<?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\Helper;

use Symfony\Component\Console\Output\OutputInterface;

/**

 * The Dialog class provides helpers to interact with the user.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 */

class DialogHelper extends Helper

{

    private $inputStream;

    /**

     * Asks a question to the user.

     *

     * @param OutputInterface $output

     * @param string|array    $question The question to ask

     * @param string          $default  The default answer if none is given by the user

     *

     * @return string The user answer

     */

    public function ask(OutputInterface $output, $question, $default = null)

    {

        $output->write($question);

        $ret = fgets($this->inputStream ?: STDIN, 4096);

        if (false === $ret) {

            throw new \RuntimeException('Aborted');

        }

        $ret = trim($ret);

        return strlen($ret) > 0 ? $ret : $default;

    }

    /**

     * Asks a confirmation to the user.

     *

     * The question will be asked until the user answer by nothing, yes, or no.

     *

     * @param OutputInterface $output

     * @param string|array    $question The question to ask

     * @param Boolean         $default  The default answer if the user enters nothing

     *

     * @return Boolean true if the user has confirmed, false otherwise

     */

    public function askConfirmation(OutputInterface $output, $question, $default = true)

    {

        $answer = 'z';

        while ($answer && !in_array(strtolower($answer[0]), array('y', 'n'))) {

            $answer = $this->ask($output, $question);

        }

        if (false === $default) {

            return $answer && 'y' == strtolower($answer[0]);

        }

        return !$answer || 'y' == strtolower($answer[0]);

    }

    /**

     * Asks for a value and validates the response.

     *

     * The validator receives the data to validate. It must return the

     * validated data when the data is valid and throw an exception

     * otherwise.

     *

     * @param OutputInterface $output

     * @param string|array    $question

     * @param callback        $validator A PHP callback

     * @param integer         $attempts Max number of times to ask before giving up (false by default, which means infinite)

     * @param string          $default  The default answer if none is given by the user

     *

     * @return mixed

     *

     * @throws \Exception When any of the validator returns an error

     */

    public function askAndValidate(OutputInterface $output, $question, $validator, $attempts = false, $default = null)

    {

        $error = null;

        while (false === $attempts || $attempts--) {

            if (null !== $error) {

                $output->writeln($this->getHelperSet()->get('formatter')->formatBlock($error->getMessage(), 'error'));

            }

            $value = $this->ask($output, $question, $default);

            try {

                return call_user_func($validator, $value);

            } catch (\Exception $error) {

            }

        }

        throw $error;

    }

    /**

     * Sets the input stream to read from when interacting with the user.

     *

     * This is mainly useful for testing purpose.

     *

     * @param resource $stream The input stream

     */

    public function setInputStream($stream)

    {

        $this->inputStream = $stream;

    }

    /**

     * Returns the helper's canonical name

     */

    public function getName()

    {

        return 'dialog';

    }

}