<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Service_Console
 * @subpackage Exception
 * @version    $Id$
 * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @copyright  Copyright (c) 2009 - 2011, RealDolmen (http://www.realdolmen.com)
 * @license    http://phpazure.codeplex.com/license
 */

/**
* @see Zend_Service_Console_Command_ParameterSource_ParameterSourceInterface
*/
require_once 'Zend/Service/Console/Command/ParameterSource/ParameterSourceInterface.php';

/**
 * @category   Zend
 * @package    Zend_Service_Console
 * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @copyright  Copyright (c) 2009 - 2011, RealDolmen (http://www.realdolmen.com)
 * @license    http://phpazure.codeplex.com/license
 */
class Zend_Service_Console_Command_ParameterSource_Env
	implements Zend_Service_Console_Command_ParameterSource_ParameterSourceInterface
{
	/**
	 * Get value for a named parameter.
	 *
	 * @param mixed $parameter Parameter to get a value for
	 * @param array $argv Argument values passed to the script when run in console.
	 * @return array|bool|string|null
     */
	public function getValueForParameter($parameter, $argv = [])
	{
		// Default value
		$parameterValue = null;

		// Fetch value for parameter
		foreach ($parameter->aliases as $alias) {
			while (strpos($alias, '-') !== false) {
				$alias = substr($alias, 1);
			}
			$value = getenv($alias);

			if (!is_null($value) && $value !== false) {
				$parameterValue = $value;
				break;
			}
		}

		if (strtolower($parameterValue) == 'true') {
			$parameterValue = true;
		} else if (strtolower($parameterValue) == 'false') {
			$parameterValue = false;
		}

		// Done!
		return $parameterValue;
	}
}
