<?php

/*
 * Author: Iñaki Ecenarro (WeblogsSL)
 */
require_once 'classes/LightPressPlugin.php';

class PostNavigation extends LightPressPlugin {
    
    var $constructor_args = array();
    var $default_context = LP_CONTEXT_POST;
    var $description = 'Show previous and next post links';
    
    var $active = true;
    var $hooks = array('parse_post');
    var $_block_previous = '';
    var $_block_next = 'plugin_postnavigation_next';
    var $post_current;
    var $post_previous;
    var $post_next;
    var $url_previous;
    var $url_next;
    
    function PostNavigation(&$frontend, $args, $dummy_run=false) {
        $this->LightPressPlugin($frontend, $args, $dummy_run);
    }
    
    function run($hook, &$hook_data) {

        $context = $this->_frontend->context;
        $db =& $this->_frontend->db;
        $tpl =& $this->_frontend->tpl;
        $post =& $this->_frontend->current_post;
        
        $prev_url = $next_url = '';

        if (!$post)
            return $this->hide();
        
        $tpl_vars = array(
            'PLUGIN_POSTNAVIGATION_PREV'            => '',
            'PLUGIN_POSTNAVIGATION_NEXT'            => '');
        
        $tpl->setFile('plugin_postnavigation', 'plugins/post_navigation.xml', true);
        
        $tables =& $this->_frontend->tables;
        
        // previous entry
        $q = "select
                p.id as post_id, p.post_name, p.post_title, p.post_category,
                UNIX_TIMESTAMP(p.post_date) as tstamp
              from {$tables['posts']} p
              where
                p.id <> {$post['post_id']} and
                {$this->_frontend->get_posts_clause} and
                UNIX_TIMESTAMP(p.post_date_gmt) <= '{$post['post_tstamp_gmt']}' and
                {$this->_frontend->only_published}
              order by p.post_date desc limit 1";

        if ($db->query($q) > 0 ) {
            $row = $db->next();
            $tpl_vars['plugin_postnavigation_prev_title'] = $row['post_title'];
            $tpl_vars['plugin_postnavigation_prev_permalink'] =  $this->_frontend->getPermalink(
                $row['post_id'], $row['post_name'], $row['tstamp'], $row['post_category']);
        } else {
            $tpl->setBlock('plugin_postnavigation', 'plugin_postnavigation_prev');
        }
        
        // next entry
        $q = "select
                p.id as post_id, p.post_name, p.post_title, p.post_category,
                UNIX_TIMESTAMP(p.post_date) as tstamp
              from {$tables['posts']} p
              where
                p.id <> {$post['post_id']} and
                {$this->_frontend->get_posts_clause} and
                UNIX_TIMESTAMP(p.post_date_gmt) >= '{$post['post_tstamp_gmt']}' and
                {$this->_frontend->only_published}
              order by p.post_date limit 1";

        if ($db->query($q) > 0 ) {
            $row = $db->next();
            $tpl_vars['plugin_postnavigation_next_title'] = $row['post_title'];
            $tpl_vars['plugin_postnavigation_next_permalink'] = $this->_frontend->getPermalink($row['post_id'], $row['post_name'], $row['tstamp'], $row['post_category']);
        } else {
            $tpl->setBlock('plugin_postnavigation', 'plugin_postnavigation_next');
        }
        
        $tpl->setVar($tpl_vars);
        
        $tpl->parse('PLUGIN_POSTNAVIGATION', 'plugin_postnavigation');
            
    }
    
}

?>