<?php
/**
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Esther Brunner <wikidesign@gmail.com>
 */

/**
 * Action part of the tag plugin, handles tag display and index updates
 */
class action_plugin_tag extends DokuWiki_Action_Plugin {

    /**
     * register the eventhandlers
     *
     * @param Doku_Event_Handler $controller
     */
    public function register(Doku_Event_Handler $controller) {
        $controller->register_hook('ACTION_ACT_PREPROCESS', 'BEFORE', $this, 'catchTagAction', array());
        $controller->register_hook('TPL_ACT_UNKNOWN', 'BEFORE', $this, 'performTagAction', array());
        $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'beautifyKeywordsInMetaHeader', array());
        if($this->getConf('toolbar_icon')) {
            $controller->register_hook('TOOLBAR_DEFINE', 'AFTER', $this, 'insertToolbarButton', array ());
        }
        $controller->register_hook('INDEXER_VERSION_GET', 'BEFORE', $this, 'setTagIndexversion', array());
        $controller->register_hook('INDEXER_PAGE_ADD', 'BEFORE', $this, 'addTagsToIndex', array());
    }

    /**
     * Add a version string to the index so it is rebuilt
     * whenever the stored data format changes.
     */
    public function setTagIndexversion(Doku_Event $event, $param) {
        global $conf;
        $event->data['plugin_tag'] = '0.2.deaccent='.$conf['deaccent'];
    }

    /**
     * Add all data of the subject metadata to the metadata index.
     */
    public function addTagsToIndex(Doku_Event $event, $param) {
        /* @var helper_plugin_tag $helper */
        if ($helper = $this->loadHelper('tag')) {
            // make sure the tags are cleaned and no duplicate tags are added to the index
            $tags = p_get_metadata($event->data['page'], 'subject');
            if (!is_array($tags)) {
                $event->data['metadata']['subject'] = array();
            } else {
                $event->data['metadata']['subject'] = $helper->cleanTagList($tags);
            }
        }
    }

    /**
     * catch tag action
     *
     * @author Michael Klier <chi@chimeric.de>
     */
    public function catchTagAction(Doku_Event $event, $param) {
        if($event->data != 'showtag') return;
        $event->preventDefault();
    }

    /**
     * Display the tag page
     *
     * @param Doku_Event $event The TPL_ACT_UNKNOWN event
     * @param array $param optional parameters (unused)
     * @return void
     */
    public function performTagAction(Doku_Event $event, $param) {
        global $lang, $INPUT;

        if($event->data != 'showtag') return;
        $event->preventDefault();

        $tagns = $this->getConf('namespace');
        $flags = explode(',', str_replace(" ", "", $this->getConf('pagelist_flags')));

        $tag   = trim(str_replace($tagns.':', '', $INPUT->str('tag')));
        $ns    = trim($INPUT->str('ns'));

        /* @var helper_plugin_tag $helper */
        if ($helper = $this->loadHelper('tag')) {
            $pages = $helper->getTopic($ns, '', $tag);
        }

        if(!empty($pages)) {

            // let Pagelist Plugin do the work for us
            if (!$pagelist = $this->loadHelper('pagelist')) {
                return;
            }

            /* @var helper_plugin_pagelist $pagelist */
            $pagelist->setFlags($flags);
            $pagelist->startList();
            foreach ($pages as $page) {
                $pagelist->addPage($page);
            }

            print '<h1>TAG: ' . hsc(str_replace('_', ' ', $INPUT->str('tag'))) . '</h1>' . DOKU_LF;
            print '<div class="level1">' . DOKU_LF;
            print $pagelist->finishList();
            print '</div>' . DOKU_LF;

        } else {
            print '<div class="level1"><p>' . $lang['nothingfound'] . '</p></div>';
        }
    }

    /**
     * Inserts the tag toolbar button
     */
    public function insertToolbarButton(Doku_Event $event, $param) {
        $event->data[] = array(
            'type' => 'format',
            'title' => $this->getLang('toolbar_icon'),
            'icon' => '../../plugins/tag/images/tag-toolbar.png',
            'open' => '{{tag>',
            'close' => '}}'
        );
    }

    /**
     * Prevent displaying underscores instead of blanks inside the page keywords
     */
    public function beautifyKeywordsInMetaHeader(Doku_Event $event) {
        global $ID;

        // Fetch tags for the page; stop proceeding when no tags specified
        $tags = p_get_metadata($ID, 'subject', METADATA_DONT_RENDER);
        if(is_null($tags)) {
            return;
        }

        // Replace underscores with blanks
        foreach($event->data['meta'] as &$meta) {
            if($meta['name'] == 'keywords') {
                $meta['content'] = str_replace('_', ' ', $meta['content']);
            }
        }
    }
}
