<?php

use dokuwiki\Extension\EventHandler;
use dokuwiki\Extension\Event;

/**
 * Action Component for the Bot Monitoring Plugin
 *
 * @license	GPL 3 (http://www.gnu.org/licenses/gpl.html)
 * @author	 Sascha Leib <sascha.leib(at)kolmio.com>
 */

class action_plugin_botmon extends DokuWiki_Action_Plugin {

	/**
	 * Registers a callback functions
	 *
	 * @param EventHandler $controller DokuWiki's event controller object
	 * @return void
	 */
	public function register(EventHandler $controller) {
		$controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'insertHeader');
	}

	/**
	 * Inserts tracking code to the page header
	 *
	 * @param Event $event event object by reference
	 * @return void
	 */
	public function insertHeader(Event $event, $param) {

		global $INFO;

		// is there a user logged in?
		$username = ( !empty($INFO['userinfo']) && !empty($INFO['userinfo']['name'])
					?  $INFO['userinfo']['name'] : '');

		// build the tracker code:
		$code = NL . DOKU_TAB . "document._botmon = {'t0': Date.now()};" . NL;
		if ($username) {
			$code .= DOKU_TAB . 'document._botmon.user = "' . $username . '";'. NL;
		}
		$code .= DOKU_TAB . "addEventListener('load',function(){" . NL;

		$code .= DOKU_TAB . DOKU_TAB . "const e=document.createElement('script');" . NL;
		$code .= DOKU_TAB . DOKU_TAB . "e.async=true;e.defer=true;" . NL;
		$code .= DOKU_TAB . DOKU_TAB . "e.src='".DOKU_BASE."lib/plugins/botmon/client.js';" . NL;
		$code .= DOKU_TAB . DOKU_TAB . "document.getElementsByTagName('head')[0].appendChild(e);" . NL;
		$code .= DOKU_TAB . "});" . NL . DOKU_TAB;

		$event->data['script'][] = [
			'_data'   => $code
        ];

		/* Write out server-side info to a server log: */
		$this->writeServerLog($username);
	}

	/**
	 * Writes data to the server log.
	 *
	 * @return void
	 */
	private function writeServerLog($username) {

		global $conf;
		global $INFO;

		// what is the session identifier?
		$sessionId = $_COOKIE['DokuWiki']  ?? '';
		$sessionType = 'dw';
		if ($sessionId == '') {
			$sessionId = $_SERVER['REMOTE_ADDR'] ?? '';
			if ($sessionId == '127.0.0.1' || $sessionId == '::1') {
				$sessionId = 'localhost';
			}
			$sessionType = 'ip';
		}

		// clean the page ID
		$pageId = preg_replace('/[\x00-\x1F]/', "\u{FFFD}", $INFO['id'] ?? '');

		// create the log array:
		$logArr = Array(
			$_SERVER['REMOTE_ADDR'] ?? '', /* remote IP */
			$pageId, /* page ID */
			$sessionId, /* Session ID */
			$sessionType, /* session ID type */
			$username,
			$_SERVER['HTTP_USER_AGENT'] ?? '', /* User agent */
			$_SERVER['HTTP_REFERER'] ?? '', /* HTTP Referrer */
			substr($conf['lang'],0,2), /* page language */
			implode(',', array_unique(array_map( function($it) { return substr($it,0,2); }, explode(',',trim($_SERVER['HTTP_ACCEPT_LANGUAGE'], " \t;,*"))))) /* accepted client languages */
		);

		//* create the log line */
		$filename = __DIR__ .'/logs/' . gmdate('Y-m-d') . '.srv.txt'; /* use GMT date for filename */
		$logline = gmdate('Y-m-d H:i:s'); /* use GMT time for log entries */
		foreach ($logArr as $tab) {
			$logline .= "\t" . $tab;
		};

		/* write the log line to the file */
		$logfile = fopen($filename, 'a');
		if (!$logfile) die();
		if (fwrite($logfile, $logline . "\n") === false) {
			fclose($logfile);
			die();
		}

		/* Done */
		fclose($logfile);
	}
}