<?php

class Application_Model_Auth
{
    public const TOKEN_LIFETIME = 'P2D'; // DateInterval syntax

    private function generateToken($action, $user_id)
    {
        $salt = md5('pro');
        $token = self::generateRandomString();

        $info = new CcSubjsToken();
        $info->setDbUserId($user_id);
        $info->setDbAction($action);
        $info->setDbToken(sha1($token . $salt));
        $info->setDbCreated(gmdate(DEFAULT_TIMESTAMP_FORMAT));
        $info->save();

        Logging::debug("generated token {$token}");

        return $token;
    }

    public function sendPasswordRestoreLink($user, $view)
    {
        $public_url = Config::getPublicUrl();

        $token = $this->generateToken('password.restore', $user->getDbId());
        $link_path = $view->url(['user_id' => $user->getDbId(), 'token' => $token], 'password-change');

        $message = sprintf(_("Hi %s, \n\nPlease click this link to reset your password: "), $user->getDbLogin());
        $message .= "{$public_url}{$link_path}";
        $message .= sprintf(_("\n\nIf you have any problems, please contact our support team: %s"), SUPPORT_ADDRESS);
        $message .= sprintf(_("\n\nThank you,\nThe %s Team"), SAAS_PRODUCT_BRANDING_NAME);

        $str = sprintf(_('%s Password Reset'), SAAS_PRODUCT_BRANDING_NAME);

        return Application_Model_Email::send($str, $message, $user->getDbEmail());
    }

    public function invalidateTokens($user, $action)
    {
        CcSubjsTokenQuery::create()
            ->filterByDbAction($action)
            ->filterByDbUserId($user->getDbId())
            ->delete();
    }

    public function checkToken($user_id, $token, $action)
    {
        $salt = md5('pro');

        $token_info = CcSubjsTokenQuery::create()
            ->filterByDbAction($action)
            ->filterByDbUserId($user_id)
            ->filterByDbToken(sha1($token . $salt))
            ->findOne();

        if (empty($token_info)) {
            return false;
        }

        $now = new DateTime();
        $token_life = new DateInterval(self::TOKEN_LIFETIME);
        $token_created = new DateTime($token_info->getDbCreated(), new DateTimeZone('UTC'));

        return $now->sub($token_life)->getTimestamp() < $token_created->getTimestamp();
    }

    /**
     * Gets the adapter for authentication against a database table.
     *
     * @return object
     */
    public static function getAuthAdapter()
    {
        $CC_CONFIG = Config::getConfig();
        if ($CC_CONFIG['auth'] !== 'local') {
            return self::getCustomAuthAdapter($CC_CONFIG['auth']);
        }

        // Database config
        $db = Zend_Db::factory('PDO_' . $CC_CONFIG['dsn']['phptype'], [
            'host' => $CC_CONFIG['dsn']['host'],
            'port' => $CC_CONFIG['dsn']['port'],
            'username' => $CC_CONFIG['dsn']['username'],
            'password' => $CC_CONFIG['dsn']['password'],
            'dbname' => $CC_CONFIG['dsn']['database'],
        ]);
        Zend_Db_Table_Abstract::setDefaultAdapter($db);
        $authAdapter = new Zend_Auth_Adapter_DbTable($db);

        $authAdapter->setTableName('cc_subjs')
            ->setIdentityColumn('login')
            ->setCredentialColumn('pass')
            ->setCredentialTreatment('MD5(?)');

        return $authAdapter;
    }

    /**
     * Gets an alternative Adapter that does not need to auth agains a databse table.
     *
     * @param mixed $adaptor
     *
     * @return object
     */
    public static function getCustomAuthAdapter($adaptor)
    {
        return new $adaptor();
    }

    /**
     * Get random string.
     *
     * @param int    $length
     * @param string $allowed_chars
     *
     * @return string
     */
    final public function generateRandomString($length = 12, $allowed_chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
    {
        $string = '';
        for ($i = 0; $i < $length; ++$i) {
            $string .= $allowed_chars[random_int(0, strlen($allowed_chars) - 1)];
        }

        return $string;
    }

    /** It is essential to do this before interacting with Zend_Auth otherwise sessions could be shared between
     *  different copies of Airtime on the same webserver. This essentially pins this session to:
     *   - The server public url.
     *
     * @param Zend_Auth $auth get this with Zend_Auth::getInstance()
     */
    public static function pinSessionToClient($auth)
    {
        $session_id = PRODUCT_NAME . '-';
        $session_id .= bin2hex(Config::getPublicUrl());
        $auth->setStorage(new Zend_Auth_Storage_Session($session_id));
    }
}