<?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\Output;

use Symfony\Component\Console\Exception\InvalidArgumentException;
use Symfony\Component\Console\Formatter\OutputFormatterInterface;

/**
 * StreamOutput writes the output to a given stream.
 *
 * Usage:
 *
 *     $output = new StreamOutput(fopen('php://stdout', 'w'));
 *
 * As `StreamOutput` can use any stream, you can also use a file:
 *
 *     $output = new StreamOutput(fopen('/path/to/output.log', 'a', false));
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class StreamOutput extends Output
{
    private $stream;

    /**
     * @param resource                      $stream    A stream resource
     * @param int                           $verbosity The verbosity level (one of the VERBOSITY constants in OutputInterface)
     * @param bool|null                     $decorated Whether to decorate messages (null for auto-guessing)
     * @param OutputFormatterInterface|null $formatter Output formatter instance (null to use default OutputFormatter)
     *
     * @throws InvalidArgumentException When first argument is not a real stream
     */
    public function __construct($stream, int $verbosity = self::VERBOSITY_NORMAL, bool $decorated = null, OutputFormatterInterface $formatter = null)
    {
        if (!\is_resource($stream) || 'stream' !== get_resource_type($stream)) {
            throw new InvalidArgumentException('The StreamOutput class needs a stream as its first argument.');
        }

        $this->stream = $stream;

        if (null === $decorated) {
            $decorated = $this->hasColorSupport();
        }

        parent::__construct($verbosity, $decorated, $formatter);
    }

    /**
     * Gets the stream attached to this StreamOutput instance.
     *
     * @return resource A stream resource
     */
    public function getStream()
    {
        return $this->stream;
    }

    /**
     * {@inheritdoc}
     */
    protected function doWrite(string $message, bool $newline)
    {
        if ($newline) {
            $message .= \PHP_EOL;
        }

        @fwrite($this->stream, $message);

        fflush($this->stream);
    }

    /**
     * Returns true if the stream supports colorization.
     *
     * Colorization is disabled if not supported by the stream:
     *
     * This is tricky on Windows, because Cygwin, Msys2 etc emulate pseudo
     * terminals via named pipes, so we can only check the environment.
     *
     * Reference: Composer\XdebugHandler\Process::supportsColor
     * https://github.com/composer/xdebug-handler
     *
     * @return bool true if the stream supports colorization, false otherwise
     */
    protected function hasColorSupport()
    {
        // Follow https://no-color.org/
        if (isset($_SERVER['NO_COLOR']) || false !== getenv('NO_COLOR')) {
            return false;
        }

        if ('Hyper' === getenv('TERM_PROGRAM')) {
            return true;
        }

        if (\DIRECTORY_SEPARATOR === '\\') {
            return (\function_exists('sapi_windows_vt100_support')
                && @sapi_windows_vt100_support($this->stream))
                || false !== getenv('ANSICON')
                || 'ON' === getenv('ConEmuANSI')
                || 'xterm' === getenv('TERM');
        }

        return stream_isatty($this->stream);
    }
}
