = 1;
  struct timeval tv;
  fd_set rfds;

  FD_ZERO(&rfds);
  FD_SET(0, &rfds);
  tv.tv_sec = 0;
  tv.tv_usec = 0;
  n = select(1, &rfds, NULL, NULL, &tv);
  if (n > 0) {
    n = read(0, &ch, 1);
    if (n == 1)
      return ch;

    return n;
  }
  return -1;
}

void term_init() {
  struct termios tty;
  if (tcgetattr(0, &tty) == 0) {
    oldtty = tty;
    restore_tty = 1;

    tty.c_iflag &=
        ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
    tty.c_oflag |= OPOST;
    tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
    tty.c_cflag &= ~(CSIZE | PARENB);
    tty.c_cflag |= CS8;
    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 0;
    tcsetattr(0, TCSANOW, &tty);
  }
}

void term_deinit() {
  if (restore_tty)
    tcsetattr(0, TCSANOW, &oldtty);
}