<?php
    /**
    * o------------------------------------------------------------------------------o
    * | This package is dual licensed as GPL and a commercial license.               |
    * | If you use the code commercially (or if you don't want to be restricted by   |
    * | the GPL license), you will need the commercial license. It's only £49 (GBP - |
    * | roughly $98 depending on the exchange rate) and helps me out a lot. Thanks.  |
    * o------------------------------------------------------------------------------o
    *
    * © Copyright Richard Heyes
    */


    define('SMTP_STATUS_DISCONNECTED', 1, true);
    define('SMTP_STATUS_CONNECTED', 2, true);

    class SMTP
    {
        /**
        * Controls printing of debug information
        */
        public $dbug = false;

        /**
        * Whether or not the class is currently authenticated with the server
        */
        private $authenticated = false;

        /**
        * The SMTP socket
        */
        private $socket;

        /**
        * An array of the recipient addresses (I think...)
        */
        private $recipients;
        
        /**
        * An associative array of headers for the message
        * ag. array('From' => 'bob@dole.com')
        */
        private $headers = array();
        
        /**
        * The network timeout
        */
        private $timeout;

        /**
        * The current status
        */
        public $status = SMTP_STATUS_DISCONNECTED;

        /**
        * The email to send, excluding headers
        */
        private $body;
        
        /**
        * The from address to use in the MAIL FROM command
        */
        private $from;
        
        /**
        * The remote SMTP host to connect to
        */
        private $host;
        
        /**
        * The remote SMTP servers' port
        */
        private $port;
        
        /**
        * The host name to use in the SMTP HELO command
        */
        private $helo;
        
        /**
        * Whether to use authentication or not
        */
        private $auth;
        
        /**
        * The authentication username
        */
        private $user;
        
        /**
        * The authentication password
        */
        private $pass;

        /**
        * Constructor. Arguments:
        * $params - An assoc array of parameters:
        *
        *   host    - The hostname of the smtp server        Default: localhost
        *   port    - The port the smtp server runs on        Default: 25
        *   helo    - What to send as the HELO command        Default: localhost
        *             (typically the hostname of the
        *             machine this script runs on)
        *   auth    - Whether to use basic authentication    Default: FALSE
        *   user    - Username for authentication            Default: null
        *   pass    - Password for authentication            Default: null
        *   timeout - The timeout in seconds for the call    Default: 5
        *             to fsockopen()
        */
        public function __construct($host = 'localhost', $port = 25, $helo = 'localhost', $auth = false, $user = null, $pass = null, $timeout = 5)
        {
            if(!defined('CRLF')) {
                define('CRLF', "\r\n", true);
            }

            $this->authenticated = false;
            $this->timeout       = $timeout;
            $this->status        = SMTP_STATUS_DISCONNECTED;
            $this->host          = $host;
            $this->port          = $port;
            $this->helo          = $helo;
            $this->auth          = $auth;
            $this->user          = $user;
            $this->pass          = $pass;
        }
        
        /**
        * Getter
        *
        * @param $name Name of proprty
        */
        public function __get($name)
        {
            return $this->$name;
        }

        /**
        * Setter
        *
        * @param $name  Name of property
        * @param $value Value of property
        *
        */
        public function __set($name, $value)
        {
            $this->$name = $value;
        }

        /***
        * Connect function. This will connect using the parameters
        * suppllied to the constructor
        */
        public function Connect()
        {
            $this->socket = @fsockopen($this->host, $this->port, $errno, $errstr, $this->timeout);

            if (!$this->socket) {
                throw new SMTPException("Failed to connect to socket at: {$this->host}:{$this->port}");
            }

            /**
            * Set the timeout on the socket
            */
            stream_set_timeout($this->socket, $this->timeout);

            $greeting = $this->getData();

            return $this->auth ? $this->ehlo() : $this->helo();
        }
        
        /**
        * Returns true/false as to whether the object is connected or not
        *
        * @return bool
        */
        public function Connected()
        {
            return is_resource($this->socket);
        }
        
        /**
        * Returns true/false as to whether the object is authenticated or not
        */
        public function Authenticated()
        {
            return $this->authenticated;
        }

        /**
        * Function which handles sending the data over the socket
        *
        * @param string $recipients An array of email addresses whp will be the recipients
        * @param string $from       An email address who the email address is from
        * @param string $headers    Headers for the email
        * @param string $body       The body of the email
        */
        public function Send($recipients, $from, $headers, $body)
        {
            if(!$this->Connected()) {
                throw new SMTPException('Please connect first!');
            }

            // Do we auth or not? Note the distinction between the auth variable and auth() function
            if($this->auth AND !$this->Authenticated()){
                if(!$this->Auth())
                    return false;
            }

            $this->mail($from);

            foreach($recipients as $v) {
                $this->rcpt($v);
            }

            $this->data();

            /**
            * Headers
            */
            foreach ($headers as $k => $v) {
                $tmp[] = "{$k}: {$v}";
            }
            $headers = implode(CRLF, $tmp);
            $headers = preg_replace('/^\.[^.]/mis', '', $headers);

            $body    = str_replace(CRLF . '.', CRLF . '..', $body);
            $body    = strlen($body) > 0 && $body{0} == '.' ? '.' . $body : $body;

            $this->SendData($headers);
            $this->SendData('');
            $this->SendData($body);
            $this->SendData('.');

            $result = substr($this->getData(), 0, 3) === '250';
            $this->rset();
            return $result;
        }

        /**
        * Sends the HELO command
        */
        public function helo()
        {
            if(    $this->Connected()
               AND $this->SendData('HELO ' . $this->helo)
               AND substr($error = $this->getData(), 0, 3) === '250'){

                return true;

            }

            throw new SMTPException('HELO command failed, output: ' . trim(substr(trim($error),3)));
        }

        /**
        * Implements the EHLO ESMTP command
        */
        public function ehlo()
        {
            if(    $this->Connected()
               AND $this->SendData('EHLO '.$this->helo)
               AND substr($error = $this->getData(), 0, 3) === '250' ){

                return true;

            }
            
            throw new SMTPException('EHLO command failed, output: ' . trim(substr(trim($error),3)));
        }

        /**
        * Implements the RSET command
        */
        public function rset()
        {
            if(    $this->Connected()
               AND $this->SendData('RSET')
               AND substr($error = $this->getData(), 0, 3) === '250' ){

                return true;
            }

            throw new SMTPException('RSET command failed, output: ' . trim(substr(trim($error),3)));
        }

        /**
        * Sends the QUIT command
        */
        public function quit()
        {
            if(    $this->Connected()
               AND $this->SendData('QUIT')
               AND substr($error = $this->getData(), 0, 3) === '221' ){

                fclose($this->socket);
                $this->status = SMTP_STATUS_DISCONNECTED;

                return true;

            }
            
            throw new SMTPException('QUIT command failed, output: ' . trim(substr(trim($error),3)));
        }

        /**
        * Function which implements the AUTH command
        */
        public function auth()
        {
            $error = '';

            if(    $this->Connected()
               AND $this->SendData('AUTH LOGIN')
               AND substr($error = $this->getData(), 0, 3) === '334'
               AND $this->SendData(base64_encode($this->user)) // Send username
               AND substr($error = $this->getData(),0,3) === '334'
               AND $this->SendData(base64_encode($this->pass)) // Send password
               AND substr($error = $this->getData(),0,3) === '235' ){

                $this->authenticated = true;
                return true;

            }

            throw new SMTPException('AUTH command failed: ' . trim(substr($error, 3)));
        }
        
        /**
        * Implements the MAIL FROM command
        *
        * @param $from The SMTP envelope from
        */
        public function mail($from)
        {
            if(     $this->Connected()
                AND $this->SendData("MAIL FROM:<{$from}>")
                AND substr($error = $this->getData(), 0, 3) === '250' ){

                return true;

            }
            
            throw new SMTPException('Failed to send SMTP data: ' . $error);
        }

        /**
        * Implements the RCPT TO command
        *
        * @param $to The recipient address
        */
        public function rcpt($to)
        {
            if(    $this->Connected()
               AND $this->SendData('RCPT TO:<'.$to.'>')
               AND substr($error = $this->getData(), 0, 2) === '25' ){

                return true;
            }
            
            throw new SMTPException(trim(substr(trim($error), 3)));
        }

        /**
        * Implements the SMTP DATA command
        */
        public function data()
        {
            $error = '';

            if(    $this->Connected()
               AND $this->SendData('DATA')
               AND substr($error = $this->getData(), 0, 3) === '354' ){

                return true;

            }
            
            throw new SMTPException(trim(substr($error, 3)));
        }


        /**
        * Sends some data. Surprising that
        */
        private function SendData($data)
        {
            if ($this->Connected()) {
                if ($this->dbug) {
                    echo ' SENDING: ' . htmlspecialchars("{$data}") . '<br />';
                }

                return fwrite($this->socket, $data . CRLF, strlen($data)+2);
                
            }

            throw new SMTPException('Please connect first!');
        }

        
        /**
        * Fetches data from the socket
        *
        * @return string The data that has been read from the socket
        */
        private function getData()
        {
            $return = '';
            $line   = '';
            $loops  = 0;

            if ($this->Connected()) {
                while ((strpos($return, CRLF) === false OR substr($line,3,1) !== ' ') AND $loops < 100) {
                    $line    = fgets($this->socket, 512);
                    $return .= $line;
                    $loops++;
                }
                
                if ($this->dbug) {
                    echo 'RECIEVED: ' . htmlspecialchars($return);
                }

                return trim($return);

            }
            
            return false;
        }

    }
    
    /**
    * SMTP Exception class for errors
    */
    class SMTPException extends Exception
    {
    }
?>