<?php

if (is_callable('mb_internal_encoding')) {
	mb_internal_encoding("UTF-8");
	ini_set("mbstring.internal_encoding", "UTF-8");
}

// Setting include_path and __autoload
set_include_path(
	get_include_path().
	PATH_SEPARATOR.dirname(__FILE__)."/lib/backoffice".
	PATH_SEPARATOR.dirname(__FILE__)."/lib/handler".
	PATH_SEPARATOR.dirname(__FILE__)."/lib/object".
	PATH_SEPARATOR.dirname(__FILE__)."/lib/additional".
	PATH_SEPARATOR.dirname(__FILE__)."/lib/classes"
);

function __autoload($classname) {
	require_once($classname.".php");
}

require_once(dirname(dirname(__FILE__))."/config/config.php");
require_once(dirname(__FILE__)."/lib/phptal/PHPTAL.php");
require_once(dirname(__FILE__)."/lib/database/database.php");
require_once(dirname(__FILE__)."/dippler.php");
require_once(dirname(__FILE__)."/lib/recaptcha/recaptchalib.php");
require_once(dirname(__FILE__)."/lib/image/Image.php");

session_name("Dippler");
session_start();

if (!isset($_SESSION['__sid'])) {
	$_SESSION['__sid'] = md5(microtime().rand());
}

$Dippler = new Dippler();

$handler = get_input("handler");
$page = get_input("page");
$page = explode('/',$page);
if ($page[count($page) - 1] === '') {
	array_pop($page);
}
if (is_array($page) AND count($page)>0) {
    $Dippler->view_page($page, $handler);
} else if (is_array($page) AND count($page)<=0){
    $page []= "home";
    $Dippler->view_page($page, "courses");
} else {
    $Dippler->view_page("page_not_found");
}

function forward($location = "") {
	if (!headers_sent()) {
	    if ((substr_count($location, 'http://') == 0) && (substr_count($location, 'https://') == 0)) {
			$location = WWW_ROOT.$location;
		}
		// Only our own locations are acceptable
		if (!(strpos($location,WWW_ROOT) === 0)) {
			$location = WWW_ROOT;
		}
		header("location:".$location);
		exit;
	}

	return false;
}

function gatekeeper() {
	global $Dippler;
	if (!$Dippler->is_logged_in()) {
		$Dippler->add_system_message(_("Login required."), "error");
		forward();
	}
}

function admin_gatekeeper() {
	global $Dippler;
	if (!($Dippler->is_logged_in() && $Dippler->is_admin())) {
		$Dippler->add_system_message(_("Admin login required."), "error");
		forward();
	}
}

function query($sql) {
    global $Dippler;
    return $Dippler->db->query($sql);
}

function query_row($sql) {
    $res = query($sql);
    if ($res) {
        $ret = mysql_fetch_object($res);
        return $ret;
    }
    return false;
}

function query_insert($sql) {
    $res = query($sql);
    if ($res) {
        return mysql_insert_id();
    }
    return false;
}

function query_update($sql) {
    $res = query($sql);
    if ($res) {
        return true;
    }
    return false;
}

function get_input($variable, $default = "") {
    if (isset($_REQUEST[$variable])) {
        if (is_array($_REQUEST[$variable])) {
            $var = $_REQUEST[$variable];
        } else {
            $var = trim($_REQUEST[$variable]);
        }
        return $var;
    }
    return $default;
}

function get_user_by_id($user_id) {
    $user = new User($user_id);
    $user->load();
    return $user;
}

function get_course_by_id($course_id) {
    $course = new Course($course_id);
    $course->load();
    return $course;
}

function is_logged_in() {
	global $Dippler;
	return $Dippler->is_logged_in();
}

function is_admin_logged_in() {
    global $Dippler;
    if ($Dippler->is_logged_in()) {
        return $Dippler->is_admin();
    }
    return false;
}

function is_admin($user = NULL) {
	global $Dippler;
	return $Dippler->is_admin($user);
}

function is_teacher($user = NULL) {
	global $Dippler;
	return $Dippler->is_teacher($user);
}

function is_learner($user = NULL) {
	global $Dippler;
	return $Dippler->is_learner($user);
}

function get_logged_in_user() {
	global $Dippler;
	return $Dippler->get_logged_in_user();
}

function get_logged_in_user_id() {
    global $Dippler;
    $user = $Dippler->get_logged_in_user();
    if ($user) {
        return $user->getId();
    }
    return 0;
}

function normalize_credits($value) {
	if (substr_count($value, ',') > 0) {
		return str_replace(',', '.', $value);
	}
	return $value;
}

function check_credits($value) {
	$value = normalize_credits($value);
	if (is_numeric($value)) {
		return true;
	}
	return false;
}

function date_into_timestamp($date) {
	if (is_numeric($date) && $date > 86400) {
		return $date;
	}
	$replacables = array('.', ' ', '/', ',');
	$date = str_replace($replacables, '-', $date);
	return strtotime($date);
}

/* Action token system */

// TODO Consider adding $visibleerrors as first parameter
function validate_action_token($token = NULL, $ts = NULL) {
	global $Dippler;

	if (!$token) {
		$token = get_input("__token");
	}

	if (!$ts) {
		$ts = get_input("__ts");
	}

	// TODO Either define that in the config.php or just drop that alltogether and use the hard-coded value
	if (!defined('ACTION_TOKEN_TIMEOUT')) {
		$timeout = 2;
	} else {
		$timeout = ACTION_TOKEN_TIMEOUT;
	}

	$session_id = session_id();
    $bos_session_id = $_SESSION['__sid'];

	if (($token) && ($ts) && ($session_id) && ($bos_session_id)) {
		$generated_token = generate_action_token($ts);
		if ($token == $generated_token) {
			$hour = 60 * 60;
			$timeout = $timeout * $hour;
			$now = time();
			if (($timeout == 0) || (($ts>$now-$timeout) && ($ts<$now+$timeout))) {
				return true;
			} else {
				$Dippler->add_system_message(_("Action has timed out."), "error");
			}
		} else {
			$Dippler->add_system_message(_("Token mismatch"), "error");
		}
	} else {
		$Dippler->add_system_message(_("Missing token values"), "error");
	}

	return false;
}

function generate_action_token($timestamp) {
	global $Dippler;
	return $Dippler->generate_action_token($timestamp);
}

function action_gatekeeper() {
	if (validate_action_token()) {
		return true;
	}

	// TODO Check if using referer makes sense
	if ($_SERVER['HTTP_REFERER'] && (strpos($_SERVER['HTTP_REFERER'],WWW_ROOT) === 0)) {
		forward($_SERVER['HTTP_REFERER']);
	} else {
		forward();
	}
	exit;
}

function check_url_exists($url) {
	if (!empty($url)) {
		$parsed_url = parse_url($url);
		if ($parsed_url && isset($parsed_url['scheme'])) {
			$ch = curl_init($url);
			curl_setopt($ch, CURLOPT_TIMEOUT, 5);
			curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
			curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
			curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
			curl_setopt($ch, CURLOPT_MAXREDIRS, 5);
			curl_exec($ch);
			$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
			curl_close($ch);

			if ($httpcode>=200 && $httpcode<300) return true;
		}
	}
	return false;
}

function get_oembed_code($url) {
	$oembed_url = "";
	$parsed_url = parse_url($url);
	
	if (in_array($parsed_url['host'], array('youtube.com', 'www.youtube.com'))) {
		$oembed_url = "http://www.youtube.com/oembed?url=".urlencode($url)."&format=json&maxwidth=560";
	} else if (in_array($parsed_url['host'], array('slideshare.net', 'www.slideshare.net'))) {
		$oembed_url = "http://www.slideshare.net/api/oembed/2?url=".urlencode($url)."&format=json&maxwidth=560";
    } else if (in_array($parsed_url['host'], array('lemill.net', 'www.lemill.net'))) {
        // Hard-coded collection case for lemill.net
        $lemill_collection_regex_pattern = "/^http\:\/\/(?:www\.)?lemill.net\/(?:lemill-server\/)?community\/people\/[a-zA-Z0-9_-]+\/collections\/[a-zA-Z0-9_-]+\//";
        // Add slash to the end of the URL if not present, regualr expression requires that
        if (!(substr($url, -1) == '/')) {
            $url .= '/';
        }
        if(preg_match($lemill_collection_regex_pattern, $url, $matches) === 1) {
            // Using the result returned for the first match
            return "<iframe src=\"{$matches[0]}collection_clean_view\" width=\"100%\" height=\"550px\" scrolling=\"auto\" frameborder=\"1\"></iframe>";
        }
        // Fail if pattern does not match
        return false;
	} else {
		return false;
	}
    $ch = curl_init($oembed_url);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5);
	curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
	curl_setopt($ch, CURLOPT_MAXREDIRS, 5);
	$data = curl_exec($ch);
	$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
	curl_close($ch);

	if ($httpcode == 200) {
		$data = json_decode($data);
		if (is_object($data) && isset($data->html)) return $data->html;
	}
	return false;
}
?>