<?php

/**
 * Ajax Handler
 * 
 * @author vesta, http://vestacp.com/
 * @author Dmitry Malishev <dima.malishev@gmail.com>
 * @author Dmitry Naumov-Socolov <naumov.socolov@gmail.com>
 * @copyright vesta 2010-2011
 */
class AjaxHandler {
    
    static public $instance = null;

    const JSON      = 'json';
    const TEXT	    = 'text';
    public $errors  = array();
    public $status  = TRUE;

    /**
     * Grab current instance or create it
     *
     * @return AjaxHandler
     */
    static function getInstance($request=null) 
    {
        return null == self::$instance ? self::$instance = new self() : self::$instance;
    }
    
    public function getLoggedUser()
    {
        return VestaSession::getInstance()->getUser();
    }

    /**
     * Called functions should reply in the following way
     * return $this->reply($result, $data, $msg, $extra);
     * 
     * @param Request $request
     * @return string 
     */
    public function dispatch(Request $request) 
    {
        VestaSession::start();
        
        $allowed_actions = array(
                                'MAIN.signin', 
                                'MAIN.logout', 
                                'MAIN.requestPassword',
                                'MAIN.resetPassword',
                                'MAIN.about');
        $method = Request::parseAjaxMethod($request);
        
        if (!in_array($method['namespace'].'.'.$method['function'], $allowed_actions)) {
            $user = $this->getLoggedUser();
        }

        $inc_file = V_ROOT_DIR . 'api' . DIRECTORY_SEPARATOR . $method['namespace'] . '.class.php';
        if (!is_readable($inc_file)) {
            throw new SystemException(Message::INVALID_METHOD);
        }
        require $inc_file;

        $space = new $method['namespace'];
        $method = $method['function'] . 'Execute';

        if (!method_exists($space, $method)) {
            throw new SystemException(Message::INVALID_METHOD);
        }

        return $space->$method($request);
    }

    /**
     * Prepare response for ajax
     */
    public function reply($result, $data, $message = '', $extra = array()) 
    {
        return json_encode(array('result' => $result,
                   'data' => $data,
                   'message' => $message,
                   'extra' => $extra,
                   'errors' => $this->errors
                   ));
    }

    static function makeReply($reply) 
    {
        print $reply;
    }

    //
    // Error handlers
    //
    
    static function generalError($error) 
    {
        self::renderGlobalError(Message::ERROR, Message::GENERAL_ERROR, $error);
    }

    static function protectionError($error) 
    {
        self::renderGlobalError(Message::ERROR, Message::PROTECTION_ERROR, $error);
    }

    static function systemError($error) 
    {
        self::renderGlobalError(Message::ERROR, Message::SYSTEM_ERROR, $error);
    }

    static function renderGlobalError($type, $message, $error) 
    {
        /*$trace = $error->getTrace();
        AjaxHandler::makeReply(
                        AjaxHandler::getInstance()->reply(false, $type, $message . ': ' . $error->getMessage(), $trace[0]['file'] . ' / ' . $trace[0]['line'])
        );*/
        print $message;
    }

}