<?php
/**
 * Mahara: Electronic portfolio, weblog, resume builder and social networking
 * Copyright (C) 2006-2007 Catalyst IT Ltd (http://www.catalyst.net.nz)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @package    mahara
 * @subpackage core
 * @author     Penny Leach <penny@catalyst.net.nz>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL
 * @copyright  (C) 2006,2007 Catalyst IT Ltd http://catalyst.net.nz
 * @copyright  (C) portions from Moodle, (C) Martin Dougiamas http://dougiamas.com
 */

defined('INTERNAL') || die();


function &smarty_core() {

    require_once(get_config('libroot') . 'smarty/Smarty.class.php');
    $smarty =& new Smarty();
    
    $theme = theme_setup();
    $themepaths = themepaths();

    $smarty->template_dir = $theme->template_dir;

    $smarty->compile_dir  = get_config('dataroot').'smarty/compile';
    $smarty->cache_dir    = get_config('dataroot').'smarty/cache';

    $smarty->assign('THEMEURL', get_config('themeurl'));
    $smarty->assign('WWWROOT', get_config('wwwroot'));

    $theme_list = array();
    foreach ($themepaths['mahara'] as $themepath) {
        $theme_list[$themepath] = theme_get_url($themepath);
    }
    $smarty->assign('THEMELIST', json_encode($theme_list));

    return $smarty;
}


/**
 * This function creates a Smarty object and sets it up for use within our
 * podclass app, setting up some variables.
 *
 * The variables that it sets up are:
 *
 * - THEMEURL: The base url for static content
 * - WWWROOT: The base url for the Mahara system
 * - USER: The user object
 * - JAVASCRIPT: A list of javascript files to include in the header.  This
 *   list is passed into this function (see below).
 * - HEADERS: An array of any further headers to set.  Each header is just
 *   straight HTML (see below).
 * - PUBLIC: Set true if this page is a public page
 * - MAINNAV: Array defining the main navigation
 *
 * @param $javascript A list of javascript includes.  Each include should be just
 *                    the name of a file, and reside in {$THEMEURL}js/{filename}
 * @param $headers    A list of additional headers.  These are to be specified as
 *                    actual HTML.
 * @param $strings    A list of language strings required by the javascript code.
 * @return Smarty
 */

//smarty(array('js/tablerenderer.js', 'artefact/file/js/filebrowser.js'))
function &smarty($javascript = array(), $headers = array(), $pagestrings = array(), $extraconfig = array()) {
    global $USER, $SESSION;

    if (!is_array($headers)) {
        $headers = array();
    }
    if (!is_array($pagestrings)) {
        $pagestrings = array();
    }
    if (!is_array($extraconfig)) {
        $extraconfig = array();
    }

    $SIDEBLOCKS = array();

    $smarty = smarty_core();

    $wwwroot = get_config('wwwroot');
    $jswwwroot = json_encode($wwwroot);

    $theme_list = array();
    
    if (function_exists('pieform_get_headdata')) {
        $headers = array_merge($headers, pieform_get_headdata());
    }

    // Insert the appropriate javascript tags 
    $javascript_array = array();
    $jsroot = $wwwroot . 'js/';

    // TinyMCE must be included first for some reason we're not sure about
    $checkarray = array(&$javascript, &$headers);
    $found_tinymce = false;
    foreach ($checkarray as &$check) {
        if (($key = array_search('tinymce', $check)) !== false || ($key = array_search('tinytinymce', $check)) !== false) {
            if (!$found_tinymce) {
                $found_tinymce = $check[$key];
                $javascript_array[] = $jsroot . 'tinymce/tiny_mce.js';
                if (isset($extraconfig['tinymceinit'])) {
                    $headers[] = $extraconfig['tinymceinit'];
                }
                else {
                    $content_css = json_encode(theme_get_url('style/tinymce.css'));
                    $language = substr(current_language(), 0, 2);

                    if ($check[$key] == 'tinymce') {
                        $tinymce_config = <<<EOF
    editor_selector: 'wysiwyg',
    theme: "advanced",
    plugins: "table,emotions,iespell,inlinepopups,paste",
    theme_advanced_buttons1 : "bold,italic,underline,strikethrough,separator,forecolor,backcolor,separator,justifyleft,justifycenter,justifyright,justifyfull,separator,hr,emotions,iespell,cleanup,separator,link,unlink,separator,code",
    theme_advanced_buttons2 : "bullist,numlist,separator,tablecontrols,separator,cut,copy,paste,pasteword",
    theme_advanced_buttons3 : "fontselect,separator,fontsizeselect,separator,formatselect",
    theme_advanced_toolbar_location : "top",
    theme_advanced_toolbar_align : "center",
    width: '512',
EOF;
                    }
                    else {
                        $tinymce_config = <<<EOF
    editor_selector: 'tinywysiwyg',
    theme: "advanced",
    plugins: "fullscreen",
    theme_advanced_buttons1 : "bold,italic,underline,separator,justifyleft,justifycenter,justifyright,justifyfull",
    theme_advanced_buttons2 : "bullist,numlist,separator,link,unlink,separator,code,fullscreen",
    theme_advanced_buttons3 : "",
    theme_advanced_toolbar_location : "top",
    theme_advanced_toolbar_align : "center",
    fullscreen_new_window: true,
    fullscreen_settings: {
        theme: "advanced",
        plugins: "table,emotions,iespell,inlinepopups,paste",
        theme_advanced_buttons1 : "bold,italic,underline,strikethrough,separator,forecolor,backcolor,separator,justifyleft,justifycenter,justifyright,justifyfull,separator,hr,emotions,iespell,cleanup,separator,link,unlink,separator,code",
        theme_advanced_buttons2 : "bullist,numlist,separator,tablecontrols,separator,cut,copy,paste,pasteword",
        theme_advanced_buttons3 : "fontselect,separator,fontsizeselect,separator,formatselect"
    },
EOF;
                    }

                    $headers[] = <<<EOF
<script type="text/javascript">
tinyMCE.init({
    mode: "textareas",
    button_tile_map: true,
    {$tinymce_config}
    language: '{$language}',
    content_css : {$content_css},
    document_base_url: {$jswwwroot},
    relative_urls: false
});
</script>

EOF;
                }
                unset($check[$key]);
            }
            else {
                if ($check[$key] != $found_tinymce) {
                    log_warn('Two differently configured tinyMCE instances have been asked for on this page! This is not possible');
                }
                unset($check[$key]);
            }
        }
    }

    if (get_config('developermode')) {
        $javascript_array[] = $jsroot . 'MochiKit/MochiKit.js';
        $javascript_array[] = $jsroot . 'MochiKit/Position.js';
        $javascript_array[] = $jsroot . 'MochiKit/Color.js';
        $javascript_array[] = $jsroot . 'MochiKit/Visual.js';
        $javascript_array[] = $jsroot . 'MochiKit/DragAndDrop.js';
        $javascript_array[] = $jsroot . 'MochiKit/Format.js';
    }
    else {
        $javascript_array[] = $jsroot . 'MochiKit/Packed.js';
    }
    $javascript_array[] = $jsroot . 'keyboardNavigation.js';

    $strings = array();
    foreach ($pagestrings as $k => $v) {
        if (is_array($v)) {
            foreach ($v as $tag) {
                $strings[$tag] = get_raw_string($tag, $k);
            }
        }
        else {
            $strings[$k] = get_raw_string($k, $v);
        }
    }

    $jsstrings = jsstrings();
    $themepaths = themepaths();

    foreach ($javascript as $jsfile) {
        // For now, if there's no path in the js file, assume it's in
        // $jsroot and append '.js' to the name.  Later we may want to
        // ensure all smarty() calls include the full path to the js
        // file, with the proper extension.
        if (strpos($jsfile, '/') === false) {
            $javascript_array[] = $jsroot . $jsfile . '.js';
            if (isset($jsstrings[$jsfile])) {
                foreach ($jsstrings[$jsfile] as $section => $tags) {
                    foreach ($tags as $tag) {
                        $strings[$tag] = get_raw_string($tag, $section);
                    }
                }
            }
            if (isset($themepaths[$jsfile])) {
                foreach ($themepaths[$jsfile] as $themepath) {
                    $theme_list[$themepath] = theme_get_url($themepath);
                }
            }
        }
        else {
            // A .js file with a fully specified path
            $javascript_array[] = $wwwroot . $jsfile;
            // If $jsfile is from a plugin (i.e. plugintype/pluginname/js/foo.js)
            // Then get js strings from static function jsstrings in plugintype/pluginname/lib.php 
            $bits = explode('/', $jsfile);
            if (count($bits) == 4) {
                safe_require($bits[0], $bits[1]);
                $pluginclass = generate_class_name($bits[0], $bits[1]);
                $name = substr($bits[3], 0, strpos($bits[3], '.js'));
                if (is_callable(array($pluginclass, 'jsstrings'))) {
                    $tempstrings = call_static_method($pluginclass, 'jsstrings', $name);
                    foreach ($tempstrings as $section => $tags) {
                        foreach ($tags as $tag) {
                            $strings[$tag] = get_raw_string($tag, $section);
                        }
                    }
                }
                if (is_callable(array($pluginclass, 'jshelp'))) {
                    $tempstrings = call_static_method($pluginclass, 'jshelp', $name);
                    foreach ($tempstrings as $section => $tags) {
                        foreach ($tags as $tag) {
                            $strings[$tag . '.help'] = get_help_icon($bits[0], $bits[1], null, null,
                                                                     null, $tag);
                        }
                    }
                }
                if (is_callable(array($pluginclass, 'themepaths'))) {
                    $tmpthemepaths = call_static_method($pluginclass, 'themepaths', $name);
                    foreach ($tmpthemepaths as $themepath) {
                        $theme_list[$themepath] = theme_get_url($themepath);
                    }
                }
            }
        }
    }

    $javascript_array[] = $jsroot . 'mahara.js';
    if (get_config('developermode')) {
        $javascript_array[] = $jsroot . 'debug.js';
        if (isset($_SERVER['HTTP_USER_AGENT']) && false === stripos($_SERVER['HTTP_USER_AGENT'], 'gecko')) {
            $javascript_array[] = $jsroot . 'firebug/firebug.js';
        }
    }

    foreach ($jsstrings['mahara'] as $section => $tags) {
        foreach ($tags as $tag) {
            $strings[$tag] = get_raw_string($tag, $section);
        }
    }
    if (isset($extraconfig['themepaths']) && is_array($extraconfig['themepaths'])) {
        foreach ($extraconfig['themepaths'] as $themepath) {
            $theme_list[$themepath] = theme_get_url($themepath);
        }
    }

    $stringjs = '<script type="text/javascript">';
    $stringjs .= 'var strings = ' . json_encode($strings) . ';';
    $stringjs .= '</script>';


    // stylesheet set up - if we're in a plugin also get its stylesheet
    $stylesheets = array_reverse(theme_get_url('style/style.css', null, true));
    if (defined('SECTION_PLUGINTYPE') && defined('SECTION_PLUGINNAME') && SECTION_PLUGINTYPE != 'core') {
        if ($pluginsheets = theme_get_url('style/style.css', SECTION_PLUGINTYPE . '/' . SECTION_PLUGINNAME . '/', true)) {
            $stylesheets = array_merge($stylesheets, array_reverse($pluginsheets));
        }
    }
    if (get_config('developermode')) {
        $stylesheets[] = get_config('wwwroot') . 'theme/debug.css';
    }

    // look for extra stylesheets
    if (isset($extraconfig['stylesheets']) && is_array($extraconfig['stylesheets'])) {
        foreach ($extraconfig['stylesheets'] as $extrasheet) {
            if ($sheet = theme_get_url($extrasheet)) {
                $stylesheets[] = $sheet;
            }
        }
    }

    $smarty = smarty_core();
    $smarty->assign('STRINGJS', $stringjs);

    $smarty->assign('STYLESHEETLIST', $stylesheets);
    if (!empty($theme_list)) {
        // this gets assigned in smarty_core, but do it again here if it's changed locally
        $smarty->assign('THEMELIST', json_encode(array_merge((array)json_decode($smarty->get_template_vars('THEMELIST')),  $theme_list))); 
    }

    if (defined('TITLE')) {
        $smarty->assign('PAGETITLE', TITLE . ' - ' . get_config('sitename'));
    }
    else {
        $smarty->assign('PAGETITLE', get_config('sitename'));
    }


    $sitename = get_config('sitename');
    $smarty->assign('title', $sitename);
    $smarty->assign('heading', $sitename);

    if (defined('PUBLIC')) {
        $smarty->assign('PUBLIC', true);
    }
    if (defined('ADMIN')) {
        $smarty->assign('ADMIN', true);
    }
    if (defined('INSTITUTIONALADMIN')) {
        $smarty->assign('INSTITUTIONALADMIN', true);
    }

    $smarty->assign('LOGGEDIN', $USER->is_logged_in());
    if ($USER->is_logged_in()) {
        $smarty->assign('MAINNAV', main_nav());
        $smarty->assign('LOGGEDINSTR', get_loggedin_string());
    }

    $smarty->assign_by_ref('USER', $USER);
    $smarty->assign('SESSKEY', $USER->get('sesskey'));
    $smarty->assign_by_ref('JAVASCRIPT', $javascript_array);
    $smarty->assign_by_ref('HEADERS', $headers);

    $smarty->assign('searchform', searchform());

    if ($help = has_page_help()) {
        $smarty->assign('PAGEHELPNAME', $help[0]);
        $smarty->assign('PAGEHELPICON', $help[1]);
    }

    // ---------- sideblock stuff ----------
    if (!defined('INSTALLER') && (defined('MENUITEM') && substr(MENUITEM, 0, 5) != 'admin')) {
        if (get_config('installed')) {
            $data = site_menu();
            if (!empty($data)) {
                $smarty->assign('SITEMENU', site_menu());
                $SIDEBLOCKS[] = array(
                    'name'   => 'mainmenu',
                    'weight' => 10,
                    'data'   => $data,
                );
            }
        }

        if ($USER->is_logged_in() && defined('MENUITEM') && substr(MENUITEM, 0, 11) == 'myportfolio') {
            $SIDEBLOCKS[] = array(
                'name'   => 'selfsearch',
                'weight' => 0,
                'data'   => array(),
            );
        }

        if($USER->is_logged_in()) {
            $SIDEBLOCKS[] = array(
                'name'   => 'profile',
                'weight' => -20,
                'data'   => profile_sideblock()
            );
        }

       if (!$USER->is_logged_in()) {
            $SIDEBLOCKS[] = array(
                'name'   => 'login',
                'weight' => -10,
                'id'     => 'loginbox',
                'data'   => array(
                    'loginform' => auth_generate_login_form(),
                ),
            );
        }

        if (get_config('enablenetworking')) {
            require_once(get_config('docroot') .'api/xmlrpc/lib.php');
            if ($USER->is_logged_in() && $ssopeers = get_service_providers($USER->authinstance)) {
                $SIDEBLOCKS[] = array(
                    'name'   => 'ssopeers',
                    'weight' => 1,
                    'data'   => $ssopeers,
                );
            }
        }

        if (isset($extraconfig['sideblocks']) && is_array($extraconfig['sideblocks'])) {
            foreach ($extraconfig['sideblocks'] as $sideblock) {
                $SIDEBLOCKS[] = $sideblock;
            }
        }

        usort($SIDEBLOCKS, create_function('$a,$b', 'if ($a["weight"] == $b["weight"]) return 0; return ($a["weight"] < $b["weight"]) ? -1 : 1;'));

        $smarty->assign('userauthinstance', $USER->lastauthinstance);
        $smarty->assign('SIDEBLOCKS', $SIDEBLOCKS);
    }

    return $smarty;
}

/** 
 * Returns the lists of strings used in the .js files
 * @return array                   
 */

function jsstrings() {
    return array(
       'mahara' => array(                        // js file
            'mahara' => array(                   // section
                'namedfieldempty',               // string name
                'processing',
                'requiredfieldempty',
                'unknownerror',
                'loading',
                'showtags',
                'unreadmessages',
                'unreadmessage',
                'couldnotgethelp',
            ),
        ),
        'tablerenderer' => array(
            'mahara' => array(
                'firstpage',
                'nextpage',
                'prevpage',
                'lastpage',
            )
        ),
        'friends' => array(
            'group' => array(
                'confirmremovefriend',
                'seeallviews',
                'noviewstosee',
                'sendmessage',
                'whymakemeyourfriend',
                'approverequest',
                'denyrequest',
                'pending',
                'removefromfriendslist',
                'views',
                'trysearchingforfriends',
                'nobodyawaitsfriendapproval',
                'sendfriendrequest',
                'addtomyfriends',
                'friendshiprequested',
                'userdoesntwantfriends',
                'existingfriend',
                'nosearchresultsfound',
                'reason',
                'requestfriendship',
                'cancel',
            ),
            'mahara' => array(
                'pendingfriend',
                'pendingfriends',
            ),
        ),
        'views' => array(
            'view' => array(
                'confirmdeleteblockinstance',
            ),
        ),
        'adminusersearch' => array(
            'admin' => array(
                'suspenduser',
                'suspensionreason',
            ),
            'mahara' => array(
                'cancel',
            ),
        ),
    );
}

function themepaths() {

    static $paths;
    if (empty($paths)) {
        $paths = array(
            'mahara' => array(
                'images/icon_close.gif',
                'images/failure.gif',
                'images/loading.gif',
                'images/success.gif',
                'images/icon_help.gif',
            ),
        );
    }
    return $paths;
}

/** 
 * Takes an array of string identifiers and returns an array of the
 * corresponding strings, quoted for use in inline javascript here
 * docs.
 */

function quotestrings($strings) {
    $qstrings = array();
    foreach ($strings as $section => $tags) {
        foreach ($tags as $tag) {
            $qstrings[$tag] = json_encode(get_string($tag, $section));
        }
    }
    return $qstrings;
}

/** 
 * This function sets up and caches info about the current selected theme
 * contains inheritance path (used for locating images) and template dirs
 * and potentially more stuff later ( like mime header to send (html vs xhtml))
 * @return object
 */

function theme_setup() {
    
    static $theme;

    if (!empty($theme)) {
        return $theme;
    }
    
    $theme = new StdClass;
    global $USER;
    if (!empty($USER)) {
        $theme->theme = $USER->get('theme');
    }
    if (empty($theme->theme)) {
        $theme->theme = get_config('theme');
    }
    $theme->path = get_config('docroot') . 'theme/' . $theme->theme . '/';
    $theme->template_dir = array($theme->path . 'templates/');
    $theme->inheritance = array($theme->theme);

    $parent = $theme->theme;

    while (true) {
        if (!$parent = theme_get_parent($parent)) {
            break;
        }
        if ($parent != 'default') {
            $theme->template_dir[] = get_config('docroot') . 'theme/' . $parent . '/templates/';
            $theme->inheritance[] = $parent;
        }
    }

    // always put the default theme at the top of the tree, unless we're already it
    if ($theme->theme != 'default') {
        $theme->template_dir[] = get_config('docroot')  . 'theme/default/templates/';
        $theme->inheritance[] = 'default';
    }

    return $theme;
}

/** 
 * helper function to walk up the inheritance tree and find a parent
 * @param $currtheme the name of the theme to find the parent for
 * @return parent name or false
 */
function theme_get_parent($currtheme) {

    // look for a config file 
    if (is_readable(get_config('docroot') . 'theme/ ' . $currtheme. '/config.php')) {
        require_once(get_config('docroot') . 'theme/ ' . $currtheme. '/config.php');
        if (!empty($theme->parent) && is_dir(get_config('docroot') . 'theme/ ' . $theme->parent)) {
            return $theme->parent;
        }
    }
    return false;
}

/** 
 * This function returns the full url to an image
 * Always use it to get image urls
 * @param $imagelocation path to image relative to theme/$theme/static/
 * @param $pluginlocation path to plugin relative to docroot
 */
function theme_get_url($location, $pluginlocation='', $all = false) {
    $theme = theme_setup();
    $list = array();

    foreach ($theme->inheritance as $themedir) {
        if (is_readable(get_config('docroot') . $pluginlocation . 'theme/' . $themedir . '/static/' . $location)) {
            if ($all) {
                $list[] = get_config('wwwroot') . $pluginlocation . 'theme/' . $themedir . '/static/' . $location;
            }
            else {
                return get_config('wwwroot') . $pluginlocation . 'theme/' . $themedir . '/static/' . $location;
            }
        }
    }
    if ($all) {
        return $list;
    }
    return;
}

/** 
 * This function returns the full path to an image
 * Always use it to get image paths
 * @param $imagelocation path to image relative to theme/$theme/static/
 * @param $pluginlocation path to plugin relative to docroot
 */
function theme_get_path($location, $pluginlocation='') {
    $theme = theme_setup();

    foreach ($theme->inheritance as $themedir) {
        if (is_readable(get_config('docroot') . $pluginlocation . 'theme/' . $themedir . '/static/' . $location)) {
            return get_config('docroot') . $pluginlocation . 'theme/' . $themedir . '/static/' . $location;
        }
    }
}

/**
 * This function sends headers suitable for all JSON returning scripts.
 *
 */
function json_headers() {
    // @todo martyn This should be changed, but for now it's useful for debugging
    // header('Content-type: text/x-json');
    header('Content-type: text/plain');
    header('Pragma: no-cache');
}

/**
 * This function sends a JSON message, and ends the script.
 *
 * Scripts receiving replies will recieve a JSON array with two fields:
 *
 *  - error: True or false depending on whether the request was successful
 *  - message: JSON data representing a message sent back from the script
 *
 * @param boolean $error   Whether the script ended in an error or not
 * @param string  $message A message to pass back to the user, can be an
 *                         array of JSON data
 */
function json_reply($error, $message, $returncode=0) {
    json_headers();
    echo json_encode(array('error' => $error, 'message' => $message, 'returnCode' => $returncode));
    perf_to_log();
    exit;
}

function _param_retrieve($name) {
    // prefer post
    if (isset($_POST[$name])) {
        $value = $_POST[$name];
    } 
    else if (isset($_GET[$name])) {
        $value = $_GET[$name];
    }
    else if (func_num_args() == 2) {
        $php_work_around = func_get_arg(1);
        return array($php_work_around, true);
    }
    else {
        throw new ParameterException("Missing parameter '$name' and no default supplied");
    }

    return array($value, false);
}

/**
 * This function returns a GET or POST parameter with optional default.  If the
 * default isn't specified and the parameter hasn't been sent, a
 * ParameterException exception is thrown
 *
 * @param string The GET or POST parameter you want returned
 * @param mixed [optional] the default value for this parameter
 *
 * @return string The value of the parameter
 *
 */
function param_variable($name) {
    $args = func_get_args();
    list ($value) = call_user_func_array('_param_retrieve', $args);
    return $value;
}

/**
 * This function returns a GET or POST parameter as an integer with optional
 * default.  If the default isn't specified and the parameter hasn't been sent,
 * a ParameterException exception is thrown. Likewise, if the parameter isn't a
 * valid integer, a ParameterException exception is thrown
 *
 * @param string The GET or POST parameter you want returned
 * @param mixed [optional] the default value for this parameter
 *
 * @return int The value of the parameter
 *
 */
function param_integer($name) {
    $args = func_get_args();

    list ($value, $defaultused) = call_user_func_array('_param_retrieve', $args);

    if ($defaultused) {
        return $value;
    }

    if (preg_match('/^\d+$/',$value)) {
        return (int)$value;
    }

    throw new ParameterException("The '$name' parameter is not an integer");
}

/**
 * This function returns a GET or POST parameter as an alpha string with optional
 * default.  If the default isn't specified and the parameter hasn't been sent,
 * a ParameterException exception is thrown. Likewise, if the parameter isn't a
 * valid alpha string, a ParameterException exception is thrown
 *
 * Valid characters are a-z and A-Z
 *
 * @param string The GET or POST parameter you want returned
 * @param mixed [optional] the default value for this parameter
 *
 * @return string The value of the parameter
 *
 */
function param_alpha($name) {
    $args = func_get_args();

    list ($value, $defaultused) = call_user_func_array('_param_retrieve', $args);

    if ($defaultused) {
        return $value;
    }

    if (preg_match('/^[a-zA-Z]+$/',$value)) {
        return $value;
    }

    throw new ParameterException("The '$name' parameter is not alphabetical only");
}

/**
 * This function returns a GET or POST parameter as an alphanumeric string with optional
 * default.  If the default isn't specified and the parameter hasn't been sent,
 * a ParameterException exception is thrown. Likewise, if the parameter isn't a
 * valid alpha string, a ParameterException exception is thrown
 *
 * Valid characters are a-z and A-Z and 0-9
 *
 * @param string The GET or POST parameter you want returned
 * @param mixed [optional] the default value for this parameter
 *
 * @return string The value of the parameter
 *
 */
function param_alphanum($name) {
    $args = func_get_args();

    list ($value, $defaultused) = call_user_func_array('_param_retrieve', $args);

    if ($defaultused) {
        return $value;
    }

    if (preg_match('/^[a-zA-Z0-9]+$/',$value)) {
        return $value;
    }

    throw new ParameterException("The '$name' parameter is not alphanumeric only");
}

/**
 * This function returns a GET or POST parameter as an alphanumeric string with optional
 * default.  If the default isn't specified and the parameter hasn't been sent,
 * a ParameterException exception is thrown. Likewise, if the parameter isn't a
 * valid alpha string, a ParameterException exception is thrown
 *
 * Valid characters are a-z and A-Z and 0-9 and _ and - and .
 *
 * @param string The GET or POST parameter you want returned
 * @param mixed [optional] the default value for this parameter
 *
 * @return string The value of the parameter
 *
 */
function param_alphanumext($name) {
    $args = func_get_args();

    list ($value, $defaultused) = call_user_func_array('_param_retrieve', $args);

    if ($defaultused) {
        return $value;
    }

    if (preg_match('/^[a-zA-Z0-9_.-]+$/',$value)) {
        return $value;
    }

    throw new ParameterException("The '$name' parameter contains invalid characters");
}

/**
 * This function returns a GET or POST parameter as an array of integers with optional
 * default.  If the default isn't specified and the parameter hasn't been sent,
 * a ParameterException exception is thrown. Likewise, if the parameter isn't a
 * valid integer list , a ParameterException exception is thrown.
 *
 * An integer list is integers separated by commas (with optional whitespace),
 * or just whitespace which indicates an empty list
 *
 * @param string The GET or POST parameter you want returned
 * @param mixed [optional] the default value for this parameter
 *
 * @return array The value of the parameter
 *
 */
function param_integer_list($name) {
    $args = func_get_args();

    list ($value, $defaultused) = call_user_func_array('_param_retrieve', $args);

    if ($defaultused) {
        return $value;
    }

    if ($value == '') {
        return array();
    }

    if (preg_match('/^(\d+(,\d+)*)$/',$value)) {
        return array_map('intval', explode(',', $value));
    }

    throw new ParameterException("The '$name' parameter is not an integer list");
}

/**
 * This function returns a GET or POST parameter as a boolean.
 *
 * @param string The GET or POST parameter you want returned
 *
 * @return bool The value of the parameter
 *
 */
function param_boolean($name) {
    
    list ($value) = _param_retrieve($name, false);

    if (empty($value) || $value == 'off' || $value == 'no' || $value == 'false') {
        return false;
    }
    else {
        return true;
    }
}

/**
 * NOTE: this function is only meant to be used by get_imagesize_parameters(),
 * which you should use in your scripts.
 *
 * This function returns a GET or POST parameter as a two element array 
 * repesenting an allowed width and height value for a resized image. If the 
 * default isn't specified and the parameter hasn't been sent, a 
 * ParameterException is thrown. Likewise, if the parameter isn't a valid size 
 * dimension, a ParameterException is thrown.
 *
 * A size parameter is a string, in the form /\d+x\d+/ - e.g. 200x150. The 
 * width and height are not allowed to be greater than the configured allowed
 * maximums - config variables imagemaxwidth and imagemaxheight.
 *
 * You call this function like so:
 *
 * list($width, $height) = param_imagesize('size');
 *
 * @param string The GET or POST parameter you want returned.
 * TODO: i18n for the error messages
 */
function param_imagesize($name) {
    $args = func_get_args();

    list ($value, $defaultused) = call_user_func_array('_param_retrieve', $args);

    if ($defaultused) {
        return $value;
    }

    if (!preg_match('/\d+x\d+/', $value)) {
        throw new ParameterException('Invalid size for image specified');
    }

    list($width, $height) = explode('x', $value);
    if ($width > get_config('imagemaxwidth') || $height > get_config('imagemaxheight')) {
        throw new ParameterException('Requested image size is too big');
    }
    if ($width < 16 || $height < 16) {
        throw new ParameterException('Requested image size is too small');
    }
    return array('w' => $width, 'h' => $height);
}

/**
 * Works out what size a requested image should be, based on request parameters
 *
 * The result of this function can be passed to get_dataroot_image_path to 
 * retrieve the filesystem path of the appropriate image
 */
function get_imagesize_parameters($sizeparam='size', $widthparam='width', $heightparam='height',
    $maxsizeparam='maxsize', $maxwidthparam='maxwidth', $maxheightparam='maxheight') {

    $size      = param_imagesize($sizeparam, '');
    $width     = param_integer($widthparam, 0);
    $height    = param_integer($heightparam, 0);
    $maxsize   = param_integer($maxsizeparam, 0);
    $maxwidth  = param_integer($maxwidthparam, 0);
    $maxheight = param_integer($maxheightparam, 0);

    $imagemaxwidth  = get_config('imagemaxwidth');
    $imagemaxheight = get_config('imagemaxheight');

    if ($size) {
        return $size;
    }
    if ($maxsize) {
        if ($maxsize > $imagemaxwidth && $maxsize > $imagemaxheight) {
            throw new ParameterException('Requested image size is too big');
        }
        if ($maxsize < 16) {
            throw new ParameterException('Requested image size is too small');
        }
        return $maxsize;
    }
    if ($width) {
        if ($width > $imagemaxwidth) {
            throw new ParameterException('Requested image size is too big');
        }
        if ($width < 16) {
            throw new ParameterException('Requested image size is too small');
        }
        return array('w' => $width);
    }
    if ($height) {
        if ($height > $imagemaxheight) {
            throw new ParameterException('Requested image size is too big');
        }
        if ($height < 16) {
            throw new ParameterException('Requested image size is too small');
        }
        return array('h' => $height);
    }
    if ($maxwidth) {
        if ($maxwidth > $imagemaxwidth) {
            throw new ParameterException('Requested image size is too big');
        }
        if ($maxwidth < 16) {
            throw new ParameterException('Requested image size is too small');
        }
        return array('maxw' => $maxwidth);
    }
    if ($maxheight) {
        if ($maxheight > $imagemaxheight) {
            throw new ParameterException('Requested image size is too big');
        }
        if ($maxheight < 16) {
            throw new ParameterException('Requested image size is too small');
        }
        return array('maxh' => $maxheight);
    }
    return null;
}

/**
 * Gets a cookie, respecting the configured cookie prefix
 *
 * @param string $name The name of the cookie to get the value of
 * @return string      The value of the cookie, or null if the cookie does not
 *                     exist.
 */
function get_cookie($name) {
    $name = get_config('cookieprefix') . $name;
    return (isset($_COOKIE[$name])) ? $_COOKIE[$name] : null;
}

/**
 * Sets a cookie, respecting the configured cookie prefix
 *
 * @param string $name    The name of the cookie
 * @param string $value   The value for the cookie
 * @param int    $expires The unix timestamp of the time the cookie should expire
 * @todo path/domain/secure: should be set automatically by this function if possible (?)
 */
function set_cookie($name, $value='', $expires=0, $path='', $domain='', $secure=false) {
    $name = get_config('cookieprefix') . $name;
    setcookie($name, $value, $expires, $path, $domain, $secure);
}

/**
 * Returns an assoc array of countrys suitable for use with the "select" form
 * element
 *
 * @return array Associative array of countrycodes => countrynames
 */
function getoptions_country() {
    static $countries;
    if (!empty($countries)) {
        return $countries;
    }
    $codes = array(
        'af',
        'ax',
        'al',
        'dz',
        'as',
        'ad',
        'ao',
        'ai',
        'aq',
        'ag',
        'ar',
        'am',
        'aw',
        'au',
        'at',
        'az',
        'bs',
        'bh',
        'bd',
        'bb',
        'by',
        'be',
        'bz',
        'bj',
        'bm',
        'bt',
        'bo',
        'ba',
        'bw',
        'bv',
        'br',
        'io',
        'bn',
        'bg',
        'bf',
        'bi',
        'kh',
        'cm',
        'ca',
        'cv',
        'ky',
        'cf',
        'td',
        'cl',
        'cn',
        'cx',
        'cc',
        'co',
        'km',
        'cg',
        'cd',
        'ck',
        'cr',
        'ci',
        'hr',
        'cu',
        'cy',
        'cz',
        'dk',
        'dj',
        'dm',
        'do',
        'ec',
        'eg',
        'sv',
        'gq',
        'er',
        'ee',
        'et',
        'fk',
        'fo',
        'fj',
        'fi',
        'fr',
        'gf',
        'pf',
        'tf',
        'ga',
        'gm',
        'ge',
        'de',
        'gh',
        'gi',
        'gr',
        'gl',
        'gd',
        'gp',
        'gu',
        'gt',
        'gg',
        'gn',
        'gw',
        'gy',
        'ht',
        'hm',
        'va',
        'hn',
        'hk',
        'hu',
        'is',
        'in',
        'id',
        'ir',
        'iq',
        'ie',
        'im',
        'il',
        'it',
        'jm',
        'jp',
        'je',
        'jo',
        'kz',
        'ke',
        'ki',
        'kp',
        'kr',
        'kw',
        'kg',
        'la',
        'lv',
        'lb',
        'ls',
        'lr',
        'ly',
        'li',
        'lt',
        'lu',
        'mo',
        'mk',
        'mg',
        'mw',
        'my',
        'mv',
        'ml',
        'mt',
        'mh',
        'mq',
        'mr',
        'mu',
        'yt',
        'mx',
        'fm',
        'md',
        'mc',
        'mn',
        'ms',
        'ma',
        'mz',
        'mm',
        'na',
        'nr',
        'np',
        'nl',
        'an',
        'nc',
        'nz',
        'ni',
        'ne',
        'ng',
        'nu',
        'nf',
        'mp',
        'no',
        'om',
        'pk',
        'pw',
        'ps',
        'pa',
        'pg',
        'py',
        'pe',
        'ph',
        'pn',
        'pl',
        'pt',
        'pr',
        'qa',
        're',
        'ro',
        'ru',
        'rw',
        'sh',
        'kn',
        'lc',
        'pm',
        'vc',
        'ws',
        'sm',
        'st',
        'sa',
        'sn',
        'cs',
        'sc',
        'sl',
        'sg',
        'sk',
        'si',
        'sb',
        'so',
        'za',
        'gs',
        'es',
        'lk',
        'sd',
        'sr',
        'sj',
        'sz',
        'se',
        'ch',
        'sy',
        'tw',
        'tj',
        'tz',
        'th',
        'tl',
        'tg',
        'tk',
        'to',
        'tt',
        'tn',
        'tr',
        'tm',
        'tc',
        'tv',
        'ug',
        'ua',
        'ae',
        'gb',
        'us',
        'um',
        'uy',
        'uz',
        'vu',
        've',
        'vn',
        'vg',
        'vi',
        'wf',
        'eh',
        'ye',
        'zm',
        'zw',
    );

    foreach ($codes as $c) {
        $countries[$c] = get_string("country.{$c}");
    };
    uasort($countries, 'strcoll');
    return $countries;
}

/**
 * 
 */

function get_help_icon($plugintype, $pluginname, $form, $element, $page='', $section='') {
    // I see no reason why IE has to drag the quality of the interwebs down with it
    $imageext = (isset($_SERVER['HTTP_USER_AGENT']) && false !== stripos($_SERVER['HTTP_USER_AGENT'], 'msie 6.0')) ? 'gif' : 'png';
    return ' <span class="help"><a href="" onclick="'. 
        hsc(
            'contextualHelp(' . json_encode($form) . ',' . 
            json_encode($element) . ',' . json_encode($plugintype) . ',' . 
            json_encode($pluginname) . ',' . json_encode($page) . ',' . 
            json_encode($section)
            . ',this); return false;'
        ) . '"><img src="' . theme_get_url('images/icon_help.' . $imageext) . '" alt="?"></a></span>';
}

function pieform_get_help(Pieform $form, $element) {
    return get_help_icon($form->get_property('plugintype'),
        $form->get_property('pluginname'),
        $form->get_name(), $element['name']);
}

function make_link($url) {
    return '<a href="' . $url . '">' . $url . '</a>';
}


/**
 * Returns the entries in the standard admin menu
 *
 * @return $adminnav a data structure containing the admin navigation
 */
function admin_nav() {
    $menu = array(
        array(
            'path'   => 'adminhome',
            'url'    => 'admin/',
            'title'  => get_string('adminhome', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'configsite',
            'url'    => 'admin/site/options.php',
            'title'  => get_string('configsite', 'admin'),
            'weight' => 20,
        ),
        array(
            'path'   => 'configsite/siteoptions',
            'url'    => 'admin/site/options.php',
            'title'  => get_string('siteoptions', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'configsite/sitepages',
            'url'    => 'admin/site/pages.php',
            'title'  => get_string('sitepages', 'admin'),
            'weight' => 20
        ),
        array(
            'path'   => 'configsite/sitemenu',
            'url'    => 'admin/site/menu.php',
            'title'  => get_string('sitemenu', 'admin'),
            'weight' => 30,
        ),
        array(
            'path'   => 'configsite/adminfiles',
            'url'    => 'admin/site/files.php',
            'title'  => get_string('adminfiles', 'admin'),
            'weight' => 40,
        ),
        array(
            'path'   => 'configsite/networking',
            'url'    => 'admin/site/networking.php',
            'title'  => get_string('networking', 'admin'),
            'weight' => 50,
        ),
        array(
            'path'   => 'configusers',
            'url'    => 'admin/users/search.php',
            'title'  => get_string('configusers', 'admin'),
            'weight' => 30,
        ),
        array(
            'path'   => 'configusers/usersearch',
            'url'    => 'admin/users/search.php',
            'title'  => get_string('usersearch', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'configusers/suspendedusers',
            'url'    => 'admin/users/suspended.php',
            'title'  => get_string('suspendedusers', 'admin'),
            'weight' => 15,
        ),
        array(
            'path'   => 'configusers/staffusers',
            'url'    => 'admin/users/staff.php',
            'title'  => get_string('sitestaff', 'admin'),
            'weight' => 20,
        ),
        array(
            'path'   => 'configusers/adminusers',
            'url'    => 'admin/users/admins.php',
            'title'  => get_string('siteadmins', 'admin'),
            'weight' => 30,
        ),
        array(
            'path'   => 'configusers/adminnotifications',
            'url'    => 'admin/users/notifications.php',
            'title'  => get_string('adminnotifications', 'admin'),
            'weight' => 40,
        ),
        array(
            'path'   => 'configusers/adduser',
            'url'    => 'admin/users/add.php',
            'title'  => get_string('adduser', 'admin'),
            'weight' => 50,
        ),
        array(
            'path'   => 'configusers/uploadcsv',
            'url'    => 'admin/users/uploadcsv.php',
            'title'  => get_string('uploadcsv', 'admin'),
            'weight' => 60,
        ),
        array(
            'path'   => 'manageinstitutions',
            'url'    => 'admin/users/institutions.php',
            'title'  => get_string('manageinstitutions', 'admin'),
            'weight' => 35,
        ),
        array(
            'path'   => 'manageinstitutions/institutions',
            'url'    => 'admin/users/institutions.php',
            'title'  => get_string('institutions', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'manageinstitutions/institutionusers',
            'url'    => 'admin/users/institutionusers.php',
            'title'  => get_string('institutionmembers', 'admin'),
            'weight' => 20,
        ),
        array(
            'path'   => 'manageinstitutions/institutionstaff',
            'url'    => 'admin/users/institutionstaff.php',
            'title'  => get_string('institutionstaff', 'admin'),
            'weight' => 30,
        ),
        array(
            'path'   => 'manageinstitutions/institutionadmins',
            'url'    => 'admin/users/institutionadmins.php',
            'title'  => get_string('institutionadmins', 'admin'),
            'weight' => 40,
        ),
        array(
            'path'   => 'configextensions',
            'url'    => 'admin/extensions/plugins.php',
            'title'  => get_string('configextensions', 'admin'),
            'weight' => 40,
        ),
        array(
            'path'   => 'configextensions/pluginadmin',
            'url'    => 'admin/extensions/plugins.php',
            'title'  => get_string('pluginadmin', 'admin'),
            'weight' => 10,
        ),
    );

    return $menu;
}

/**
 * Returns the entries in the standard institutional admin menu
 *
 * @return $adminnav a data structure containing the admin navigation
 */
function institutional_admin_nav() {

    return array(
        array(
            'path'   => 'configusers',
            'url'    => 'admin/users/search.php',
            'title'  => get_string('configusers', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'configusers/usersearch',
            'url'    => 'admin/users/search.php',
            'title'  => get_string('usersearch', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'configusers/suspendedusers',
            'url'    => 'admin/users/suspended.php',
            'title'  => get_string('suspendedusers', 'admin'),
            'weight' => 20,
        ),
        array(
            'path'   => 'configusers/adduser',
            'url'    => 'admin/users/add.php',
            'title'  => get_string('adduser', 'admin'),
            'weight' => 30,
        ),
        array(
            'path'   => 'configusers/uploadcsv',
            'url'    => 'admin/users/uploadcsv.php',
            'title'  => get_string('uploadcsv', 'admin'),
            'weight' => 40,
        ),
        array(
            'path'   => 'manageinstitutions',
            'url'    => 'admin/users/institutions.php',
            'title'  => get_string('manageinstitutions', 'admin'),
            'weight' => 20,
        ),
        array(
            'path'   => 'manageinstitutions/institutions',
            'url'    => 'admin/users/institutions.php',
            'title'  => get_string('institutionsettings', 'admin'),
            'weight' => 10,
        ),
        array(
            'path'   => 'manageinstitutions/institutionusers',
            'url'    => 'admin/users/institutionusers.php',
            'title'  => get_string('institutionmembers', 'admin'),
            'weight' => 20,
        ),
        array(
            'path'   => 'manageinstitutions/institutionstaff',
            'url'    => 'admin/users/institutionstaff.php',
            'title'  => get_string('institutionstaff', 'admin'),
            'weight' => 30,
        ),
        array(
            'path'   => 'manageinstitutions/institutionadmins',
            'url'    => 'admin/users/institutionadmins.php',
            'title'  => get_string('institutionadmins', 'admin'),
            'weight' => 40,
        ),
        array(
            'path'   => 'manageinstitutions/adminnotifications',
            'url'    => 'admin/users/notifications.php',
            'title'  => get_string('adminnotifications', 'admin'),
            'weight' => 50,
        ),
    );

}

/**
 * Builds a data structure representing the menu for Mahara.
 */
function main_nav() {
    if (defined('ADMIN') || defined('INSTITUTIONALADMIN')) {
        global $USER;
        $menu = $USER->get('admin') ? admin_nav() : institutional_admin_nav();
    }
    else {
        // Build the menu structure for the site

        // The keys of each entry are as follows:
        //   path: Where the link sits in the menu. E.g. 'myporfolio/myplugin'
        //   url:  The URL to the page, relative to wwwroot. E.g. 'artefact/myplugin/'
        //   title: Translated text to use for the text of the link. E.g. get_string('myplugin', 'artefact.myplugin')
        //   weight: Where in the menu the item should be inserted. Larger number are to the right.
        $menu = array(
            array(
                'path' => '',
                'url' => '',
                'title' => get_string('home'),
                'weight' => 10,
            ),
            array(
                'path' => 'myportfolio',
                'url' => 'view/',
                'title' => get_string('myportfolio'),
                'weight' => 30,
            ),
            array(
                'path' => 'myportfolio/views',
                'url' => 'view/',
                'title' => get_string('views'),
                'weight' => 10
            ),
            array(
                'path' => 'groups',
                'url' => 'group/mygroups.php',
                'title' => get_string('groups'),
                'weight' => 40,
            ),
            array(
                'path' => 'groups/mygroups',
                'url' => 'group/mygroups.php',
                'title' => get_string('mygroups'),
                'weight' => 10
            ),
            array(
                'path' => 'groups/myfriends',
                'url' => 'user/',
                'title' => get_string('myfriends'),
                'weight' => 20,
            ),
            array(
                'path' => 'groups/find',
                'url' => 'group/find.php',
                'title' => get_string('findgroups'),
                'weight' => 30
            ),

            array(
                'path' => 'settings',
                'url' => 'account/',
                'title' => get_string('settings'),
                'weight' => 60
            ),
            array(
                'path' => 'settings/preferences',
                'url' => 'account/',
                'title' => get_string('preferences'),
                'weight' => 10,
            ),
            array(
                'path' => 'settings/notifications',
                'url' => 'account/activity/',
                'title' => get_string('notifications'),
                'weight' => 20,
            ),
            array(
                'path' => 'settings/activitypreferences',
                'url' => 'account/activity/preferences/',
                'title' => get_string('activityprefs'),
                'weight' => 30,
            ),
        );

        if ($plugins = get_records_array('artefact_installed', 'active', 1)) {
            foreach ($plugins as &$plugin) {
                safe_require('artefact', $plugin->name);
                $plugin_menu = call_static_method(generate_class_name('artefact',$plugin->name), 'menu_items');
                $menu = array_merge($menu, $plugin_menu);
            }
        }
    }

    $menu_structure = find_menu_children($menu, '');
    return $menu_structure;
}

/**
 * Given a menu structure and a path, returns a data structure representing all 
 * of the child menu items of the path, and removes those items from the menu 
 * structure
 *
 * Used by main_nav()
 */
function find_menu_children(&$menu, $path) {
    $result = array();
    if (!$menu) {
        return array();
    }

    foreach ($menu as $key => $item) {
        $len = strlen($item['path']);
        $item['selected'] = defined('MENUITEM')
            && ($item['path'] == MENUITEM
                || ($item['path'] . '/' == substr(MENUITEM, 0, strlen($item['path'])+1)));
        if (
            ($path == '' && $item['path'] == '') ||
            ($item['path'] != '' && substr($item['path'], 0, strlen($path)) == $path && !preg_match('%/%', substr($item['path'], strlen($path) + 1)))) {
            $result[] = $item;
            unset($menu[$key]);
        }
    }

    if ($menu) {
        foreach ($result as &$item) {
            $item['submenu'] = find_menu_children($menu, $item['path']);
        }
    }

    uasort($result, 'menu_sort_items');

    return $result;
}

/**
 * Comparison function for sorting menu items
 */
function menu_sort_items(&$a, &$b) {
    !isset($a['weight']) && $a['weight'] = 0;
    !isset($b['weight']) && $b['weight'] = 0;
    return $a['weight'] > $b['weight'];
}

/**
 * Site-level sidebar menu (list of links)
 * There is no admin files table yet so just get the urls.
 * @return $menu a data structure containing the site menu
 */
function site_menu() {
    global $USER;
    $menu = array();
    if ($menuitems = get_records_array('site_menu','public',(int) !$USER->is_logged_in(),'displayorder')) {
        foreach ($menuitems as $i) {
            if ($i->url) {
                $menu[] = array('name' => $i->title,
                                'link' => $i->url);
            }
            else if ($i->file) {
                $menu[] = array('name' => $i->title,
                                'link' => get_config('wwwroot') . 'artefact/file/download.php?file=' . $i->file);
            }
        }
    }
    return $menu;
}

/**
 * Returns the list of site content pages
 * @return array of names
 */
function site_content_pages() {
    return array('about', 'home', 'loggedouthome', 'privacy', 'termsandconditions', 'uploadcopyright');
}

function get_site_page_content($pagename) {
    if ($pagedata = @get_record('site_content', 'name', $pagename)) {
        return $pagedata->content;
    }
    return get_string('sitecontentnotfound', 'mahara', get_string($pagename));
}


/** 
 * Redirects the browser to a new location. The path to redirect to can take
 * two forms:
 *  
 * - http[something]: will redirect the user to that exact URL
 * - /[something]: will redirect to WWWROOT/[something]
 *       
 * Any other form is illegal and will cause an error.
 *      
 * @param string $location The location to redirect the user to. Defaults to
 *                         the application home page.
 */     
function redirect($location='/') {
    if (headers_sent()) {
        throw new Exception('Headers already sent when redirect() was called');
    }

    if (substr($location, 0, 4) != 'http') {
        if (substr($location, 0, 1) != '/') {
            throw new SystemException('redirect() should be called with either'
                . ' /[something] for local redirects or http[something] for'
                . ' absolute redirects');
        }

        $location = get_config('wwwroot') . substr($location, 1);
    }

    header('HTTP/1.1 303 See Other');
    header('Location:' . $location);
    exit;
}

/**
 * Returns a string, HTML escaped
 *
 * @param string $text The text to escape
 * @return string      The text, HTML escaped
 */
function hsc ($text) {
    return htmlspecialchars($text, ENT_COMPAT, 'UTF-8');
}

function searchform() {
    require_once('pieforms/pieform.php');
    return pieform(array(
        'name'                => 'searchform',
        'action'              => get_config('wwwroot') . 'search.php',
        'renderer'            => 'oneline',
        'autofocus'           => false,
        'validate'            => false,
        'elements'            => array(
            'query' => array(
                'type'           => 'text',
                'defaultvalue'   => get_string('search'),
                'class'          => 'emptyonfocus'
            ),
            'submit' => array(
                'type' => 'image',
                'src'  => theme_get_url('images/btn_search_off.gif')
            )
        )
    ));
}

function get_loggedin_string() {
    global $USER;

    $str = get_string('youareloggedinas', 'mahara', display_name($USER));

    safe_require('notification', 'internal');
    $count = call_static_method(generate_class_name('notification', 'internal'), 'unread_count', $USER->get('id'));
    if ($count == 1) {
        $key = 'unreadmessage';
    }
    else {
        $key = 'unreadmessages';
    }

    if ($count > 0) {
        // these spans are here so that on the ajax page that marks messages as read, the contents can be updated.
        $str .=
            ' (<a href="' . get_config('wwwroot') . 'account/activity/">'  . 
            '<span class="unreadmessagescontainer"><span class="unreadmessagecount">' . $count . '</span> ' .
            '<span class="unreadmessages">' . get_string($key) . '</span></span></a>)';
    }

    $saveduser = $USER->get('parentuser');
    if (!empty($saveduser) && $saveduser->name) {
        $str .= ' (<a href="' . get_config('wwwroot') . 'admin/users/changeuser.php?restore=1">'
            . get_string('becomeadminagain', 'admin', $saveduser->name) . '</a>)';
    }

    return $str;
}


/**
 * Returns the name of the current script, WITH the querystring portion.
 * this function is necessary because PHP_SELF and REQUEST_URI and SCRIPT_NAME
 * return different things depending on a lot of things like your OS, Web
 * server, and the way PHP is compiled (ie. as a CGI, module, ISAPI, etc.)
 * <b>NOTE:</b> This function returns false if the global variables needed are not set.
 *
 * @return string
 */
function get_script_path() {

    if (!empty($_SERVER['REQUEST_URI'])) {
        return $_SERVER['REQUEST_URI'];

    } else if (!empty($_SERVER['PHP_SELF'])) {
        if (!empty($_SERVER['QUERY_STRING'])) {
            return $_SERVER['PHP_SELF'] .'?'. $_SERVER['QUERY_STRING'];
        }
        return $_SERVER['PHP_SELF'];

    } else if (!empty($_SERVER['SCRIPT_NAME'])) {
        if (!empty($_SERVER['QUERY_STRING'])) {
            return $_SERVER['SCRIPT_NAME'] .'?'. $_SERVER['QUERY_STRING'];
        }
        return $_SERVER['SCRIPT_NAME'];

    } else if (!empty($_SERVER['URL'])) {     // May help IIS (not well tested)
        if (!empty($_SERVER['QUERY_STRING'])) {
            return $_SERVER['URL'] .'?'. $_SERVER['QUERY_STRING'];
        }
        return $_SERVER['URL'];

    } else {
        log_warn('Warning: Could not find any of these web server variables: $REQUEST_URI, $PHP_SELF, $SCRIPT_NAME or $URL');
        return false;
    }
}

/**
 * Like {@link me()} but returns a full URL
 * @see me()
 * @return string
 */
function get_full_script_path() {

    global $CFG;

    if (!empty($CFG->wwwroot)) {
        $url = parse_url($CFG->wwwroot);
    }

    if (!empty($url['host'])) {
        $hostname = $url['host'];
    } else if (!empty($_SERVER['SERVER_NAME'])) {
        $hostname = $_SERVER['SERVER_NAME'];
    } else if (!empty($_ENV['SERVER_NAME'])) {
        $hostname = $_ENV['SERVER_NAME'];
    } else if (!empty($_SERVER['HTTP_HOST'])) {
        $hostname = $_SERVER['HTTP_HOST'];
    } else if (!empty($_ENV['HTTP_HOST'])) {
        $hostname = $_ENV['HTTP_HOST'];
    } else {
        log_warn('Warning: could not find the name of this server!');
        return false;
    }

    if (!empty($url['port'])) {
        $hostname .= ':'.$url['port'];
    } else if (!empty($_SERVER['SERVER_PORT'])) {
        if ($_SERVER['SERVER_PORT'] != 80 && $_SERVER['SERVER_PORT'] != 443) {
            $hostname .= ':'.$_SERVER['SERVER_PORT'];
        }
    }

    if (isset($_SERVER['HTTPS'])) {
        $protocol = ($_SERVER['HTTPS'] == 'on') ? 'https://' : 'http://';
    } else if (isset($_SERVER['SERVER_PORT'])) { # Apache2 does not export $_SERVER['HTTPS']
        $protocol = ($_SERVER['SERVER_PORT'] == '443') ? 'https://' : 'http://';
    } else {
        $protocol = 'http://';
    }

    $url_prefix = $protocol.$hostname;
    return $url_prefix . get_script_path();
}

/**
 * Remove query string from url
 *
 * Takes in a URL and returns it without the querystring portion
 *
 * @param string $url the url which may have a query string attached
 * @return string
 */
 function strip_querystring($url) {

    if ($commapos = strpos($url, '?')) {
        return substr($url, 0, $commapos);
    } else {
        return $url;
    }
}

function has_page_help() {
    $pt = defined('SECTION_PLUGINTYPE') ? SECTION_PLUGINTYPE : null;
    $pn = defined('SECTION_PLUGINNAME') ? SECTION_PLUGINNAME : null;
    $sp = defined('SECTION_PAGE')       ? SECTION_PAGE       : null;

    if (empty($pt) || ($pt != 'core' && empty($pn))) {
        // we can't have a plugin type but no plugin name
        return false;
    }

    if (in_array($pt, plugin_types())) {
        $pagehelp = get_config('docroot') . $pt . '/' . $pn . '/lang/en.utf8/help/pages/' . $sp . '.html';
    }
    else {
        $pagehelp = get_config('docroot') . 'lang/en.utf8/help/pages/' . $pn . '/' . $sp . '.html';
    }

    if (is_readable($pagehelp)) {
        return array($sp, get_help_icon($pt, $pn, '', '', $sp));
    }
    return false;
}

//
// Cleaning/formatting functions
//
function format_whitespace($text) {
    $text = str_replace("\r\n", "\n", $text);
    $text = str_replace("\r", "\n", $text);
    $text = hsc($text);
    $text = str_replace('  ', ' &nbsp;', $text);
    $text = str_replace('  ', '&nbsp; ', $text);
    $text = nl2br($text);
    return $text;
}

/**
 * Returns only the first short snippet of a user's introduction
 */
function format_introduction($introduction) {
    $introduction = strip_tags($introduction);
    // Note: the lengths are different to prevent chopping off just one or two characters in order to add an ellipsis
    if (strlen($introduction) < 110) {
        return $introduction;
    }
    return substr($introduction, 0, 100) . '...';
}

/**
 * Given raw text (eg typed in by a user), this function cleans it up
 * and removes any nasty tags that could mess up pages.
 *
 * @param string $text The text to be cleaned
 * @return string The cleaned up text
 */
function clean_text($text) {
    require_once('htmlpurifier/HTMLPurifier.auto.php');
    $config = HTMLPurifier_Config::createDefault();
    $config->set('Cache', 'SerializerPath', get_config('dataroot') . 'htmlpurifier');
    $purifier = new HTMLPurifier($config);
    return $purifier->purify($text);
}


/**
 * Displays purified html on a page with an explanatory message.
 * 
 * @param string $html  The purified html.
 * @param array $params Variables passed to the template. Currently
 *                      downloadurl - link to download the original (dirty) file.
 */
function display_cleaned_html($html, $params) {
    $smarty = smarty_core();
    $smarty->assign('params', $params);
    $smarty->assign('content', clean_text($html));
    $smarty->display('cleanedhtml.tpl');
    exit;
}


/**
 * Builds pagination links for HTML display.
 *
 * The pagination is quite configurable, but at the same time gives a consitent 
 * look and feel to all pagination.
 *
 * This function takes one array that contains the options to configure the 
 * pagination. Required options include:
 *
 * - url: The base URL to use for all links
 * - count: The total number of results to paginate for
 * - limit: How many to show per page
 * - offset: At which result to start showing results
 *
 * Optional options include:
 *
 * - id: The ID of the div enclosing the pagination
 * - class: The class of the div enclosing the pagination
 * - offsetname: The name of the offset parameter in the url
 * - firsttext: The text to use for the 'first page' link
 * - previoustext: The text to use for the 'previous page' link
 * - nexttext: The text to use for the 'next page' link
 * - lasttext: The text to use for the 'last page' link
 * - numbersincludefirstlast: Whether the page numbering should include links 
 *   for the first and last pages
 * - resultcounttextsingular: The text to use for 'result'
 * - resultcounttextplural: The text to use for 'results'
 *
 * Optional options to support javascript pagination include:
 *
 * - datatable: The ID of the table whose TBODY's rows will be replaced with the 
 *   resulting rows
 * - jsonscript: The script to make a json request to in order to retrieve 
 *   both the new rows and the new pagination. See js/artefactchooser.json.php 
 *   for an example. Note that the paginator javascript library is NOT 
 *   automatically included just because you call this function, so make sure 
 *   that your smarty() call hooks it in.
 *
 * @param array $params Options for the pagination
 */
function build_pagination($params) {
    // Bail if the required attributes are not present
    $required = array('url', 'count', 'limit', 'offset');
    foreach ($required as $option) {
        if (!isset($params[$option])) {
            throw new ParameterException('You must supply option "' . $option . '" to build_pagination');
        }
    }

    // Work out default values for parameters
    if (!isset($params['id'])) {
        $params['id'] = substr(md5(microtime()), 0, 4);
    }

    $params['offsetname'] = (isset($params['offsetname'])) ? $params['offsetname'] : 'offset';
    $params['offset'] = param_integer($params['offsetname'], 0);
    // Correct for odd offsets
    $params['offset'] -= $params['offset'] % $params['limit'];

    $params['firsttext'] = (isset($params['firsttext'])) ? $params['firsttext'] : get_string('first');
    $params['previoustext'] = (isset($params['previoustext'])) ? $params['previoustext'] : get_string('previous');
    $params['nexttext']  = (isset($params['nexttext']))  ? $params['nexttext'] : get_string('next');
    $params['lasttext']  = (isset($params['lasttext']))  ? $params['lasttext'] : get_string('last');
    $params['resultcounttextsingular'] = (isset($params['resultcounttextsingular'])) ? $params['resultcounttextsingular'] : get_string('result');
    $params['resultcounttextplural'] = (isset($params['resultcounttextplural'])) ? $params['resultcounttextplural'] : get_string('results');

    if (!isset($params['numbersincludefirstlast'])) {
        $params['numbersincludefirstlast'] = true;
    }
    if (!isset($params['numbersincludeprevnext'])) {
        $params['numbersincludeprevnext'] = true;
    }

    if (!isset($params['extradata'])) {
        $params['extradata'] = null;
    }

    // Begin building the output
    $output = '<div id="' . $params['id'] . '" class="pagination';
    if (isset($params['class'])) {
        $output .= ' ' . hsc($params['class']);
    }
    $output .= '">';

    if ($params['limit'] <= $params['count']) {
        $pages = ceil($params['count'] / $params['limit']);
        $page = $params['offset'] / $params['limit'];

        $last = $pages - 1;
        $next = min($last, $page + 1);
        $prev = max(0, $page - 1);

        // Build a list of what pagenumbers will be put between the previous/next links
        $pagenumbers = array();
        if ($params['numbersincludefirstlast']) {
            $pagenumbers[] = 0;
        }
        if ($params['numbersincludeprevnext']) {
            $pagenumbers[] = $prev;
        }
        $pagenumbers[] = $page;
        if ($params['numbersincludeprevnext']) {
            $pagenumbers[] = $next;
        }
        if ($params['numbersincludefirstlast']) {
            $pagenumbers[] = $last;
        }
        $pagenumbers = array_unique($pagenumbers);

        // Build the first/previous links
        $isfirst = $page == 0;
        $output .= build_pagination_pagelink('first', $params['url'], 0, '&laquo; ' . $params['firsttext'], get_string('firstpage'), $isfirst, $params['offsetname']);
        $output .= build_pagination_pagelink('prev', $params['url'], $params['limit'] * $prev, 
            '&larr; ' . $params['previoustext'], get_string('prevpage'), $isfirst, $params['offsetname']);

        // Build the pagenumbers in the middle
        foreach ($pagenumbers as $k => $i) {
            if ($k != 0 && $prevpagenum < $i - 1) {
                $output .= '…';
            }
            if ($i == $page) {
                $output .= '<span class="selected">' . ($i + 1) . '</span>';
            }
            else {
                $output .= build_pagination_pagelink('', $params['url'],
                    $params['limit'] * $i, $i + 1, '', false, $params['offsetname']);
            }
            $prevpagenum = $i;
        }

        // Build the next/last links
        $islast = $page == $last;
        $output .= build_pagination_pagelink('next', $params['url'], $params['limit'] * $next,
            $params['nexttext'] . ' &rarr;', get_string('nextpage'), $islast, $params['offsetname']);
        $output .= build_pagination_pagelink('last', $params['url'], $params['limit'] * $last,
            $params['lasttext'] . ' &raquo;', get_string('lastpage'), $islast, $params['offsetname']);
    }

    // Work out what javascript we need for the paginator
    $js = '';
    if (isset($params['jsonscript']) && isset($params['datatable'])) {
        $paginator_js = hsc(get_config('wwwroot') . 'js/paginator.js');
        $id           = json_encode($params['id']);
        $datatable    = json_encode($params['datatable']);
        $jsonscript   = json_encode($params['jsonscript']);
        $extradata    = json_encode($params['extradata']);
        $js .= "new Paginator($id, $datatable, $jsonscript, $extradata);";
    }

    // Output the count of results
    $resultsstr = ($params['count'] == 1) ? $params['resultcounttextsingular'] : $params['resultcounttextplural'];
    $output .= '<div class="results">' . $params['count'] . ' ' . $resultsstr . '</div>';

    // Close the container div
    $output .= '</div>';

    return array('html' => $output, 'javascript' => $js);

}

/**
 * Used by build_pagination to build individual links. Shouldn't be used 
 * elsewhere.
 */
function build_pagination_pagelink($class, $url, $offset, $text, $title, $disabled=false, $offsetname='offset') {
    $return = '<span class="pagination';
    $return .= ($class) ? " $class" : '';

    if ($disabled) {
        $return .= ' disabled">' . $text . '</span>';
    }
    else {
        $return .= '">'
            . '<a href="' . $url . '&amp;' . $offsetname . '=' . $offset
            . '" title="' . $title . '">' . $text . '</a></span>';
    }

    return $return;
}

?>