<?php
/**
 * Laconica, the distributed open-source microblogging tool
 *
 * Base class for RSS 1.0 feed actions
 *
 * 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  Mail
 * @package   Laconica
 * @author    Evan Prodromou <evan@controlyourself.ca>
 * @author    Earle Martin <earle@downlode.org>
 * @copyright 2008-9 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); }

define('DEFAULT_RSS_LIMIT', 48);

class Rss10Action extends Action
{
    # This will contain the details of each feed item's author and be used to generate SIOC data.
    
    var $creators = array();
    var $limit = DEFAULT_RSS_LIMIT;
    
    /**
     * Constructor
     *
     * Just wraps the Action constructor.
     *
     * @param string  $output URI to output to, default = stdout
     * @param boolean $indent Whether to indent output, default true
     *
     * @see Action::__construct
     */

    function __construct($output='php://output', $indent=true)
    {
        parent::__construct($output, $indent);
    }

    /**
     * Do we need to write to the database?
     * 
     * @return boolean true
     */
    
    function isReadonly()
    {
        return true;
    }

    /**
     * Read arguments and initialize members
     * 
     * @param array $args Arguments from $_REQUEST
     * @return boolean success
     */
    
    function prepare($args)
    {
	$this->limit = (int) $this->trimmed('limit');
	if ($this->limit == 0) {
	    $this->limit = DEFAULT_RSS_LIMIT;
	}
	return true;
    }
	
    /**
     * Handle a request
     * 
     * @param array $args Arguments from $_REQUEST
     * 
     * @return void
     */
    
    function handle($args)
    {
        parent::handle($args);
        $this->show_rss($limit);
    }

    /**
     * Get the notices to output in this stream
     * 
     * @return array an array of Notice objects sorted in reverse chron
     */
    
    function getNotices()
    {
        return array();
    }

    /**
     * Get a description of the channel
     * 
     * Returns an array with the following 
     * @return array 
    function get_channel()
    {
        return array('url' => '',
                     'title' => '',
                     'link' => '',
                     'description' => '');
    }

    function get_image()
    {
        return null;
    }

    function show_rss($limit=0)
    {
        $notices = $this->get_notices($limit);

        $this->init_rss();
        $this->show_channel($notices);
        $this->show_image();

        foreach ($notices as $n) {
            $this->show_item($n);
        }

        $this->show_creators();
        $this->end_rss();
    }

    function show_channel($notices)
    {

        $channel = $this->get_channel();
        $image = $this->get_image();

        common_element_start('channel', array('rdf:about' => $channel['url']));
        common_element('title', null, $channel['title']);
        common_element('link', null, $channel['link']);
        common_element('description', null, $channel['description']);
        common_element('cc:licence', array('rdf:resource' => common_config('license','url')));

        if ($image) {
            common_element('image', array('rdf:resource' => $image));
        }

        common_element_start('items');
        common_element_start('rdf:Seq');

        foreach ($notices as $notice) {
            common_element('sioct:MicroblogPost', array('rdf:resource' => $notice->uri));
        }

        common_element_end('rdf:Seq');
        common_element_end('items');

        common_element_end('channel');
    }

    function show_image()
    {
        $image = $this->get_image();
        if ($image) {
            $channel = $this->get_channel();
            common_element_start('image', array('rdf:about' => $image));
            common_element('title', null, $channel['title']);
            common_element('link', null, $channel['link']);
            common_element('url', null, $image);
            common_element_end('image');
        }
    }

    function show_item($notice)
    {
        $profile = Profile::staticGet($notice->profile_id);
        $nurl = common_local_url('shownotice', array('notice' => $notice->id));
        $creator_uri = common_profile_uri($profile);
        common_element_start('item', array('rdf:about' => $notice->uri));
        $title = $profile->nickname . ': ' . common_xml_safe_str(trim($notice->content));
        common_element('title', null, $title);
        common_element('link', null, $nurl);
        common_element('description', null, $profile->nickname."'s status on ".common_exact_date($notice->created));
        common_element('dc:date', null, common_date_w3dtf($notice->created));
        common_element('dc:creator', null, ($profile->fullname) ? $profile->fullname : $profile->nickname);
        common_element('sioc:has_creator', array('rdf:resource' => $creator_uri));
        common_element('laconica:postIcon', array('rdf:resource' => common_profile_avatar_url($profile)));
        common_element('cc:licence', array('rdf:resource' => common_config('license', 'url')));
        common_element_end('item');
        $this->creators[$creator_uri] = $profile;
    }

    function show_creators()
    {
        foreach ($this->creators as $uri => $profile) {
            $id = $profile->id;
            $nickname = $profile->nickname;
            common_element_start('sioc:User', array('rdf:about' => $uri));
            common_element('foaf:nick', null, $nickname);
            if ($profile->fullname) {
                common_element('foaf:name', null, $profile->fullname);
            }
            common_element('sioc:id', null, $id);
            $avatar = common_profile_avatar_url($profile);
            common_element('sioc:avatar', array('rdf:resource' => $avatar));
            common_element_end('sioc:User');
        }
    }

    function init_rss()
    {
        $channel = $this->get_channel();
        header('Content-Type: application/rdf+xml');

        common_start_xml();
        common_element_start('rdf:RDF', array('xmlns:rdf' =>
                                              'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
                                              'xmlns:dc' =>
                                              'http://purl.org/dc/elements/1.1/',
                                              'xmlns:cc' =>
                                              'http://web.resource.org/cc/',
                                              'xmlns:content' =>
                                              'http://purl.org/rss/1.0/modules/content/',
                                              'xmlns:foaf' =>
                                              'http://xmlns.com/foaf/0.1/',
                                              'xmlns:sioc' =>
                                              'http://rdfs.org/sioc/ns#',
                                              'xmlns:sioct' =>
                                              'http://rdfs.org/sioc/types#',
                                              'xmlns:laconica' =>
                                              'http://laconi.ca/ont/',
                                              'xmlns' => 'http://purl.org/rss/1.0/'));
        common_element_start('sioc:Site', array('rdf:about' => common_root_url()));
        common_element('sioc:name', null, common_config('site', 'name'));
        common_element_start('sioc:container_of');
        common_element('sioc:Container', array('rdf:about' =>
                                               $channel['url']));
        common_element_end('sioc:container_of');
        common_element_end('sioc:Site');
    }

    function end_rss()
    {
        common_element_end('rdf:RDF');
    }
}