<?php
/**
 * StatusNet, the distributed open-source microblogging tool
 *
 * List of popular notices
 *
 * 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  Public
 * @package   StatusNet
 * @author    Zach Copley <zach@status.net>
 * @author    Evan Prodromou <evan@status.net>
 * @copyright 2008-2009 StatusNet, Inc.
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link      http://status.net/
 */

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

require_once INSTALLDIR.'/lib/publicgroupnav.php';
require_once INSTALLDIR.'/lib/noticelist.php';

/**
 * List of popular notices
 *
 * We provide a list of the most popular notices. Popularity
 * is measured by
 *
 * @category Personal
 * @package  StatusNet
 * @author   Zach Copley <zach@status.net>
 * @author   Evan Prodromou <evan@status.net>
 * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link     http://status.net/
 */

class FavoritedAction extends Action
{
    var $page = null;

    /**
     * Title of the page
     *
     * @return string Title of the page
     */

    function title()
    {
        if ($this->page == 1) {
            return _('Popular notices');
        } else {
            return sprintf(_('Popular notices, page %d'), $this->page);
        }
    }

    /**
     * Instructions for use
     *
     * @return instructions for use
     */

    function getInstructions()
    {
        return _('The most popular notices on the site right now.');
    }

    /**
     * Is this page read-only?
     *
     * @return boolean true
     */

    function isReadOnly($args)
    {
        return true;
    }

    /**
     * Take arguments for running
     *
     * @param array $args $_REQUEST args
     *
     * @return boolean success flag
     *
     * @todo move queries from showContent() to here
     */

    function prepare($args)
    {
        parent::prepare($args);
        $this->page = ($this->arg('page')) ? ($this->arg('page')+0) : 1;

        common_set_returnto($this->selfUrl());

        return true;
    }

    /**
     * Handle request
     *
     * Shows a page with list of favorite notices
     *
     * @param array $args $_REQUEST args; handled in prepare()
     *
     * @return void
     */

    function handle($args)
    {
        parent::handle($args);

        $this->showPage();
    }

    /**
     * Show the page notice
     *
     * Shows instructions for the page
     *
     * @return void
     */

    function showPageNotice()
    {
        $instr  = $this->getInstructions();
        $output = common_markup_to_html($instr);

        $this->elementStart('div', 'instructions');
        $this->raw($output);
        $this->elementEnd('div');
    }

    function showEmptyList()
    {
        $message = _('Favorite notices appear on this page but no one has favorited one yet.') . ' ';

        if (common_logged_in()) {
            $message .= _('Be the first to add a notice to your favorites by clicking the fave button next to any notice you like.');
        }
        else {
            $message .= _('Why not [register an account](%%action.register%%) and be the first to add a notice to your favorites!');
        }

        $this->elementStart('div', 'guide');
        $this->raw(common_markup_to_html($message));
        $this->elementEnd('div');
    }

    /**
     * Local navigation
     *
     * This page is part of the public group, so show that.
     *
     * @return void
     */

    function showLocalNav()
    {
        $nav = new PublicGroupNav($this);
        $nav->show();
    }

    /**
     * Content area
     *
     * Shows the list of popular notices
     *
     * @return void
     */

    function showContent()
    {
        if (common_config('db', 'type') == 'pgsql') {
            $weightexpr='sum(exp(-extract(epoch from (now() - fave.modified)) / %s))';
        } else {
            $weightexpr='sum(exp(-(now() - fave.modified) / %s))';
        }

        $qry = 'SELECT notice.*, '.
          $weightexpr . ' as weight ' .
          'FROM notice JOIN fave ON notice.id = fave.notice_id ' .
          'GROUP BY id,profile_id,uri,content,rendered,url,created,notice.modified,reply_to,is_local,source,notice.conversation ' .
          'ORDER BY weight DESC';

        $offset = ($this->page - 1) * NOTICES_PER_PAGE;
        $limit  = NOTICES_PER_PAGE + 1;

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

        $notice = Memcached_DataObject::cachedQuery('Notice',
                                                    sprintf($qry, common_config('popular', 'dropoff')),
                                                    600);

        $nl = new NoticeList($notice, $this);

        $cnt = $nl->show();

        if ($cnt == 0) {
            $this->showEmptyList();
        }

        $this->pagination($this->page > 1, $cnt > NOTICES_PER_PAGE,
                          $this->page, 'favorited');
    }
}