<?php

/**
 * Bloglinks Plugin: displays a link to the previous and the next blog entry above posts in configured namespaces
 * 
 * @license  GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author   Gina Haeussge <osd@foosel.net>
 */

// must be run within Dokuwiki
if (!defined('DOKU_INC'))
    die();

if (!defined('DOKU_LF'))
    define('DOKU_LF', "\n");
if (!defined('DOKU_TAB'))
    define('DOKU_TAB', "\t");
if (!defined('DOKU_PLUGIN'))
    define('DOKU_PLUGIN', DOKU_INC . 'lib/plugins/');

require_once (DOKU_PLUGIN . 'action.php');
require_once(DOKU_INC . 'inc/pageutils.php');

class action_plugin_bloglinks extends DokuWiki_Action_Plugin {

    function getInfo() {
        return array (
            'author' => 'Gina Haeussge',
            'email' => 'osd@foosel.net',
            'date' => @file_get_contents(DOKU_PLUGIN . 'blog/VERSION'),
            'name' => 'Bloglinks Plugin',
            'desc' => 'Displays a link to the previous and the next blog entry above posts in configured namespaces',
            'url' => 'http://foosel.org/snippets/dokuwiki/bloglinks',
            
        );
    }

    /**
     * Register the eventhandlers.
     */
    function register(& $controller) {
        $controller->register_hook('TPL_ACT_RENDER', 'BEFORE', $this, 'handle_act_render', array ());
        $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'handle_metaheader_output', array ());
    }

	function handle_metaheader_output(& $event, $params) {
		global $ACT;
		
		if ($ACT != 'show')
			return;
		
		$namespace = $this->_getActiveNamespace();
		if (!$namespace)
			return;
			
		$relatedEntries = $this->_getRelatedEntries($namespace);

        if (isset ($relatedEntries['prev'])) {
	        $event->data['link'][] = array (
	            'rel' => 'prev',
	            'href' => wl($relatedEntries['prev']['id'], '')
	        );
        }
        if (isset ($relatedEntries['next'])) {
	        $event->data['link'][] = array (
	            'rel' => 'next',
	            'href' => wl($relatedEntries['next']['id'], '')
	        );
        }

        return true;
	}

    function handle_act_render(& $event, $params) {
		global $ACT;
		
		if ($ACT != 'show')
			return;

		$namespace = $this->_getActiveNamespace();
		if ($namespace)
			$this->_printLinks($this->_getRelatedEntries($namespace));

        return true;
    }
    
    function _getActiveNamespace() {
    	global $ID;
    	global $INFO;
    	
    	$pattern = $this->getConf('excluded_pages');
		if (strlen($pattern) > 0 && preg_match($pattern, $ID)) {
			return false;
		}

		if (!$INFO['exists'])
			return false;
		
        $namespaces = explode(',', $this->getConf('enabled_namespaces'));
        foreach ($namespaces as $namespace) {
            if (trim($namespace) && (strpos($ID, $namespace . ':') === 0)) {
                return $namespace;
            }
        }

        return false;
    }
    
    function _getRelatedEntries($namespace) {
        global $ID;

        // get the blog entries for the namespace
        if ($my = & plugin_load('helper', 'blog'))
            $entries = $my->getBlog($namespace);

        if (!$entries)
            return;

		// normalize keys
        $entries = array_values($entries);

		// prepare search for current page
        $meta = p_get_metadata($ID);
        if ($my->sort == 'mdate') {
            $date = $meta['date']['modified'];
            if (!$date) $date = filemtime(wikiFN($ID));
        } else {
            $date = $meta['date']['created'];
            if (!$date) $date = filectime(wikiFN($ID));
        }
        $perm = auth_quickaclcheck($ID);
        $curPage = array (
            'id' => $ID,
            'title' => $meta['title'],
            'date' => $date,
            'user' => $meta['creator'],
            'desc' => $meta['description']['abstract'],
            'exists' => true,
            'perm' => $perm,
            'draft' => ($meta['type'] == 'draft'),
        );
        
        // get index of current page 
        $curIndex = array_search($curPage, $entries);

		// get previous and next entries
        if ($curIndex > 0 && curIndex < count($entries) - 1) { // got a prev and a next
            list ($next, $cur, $prev) = array_slice($entries, $curIndex -1, 3);
        } else if ($curIndex == 0) { // only got a prev
            list ($cur, $prev) = array_slice($entries, $curIndex, 2);
        } else { // only got a next
            list ($next, $cur) = array_slice($entries, $curIndex -1, 2);
        }
		
		return array('prev' => $prev, 'cur' => $cur, 'next' => $next);
    }

	/**
	 * Prints the links to the related entries
	 */
    function _printLinks($relatedEntries) {
		// display links
        echo '<div id="plugin_bloglinks__links">' . DOKU_LF;
        
        foreach(array('prev', 'next') as $type) {
	        if (isset ($relatedEntries[$type])) {
		        echo '<div class="plugin_bloglinks__'.$type.'">';
	            echo '<a href="' . wl($relatedEntries[$type]['id'], '') . '" class="wikilink1" rel="'.$type.'">' . $this->_linkTemplate($relatedEntries[$type], $type) . '</a>';
		        echo '</div>';
	        }
        }
        echo DOKU_LF . '</div>';
    }
    
    function _linkTemplate($entry, $type) {
        global $conf;
        
        $replace = array(
        	'@@TITLE@@' => $entry['title'],
        	'@@AUTHOR@@' => $entry['user'],
        	'@@DATE@@' => date($conf['dformat'], $entry['date']),
        	'@@NAME@@' => $this->getLang($type . '_link'),
        );
        
        $linktext = $this->getConf($type.'_template');
        $linktext = str_replace(array_keys($replace), array_values($replace), $linktext);
        return $linktext;
    }
}

//Setup VIM: ex: et ts=4 enc=utf-8 :