<?php
/**
 * Laconica, the distributed open-source microblogging tool
 *
 * utility functions for Jabber/GTalk/XMPP messages
 *
 * PHP version 5
 *
 * LICENCE: This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @category  Network
 * @package   Laconica
 * @author    Evan Prodromou <evan@controlyourself.ca>
 * @copyright 2008 Control Yourself, Inc.
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link      http://laconi.ca/
 */

if (!defined('LACONICA')) {
    exit(1);
}

require_once 'XMPPHP/XMPP.php';

/**
 * checks whether a string is a syntactically valid Jabber ID (JID)
 *
 * @param string $jid string to check
 *
 * @return     boolean whether the string is a valid JID
 */

function jabber_valid_base_jid($jid)
{
    // Cheap but effective
    return Validate::email($jid);
}

/**
 * normalizes a Jabber ID for comparison
 *
 * @param string $jid JID to check
 *
 * @return string an equivalent JID in normalized (lowercase) form
 */

function jabber_normalize_jid($jid)
{
    if (preg_match("/(?:([^\@]+)\@)?([^\/]+)(?:\/(.*))?$/", $jid, $matches)) {
        $node   = $matches[1];
        $server = $matches[2];
        return strtolower($node.'@'.$server);
    } else {
        return null;
    }
}

/**
 * the JID of the Jabber daemon for this Laconica instance
 *
 * @return string JID of the Jabber daemon
 */

function jabber_daemon_address()
{
    return common_config('xmpp', 'user') . '@' . common_config('xmpp', 'server');
}

/**
 * connect the configured Jabber account to the configured server
 *
 * @param string $resource Resource to connect (defaults to configured resource)
 *
 * @return XMPPHP connection to the configured server
 */

function jabber_connect($resource=null)
{
    static $conn = null;
    if (!$conn) {
        $conn = new XMPPHP_XMPP(common_config('xmpp', 'host') ?
                                common_config('xmpp', 'host') :
                                common_config('xmpp', 'server'),
                                common_config('xmpp', 'port'),
                                common_config('xmpp', 'user'),
                                common_config('xmpp', 'password'),
                                ($resource) ? $resource :
                                common_config('xmpp', 'resource'),
                                common_config('xmpp', 'server'),
                                common_config('xmpp', 'debug') ?
                                true : false,
                                common_config('xmpp', 'debug') ?
                                XMPPHP_Log::LEVEL_VERBOSE :  null
                                );

        if (!$conn) {
            return false;
        }

        $conn->autoSubscribe();
        $conn->useEncryption(common_config('xmpp', 'encryption'));

        try {
            $conn->connect(true); // true = persistent connection
        } catch (XMPPHP_Exception $e) {
            common_log(LOG_ERROR, $e->getMessage());
            return false;
        }

        $conn->processUntil('session_start');
    }
    return $conn;
}

/**
 * send a single notice to a given Jabber address
 *
 * @param string $to     JID to send the notice to
 * @param Notice $notice notice to send
 *
 * @return boolean success value
 */

function jabber_send_notice($to, $notice)
{
    $conn = jabber_connect();
    if (!$conn) {
        return false;
    }
    $profile = Profile::staticGet($notice->profile_id);
    if (!$profile) {
        common_log(LOG_WARNING, 'Refusing to send notice with ' .
                   'unknown profile ' . common_log_objstring($notice),
                   __FILE__);
        return false;
    }
    $msg   = jabber_format_notice($profile, $notice);
    $entry = jabber_format_entry($profile, $notice);
    $conn->message($to, $msg, 'chat', null, $entry);
    $profile->free();
    return true;
}

/**
 * extra information for XMPP messages, as defined by Twitter
 *
 * @param Profile $profile Profile of the sending user
 * @param Notice  $notice  Notice being sent
 *
 * @return string Extra information (Atom, HTML, addresses) in string format
 */

function jabber_format_entry($profile, $notice)
{
    // FIXME: notice url might be remote

    $noticeurl = common_local_url('shownotice',
                                  array('notice' => $notice->id));

    $msg = jabber_format_notice($profile, $notice);

    $self_url = common_local_url('userrss', array('nickname' => $profile->nickname));

    $entry  = "\n<entry xmlns='http://www.w3.org/2005/Atom'>\n";
    $entry .= "<source>\n";
    $entry .= "<title>" . $profile->nickname . " - " . common_config('site', 'name') . "</title>\n";
    $entry .= "<link href='" . htmlspecialchars($profile->profileurl) . "'/>\n";
    $entry .= "<link rel='self' type='application/rss+xml' href='" . $self_url . "'/>\n";
    $entry .= "<author><name>" . $profile->nickname . "</name></author>\n";
    $entry .= "<icon>" . $profile->avatarUrl(AVATAR_PROFILE_SIZE) . "</icon>\n";
    $entry .= "</source>\n";
    $entry .= "<title>" . htmlspecialchars($msg) . "</title>\n";
    $entry .= "<summary>" . htmlspecialchars($msg) . "</summary>\n";
    $entry .= "<link rel='alternate' href='" . $noticeurl . "' />\n";
    $entry .= "<id>". $notice->uri . "</id>\n";
    $entry .= "<published>".common_date_w3dtf($notice->created)."</published>\n";
    $entry .= "<updated>".common_date_w3dtf($notice->modified)."</updated>\n";
    $entry .= "</entry>\n";

    $html  = "\n<html xmlns='http://jabber.org/protocol/xhtml-im'>\n";
    $html .= "<body xmlns='http://www.w3.org/1999/xhtml'>\n";
    $html .= "<a href='".htmlspecialchars($profile->profileurl)."'>".$profile->nickname."</a>: ";
    $html .= ($notice->rendered) ? $notice->rendered : common_render_content($notice->content, $notice);
    $html .= "\n</body>\n";
    $html .= "\n</html>\n";

    $address  = "<addresses xmlns='http://jabber.org/protocol/address'>\n";
    $address .= "<address type='replyto' jid='" . jabber_daemon_address() . "' />\n";
    $address .= "</addresses>\n";

    // FIXME: include a pubsub event, too.

    return $html . $entry . $address;
}

/**
 * sends a single text message to a given JID
 *
 * @param string $to      JID to send the message to
 * @param string $body    body of the message
 * @param string $type    type of the message
 * @param string $subject subject of the message
 *
 * @return boolean success flag
 */

function jabber_send_message($to, $body, $type='chat', $subject=null)
{
    $conn = jabber_connect();
    if (!$conn) {
        return false;
    }
    $conn->message($to, $body, $type, $subject);
    return true;
}

/**
 * sends a presence stanza on the Jabber network
 *
 * @param string $status   current status, free-form string
 * @param string $show     structured status value
 * @param string $to       recipient of presence, null for general
 * @param string $type     type of status message, related to $show
 * @param int    $priority priority of the presence
 *
 * @return boolean success value
 */

function jabber_send_presence($status, $show='available', $to=null,
                              $type = 'available', $priority=null)
{
    $conn = jabber_connect();
    if (!$conn) {
        return false;
    }
    $conn->presence($status, $show, $to, $type, $priority);
    return true;
}

/**
 * sends a confirmation request to a JID
 *
 * @param string $code     confirmation code for confirmation URL
 * @param string $nickname nickname of confirming user
 * @param string $address  JID to send confirmation to
 *
 * @return boolean success flag
 */

function jabber_confirm_address($code, $nickname, $address)
{
    $body = 'User "' . $nickname . '" on ' . common_config('site', 'name') . ' ' .
      'has said that your Jabber ID belongs to them. ' .
      'If that\'s true, you can confirm by clicking on this URL: ' .
      common_local_url('confirmaddress', array('code' => $code)) .
      ' . (If you cannot click it, copy-and-paste it into the ' .
      'address bar of your browser). If that user isn\'t you, ' .
      'or if you didn\'t request this confirmation, just ignore this message.';

    return jabber_send_message($address, $body);
}

/**
 * sends a "special" presence stanza on the Jabber network
 *
 * @param string $type   Type of presence
 * @param string $to     JID to send presence to
 * @param string $show   show value for presence
 * @param string $status status value for presence
 *
 * @return boolean success flag
 *
 * @see jabber_send_presence()
 */

function jabber_special_presence($type, $to=null, $show=null, $status=null)
{
    // FIXME: why use this instead of jabber_send_presence()?
    $conn = jabber_connect();

    $to     = htmlspecialchars($to);
    $status = htmlspecialchars($status);

    $out = "<presence";
    if ($to) {
        $out .= " to='$to'";
    }
    if ($type) {
        $out .= " type='$type'";
    }
    if ($show == 'available' and !$status) {
        $out .= "/>";
    } else {
        $out .= ">";
        if ($show && ($show != 'available')) {
            $out .= "<show>$show</show>";
        }
        if ($status) {
            $out .= "<status>$status</status>";
        }
        $out .= "</presence>";
    }
    $conn->send($out);
}

/**
 * broadcast a notice to all subscribers and reply recipients
 *
 * This function will send a notice to all subscribers on the local server
 * who have Jabber addresses, and have Jabber notification enabled, and
 * have this subscription enabled for Jabber. It also sends the notice to
 * all recipients of @-replies who have Jabber addresses and Jabber notification
 * enabled. This is really the heart of Jabber distribution in Laconica.
 *
 * @param Notice $notice The notice to broadcast
 *
 * @return boolean success flag
 */

function jabber_broadcast_notice($notice)
{
    if (!common_config('xmpp', 'enabled')) {
        return true;
    }
    $profile = Profile::staticGet($notice->profile_id);

    if (!$profile) {
        common_log(LOG_WARNING, 'Refusing to broadcast notice with ' .
                   'unknown profile ' . common_log_objstring($notice),
                   __FILE__);
        return false;
    }

    $msg   = jabber_format_notice($profile, $notice);
    $entry = jabber_format_entry($profile, $notice);

    $profile->free();
    unset($profile);

    $sent_to = array();

    $conn = jabber_connect();

    // First, get users to whom this is a direct reply
    $user = new User();
    $UT = common_config('db','type')=='pgsql'?'"user"':'user';
    $user->query("SELECT $UT.id, $UT.jabber " .
                 "FROM $UT JOIN reply ON $UT.id = reply.profile_id " .
                 'WHERE reply.notice_id = ' . $notice->id . ' ' .
                 "AND $UT.jabber is not null " .
                 "AND $UT.jabbernotify = 1 " .
                 "AND $UT.jabberreplies = 1 ");

    while ($user->fetch()) {
        common_log(LOG_INFO,
                   'Sending reply notice ' . $notice->id . ' to ' . $user->jabber,
                   __FILE__);
        $conn->message($user->jabber, $msg, 'chat', null, $entry);
        $conn->processTime(0);
        $sent_to[$user->id] = 1;
    }

    $user->free();

    // Now, get users subscribed to this profile

    $user = new User();
    $user->query("SELECT $UT.id, $UT.jabber " .
                 "FROM $UT JOIN subscription " .
                 "ON $UT.id = subscription.subscriber " .
                 'WHERE subscription.subscribed = ' . $notice->profile_id . ' ' .
                 "AND $UT.jabber is not null " .
                 "AND $UT.jabbernotify = 1 " .
                 'AND subscription.jabber = 1 ');

    while ($user->fetch()) {
        if (!array_key_exists($user->id, $sent_to)) {
            common_log(LOG_INFO,
                       'Sending notice ' . $notice->id . ' to ' . $user->jabber,
                       __FILE__);
            $conn->message($user->jabber, $msg, 'chat', null, $entry);
            // To keep the incoming queue from filling up,
            // we service it after each send.
            $conn->processTime(0);
            $sent_to[$user->id] = 1;
        }
    }

    // Now, get users who have it in their inbox because of groups

    $user = new User();
    $user->query("SELECT $UT.id, $UT.jabber " .
                 "FROM $UT JOIN notice_inbox " .
                 "ON $UT.id = notice_inbox.user_id " .
                 'WHERE notice_inbox.notice_id = ' . $notice->id . ' ' .
                 'AND notice_inbox.source = 2 ' .
                 'AND user.jabber is not null ' .
                 'AND user.jabbernotify = 1 ');

    while ($user->fetch()) {
        if (!array_key_exists($user->id, $sent_to)) {
            common_log(LOG_INFO,
                       'Sending notice ' . $notice->id . ' to ' . $user->jabber,
                       __FILE__);
            $conn->message($user->jabber, $msg, 'chat', null, $entry);
            // To keep the incoming queue from filling up,
            // we service it after each send.
            $conn->processTime(0);
            $sent_to[$user->id] = 1;
        }
    }

    $user->free();

    return true;
}

/**
 * send a notice to all public listeners
 *
 * For notices that are generated on the local system (by users), we can optionally
 * forward them to remote listeners by XMPP.
 *
 * @param Notice $notice notice to broadcast
 *
 * @return boolean success flag
 */

function jabber_public_notice($notice)
{
    // Now, users who want everything

    $public = common_config('xmpp', 'public');

    // FIXME PRIV don't send out private messages here
    // XXX: should we send out non-local messages if public,localonly
    // = false? I think not

    if ($public && $notice->is_local) {
        $profile = Profile::staticGet($notice->profile_id);

        if (!$profile) {
            common_log(LOG_WARNING, 'Refusing to broadcast notice with ' .
                       'unknown profile ' . common_log_objstring($notice),
                       __FILE__);
            return false;
        }

        $msg   = jabber_format_notice($profile, $notice);
        $entry = jabber_format_entry($profile, $notice);

        $conn = jabber_connect();

        foreach ($public as $address) {
            common_log(LOG_INFO,
                       'Sending notice ' . $notice->id .
                       ' to public listener ' . $address,
                       __FILE__);
            $conn->message($address, $msg, 'chat', null, $entry);
            $conn->processTime(0);
        }
        $profile->free();
    }

    return true;
}

/**
 * makes a plain-text formatted version of a notice, suitable for Jabber distribution
 *
 * @param Profile &$profile profile of the sending user
 * @param Notice  &$notice  notice being sent
 *
 * @return string plain-text version of the notice, with user nickname prefixed
 */

function jabber_format_notice(&$profile, &$notice)
{
    return $profile->nickname . ': ' . $notice->content;
}