<?php

/**
 * @author Sebastian Sauer <info@dynpages.de>
 * @copyright Sebastian Sauer 2009/2010
 * @license library/LICENSE New BSD License
 * @package auth
 * @version 1.9
 */

abstract class ExtZend_Auth_Abstract {

    protected $_request;

    /**
     * database table name
     * @var string
     */
    protected $_authTable = "";

    /**
     * database table userfield field name
     * @var string
     */
    protected $_userField = "";

    /**
     * database table password field name
     * @var string
     */
    protected $_passwordField = "";

    /**
     * database table password salt field name
     * @var string
     */
    protected $_passwordSaltField = "password_salt";

    /**
     * cache auth adapter object for child classes
     * @var object Zend_Auth_Adapter_DbTable
     */
    private $_authAdapter = null;

    const storageModuleAppendix = "AuthStorage";
    /**
     * login user
     */
    public function identify() {
        $request = $this->_request;
        $post = $request->getPost();
        $username = $this->_filterUsername($post['username']);
        $password = $post['password'];
        if(empty($username) || empty($password)) {
            return;
        }
        $this->_doAuth($username, $password);
    }

    abstract public function getRole();

    /**
     * @param object Zend_Controller_Request_Abstract $request
     */
    public function __construct(
        Zend_Controller_Request_Abstract $request
    ) {
        $this->_request = $request;
        $auth = Zend_Auth::getInstance();
        $module = (null === $request->getModuleName())
            ? 'default'
            : $request->getModuleName();
        $namespace = $module . self::storageModuleAppendix;
        $auth->setStorage(new Zend_Auth_Storage_Session($namespace));
    }

    /**
     * getter for auth adapter object
     *
     * @return object Zend_Auth_Adapter_DbTable
     *
     * Initialisiere Authentifizierungsadapter
     * gesaltet! bootstrapping beachten
     * Führe Authentifizierung durch
     */
    protected function _getAuthAdapter () {
        if(null === $this->_authAdapter) {
            $authAdapter = $this->_authAdapter = new Zend_Auth_Adapter_DbTable(
                Zend_Registry::get('Zend_Db'),
                $this->_authTable,
                $this->_userField,
                $this->_passwordField,
                "MD5(
                    CONCAT('"
                        . Zend_Registry::get('staticSalt')
                        . "', password_salt, ?
                    )
                )"
            );
        }
        return $this->_authAdapter;
    }

    /**
     * filters Username
     * @see Zend_Filter_Alnum
     * @param string $username
     */
    protected function _filterUsername ($username) {
        $filter = new Zend_Filter_Alnum(true);
        return $filter->filter($username);
    }

    public function logout() {
        Zend_Auth::getInstance()->clearIdentity();
        unset($_SESSION);
        // tweak the garbage collector
        $_SESSION = null;
    }

    /**
     * check if username / password combination exists in database
     * sets storage data if auth is valid
     * @return bool
     */
    protected function _doAuth($username, $password) {
        $authAdapter = $this->_getAuthAdapter();
        // Übergebe Daten an Adapter
        $authAdapter->setIdentity($username);
        $authAdapter->setCredential($password);
        $result = Zend_Auth::getInstance()->authenticate($authAdapter);
        if($result->isValid()) {
            $authData = $authAdapter->getResultRowObject();
            unset(
              $authData->{$this->_passwordField},
              $authData->{$this->_passwordSaltField}
            );
            Zend_Auth::getInstance()->getStorage()->write
            (
                $authData
            );
        }
        return $result->isValid();
    }
}