<?php
/**
 * CAPTCHA Tools
 *
 * @package Wombat
 */

/**
 * CAPTCHA Tools
 *
 * @version 0.2.0
 * @package Wombat
 */
class WBUte_Captcha extends WBStdClass
{
    /**
     * Current Authentication Status
     *
     * True: user is loged in
     * False: no user
     *
     * @var bool
     */
    private $auth;

    /**
     * Current Namespace
     *
     * @var string
     */
    private $namespace;

    /**
     * Table Access
     * @var WBDatasource_Table
     */
    private $table;

    /**
     * Session Object
     * @var patSession_Storage
     */
    private $sess;

    /**
     * Configuration for namespaces
     *
     * @var array
     */
    private $config;

    const NAMESPACE_GLOBAL      =   'global';

    const TABLE_CAPTCHAREQUEST  =   'captcharequest';

    /**
     * Standard Constructor
     *
     * Make sure all subclasses execute this constructor
     * @param array parameter
     */
    public function __construct($parameter = array())
    {
        $this->auth =   false;

        if (empty($parameter['table'])) {
            $parameter['table'] =   WBClass::create('WBDatasource_Table', $parameter);
        }
        $this->table    =   $parameter['table'];

        // set default namespace
        $this->namespace    =   self::NAMESPACE_GLOBAL;

        $config =   WBClass::create('WBConfig');
        $c  =   array();
        if ($config->load('captcha', true)) {
            $c  =   $config->get('mode/auto', array());
        }

        if (isset($c[self::NAMESPACE_GLOBAL])) {
            $c[self::NAMESPACE_GLOBAL]  =   array_merge(array('limit' => 10, 'timeout' => 600), $c[self::NAMESPACE_GLOBAL]);
        }

        $this->config   =   $c;
    }

    /**
     * Set Current Authentication Status
     *
     * @param bool
     * @return WBUte_Captcha
     */
    public function setAuth($auth = true)
    {
        $this->auth =   $auth;
        return $this;
    }

    /**
     * Set Current Namespace
     *
     * @param bool
     * @return WBUte_Captcha
     */
    public function setNamespace($namespace = null)
    {
        if (empty($namespace)) {
            $namespace  =   self::NAMESPACE_GLOBAL;
        }
        $this->namespace    =   $namespace;
        return $this;
    }

    /**
     * Add Request
     *
     * @return WBUte_Captcha
     */
    public function addRequest()
    {
        if (1 == rand(1, 1000)) {
            $this->flushOldRequests();
        }

        $save   =   array(
                        'created'       =>  date('Y-m-d H:i:s'),
                        'namespace'     =>  $this->namespace,
                        'authenticated' =>  intval($this->auth)
                    );

        $this->table->save(self::TABLE_CAPTCHAREQUEST, '__new', $save);
    }

    /**
     * Delete Old Captcha-Requests
     * 
     * Remove all stored requests for current namespace, that are older than 5 times the timeout
     */
    private function flushOldRequests()
    {
        // find timeout of configured namespace
        if (isset($this->config[$this->namespace]) && isset($this->config[$this->namespace]['timeout'])) {
            $timeout    =   $this->config[$this->namespace]['timeout'];
        }
        else {
            $timeout    =   $this->config[self::NAMESPACE_GLOBAL]['timeout'];
        }

        // 5 times the timout
        $until      =   time() - 5 * $timeout;
    
        $clause     =   array();
        $clause[]   =   array(
                                'field'     =>  'created',
                                'relation'  =>  'lt',
                                'value'     =>  date('Y-m-d H:i:s', $until)
                            );
        $clause[]   =   array(
                                'field'     =>  'namespace',
                                'value'     =>  $this->namespace
                            );

        $this->table->delete(self::TABLE_CAPTCHAREQUEST, null, null, $clause);
    }

    /**
     * See if CAPTCHA is required
     *
     * Return true if CAPTCHA is required
     *
     * @return bool
     */
    public function isRequired($mode)
    {
        switch (strtolower($mode)) {
            case 'auto':
                break;

            // CAPTCHA is not required
            case 'none':
            case '0':
                return false;
                break;

            // default: CAPTCHA is required
            default:
            case '1';
                return true;
                break;
        }

        if ($this->auth) {
            return false;
        }

        // don't count
        if (1 > $this->config[$this->namespace]['limit']) {
            return true;
        }

        $min        =   date('Y-m-d H:i:s', time() - $this->config[$this->namespace]['timeout']);
        $clause     =   array();
        $clause[]   =   array(
                                'field'     =>  'created',
                                'relation'  =>  'ge',
                                'value'     =>  $min
                            );
        $clause[]   =   array(
                                'field'     =>  'namespace',
                                'value'     =>  $this->namespace
                            );
        $cnt    =   $this->table->count(self::TABLE_CAPTCHAREQUEST, null, null, $clause);
        if ($cnt > $this->config[$this->namespace]['limit']) {
            return true;
        }

        return false;

        // session
        if (empty($this->config[$this->namespace]['sessiontimeout'])) {
            return false;
        }

        $this->sess =   WBClass::create('patSession');
        $sto    =   $this->sess->get('wb.captcha.timeout');
        if (empty($sto) || time() > $sto) {
            $this->sess->set('wb.captcha.timeout', time() + $this->config[$this->namespace]['sessiontimeout']);
            $this->sess->set('wb.captcha.limit', $this->config[$this->namespace]['sessionlimit']);
            return true;
        }

        $sli    =   $this->sess->get('wb.captcha.limit');
        --$sli;
        if (1 > $sli) {
            $this->sess->set('wb.captcha.limit', $this->config[$this->namespace]['sessionlimit']);
            return true;
        }
        $this->sess->set('wb.captcha.limit', $sli);
        return false;
    }

}