<?php
    class HttpValidationMonitor extends Monitor
    {
        public static $MODE_DOES_CONTAIN = 0x01;
        public static $MODE_DOESNT_CONTAIN = 0x02;

        public static $MATCH_FIND = 0x01;
        public static $MATCH_REGEX = 0x02;

        public function getName()
        {
            return 'HTTP Validation Monitor';
        }

        public function getDescription()
        {
            return 'This type of monitor attempts to establish a connection to a web service running over HTTP and
            validate the returned information.  For example, one could check to see if the phrase "Error" is present in
            output to determine if the service is offline, even if the connection is successful.';
        }

        public function getTimeout()
        {
            return $this->config['timeout'];
        }

        public function getMatchString()
        {
            return $this->config['match_str'];
        }

        public function getMatchMethod()
        {
            return $this->config['match_method'] ? $this->config['match_method'] : HttpValidationMonitor::$MATCH_FIND;
        }

        public function getMode()
        {
            return $this->config['mode'] ? $this->config['mode'] : HttpValidationMonitor::$MODE_DOES_CONTAIN;
        }

        public function isValid($resp)
        {
            if($this->getMatchMethod() == HttpValidationMonitor::$MATCH_FIND)
            {
                if(strpos($resp, $this->config['match_str']) === false)
                    return false;
                return true;
            }
            else
            {
                if(preg_match($this->config['match_str'], $resp))
                    return true;
                return false;
            }
        }

        public function queryMonitor()
        {
            $sock = @fsockopen($this->hostname, $this->port, $errno, $errstr, intval($this->config['timeout']));
            if(!$sock)
                return false;
            $req  = "GET / HTTP/1.1\r\n";
            $req .= "Host: " . $this->hostname . "\r\n";
            $req .= "Connection: Close\r\n\r\n";
            fwrite($sock, $req);

            $resp = '';
            while(!feof($sock))
            {
                $resp .= fread($sock, 1024);
            }

            $valid = $this->isValid($resp);
            fclose($sock);
            if($this->getMode() == HttpValidationMonitor::$MODE_DOES_CONTAIN)
                return $valid;
            else
                return !$valid;
        }

        public function customProcessAddEdit($data, $errors)
        {
            if(!is_numeric($data['timeout']) || intval($data['timeout']) <= 0)
                $errors['timeout'] = 'Timeout must be a positive integer.';
            $this->config['timeout'] = intval($data['timeout']);
            if(strlen($data['match_str']) == 0)
                $errors['match_str'] = 'String to match cannot be blank.';
            $this->config['match_str'] = $data['match_str'];
            $this->config['mode'] = $data['mode'];
            $this->config['match_method'] = $data['match_method'];
            return $errors;
        }

        public function customProcessDelete()
        {
        }
    }
?>