<?php
/*********************************************************************
    class.mailer.php

    osTicket mailer

    It's mainly PEAR MAIL wrapper for now (more improvements planned).

    Peter Rotich <peter@osticket.com>
    Copyright (c)  2006-2013 osTicket
    http://www.osticket.com

    Released under the GNU General Public License WITHOUT ANY WARRANTY.
    See LICENSE.TXT for details.

    vim: expandtab sw=4 ts=4 sts=4:
**********************************************************************/

include_once(INCLUDE_DIR.'class.email.php');
require_once(INCLUDE_DIR.'html2text.php');

class Mailer {

    var $email;

    var $ht = array();
    var $attachments = array();
    var $options = array();

    var $smtp = array();
    var $eol="\n";

    function __construct($email=null, array $options=array()) {
        global $cfg;

        if(is_object($email) && $email->isSMTPEnabled() && ($info=$email->getSMTPInfo())) { //is SMTP enabled for the current email?
            $this->smtp = $info;
        } elseif($cfg && ($e=$cfg->getDefaultSMTPEmail()) && $e->isSMTPEnabled()) { //What about global SMTP setting?
            $this->smtp = $e->getSMTPInfo();
            if(!$e->allowSpoofing() || !$email)
                $email = $e;
        } elseif(!$email && $cfg && ($e=$cfg->getDefaultEmail())) {
            if($e->isSMTPEnabled() && ($info=$e->getSMTPInfo()))
                $this->smtp = $info;
            $email = $e;
        }

        $this->email = $email;
        $this->attachments = array();
        $this->options = $options;
    }

    function getEOL() {
        return $this->eol;
    }

    function getEmail() {
        return $this->email;
    }

    function getSMTPInfo() {
        return $this->smtp;
    }
    /* FROM Address */
    function setFromAddress($from) {
        $this->ht['from'] = $from;
    }

    function getFromAddress($options=array()) {

        if (!$this->ht['from'] && ($email=$this->getEmail())) {
            if (($name = $options['from_name'] ?: $email->getName()))
                $this->ht['from'] =sprintf('"%s" <%s>', $name, $email->getEmail());
            else
                $this->ht['from'] =sprintf('<%s>', $email->getEmail());
        }

        return $this->ht['from'];
    }

    /* attachments */
    function getAttachments() {
        return $this->attachments;
    }

    function addAttachment(Attachment $attachment) {
        // XXX: This looks too assuming; however, the attachment processor
        // in the ::send() method seems hard coded to expect this format
        $this->attachments[$attachment->file_id] = $attachment;
    }

    function addFile(AttachmentFile $file) {
        // XXX: This looks too assuming; however, the attachment processor
        // in the ::send() method seems hard coded to expect this format
        $this->attachments[$file->file_id] = $file;
    }

    function addAttachments($attachments) {
        foreach ($attachments as $a) {
            if ($a instanceof Attachment)
                $this->addAttachment($a);
            elseif ($a instanceof AttachmentFile)
                $this->addFile($a);
        }
    }

    /**
     * getMessageId
     *
     * Generates a unique message ID for an outbound message. Optionally,
     * the recipient can be used to create a tag for the message ID where
     * the user-id and thread-entry-id are encoded in the message-id so
     * the message can be threaded if it is replied to without any other
     * indicator of the thread to which it belongs. This tag is signed with
     * the secret-salt of the installation to guard against false positives.
     *
     * Parameters:
     * $recipient - (EmailContact|null) recipient of the message. The ID of
     *      the recipient is placed in the message id TAG section so it can
     *      be recovered if the email replied to directly by the end user.
     * $options - (array) - options passed to ::send(). If it includes a
     *      'thread' element, the threadId will be recorded in the TAG
     *
     * Returns:
     * (string) - email message id, without leading and trailing <> chars.
     * See the Format below for the structure.
     *
     * Format:
     * VA-B-C, with dash separators and A-C explained below:
     *
     * V: Version code of the generated Message-Id
     * A: Predictable random code — used for loop detection (sysid)
     * B: Random data for unique identifier (rand)
     * C: TAG: Base64(Pack(userid, entryId, threadId, type, Signature)),
     *    '=' chars discarded
     * where Signature is:
     *   Signed Tag value, last 5 chars from
     *        HMAC(sha1, Tag + rand + sysid, SECRET_SALT),
     *   where Tag is:
     *     pack(userId, entryId, threadId, type)
     */
    function getMessageId($recipient, $options=array(), $version='B') {
        $tag = '';
        $rand = Misc::randCode(5,
            // RFC822 specifies the LHS of the addr-spec can have any char
            // except the specials — ()<>@,;:\".[], dash is reserved as the
            // section separator, and + is reserved for historical reasons
            'abcdefghiklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_=');
        $sig = $this->getEmail()?$this->getEmail()->getEmail():'@osTicketMailer';
        $sysid = static::getSystemMessageIdCode();
        // Create a tag for the outbound email
        $entry = (isset($options['thread']) && $options['thread'] instanceof ThreadEntry)
            ? $options['thread'] : false;
        $thread = $entry ? $entry->getThread()
            : (isset($options['thread']) && $options['thread'] instanceof Thread
                ? $options['thread'] : false);

        switch (true) {
        case $recipient instanceof Staff:
            $utype = 'S';
            break;
        case $recipient instanceof TicketOwner:
            $utype = 'U';
            break;
        case $recipient instanceof Collaborator:
            $utype = 'C';
            break;
        case  $recipient instanceof MailingList:
            $utype = 'M';
            break;
        default:
            $utype = $options['utype'] ?: is_array($recipient) ? 'M' : '?';
        }


        $tag = pack('VVVa',
            $recipient instanceof EmailContact ? $recipient->getUserId() : 0,
            $entry ? $entry->getId() : 0,
            $thread ? $thread->getId() : 0,
            $utype ?: '?'
        );
        // Sign the tag with the system secret salt
        $tag .= substr(hash_hmac('sha1', $tag.$rand.$sysid, SECRET_SALT, true), -5);
        $tag = str_replace('=','',base64_encode($tag));
        return sprintf('B%s-%s-%s-%s',
            $sysid, $rand, $tag, $sig);
    }

    /**
     * decodeMessageId
     *
     * Decodes a message-id generated by osTicket using the ::getMessageId()
     * method of this class. This will digest the received message-id token
     * and return an array with some information about it.
     *
     * Parameters:
     * $mid - (string) message-id from an email Message-Id, In-Reply-To, and
     *      References header.
     *
     * Returns:
     * (array) of information containing all or some of the following keys
     *      'loopback' - (bool) true or false if the message originated by
     *          this osTicket installation.
     *      'version' - (string|FALSE) version code of the message id
     *      'code' - (string) unique but predictable help desk message-id
     *      'id' - (string) random characters serving as the unique id
     *      'entryId' - (int) thread-entry-id from which the message originated
     *      'threadId' - (int) thread-id from which the message originated
     *      'staffId' - (int|null) staff the email was originally sent to
     *      'userId' - (int|null) user the email was originally sent to
     *      'userClass' - (string) class of user the email was sent to
     *          'U' - TicketOwner
     *          'S' - Staff
     *          'C' - Collborator
     *          'M' - Multiple
     *          '?' - Something else
     */
    static function decodeMessageId($mid) {
        // Drop <> tokens
        $mid = trim($mid, '<> ');
        // Drop email domain on rhs
        list($lhs, $sig) = explode('@', $mid, 2);
        // LHS should be tokenized by '-'
        $parts = explode('-', $lhs);

        $rv = array('loopback' => false, 'version' => false);

        // There should be at least two tokens if the message was sent by
        // this system. Otherwise, there's nothing to be detected
        if (count($parts) < 2)
            return $rv;

        $self = get_called_class();
        $decoders = array(
        'A' => function($id, $tag) use ($sig) {
            // Old format was VA-B-C-D@sig, where C was the packed tag and D
            // was blank
            $format = 'Vuid/VentryId/auserClass';
            $chksig = substr(hash_hmac('sha1', $tag.$id, SECRET_SALT), -10);
            if ($tag && $sig == $chksig && ($tag = base64_decode($tag))) {
                // Find user and ticket id
                return unpack($format, $tag);
            }
            return false;
        },
        'B' => function($id, $tag) use ($self) {
            $format = 'Vuid/VentryId/VthreadId/auserClass/a*sig';
            if ($tag && ($tag = base64_decode($tag))) {
                if (!($info = @unpack($format, $tag)) || !isset($info['sig']))
                    return false;
                $sysid = $self::getSystemMessageIdCode();
                $shorttag = substr($tag, 0, 13);
                $chksig = substr(hash_hmac('sha1', $shorttag.$id.$sysid,
                    SECRET_SALT, true), -5);
                if ($chksig == $info['sig']) {
                    return $info;
                }
            }
            return false;
        },
        );

        // Detect the MessageId version, which should be the first char
        $rv['version'] = @$parts[0][0];
        if (!isset($decoders[$rv['version']]))
            // invalid version code
            return null;

        // Drop the leading version code
        list($rv['code'], $rv['id'], $tag) = $parts;
        $rv['code'] = substr($rv['code'], 1);

        // Verify tag signature and unpack the tag
        $info = $decoders[$rv['version']]($rv['id'], $tag);
        if ($info === false)
            return $rv;

        $rv += $info;

        // Attempt to make the user-id more specific
        $classes = array(
            'S' => 'staffId', 'U' => 'userId', 'C' => 'userId',
        );
        if (isset($classes[$rv['userClass']]))
            $rv[$classes[$rv['userClass']]] = $rv['uid'];

        // Round-trip detection - the first section is the local
        // system's message-id code
        $rv['loopback'] = (0 === strcmp($rv['code'],
            static::getSystemMessageIdCode()));

        return $rv;
    }

    static function getSystemMessageIdCode() {
        return substr(str_replace('+', '=',
            base64_encode(md5('mail'.SECRET_SALT, true))),
            0, 6);
    }

    function send($recipients, $subject, $message, $options=null) {
        global $ost, $cfg;

        //Get the goodies
        require_once (PEAR_DIR.'Mail.php'); // PEAR Mail package
        require_once (PEAR_DIR.'Mail/mime.php'); // PEAR Mail_Mime packge

        $messageId = $this->getMessageId($recipients, $options);
        $subject = preg_replace("/(\r\n|\r|\n)/s",'', trim($subject));
        $headers = array (
            'From' => $this->getFromAddress($options),
            'Subject' => $subject,
            'Date'=> date('D, d M Y H:i:s O'),
            'Message-ID' => "<{$messageId}>",
            'X-Mailer' =>'osTicket Mailer',
        );

        // Add in the options passed to the constructor
        $options = ($options ?: array()) + $this->options;

        // Message Id Token
        $mid_token = '';
        // Check if the email is threadable
        if (isset($options['thread'])
            && $options['thread'] instanceof ThreadEntry
            && ($thread = $options['thread']->getThread())) {

            // Add email in-reply-to references if not set
            if (!isset($options['inreplyto'])) {

                $entry = null;
                switch (true) {
                case $recipients instanceof TicketOwner:
                case $recipients instanceof Collaborator:
                    $entry = $thread->getLastEmailMessage(array(
                                'user_id' => $recipients->getUserId()));
                    break;
                case $recipients instanceof Staff:
                    //XXX: is it necessary ??
                    break;
                }

                if ($entry && ($mid=$entry->getEmailMessageId())) {
                    $options['inreplyto'] = $mid;
                    $options['references'] = $entry->getEmailReferences();
                }
            }

            // Embedded message id token
            $mid_token = $messageId;
            // Set Reply-Tag
            if (!isset($options['reply-tag'])) {
                if ($cfg && $cfg->stripQuotedReply())
                    $options['reply-tag'] = $cfg->getReplySeparator() . '<br/><br/>';
                else
                    $options['reply-tag'] = '';
            } elseif ($options['reply-tag'] === false) {
                $options['reply-tag'] = '';
            }
        }

        // Return-Path
        if (isset($options['nobounce']) && $options['nobounce'])
            $headers['Return-Path'] = '<>';
        elseif ($this->getEmail() instanceof Email)
            $headers['Return-Path'] = $this->getEmail()->getEmail();

        // Bulk.
        if (isset($options['bulk']) && $options['bulk'])
            $headers+= array('Precedence' => 'bulk');

        // Auto-reply - mark as autoreply and supress all auto-replies
        if (isset($options['autoreply']) && $options['autoreply']) {
            $headers+= array(
                    'Precedence' => 'auto_reply',
                    'X-Autoreply' => 'yes',
                    'X-Auto-Response-Suppress' => 'DR, RN, OOF, AutoReply',
                    'Auto-Submitted' => 'auto-replied');
        }

        // Notice (sort of automated - but we don't want auto-replies back
        if (isset($options['notice']) && $options['notice'])
            $headers+= array(
                    'X-Auto-Response-Suppress' => 'OOF, AutoReply',
                    'Auto-Submitted' => 'auto-generated');
        // In-Reply-To
        if (isset($options['inreplyto']) && $options['inreplyto'])
            $headers += array('In-Reply-To' => $options['inreplyto']);

        // References
        if (isset($options['references']) && $options['references']) {
            if (is_array($options['references']))
                $headers += array('References' =>
                    implode(' ', $options['references']));
            else
                $headers += array('References' => $options['references']);
        }

        // Use general failsafe default initially
        $eol = "\n";
        // MAIL_EOL setting can be defined in `ost-config.php`
        if (defined('MAIL_EOL') && is_string(MAIL_EOL))
            $eol = MAIL_EOL;
        $mime = new Mail_mime($eol);
        // Add recipients
        if (!is_array($recipients) && (!$recipients instanceof MailingList))
            $recipients =  array($recipients);
        foreach ($recipients as $recipient) {
            if ($recipient instanceof ClientSession)
                $recipient = $recipient->getSessionUser();
            switch (true) {
                case $recipient instanceof EmailRecipient:
                    $addr = sprintf('"%s" <%s>',
                            $recipient->getName(),
                            $recipient->getEmail());
                    switch ($recipient->getType()) {
                        case 'to':
                            $mime->addTo($addr);
                            break;
                        case 'cc':
                            $mime->addCc($addr);
                            break;
                        case 'bcc':
                            $mime->addBcc($addr);
                            break;
                    }
                    break;
                case $recipient instanceof TicketOwner:
                case $recipient instanceof Staff:
                    $mime->addTo(sprintf('"%s" <%s>',
                                $recipient->getName(),
                                $recipient->getEmail()));
                    break;
                case $recipient instanceof Collaborator:
                    $mime->addCc(sprintf('"%s" <%s>',
                                $recipient->getName(),
                                $recipient->getEmail()));
                    break;
                case $recipient instanceof EmailAddress:
                    $mime->addTo($recipient->getAddress());
                    break;
                default:
                    // Assuming email address.
                    $mime->addTo($recipient);
            }
        }

        // Add in extra attachments, if any from template variables
        if ($message instanceof TextWithExtras
            && ($attachments = $message->getAttachments())
        ) {
            foreach ($attachments as $a) {
                $file = $a->getFile();
                $mime->addAttachment($file->getData(),
                    $file->getType(), $file->getName(), false);
            }
        }

        // If the message is not explicitly declared to be a text message,
        // then assume that it needs html processing to create a valid text
        // body
        $isHtml = true;
        if (!(isset($options['text']) && $options['text'])) {
            // Embed the data-mid in such a way that it should be included
            // in a response
            if ($options['reply-tag'] || $mid_token) {
                $message = sprintf('<div style="display:none"
                        class="mid-%s">%s</div>%s',
                        $mid_token,
                        $options['reply-tag'],
                        $message);
            }

            $txtbody = rtrim(Format::html2text($message, 90, false))
                . ($messageId ? "\nRef-Mid: $messageId\n" : '');
            $mime->setTXTBody($txtbody);
        }
        else {
            $mime->setTXTBody($message);
            $isHtml = false;
        }

        if ($isHtml && $cfg && $cfg->isRichTextEnabled()) {
            // Pick a domain compatible with pear Mail_Mime
            $matches = array();
            if (preg_match('#(@[0-9a-zA-Z\-\.]+)#', $this->getFromAddress(), $matches)) {
                $domain = $matches[1];
            } else {
                $domain = '@localhost';
            }
            // Format content-ids with the domain, and add the inline images
            // to the email attachment list
            $self = $this;
            $message = preg_replace_callback('/cid:([\w.-]{32})/',
                function($match) use ($domain, $mime, $self) {
                    $file = false;
                    foreach ($self->attachments as $id=>$F) {
                        if ($F instanceof Attachment)
                            $F = $F->getFile();
                        if (strcasecmp($F->getKey(), $match[1]) === 0) {
                            $file = $F;
                            break;
                        }
                    }
                    if (!$file)
                        // Not attached yet attempt to attach it inline
                        $file = AttachmentFile::lookup($match[1]);
                    if (!$file)
                        return $match[0];
                    $mime->addHTMLImage($file->getData(),
                        $file->getType(), $file->getName(), false,
                        $match[1].$domain);
                    // Don't re-attach the image below
                    unset($self->attachments[$file->getId()]);
                    return $match[0].$domain;
                }, $message);
            // Add an HTML body
            $mime->setHTMLBody($message);
        }
        //XXX: Attachments
        if(($attachments=$this->getAttachments())) {
            foreach($attachments as $id=>$file) {
                // Read the filename from the Attachment if possible
                if ($file instanceof Attachment) {
                    $filename = $file->getFilename();
                    $file = $file->getFile();
                }
                else {
                    $filename = $file->getName();
                }
                $mime->addAttachment($file->getData(),
                    $file->getType(), $filename, false);
            }
        }

        //Desired encodings...
        $encodings=array(
                'head_encoding' => 'quoted-printable',
                'text_encoding' => 'base64',
                'html_encoding' => 'base64',
                'html_charset'  => 'utf-8',
                'text_charset'  => 'utf-8',
                'head_charset'  => 'utf-8'
                );
        //encode the body
        $body = $mime->get($encodings);
        //encode the headers.
        $headers = $mime->headers($headers, true);
        $to = implode(',', array_filter(array($headers['To'], $headers['Cc'],
                    $headers['Bcc'])));
        // Cache smtp connections made during this request
        static $smtp_connections = array();
        if(($smtp=$this->getSMTPInfo())) { //Send via SMTP
            $key = sprintf("%s:%s:%s", $smtp['host'], $smtp['port'],
                $smtp['username']);
            if (!isset($smtp_connections[$key])) {
                $mail = mail::factory('smtp', array(
                    'host' => $smtp['host'],
                    'port' => $smtp['port'],
                    'auth' => $smtp['auth'],
                    'username' => $smtp['username'],
                    'password' => $smtp['password'],
                    'timeout'  => 20,
                    'debug' => false,
                    'persist' => true,
                ));
                if ($mail->connect())
                    $smtp_connections[$key] = $mail;
            }
            else {
                // Use persistent connection
                $mail = $smtp_connections[$key];
            }

            $result = $mail->send($to, $headers, $body);
            if(!PEAR::isError($result))
                return $messageId;

            // Force reconnect on next ->send()
            unset($smtp_connections[$key]);

            $alert=_S("Unable to email via SMTP")
                    .sprintf(":%1\$s:%2\$d [%3\$s]\n\n%4\$s\n",
                    $smtp['host'], $smtp['port'], $smtp['username'], $result->getMessage());
            $this->logError($alert);
        }

        //No SMTP or it failed....use php's native mail function.
        $args = array();
        if (isset($options['from_address']))
            $args[] = '-f '.$options['from_address'];
        elseif ($this->getEmail())
            $args = array('-f '.$this->getEmail()->getEmail());
        $mail = mail::factory('mail', $args);
        $to = $headers['To'];
        $result = $mail->send($to, $headers, $body);
        if(!PEAR::isError($result))
            return $messageId;

        $alert=_S("Unable to email via php mail function")
                .sprintf(":%1\$s\n\n%2\$s\n",
                $to, $result->getMessage());
        $this->logError($alert);
        return false;
    }

    function logError($error) {
        global $ost;
        //NOTE: Admin alert override - don't email when having email trouble!
        $ost->logError(_S('Mailer Error'), $error, false);
    }

    /******* Static functions ************/

    //Emails using native php mail function - if DB connection doesn't exist.
    //Don't use this function if you can help it.
    function sendmail($to, $subject, $message, $from, $options=null) {
        $mailer = new Mailer(null, array('notice'=>true, 'nobounce'=>true));
        $mailer->setFromAddress($from);
        return $mailer->send($to, $subject, $message, $options);
    }
}
?>
