<?php
/*
 * Laconica - a distributed open-source microblogging tool
 * Copyright (C) 2008, Controlez-Vous, Inc.
 *
 * 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/>.
 */

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

/**
 * Table Definition for notice
 */
require_once INSTALLDIR.'/classes/Memcached_DataObject.php';

/* We keep the first three 20-notice pages, plus one for pagination check,
 * in the memcached cache. */

define('NOTICE_CACHE_WINDOW', 61);

class Notice extends Memcached_DataObject
{
    ###START_AUTOCODE
    /* the code below is auto generated do not remove the above tag */

    public $__table = 'notice';                             // table name
    public $id;                                 // int(4)    primary_key not_null
    public $profile_id;                         // int(4)     not_null
    public $uri;                             // varchar(255)  unique_key
    public $content;                         // varchar(140)
    public $rendered;                         // text()
    public $url;                             // varchar(255)
    public $created;                         // datetime()     not_null
    public $modified;                         // timestamp()      not_null default_CURRENT_TIMESTAMP
    public $reply_to;                         // int(4)
    public $is_local;                         // tinyint(1)
    public $source;                             // varchar(32)

    /* Static get */
    function staticGet($k,$v=null)
    { return Memcached_DataObject::staticGet('Notice',$k,$v); }

    /* the code above is auto generated do not remove the tag below */
    ###END_AUTOCODE

    function getProfile()
    {
        return Profile::staticGet('id', $this->profile_id);
    }

    function delete()
    {
        $this->blowCaches(true);
        $this->blowFavesCache(true);
        $this->blowInboxes();
        return parent::delete();
    }

    function saveTags()
    {
        /* extract all #hastags */
        $count = preg_match_all('/(?:^|\s)#([A-Za-z0-9_\-\.]{1,64})/', strtolower($this->content), $match);
        if (!$count) {
            return true;
        }

        /* elide characters we don't want in the tag */
        $match[1] = str_replace(array('-', '_', '.'), '', $match[1]);

        /* Add them to the database */
        foreach(array_unique($match[1]) as $hashtag) {
            $tag = DB_DataObject::factory('Notice_tag');
            $tag->notice_id = $this->id;
            $tag->tag = $hashtag;
            $tag->created = $this->created;
            $id = $tag->insert();
            if (!$id) {
                $last_error = PEAR::getStaticProperty('DB_DataObject','lastError');
                common_log(LOG_ERR, 'DB error inserting hashtag: ' . $last_error->message);
                common_server_error(sprintf(_('DB error inserting hashtag: %s'), $last_error->message));
                return;
            }
        }
        return true;
    }

    static function saveNew($profile_id, $content, $source=null, $is_local=1, $reply_to=null, $uri=null) {

        $profile = Profile::staticGet($profile_id);

        if (!$profile) {
            common_log(LOG_ERR, 'Problem saving notice. Unknown user.');
            return _('Problem saving notice. Unknown user.');
        }

        if (common_config('throttle', 'enabled') && !Notice::checkEditThrottle($profile_id)) {
            common_log(LOG_WARNING, 'Excessive posting by profile #' . $profile_id . '; throttled.');
            return _('Too many notices too fast; take a breather and post again in a few minutes.');
        }

        $banned = common_config('profile', 'banned');

        if ( in_array($profile_id, $banned) || in_array($profile->nickname, $banned)) {
            common_log(LOG_WARNING, "Attempted post from banned user: $profile->nickname (user id = $profile_id).");
            return _('You are banned from posting notices on this site.');
        }

        $notice = new Notice();
        $notice->profile_id = $profile_id;

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

        # Blacklisted are non-false, but not 1, either

        if ($blacklist && in_array($profile_id, $blacklist)) {
            $notice->is_local = -1;
        } else {
            $notice->is_local = $is_local;
        }

        $notice->reply_to = $reply_to;
        $notice->created = common_sql_now();
        $notice->content = common_shorten_links($content);
        $notice->rendered = common_render_content($notice->content, $notice);
        $notice->source = $source;
        $notice->uri = $uri;

        $id = $notice->insert();

        if (!$id) {
            common_log_db_error($notice, 'INSERT', __FILE__);
            return _('Problem saving notice.');
        }

        # Update the URI after the notice is in the database
        if (!$uri) {
            $orig = clone($notice);
            $notice->uri = common_notice_uri($notice);

            if (!$notice->update($orig)) {
                common_log_db_error($notice, 'UPDATE', __FILE__);
                return _('Problem saving notice.');
            }
        }

        # XXX: do we need to change this for remote users?

        common_save_replies($notice);
        $notice->saveTags();

        # Clear the cache for subscribed users, so they'll update at next request
        # XXX: someone clever could prepend instead of clearing the cache

        if (common_config('memcached', 'enabled')) {
            $notice->blowCaches();
        }

        $notice->addToInboxes();
        return $notice;
    }

    static function checkEditThrottle($profile_id) {
        $profile = Profile::staticGet($profile_id);
        if (!$profile) {
            return false;
        }
        # Get the Nth notice
        $notice = $profile->getNotices(common_config('throttle', 'count') - 1, 1);
        if ($notice && $notice->fetch()) {
            # If the Nth notice was posted less than timespan seconds ago
            if (time() - strtotime($notice->created) <= common_config('throttle', 'timespan')) {
                # Then we throttle
                return false;
            }
        }
        # Either not N notices in the stream, OR the Nth was not posted within timespan seconds
        return true;
    }

    function blowCaches($blowLast=false)
    {
        $this->blowSubsCache($blowLast);
        $this->blowNoticeCache($blowLast);
        $this->blowRepliesCache($blowLast);
        $this->blowPublicCache($blowLast);
        $this->blowTagCache($blowLast);
    }

    function blowTagCache($blowLast=false)
    {
        $cache = common_memcache();
        if ($cache) {
            $tag = new Notice_tag();
            $tag->notice_id = $this->id;
            if ($tag->find()) {
                while ($tag->fetch()) {
                    $cache->delete(common_cache_key('notice_tag:notice_stream:' . $tag->tag));
                    if ($blowLast) {
                        $cache->delete(common_cache_key('notice_tag:notice_stream:' . $tag->tag . ';last'));
                    }
                }
            }
            $tag->free();
            unset($tag);
        }
    }

    function blowSubsCache($blowLast=false)
    {
        $cache = common_memcache();
        if ($cache) {
            $user = new User();

            $user->query('SELECT id ' .
                         'FROM user JOIN subscription ON user.id = subscription.subscriber ' .
                         'WHERE subscription.subscribed = ' . $this->profile_id);

            while ($user->fetch()) {
                $cache->delete(common_cache_key('user:notices_with_friends:' . $user->id));
                if ($blowLast) {
                    $cache->delete(common_cache_key('user:notices_with_friends:' . $user->id . ';last'));
                }
            }
            $user->free();
            unset($user);
        }
    }

    function blowNoticeCache($blowLast=false)
    {
        if ($this->is_local) {
            $cache = common_memcache();
            if ($cache) {
                $cache->delete(common_cache_key('profile:notices:'.$this->profile_id));
                if ($blowLast) {
                    $cache->delete(common_cache_key('profile:notices:'.$this->profile_id.';last'));
                }
            }
        }
    }

    function blowRepliesCache($blowLast=false)
    {
        $cache = common_memcache();
        if ($cache) {
            $reply = new Reply();
            $reply->notice_id = $this->id;
            if ($reply->find()) {
                while ($reply->fetch()) {
                    $cache->delete(common_cache_key('user:replies:'.$reply->profile_id));
                    if ($blowLast) {
                        $cache->delete(common_cache_key('user:replies:'.$reply->profile_id.';last'));
                    }
                }
            }
            $reply->free();
            unset($reply);
        }
    }

    function blowPublicCache($blowLast=false)
    {
        if ($this->is_local == 1) {
            $cache = common_memcache();
            if ($cache) {
                $cache->delete(common_cache_key('public'));
                if ($blowLast) {
                    $cache->delete(common_cache_key('public').';last');
                }
            }
        }
    }

    function blowFavesCache($blowLast=false)
    {
        $cache = common_memcache();
        if ($cache) {
            $fave = new Fave();
            $fave->notice_id = $this->id;
            if ($fave->find()) {
                while ($fave->fetch()) {
                    $cache->delete(common_cache_key('user:faves:'.$fave->user_id));
                    if ($blowLast) {
                        $cache->delete(common_cache_key('user:faves:'.$fave->user_id.';last'));
                    }
                }
            }
            $fave->free();
            unset($fave);
        }
    }

    # XXX: too many args; we need to move to named params or even a separate
    # class for notice streams

    static function getStream($qry, $cachekey, $offset=0, $limit=20, $since_id=0, $before_id=0, $order=null, $since=null) {

        if (common_config('memcached', 'enabled')) {

            # Skip the cache if this is a since, since_id or before_id qry
            if ($since_id > 0 || $before_id > 0 || $since) {
                return Notice::getStreamDirect($qry, $offset, $limit, $since_id, $before_id, $order, $since);
            } else {
                return Notice::getCachedStream($qry, $cachekey, $offset, $limit, $order);
            }
        }

        return Notice::getStreamDirect($qry, $offset, $limit, $since_id, $before_id, $order, $since);
    }

    static function getStreamDirect($qry, $offset, $limit, $since_id, $before_id, $order, $since) {

        $needAnd = false;
        $needWhere = true;

        if (preg_match('/\bWHERE\b/i', $qry)) {
            $needWhere = false;
            $needAnd = true;
        }

        if ($since_id > 0) {

            if ($needWhere) {
                $qry .= ' WHERE ';
                $needWhere = false;
            } else {
                $qry .= ' AND ';
            }

            $qry .= ' notice.id > ' . $since_id;
        }

        if ($before_id > 0) {

            if ($needWhere) {
                $qry .= ' WHERE ';
                $needWhere = false;
            } else {
                $qry .= ' AND ';
            }

            $qry .= ' notice.id < ' . $before_id;
        }

        if ($since) {

            if ($needWhere) {
                $qry .= ' WHERE ';
                $needWhere = false;
            } else {
                $qry .= ' AND ';
            }

            $qry .= ' notice.created > \'' . date('Y-m-d H:i:s', $since) . '\'';
        }

        # Allow ORDER override

        if ($order) {
            $qry .= $order;
        } else {
            $qry .= ' ORDER BY notice.created DESC, notice.id DESC ';
        }

        if (common_config('db','type') == 'pgsql') {
            $qry .= ' LIMIT ' . $limit . ' OFFSET ' . $offset;
        } else {
            $qry .= ' LIMIT ' . $offset . ', ' . $limit;
        }

        $notice = new Notice();

        $notice->query($qry);

        return $notice;
    }

    # XXX: this is pretty long and should probably be broken up into
    # some helper functions

    static function getCachedStream($qry, $cachekey, $offset, $limit, $order) {

        # If outside our cache window, just go to the DB

        if ($offset + $limit > NOTICE_CACHE_WINDOW) {
            return Notice::getStreamDirect($qry, $offset, $limit, null, null, $order, null);
        }

        # Get the cache; if we can't, just go to the DB

        $cache = common_memcache();

        if (!$cache) {
            return Notice::getStreamDirect($qry, $offset, $limit, null, null, $order, null);
        }

        # Get the notices out of the cache

        $notices = $cache->get(common_cache_key($cachekey));

        # On a cache hit, return a DB-object-like wrapper

        if ($notices !== false) {
            $wrapper = new NoticeWrapper(array_slice($notices, $offset, $limit));
            return $wrapper;
        }

        # If the cache was invalidated because of new data being
        # added, we can try and just get the new stuff. We keep an additional
        # copy of the data at the key + ';last'

        # No cache hit. Try to get the *last* cached version

        $last_notices = $cache->get(common_cache_key($cachekey) . ';last');

        if ($last_notices) {

            # Reverse-chron order, so last ID is last.

            $last_id = $last_notices[0]->id;

            # XXX: this assumes monotonically increasing IDs; a fair
            # bet with our DB.

            $new_notice = Notice::getStreamDirect($qry, 0, NOTICE_CACHE_WINDOW,
                                                  $last_id, null, $order, null);

            if ($new_notice) {
                $new_notices = array();
                while ($new_notice->fetch()) {
                    $new_notices[] = clone($new_notice);
                }
                $new_notice->free();
                $notices = array_slice(array_merge($new_notices, $last_notices),
                                       0, NOTICE_CACHE_WINDOW);

                # Store the array in the cache for next time

                $result = $cache->set(common_cache_key($cachekey), $notices);
                $result = $cache->set(common_cache_key($cachekey) . ';last', $notices);

                # return a wrapper of the array for use now

                return new NoticeWrapper(array_slice($notices, $offset, $limit));
            }
        }

        # Otherwise, get the full cache window out of the DB

        $notice = Notice::getStreamDirect($qry, 0, NOTICE_CACHE_WINDOW, null, null, $order, null);

        # If there are no hits, just return the value

        if (!$notice) {
            return $notice;
        }

        # Pack results into an array

        $notices = array();

        while ($notice->fetch()) {
            $notices[] = clone($notice);
        }

        $notice->free();

        # Store the array in the cache for next time

        $result = $cache->set(common_cache_key($cachekey), $notices);
        $result = $cache->set(common_cache_key($cachekey) . ';last', $notices);

        # return a wrapper of the array for use now

        $wrapper = new NoticeWrapper(array_slice($notices, $offset, $limit));

        return $wrapper;
    }

    function publicStream($offset=0, $limit=20, $since_id=0, $before_id=0, $since=null)
    {

        $parts = array();

        $qry = 'SELECT * FROM notice ';

        if (common_config('public', 'localonly')) {
            $parts[] = 'is_local = 1';
        } else {
            # -1 == blacklisted
            $parts[] = 'is_local != -1';
        }

        if ($parts) {
            $qry .= ' WHERE ' . implode(' AND ', $parts);
        }

        return Notice::getStream($qry,
                                 'public',
                                 $offset, $limit, $since_id, $before_id, null, $since);
    }

    function addToInboxes()
    {
        $enabled = common_config('inboxes', 'enabled');

        if ($enabled === true || $enabled === 'transitional') {
            $inbox = new Notice_inbox();
            $qry = 'INSERT INTO notice_inbox (user_id, notice_id, created) ' .
              'SELECT user.id, ' . $this->id . ', "' . $this->created . '" ' .
              'FROM user JOIN subscription ON user.id = subscription.subscriber ' .
              'WHERE subscription.subscribed = ' . $this->profile_id . ' ' .
              'AND NOT EXISTS (SELECT user_id, notice_id ' .
              'FROM notice_inbox ' .
              'WHERE user_id = user.id ' .
              'AND notice_id = ' . $this->id . ' )';
            if ($enabled === 'transitional') {
                $qry .= ' AND user.inboxed = 1';
            }
            $inbox->query($qry);
        }
        return;
    }

    # Delete from inboxes if we're deleted.

    function blowInboxes()
    {

        $enabled = common_config('inboxes', 'enabled');

        if ($enabled === true || $enabled === 'transitional') {
            $inbox = new Notice_inbox();
            $inbox->notice_id = $this->id;
            $inbox->delete();
        }

        return;
    }

}