<?php

class Application_Model_Auth {
	
	const TOKEN_LIFETIME = 'P2D'; // DateInterval syntax
	
	private function generateToken($action, $user_id) 
	{
	   $salt = "pro";
	   $token = self::generateRandomString();
	   
	   $info = new CcSubjsToken();
	   $info->setDbUserId($user_id);
	   $info->setDbAction($action);
	   $info->setDbToken(sha1($token.$salt));
	   $info->setDbCreated(gmdate('Y-m-d H:i:s'));
	   $info->save();
	   
	   return $token;
	}
	
	public function sendPasswordRestoreLink($user, $view)
	{
        $token = $this->generateToken('password.restore', $user->getDbId());
               
        $e_link_protocol = empty($_SERVER['HTTPS']) ? "http" : "https";
        $e_link_base = $_SERVER['SERVER_NAME'];
        $e_link_path = $view->url(array('user_id' => $user->getDbId(), 
                                    'token' => $token
                                    ), 
                                    'password-change');
       
        $message = "Click this link: {$e_link_protocol}://{$e_link_base}{$e_link_path}";
       
	    Application_Model_Email::send('Airtime Password Reset', $message, $user->getDbEmail());
	}
	
	public function invalidateTokens($user, $action)
	{
	   CcSubjsTokenQuery::create()
	       ->filterByDbAction($action)
	       ->filterByDbUserId($user->getDbId())
	       ->delete();
	}
	
    public function checkToken($user_id, $token, $action)
    {
    	$salt = "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()
    {
        $dbAdapter = Zend_Db_Table::getDefaultAdapter();
        $authAdapter = new Zend_Auth_Adapter_DbTable($dbAdapter);

        $authAdapter->setTableName('cc_subjs')
                    ->setIdentityColumn('login')
                    ->setCredentialColumn('pass')
                    ->setCredentialTreatment('MD5(?)');
                    
        return $authAdapter;
    }
    
    /**
     * 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 .= $allowed_chars[mt_rand(0, strlen($allowed_chars) - 1)];
        }

        return $string;
    }
}