<?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_Tool
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/**
 * @namespace
 */
namespace Zend\Tool\Project\Context;

use Zend\Tool\Project\Context;

/**
 * @uses       Countable
 * @uses       DirectoryIterator
 * @uses       ReflectionClass
 * @uses       \Zend\Loader
 * @uses       \Zend\Tool\Project\Context\Exception
 * @uses       \Zend\Tool\Project\Context\System
 * @uses       \Zend\Tool\Project\Context\System\NotOverwritable
 * @uses       \Zend\Tool\Project\Context\System\TopLevelRestrictable
 * @category   Zend
 * @package    Zend_Tool
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Repository implements \Countable
{

    protected static $_instance = null;
    protected static $_isInitialized = false;

    protected $_shortContextNames = array();
    protected $_contexts          = array();

    /**
     * Enter description here...
     *
     * @return \Zend\Tool\Project\Context\Repository
     */
    public static function getInstance()
    {
        if (self::$_instance == null) {
            self::$_instance = new self();
        }

        return self::$_instance;
    }

    public static function resetInstance()
    {
        self::$_instance = null;
        self::$_isInitialized = false;
    }

    protected function __construct()
    {
        if (self::$_isInitialized == false) {
            $this->addContextClass('Zend\Tool\Project\Context\System\ProjectDirectory')
                 ->addContextClass('Zend\Tool\Project\Context\System\ProjectProfileFile')
                 ->addContextClass('Zend\Tool\Project\Context\System\ProjectProvidersDirectory');
            self::$_isInitialized = true;
        }
    }

    public function addContextsFromDirectory($directory, $prefix)
    {
        $prefix = trim($prefix, '\\') . '\\';
        foreach (new \DirectoryIterator($directory) as $directoryItem) {
            if ($directoryItem->isDot() || (substr($directoryItem->getFilename(), -4) !== '.php')) {
                continue;
            }
            $class = $prefix . substr($directoryItem->getFilename(), 0, -4);
            $this->addContextClass($class);
        }
    }


    public function addContextClass($contextClass)
    {
        if (!class_exists($contextClass)) {
            \Zend\Loader::loadClass($contextClass);
        }
        $reflectionContextClass = new \ReflectionClass($contextClass);
        if ($reflectionContextClass->isInstantiable()) {
            $context = new $contextClass();
            return $this->addContext($context);
        }
        return $this;
    }

    /**
     * Enter description here...
     *
     * @param \Zend\Tool\Project\Context $context
     * @return \Zend\Tool\Project\Context\Repository
     */
    public function addContext(Context\Context $context)
    {
        $isSystem       = ($context instanceof System);
        $isTopLevel     = ($context instanceof System\TopLevelRestrictable);
        $isOverwritable = !($context instanceof System\NotOverwritable);

        $index = (count($this->_contexts)) ? max(array_keys($this->_contexts)) + 1 : 1;

        $normalName = $this->_normalizeName($context->getName());

        if (isset($this->_shortContextNames[$normalName]) && ($this->_contexts[$this->_shortContextNames[$normalName]]['isOverwritable'] === false) ) {
            throw new Exception\InvalidArgumentException('Context ' . $context->getName() . ' is not overwriteable.');
        }

        $this->_shortContextNames[$normalName] = $index;
        $this->_contexts[$index] = array(
            'isTopLevel'     => $isTopLevel,
            'isSystem'       => $isSystem,
            'isOverwritable' => $isOverwritable,
            'normalName'     => $normalName,
            'context'        => $context
            );

        return $this;
    }

    public function getContext($name)
    {
        if (!$this->hasContext($name)) {
            throw new Exception\InvalidArgumentException('Context by name ' . $name . ' does not exist in the registry.');
        }

        $name = $this->_normalizeName($name);
        return clone $this->_contexts[$this->_shortContextNames[$name]]['context'];
    }

    public function hasContext($name)
    {
        $name = $this->_normalizeName($name);
        return (isset($this->_shortContextNames[$name]) ? true : false);
    }

    public function isSystemContext($name)
    {
        if (!$this->hasContext($name)) {
            return false;
        }

        $name = $this->_normalizeName($name);
        $index = $this->_shortContextNames[$name];
        return $this->_contexts[$index]['isSystemContext'];
    }

    public function isTopLevelContext($name)
    {
        if (!$this->hasContext($name)) {
            return false;
        }
        $name = $this->_normalizeName($name);
        $index = $this->_shortContextNames[$name];
        return $this->_contexts[$index]['isTopLevel'];
    }

    public function isOverwritableContext($name)
    {
        if (!$this->hasContext($name)) {
            return false;
        }
        $name = $this->_normalizeName($name);
        $index = $this->_shortContextNames[$name];
        return $this->_contexts[$index]['isOverwritable'];
    }

    public function count()
    {
        return count($this->_contexts);
    }

    protected function _normalizeName($name)
    {
        return strtolower($name);
    }

}