<?php
/**
 * Semantic Action Plugin
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Giuseppe Di Terlizzi <giuseppe.diterlizzi@gmail.com>
 * @copyright  (C) 2015, Giuseppe Di Terlizzi
 */

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

/**
 * Class Semantic Action Plugin
 *
 * Add semantic data to DokuWiki
 */
class action_plugin_semantic extends DokuWiki_Action_Plugin {

  private $helper = null;

  public function __construct() {
    $this->helper = $this->loadHelper('semantic');
  }

  /**
   * Register events
   *
   * @param  Doku_Event_Handler  $controller
   */
  public function register(Doku_Event_Handler $controller) {

    if ($this->getConf('useJSONLD')) {
      $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'website');
      $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'json_ld');
    }

    if ($this->getConf('useMetaDescription')) {
      $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'meta_description');
    }

    if ($this->getConf('useMetaAuthor')) {
      $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'meta_author');
    }

    if ($this->getConf('useDublinCore')) {
      $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'meta_dublin_core');
    }

    if ($this->getConf('exposeWebService')) {
      $controller->register_hook('AJAX_CALL_UNKNOWN', 'BEFORE', $this, 'ajax');
    }

      $controller->register_hook('DOKUWIKI_STARTED', 'AFTER', $this, 'jsinfo');
    }


    public function jsinfo(Doku_Event &$event, $param) {

      global $JSINFO;

      $JSINFO['plugin']['semantic'] = array(
        'exposeWebService' => $this->getConf('exposeWebService'),
      );

    }

  /**
   * Export in JSON-LD format
   *
   * @param   Doku_Event &$event
   * @return  string
   */
  public function ajax(Doku_Event &$event, $param) {

    if ($event->data !== 'plugin_semantic') {
      return false;
    }

    //no other ajax call handlers needed
    $event->stopPropagation();
    $event->preventDefault();

    global $INPUT;

    $export = $INPUT->str('export');
    $id     = $INPUT->str('id');

    if (! $id) return false;

    $this->helper->getMetadata($id);
    $json_ld = $this->helper->getJsonLD();

    $json = new JSON();

    header('Content-Type: application/ld+json');
    print $json->encode($json_ld);
    return true;

  }


  public function website(Doku_Event &$event, $param) {
    $event->data["script"][] = array (
      "type"  => "application/ld+json",
      "_data" => json_encode($this->helper->getWebSite()),
    );
  }


  /**
   * JSON-LD Event handler
   *
   * @param  Doku_Event  &$event
   */
  public function json_ld(Doku_Event &$event, $param) {

    global $ID;

    $this->helper->getMetadata($ID);
    $json_ld = $this->helper->getJsonLD();

    if (! count($json_ld)) return false;

    $event->data["script"][] = array (
      "type"  => "application/ld+json",
      "_data" => json_encode($json_ld),
    );

  }


  public function meta_description(Doku_Event &$event, $params) {

    global $ID;

    $this->helper->getMetadata($ID);

    if ($description = $this->helper->getDescription()) {

      $description = str_replace("\n", ' ', $description);

      $event->data['meta'][] = array(
        'name'    => 'description',
        'content' => $description,
      );

    }

  }


  public function meta_author(Doku_Event &$event, $params) {

    global $ID;

    $this->helper->getMetadata($ID);

    if ($author = $this->helper->getAuthor()) {

      $event->data['meta'][] = array(
        'name'    => 'author',
        'content' => $author,
      );

    }

  }


  public function meta_dublin_core(Doku_Event &$event, $params) {

    global $ID;

    $this->helper->getMetadata($ID);

    foreach ($this->helper->getDublinCore() as $name => $content) {

      if (! $content) continue;

      $event->data['meta'][] = array(
        'name'    => $name,
        'content' => $content,
      );

    }

  }

}