<?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\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>
   *
   * @api
   */
  class StreamOutput extends Output
  {
      private $stream;
  
      /**
       * Constructor.
       *
       * @param mixed                         $stream    A stream resource
       * @param integer                       $verbosity The verbosity level (one of the VERBOSITY constants in OutputInterface)
       * @param Boolean|null                  $decorated Whether to decorate messages (null for auto-guessing)
       * @param OutputFormatterInterface|null $formatter Output formatter instance (null to use default OutputFormatter)
       *
       * @throws \InvalidArgumentException When first argument is not a real stream
       *
       * @api
       */
      public function __construct($stream, $verbosity = self::VERBOSITY_NORMAL, $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($message, $newline)
      {
          if (false === @fwrite($this->stream, $message.($newline ? PHP_EOL : ''))) {
              // @codeCoverageIgnoreStart
              // should never happen
              throw new \RuntimeException('Unable to write output.');
              // @codeCoverageIgnoreEnd
          }
  
          fflush($this->stream);
      }
  
      /**
       * Returns true if the stream supports colorization.
       *
       * Colorization is disabled if not supported by the stream:
       *
       *  -  windows without ansicon and ConEmu
       *  -  non tty consoles
       *
       * @return Boolean true if the stream supports colorization, false otherwise
       */
      protected function hasColorSupport()
      {
          // @codeCoverageIgnoreStart
          if (DIRECTORY_SEPARATOR == '\\') {
              return false !== getenv('ANSICON') || 'ON' === getenv('ConEmuANSI');
          }
  
          return function_exists('posix_isatty') && @posix_isatty($this->stream);
          // @codeCoverageIgnoreEnd
      }
  }