web.php

<?php
/**
 * Mahara: Electronic portfolio, weblog, resume builder and social networking
 * Copyright (C) 2006-2009 Catalyst IT Ltd and others; see:
 *                         http://wiki.mahara.org/Contributors
 *
 * 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     Catalyst IT Ltd
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL
 * @copyright  (C) 2006-2009 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 'dwoo/dwoo/dwooAutoload.php';
    require_once 'dwoo/mahara/Dwoo_Mahara.php';

    return new Dwoo_Mahara();
}


/**
 * 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:
 *
 * - 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 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
 */

function smarty($javascript = array(), $headers = array(), $pagestrings = array(), $extraconfig = array()) {
    global $USER, $SESSION, $THEME, $HEADDATA;

    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');
    // NOTE: not using jswwwroot - it seems to wreck image paths if you 
    // drag them around the wysiwyg editor
    $jswwwroot = json_encode($wwwroot);

    // Workaround for $cfg->cleanurlusersubdomains.
    // When cleanurlusersubdomains is on, ajax requests might come from somewhere other than
    // the wwwroot.  To avoid cross-domain requests, set a js variable when this page is on a
    // different subdomain, and let the ajax wrapper function sendjsonrequest rewrite its url
    // if necessary.
    if (get_config('cleanurls') && get_config('cleanurlusersubdomains')) {
        if ($requesthost = get_requested_host_name()) {
            $wwwrootparts = parse_url($wwwroot);
            if ($wwwrootparts['host'] != $requesthost) {
                $fakewwwroot = $wwwrootparts['scheme'] . '://' . $requesthost . '/';
                $headers[] = '<script type="text/javascript">var fakewwwroot = ' . json_encode($fakewwwroot) . ';</script>';
            }
        }
    }

    $theme_list = array();
    
    if (function_exists('pieform_get_headdata')) {
        $headers = array_merge($headers, pieform_get_headdata());
        if (!defined('PIEFORM_GOT_HEADDATA')) {
          define('PIEFORM_GOT_HEADDATA', 1);
        }
    }

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

    $langdirection = get_string('thisdirection', 'langconfig');

    // 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';
                $content_css = json_encode($THEME->get_url('style/tinymce.css'));
                $language = substr(current_language(), 0, 2);
                if ($language != 'en' && !file_exists(get_config('docroot') . 'js/tinymce/langs/' . $language . '.js')) {
                    $language = 'en';
                }
                $extrasetup = isset($extraconfig['tinymcesetup']) ? $extraconfig['tinymcesetup'] : '';

                $adv_buttons = array(
                    "undo,redo,separator,bold,italic,underline,separator,justifyleft,justifycenter,justifyright,justifyfull,separator,bullist,numlist,separator,link,unlink,separator,code,fullscreen",
                    "bold,italic,underline,strikethrough,separator,forecolor,backcolor,separator,justifyleft,justifycenter,justifyright,justifyfull,separator,hr,emotions,image,spellchecker,cleanup,separator,link,unlink,separator,code,fullscreen",
                    "undo,redo,separator,bullist,numlist,separator,tablecontrols,separator,cut,copy,paste,pasteword",
                    "fontselect,separator,fontsizeselect,separator,formatselect",
                );

                // For right-to-left langs, reverse button order & align controls right.
                $tinymce_langdir = $langdirection == 'rtl' ? 'rtl' : 'ltr';
                $toolbar_align = 'left';

                if ($check[$key] == 'tinymce') {
                    $spellchecker_rpc = $jsroot.'tinymce/plugins/spellchecker/rpc.php';
                    $tinymce_config = <<<EOF
    mode: "none",
    theme: "advanced",
    plugins: "table,emotions,spellchecker,inlinepopups,paste,fullscreen",
    theme_advanced_buttons1 : "{$adv_buttons[1]}",
    theme_advanced_buttons2 : "{$adv_buttons[2]}",
    theme_advanced_buttons3 : "{$adv_buttons[3]}",
    theme_advanced_toolbar_location : "top",
    theme_advanced_toolbar_align : "{$toolbar_align}",
    fix_list_elements: true,
    spellchecker_rpc_url : "{$spellchecker_rpc}",
    //width: '512',
EOF;
                }
                else {
                    $tinymce_config = <<<EOF
    mode: "textareas",
    editor_selector: 'tinywysiwyg',
    theme: "advanced",
    plugins: "fullscreen,inlinepopups,autoresize",
    theme_advanced_buttons1 : "{$adv_buttons[0]}",
    theme_advanced_buttons2 : "",
    theme_advanced_buttons3 : "",
    theme_advanced_toolbar_location : "top",
    theme_advanced_toolbar_align : "{$toolbar_align}",
    fullscreen_new_window: true,
    fullscreen_settings: {
        theme: "advanced",
        plugins: "table,emotions,iespell,inlinepopups,paste,fullscreen",
        theme_advanced_buttons1 : "{$adv_buttons[1]}",
        theme_advanced_buttons2 : "{$adv_buttons[2]}",
        theme_advanced_buttons3 : "{$adv_buttons[3]}"
    },
EOF;
                }

                $headers[] = <<<EOF
<script type="text/javascript">
tinyMCE.init({
    button_tile_map: true,
    {$tinymce_config}
    extended_valid_elements : "object[width|height|classid|codebase],param[name|value],embed[src|type|width|height|flashvars|wmode],script[src,type,language],+ul[id|type|compact],iframe[src|width|height|align|title|class|type|frameborder|allowfullscreen]",
    urlconverter_callback : "custom_urlconvert",
    language: '{$language}',
    directionality: "{$tinymce_langdir}",
    content_css : {$content_css},
    //document_base_url: {$jswwwroot},
    remove_script_host: false,
    relative_urls: false,
    setup: function(ed) {
        ed.onInit.add(function(ed) {
            if (typeof(editor_to_focus) == 'string' && ed.editorId == editor_to_focus) {
                ed.focus();
            }
        });
        {$extrasetup}
    }
});
function custom_urlconvert (u, n, e) {
  // Don't convert the url on the skype status buttons.
  if (u.indexOf('skype:') == 0) {
      return u;
  }
  var t = tinyMCE.activeEditor, s = t.settings;

  // Don't convert link href since thats the CSS files that gets loaded into the editor also skip local file URLs
  if (!s.convert_urls || (e && e.nodeName == 'LINK') || u.indexOf('file:') === 0)
      return u;

  // Convert to relative
  if (s.relative_urls)
      return t.documentBaseURI.toRelative(u);

  // Convert to absolute
  u = t.documentBaseURI.toAbsolute(u, s.remove_script_host);

  return u;
}
</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 any page adds jquery explicitly, remove it from the list
        if (($key = array_search('jquery', $check)) !== false) {
            unset($check[$key]);
        }
    }

    // Make jQuery accessible with $j (Mochikit has $)
    $javascript_array[] = $jsroot . 'jquery/jquery.js';
    $headers[] = '<script type="text/javascript">$j=jQuery;</script>';

    if (get_config('developermode') & DEVMODE_UNPACKEDJS) {
        $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 if (strpos($jsfile, 'http://') === false) {
            // A local .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);
                    }
                }
            }
        }
        else {
            // A remote .js file
            $javascript_array[] = $jsfile;
        }
    }

    $javascript_array[] = $jsroot . 'mahara.js';
    if (get_config('developermode') & DEVMODE_DEBUGJS) {
        $javascript_array[] = $jsroot . 'debug.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 .= "\nfunction plural(n) { return " . get_raw_string('pluralrule', 'langconfig') . "; }\n";
    $stringjs .= '</script>';

    // stylesheet set up - if we're in a plugin also get its stylesheet
    $stylesheets = array_reverse(array_values($THEME->get_url('style/style.css', true)));
    if (defined('SECTION_PLUGINTYPE') && defined('SECTION_PLUGINNAME') && SECTION_PLUGINTYPE != 'core') {
        if ($pluginsheets = $THEME->get_url('style/style.css', true, SECTION_PLUGINTYPE . '/' . SECTION_PLUGINNAME)) {
            $stylesheets = array_merge($stylesheets, array_reverse($pluginsheets));
        }
    }

    if ($adminsection = in_admin_section()) {
        if ($adminsheets = $THEME->get_url('style/admin.css', true)) {
            $stylesheets = array_merge($stylesheets, array_reverse($adminsheets));
        }
    }
    if (get_config('developermode') & DEVMODE_DEBUGCSS) {
        $stylesheets[] = get_config('wwwroot') . 'theme/debug.css';
    }

    // look for extra stylesheets
    if (isset($extraconfig['stylesheets']) && is_array($extraconfig['stylesheets'])) {
        foreach ($extraconfig['stylesheets'] as $extrasheet) {
            if ($sheets = $THEME->get_url($extrasheet, true)) {
                $stylesheets = array_merge($stylesheets, array_reverse(array_values($sheets)));
            }
        }
    }
    if ($sheets = $THEME->additional_stylesheets()) {
        $stylesheets = array_merge($stylesheets, $sheets);
    }

    // Include rtl.css for right-to-left langs
    if ($langdirection == 'rtl') {
        $smarty->assign('LANGDIRECTION', 'rtl');
        if ($rtlsheets = $THEME->get_url('style/rtl.css', true)) {
            $stylesheets = array_merge($stylesheets, array_reverse($rtlsheets));
        }
    }

    $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))); 
    }

    $dropdownmenu = get_config('dropdownmenu');
    if ($dropdownmenu) {
        $smarty->assign('DROPDOWNMENU', $dropdownmenu);
    }

    $sitename = get_config('sitename');
    if (!$sitename) {
       $sitename = 'Mahara';
    }
    $smarty->assign('sitename', $sitename);
    $smarty->assign('sitelogo', $THEME->header_logo());
    $smarty->assign('sitelogo4facebook', $THEME->facebook_logo());
    $smarty->assign('sitedescription4facebook', get_string('facebookdescription', 'mahara'));

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

    $smarty->assign('PRODUCTIONMODE', get_config('productionmode'));
    if (function_exists('local_header_top_content')) {
        $sitetop = (isset($sitetop) ? $sitetop : '') . local_header_top_content();
    }
    if (isset($sitetop)) {
        $smarty->assign('SITETOP', $sitetop);
    }
    if (defined('PUBLIC')) {
        $smarty->assign('PUBLIC', true);
    }
    if (defined('ADMIN')) {
        $smarty->assign('ADMIN', true);
    }
    if (defined('INSTITUTIONALADMIN')) {
        $smarty->assign('INSTITUTIONALADMIN', true);
    }
    if (defined('STAFF')) {
        $smarty->assign('STAFF', true);
    }
    if (defined('INSTITUTIONALSTAFF')) {
        $smarty->assign('INSTITUTIONALSTAFF', true);
    }

    $smarty->assign('LOGGEDIN', $USER->is_logged_in());
    if ($USER->is_logged_in()) {
        global $SELECTEDSUBNAV; // It's evil, but rightnav & mainnav stuff are now in different templates.
        $smarty->assign('MAINNAV', main_nav());
        $mainnavsubnav = $SELECTEDSUBNAV;
        $smarty->assign('RIGHTNAV', right_nav());
        if (!$mainnavsubnav && $dropdownmenu) {
            // In drop-down navigation, the submenu is only usable if its parent is one of the top-level menu
            // items.  But if the submenu comes from something in right_nav (settings), it's unreachable.
            // Turning the submenu into SUBPAGENAV group-style tabs makes it usable.
            $smarty->assign('SUBPAGENAV', $SELECTEDSUBNAV);
        }
        else {
            $smarty->assign('SELECTEDSUBNAV', $SELECTEDSUBNAV);
        }
    }
    else {
        $smarty->assign('languageform', language_select_form());
    }
    $smarty->assign('FOOTERMENU', footer_menu());

    $smarty->assign_by_ref('USER', $USER);
    $smarty->assign('SESSKEY', $USER->get('sesskey'));
    $smarty->assign_by_ref('JAVASCRIPT', $javascript_array);
    $siteclosedforupgrade = get_config('siteclosed');
    if ($siteclosedforupgrade && get_config('disablelogin')) {
        $smarty->assign('SITECLOSED', 'logindisabled');
    }
    else if ($siteclosedforupgrade || get_config('siteclosedbyadmin')) {
        $smarty->assign('SITECLOSED', 'loginallowed');
    }

    if ((!isset($extraconfig['pagehelp']) || $extraconfig['pagehelp'] !== false)
        and $help = has_page_help()) {
        $smarty->assign('PAGEHELPNAME', $help[0]);
        $smarty->assign('PAGEHELPICON', $help[1]);
    }
    if (defined('GROUP')) {
        require_once('group.php');
        if ($group = group_current_group()) {
            $smarty->assign('GROUP', $group);
            if (!defined('NOGROUPMENU')) {
                $smarty->assign('SUBPAGENAV', group_get_menu_tabs());
                $smarty->assign('PAGEHEADING', $group->name);
            }
        }
    }

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

        if ($USER->is_logged_in() && defined('MENUITEM') &&
            (substr(MENUITEM, 0, 11) == 'myportfolio' || substr(MENUITEM, 0, 7) == 'content')) {
            if (get_config('showselfsearchsideblock')) {
                $SIDEBLOCKS[] = array(
                    'name'   => 'selfsearch',
                    'weight' => 0,
                    'data'   => array(),
                );
            }
            if (get_config('showtagssideblock')) {
                $SIDEBLOCKS[] = array(
                    'name'   => 'tags',
                    'id'     => 'sb-tags',
                    'weight' => 0,
                    'data'   => tags_sideblock(),
                );
            }
        }

        if ($USER->is_logged_in() && !$adminsection) {
            $SIDEBLOCKS[] = array(
                'name'   => 'profile',
                'id'     => 'sb-profile',
                'weight' => -20,
                'data'   => profile_sideblock()
            );
            $showusers = 2;
            $institutions = $USER->institutions;
            if (!empty($institutions)) {
                $showusers = 0;
                foreach ($institutions as $i) {
                    if ($i->showonlineusers == 2) {
                        $showusers = 2;
                        break;
                    }
                    if ($i->showonlineusers == 1) {
                        $showusers = 1;
                    }
                }
            }
            if (get_config('showonlineuserssideblock') && $showusers > 0) {
                $SIDEBLOCKS[] = array(
                    'name'   => 'onlineusers',
                    'id'     => 'sb-onlineusers',
                    'weight' => -10,
                    'data'   => onlineusers_sideblock(),
                );
            }
        }

        if(defined('GROUP')) {
            $SIDEBLOCKS[] = array(
                'name'   => 'group',
                'id'     => 'sb-groupnav',
                'weight' => -10,
                'data'   => group_sideblock()
            );
        }

        if (!$USER->is_logged_in() && !(get_config('siteclosed') && get_config('disablelogin'))) {
            $SIDEBLOCKS[] = array(
                'name'   => 'login',
                'weight' => -10,
                'id'     => 'sb-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;'));

        // Place all sideblocks on the right. If this structure is munged 
        // appropriately, you can put blocks on the left. In future versions of 
        // Mahara, we'll make it easy to do this.
        $sidebars = $sidebars && !empty($SIDEBLOCKS);
        $SIDEBLOCKS = array('left' => array(), 'right' => $SIDEBLOCKS);

        $smarty->assign('userauthinstance', $SESSION->get('authinstance'));
        $smarty->assign('MNETUSER', $SESSION->get('mnetuser'));
        $smarty->assign('SIDEBLOCKS', $SIDEBLOCKS);
        $smarty->assign('SIDEBARS', $sidebars);

    }

    if (is_array($HEADDATA) && !empty($HEADDATA)) {
        $headers = array_merge($HEADDATA, $headers);
    }
    $smarty->assign_by_ref('HEADERS', $headers);

    if ($USER->get('parentuser')) {
        $smarty->assign('USERMASQUERADING', true);
        $smarty->assign('masqueradedetails', get_string('youaremasqueradingas', 'mahara', display_name($USER)));
        $smarty->assign('becomeyouagain',
            ' <a href="' . hsc($wwwroot) . 'admin/users/changeuser.php?restore=1">'
            . get_string('becomeadminagain', 'admin', hsc($USER->get('parentuser')->name))
            . '</a>');
    }

    return $smarty;
}


/**
 * Manages theme configuration.
 *
 * Does its best to give the user _a_ theme, even if it's not the theme they 
 * want to use (e.g. the theme they want has been uninstalled)
 */
class Theme {

    /**
     * The base name of the theme (the name of the directory in which it lives)
     */
    public $basename = '';

    /**
     * A user may have had the header logo overridden by an institution
     */
    public $headerlogo;

    /**
     * Additional stylesheets to display after the basename theme's stylesheets
     */
    public $addedstylesheets;

    /**
     * A human-readable version of the theme name
     */
    public $displayname = '';

    /**
     * Which pieform renderer to use by default for all forms
     */
    public $formrenderer = '';

    /**
     * Directories where to look for templates by default
     */
    public $templatedirs = array();

    /**
     * Theme inheritance path from this theme to 'raw'
     */
    public $inheritance = array();

    /**
     * What unit the left/center/right column widths are in. 'pixels' or 'percent'
     */
    public $columnwidthunits    = '';

    /**
     * Width of the left column. Integer - see $columnwidthunits
     */
    public $leftcolumnwidth     = 256;

    /**
     * Background colour for the left column
     */
    public $leftcolumnbgcolor   = '#fff';

    /**
     * Background colour for the center column
     */
    public $centercolumnbgcolor = '#fff';

    /**
     * Width of the right column. Integer - see $columnwidthunits
     */
    public $rightcolumnwidth    = 256;

    /**
     * Background colour for the right column
     */
    public $rightcolumnbgcolor  = '#fff';


    /**
     * Initialises a theme object based on the theme 'hint' passed.
     *
     * If arg is a string, it's taken to be a theme name. If it's a user 
     * object, we ask it for a theme name. If it's an integer, we pretend 
     * that's a user ID and ask for the theme for that user.
     *
     * If the theme they want doesn't exist, the object is initialised for the 
     * default theme. This means you can initialise one of these for a user
     * and then use it without worrying if the theme exists.
     *
     * @param mixed $arg Theme name, user object or user ID
     */
    public function __construct($arg) {
        if (is_string($arg)) {
            $themename = $arg;
            $themedata = null;
        }
        else if ($arg instanceof User) {
            $themedata = $arg->get_themedata();
        }
        else if (is_int($arg)) {
            $user = new User();
            $user->find_by_id($arg);
            $themedata = $user->get_themedata();
        }
        else {
            throw new SystemException("Argument to Theme::__construct was not a theme name, user object or user ID");
        }

        if (isset($themedata)) {
            $themename = $themedata->basename;
        }

        if (empty($themename)) {
            // Theme to show to when no theme has been suggested
            if (!$themename = get_config('theme')) {
                $themename = 'raw';
            }
        }

        // check the validity of the name
        if (!$this->name_is_valid($themename)) {
            throw new SystemException("Theme name is in invalid form: '$themename'");
        }

        $this->init_theme($themename, $themedata);
    }

    /**
     * Given a theme name, check that it is valid
     */
    public static function name_is_valid($themename) {
        // preg_match returns 0 if invalid characters were found, 1 if not
        return (preg_match('/^[a-zA-Z0-9_-]+$/', $themename) == 1);
    }

    /**
     * Given a theme name, reads in all config and sets fields on this object
     */
    private function init_theme($themename, $themedata) {
        $this->basename = $themename;

        $themeconfigfile = get_config('docroot') . 'theme/' . $this->basename . '/themeconfig.php';
        if (!is_readable($themeconfigfile)) {
            // We can safely assume that the default theme is installed, users 
            // should never be able to remove it
            $this->basename = 'default';
            $themeconfigfile = get_config('docroot') . 'theme/default/themeconfig.php';
        }

        require($themeconfigfile);

        foreach (get_object_vars($theme) as $key => $value) {
            $this->$key = $value;
        }

        if (!isset($this->displayname)) {
            $this->displayname = $this->basename;
        }
        if (!isset($theme->parent) || !$theme->parent) {
            $theme->parent = 'raw';
        }

        $this->templatedirs[] = get_config('docroot') . 'theme/' . $this->basename . '/templates/';
        $this->inheritance[]  = $this->basename;

        $this->templatedirs[] = get_config('docroot') . 'local/theme/templates/';

        // Now go through the theme hierarchy assigning variables from the 
        // parent themes
        $currenttheme = $this->basename;
        while ($currenttheme != 'raw') {
            $currenttheme = isset($theme->parent) ? $theme->parent : 'raw';
            $parentconfigfile = get_config('docroot') . 'theme/' . $currenttheme . '/themeconfig.php';
            require($parentconfigfile);
            foreach (get_object_vars($theme) as $key => $value) {
                if (!isset($this->$key) || !$this->$key) {
                    $this->$key = $value;
                }
            }
            $this->templatedirs[] = get_config('docroot') . 'theme/' . $currenttheme . '/templates/';
            $this->inheritance[]  = $currenttheme;
        }

        if (!empty($themedata->headerlogo)) {
            $this->headerlogo = $themedata->headerlogo;
        }
        if (!empty($themedata->stylesheets)) {
            $this->addedstylesheets = $themedata->stylesheets;
        }
    }

    /**
     * stuff
     */
    public function get_url($filename, $all=false, $plugindirectory='') {
        return $this->_get_path($filename, $all, $plugindirectory, get_config('wwwroot'));
    }

    public function get_path($filename, $all=false, $plugindirectory='') {
        return $this->_get_path($filename, $all, $plugindirectory, get_config('docroot'));
    }

    private function _get_path($filename, $all, $plugindirectory, $returnprefix) {
        $list = array();
        $plugindirectory = ($plugindirectory && substr($plugindirectory, -1) != '/') ? $plugindirectory . '/' : $plugindirectory;

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

        $extra = '';
        if ($plugindirectory) {
            $extra = ", plugindir $plugindirectory";
        }
        log_debug("Missing file in theme {$this->basename}{$extra}: $filename");
        return $returnprefix . $plugindirectory . 'theme/' . $themedir . '/static/' . $filename;
    }

    public function header_logo() {
        if (!empty($this->headerlogo)) {
            return get_config('wwwroot') . 'thumb.php?type=logobyid&id=' . $this->headerlogo;
        }
        return $this->get_url('images/site-logo.png');
    }

    public function facebook_logo() {
        return $this->get_url('images/site-logo4facebook.png');
    }

    public function additional_stylesheets() {
        return $this->addedstylesheets;
    }
}


/** 
 * 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',
                'unknownerror',
                'loading',
                'showtags',
                'couldnotgethelp',
                'password',
                'username',
                'login',
                'sessiontimedout',
                'loginfailed',
                'home',
                'youhavenottaggedanythingyet',
            ),
        ),
        'tablerenderer' => array(
            'mahara' => array(
                'firstpage',
                'nextpage',
                'prevpage',
                'lastpage',
            )
        ),
        'views' => array(
            'view' => array(
                'confirmdeleteblockinstance',
                'blocksinstructionajax',
            ),
        ),
    );
}

function themepaths() {

    static $paths;
    if (empty($paths)) {
        $paths = array(
            'mahara' => array(
                'images/icon_close.gif',
                'images/edit.gif',
                'images/failure.gif',
                'images/loading.gif',
                'images/success.gif',
                'images/icon_problem.gif',
                'images/icon_help.gif',
                'style/js.css',
            ),
        );
    }
    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() {
    global $THEME;
    log_warn("theme_setup() is deprecated - please use the global \$THEME object instead");
    return $THEME;
}

/** 
 * 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) {
    global $THEME;
    log_warn("theme_get_url() is deprecated: Use \$THEME->get_url() instead");
    $plugintype = $pluginname = '';
    if ($pluginlocation) {
        list($plugintype, $pluginname) = explode('/', $pluginlocation);
        $pluginname = substr($pluginname, 0, -1);
    }
    return $THEME->get_url($location, $all, $plugintype, $pluginname);
}

/** 
 * 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='', $all=false) {
    global $THEME;
    log_warn("theme_get_path() is deprecated: Use \$THEME->get_path() instead");
    $plugintype = $pluginname = '';
    if ($pluginlocation) {
        list($plugintype, $pluginname) = explode('/', $pluginlocation);
        $pluginname = substr($pluginname, 0, -1);
    }
    return $THEME->get_path($location, $all, $plugintype, $pluginname);
}

/**
 * This function sends headers suitable for all JSON returning scripts.
 *
 */
function json_headers() {