<?php

use dokuwiki\Extension\ActionPlugin;
use dokuwiki\Extension\EventHandler;

class action_plugin_piwiktagmanager extends ActionPlugin
{
    public const PWTMID = 'PWTMID';
    public const PWTMHOST = 'PWTMHOST';

    /**
      * Register its handlers with the DokuWiki's event controller
      */
    public function register(EventHandler $controller)
    {
        $controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'addHeaders');
    }

    public function addHeaders(&$event, $param)
    {
        $host = $this->getConf(self::PWTMHOST);
        $id   = $this->getConf(self::PWTMID);

        if (!$host || !$id) return;

        $event->data['script'][] = ['type' => 'text/javascript', '_data' => <<<EOT
            var _mtm = window._mtm = window._mtm || [];
            _mtm.push({'mtm.startTime': (new Date().getTime()), 'event': 'mtm.Start'});
            (function() {
              var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
              g.async=true; g.src='https://{$host}/piwik/js/container_{$id}.js'; s.parentNode.insertBefore(g,s);
            })();
            EOT
        ];
    }
}