/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/safemacros.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/termios.h"
#include "libc/fmt/conv.h"
#include "libc/log/log.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/consts/termios.h"

/**
 * Returns dimensions of controlling terminal.
 *
 * It is recommended that programs err on the side of showing more
 * information, if this value can't be obtained with certainty.
 *
 * @param out stores determined dimensions, only on success
 * @returns -1 on error or something else on success
 */
int getttysize(int fd, struct winsize *out) {
  if (IsTerminalInarticulate()) {
    out->ws_col = strtoimax(firstnonnull(getenv("COLUMNS"), "80"), NULL, 0);
    out->ws_row = strtoimax(firstnonnull(getenv("ROWS"), "40"), NULL, 0);
    out->ws_xpixel = 0;
    out->ws_ypixel = 0;
    return 0;
  } else {
    return ioctl(fd, TIOCGWINSZ, out);
  }
}
