<?php

/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/

namespace Symfony\Component\Console;

class Terminal
{
private static $width;
private static $height;
private static $stty;

/**
* Gets the terminal width.
*
* @return int
*/
public function getWidth()
{
$width = getenv('COLUMNS');
if (false !== $width) {
return (int) trim($width);
}

if (null === self::$width) {
self::initDimensions();
}

return self::$width ?: 80;
}

/**
* Gets the terminal height.
*
* @return int
*/
public function getHeight()
{
$height = getenv('LINES');
if (false !== $height) {
return (int) trim($height);
}

if (null === self::$height) {
self::initDimensions();
}

return self::$height ?: 50;
}

/**
* @internal
*
* @return bool
*/
public static function hasSttyAvailable()
{
if (null !== self::$stty) {
return self::$stty;
}

// skip check if exec function is disabled
if (!\function_exists('exec')) {
return false;
}

exec('stty 2>&1', $output, $exitcode);

return self::$stty = 0 === $exitcode;
}

private static function initDimensions()
{
if ('\\' === \DIRECTORY_SEPARATOR) {
if (preg_match('/^(\d+)x(\d+)(?: \((\d+)x(\d+)\))?$/', trim(getenv('ANSICON')), $matches)) {
// extract [w, H] from "wxh (WxH)"
// or [w, h] from "wxh"
self::$width = (int) $matches[1];
self::$height = isset($matches[4]) ? (int) $matches[4] : (int) $matches[2];
} elseif (!self::hasVt100Support() && self::hasSttyAvailable()) {
// only use stty on Windows if the terminal does not support vt100 (e.g. Windows 7 + git-bash)
// testing for stty in a Windows 10 vt100-enabled console will implicitly disable vt100 support on STDOUT
self::initDimensionsUsingStty();
} elseif (null !== $dimensions = self::getConsoleMode()) {
// extract [w, h] from "wxh"
self::$width = (int) $dimensions[0];
self::$height = (int) $dimensions[1];
}
} else {
self::initDimensionsUsingStty();
}
}

/**
* Returns whether STDOUT has vt100 support (some Windows 10+ configurations).
*/
private static function hasVt100Support(): bool
{
return \function_exists('sapi_windows_vt100_support') && sapi_windows_vt100_support(fopen('php://stdout', 'w'));
}

/**
* Initializes dimensions using the output of an stty columns line.
*/
private static function initDimensionsUsingStty()
{
if ($sttyString = self::getSttyColumns()) {
if (preg_match('/rows.(\d+);.columns.(\d+);/i', $sttyString, $matches)) {
// extract [w, h] from "rows h; columns w;"
self::$width = (int) $matches[2];
self::$height = (int) $matches[1];
} elseif (preg_match('/;.(\d+).rows;.(\d+).columns/i', $sttyString, $matches)) {
// extract [w, h] from "; h rows; w columns"
self::$width = (int) $matches[2];
self::$height = (int) $matches[1];
}
}
}

/**
* Runs and parses mode CON if it's available, suppressing any error output.
*
* @return int[]|null An array composed of the width and the height or null if it could not be parsed
*/
private static function getConsoleMode(): ?array
{
$info = self::readFromProcess('mode CON');

if (null === $info || !preg_match('/--------+\r?\n.+?(\d+)\r?\n.+?(\d+)\r?\n/', $info, $matches)) {
return null;
}

return [(int) $matches[2], (int) $matches[1]];
}

/**
* Runs and parses stty -a if it's available, suppressing any error output.
*/
private static function getSttyColumns(): ?string
{
return self::readFromProcess('stty -a | grep columns');
}

private static function readFromProcess(string $command): ?string
{
if (!\function_exists('proc_open')) {
return null;
}

$descriptorspec = [
1 => ['pipe', 'w'],
2 => ['pipe', 'w'],
];

$process = proc_open($command, $descriptorspec, $pipes, null, null, ['suppress_errors' => true]);
if (!\is_resource($process)) {
return null;
}

$info = stream_get_contents($pipes[1]);
fclose($pipes[1]);
fclose($pipes[2]);
proc_close($process);

return $info;
}
}