<?php
/* For licensing terms, see /license.txt */

/**
 * Function library for the links tool.
 *
 * This is a complete remake of the original link tool.
 * New features:
 * - Organize links into categories;
 * - favorites/bookmarks interface;
 * - move links up/down within a category;
 * - move categories up/down;
 * - expand/collapse all categories;
 * - add link to 'root' category => category-less link is always visible.
 *
 * @author Patrick Cool, complete remake (December 2003 - January 2004)
 * @author René Haentjens, CSV file import (October 2004)
 * @package chamilo.link
 */

/* FUNCTIONS */

/**
 * Used to add a link or a category
 * @param string $type, "link" or "category"
 * @todo replace strings by constants
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function addlinkcategory($type) {
    global $catlinkstatus;
    global $msgErr;

    $ok = true;

    if ($type == 'link') {
        $tbl_link = Database :: get_course_table(TABLE_LINK);

        $title = Security::remove_XSS(stripslashes($_POST['title']));
        $urllink = Security::remove_XSS($_POST['urllink']);
        $description = Security::remove_XSS(stripslashes($_POST['description']));
        $selectcategory = Security::remove_XSS($_POST['selectcategory']);

        if ($_POST['onhomepage'] == '') {
            $onhomepage = 0;
            $target = '_self'; // Default target.
        } else {
            $onhomepage = Security::remove_XSS($_POST['onhomepage']);
            $target = Security::remove_XSS($_POST['target_link']);
        }

        $urllink = trim($urllink);
        $title = trim($title);
        $description = trim($description);

        // We ensure URL to be absolute.
        if (strpos($urllink, '://') === false) {
            $urllink = 'http://'.$urllink;
        }

        // If the title is empty, we use the URL as title.
        if ($title == '') {
            $title = $urllink;
        }

        // If the URL is invalid, an error occurs.
        // Ivan, 13-OCT-2010, Chamilo 1.8.8: Let us still tolerate PHP 5.1.x and avoid a specific bug in filter_var(), see http://bugs.php.net/51192
        //if (!filter_var($urllink, FILTER_VALIDATE_URL)) {
        if (!api_valid_url($urllink, true)) { // A check against an absolute URL.
        //
            $msgErr = get_lang('GiveURL');
            Display::display_error_message(get_lang('GiveURL'));
            $ok = false;
        } else {
            // Looking for the largest order number for this category.
            $result = Database::query("SELECT MAX(display_order) FROM  ".$tbl_link." WHERE category_id='".Database::escape_string($_POST['selectcategory'])."'");
            list($orderMax) = Database::fetch_row($result);
            $order = $orderMax + 1;

            $session_id = api_get_session_id();

            $sql = "INSERT INTO ".$tbl_link." (url, title, description, category_id, display_order, on_homepage, target, session_id)
                VALUES ('".Database::escape_string($urllink)."','".Database::escape_string($title)."','".Database::escape_string($description)."','".
                Database::escape_string($selectcategory)."','".Database::escape_string($order)."', '".Database::escape_string($onhomepage)."','".
                Database::escape_string($target)."','".Database::escape_string($session_id)."')";
            $catlinkstatus = get_lang('LinkAdded');
            Database::query($sql);
            $link_id = Database::insert_id();

            if ((api_get_setting('search_enabled') == 'true') && $link_id && extension_loaded('xapian')) {
                require_once api_get_path(LIBRARY_PATH).'search/DokeosIndexer.class.php';
                require_once api_get_path(LIBRARY_PATH).'search/IndexableChunk.class.php';
                require_once api_get_path(LIBRARY_PATH).'specific_fields_manager.lib.php';

                $courseid = api_get_course_id();
                $specific_fields = get_specific_field_list();
                $ic_slide = new IndexableChunk();

                // Add all terms to db.
                $all_specific_terms = '';
                foreach ($specific_fields as $specific_field) {
                    if (isset($_REQUEST[$specific_field['code']])) {
                        $sterms = trim($_REQUEST[$specific_field['code']]);
                        if (!empty($sterms)) {
                            $all_specific_terms .= ' '. $sterms;
                            $sterms = explode(',', $sterms);
                            foreach ($sterms as $sterm) {
                                $ic_slide->addTerm(trim($sterm), $specific_field['code']);
                                add_specific_field_value($specific_field['id'], $courseid, TOOL_LINK, $link_id, $sterm);
                            }
                        }
                    }
                }

                // Build the chunk to index.
                $ic_slide->addValue('title', $title);
                $ic_slide->addCourseId($courseid);
                $ic_slide->addToolId(TOOL_LINK);
                $xapian_data = array(
                    SE_COURSE_ID => $courseid,
                    SE_TOOL_ID => TOOL_LINK,
                    SE_DATA => array('link_id' => (int)$link_id),
                    SE_USER => (int)api_get_user_id(),
                );
                $ic_slide->xapian_data = serialize($xapian_data);
                $description = $all_specific_terms .' '.$description;
                $ic_slide->addValue('content', $description);

                // Add category name if set.
                if (isset($_POST['selectcategory']) && $selectcategory > 0) {
                    $table_link_category = Database::get_course_table(TABLE_LINK_CATEGORY);
                    $sql_cat = 'SELECT * FROM %s WHERE id=%d LIMIT 1';
                    $sql_cat = sprintf($sql_cat, $table_link_category, (int)$selectcategory);
                    $result = Database::query($sql_cat);
                    if (Database::num_rows($result) == 1) {
                        $row = Database::fetch_array($result);
                        $ic_slide->addValue('category', $row['category_title']);
                    }
                }

                $di = new DokeosIndexer();
                isset($_POST['language'])? $lang = Database::escape_string($_POST['language']): $lang = 'english';
                $di->connectDb(NULL, NULL, $lang);
                $di->addChunk($ic_slide);

                // Index and return search engine document id.
                $did = $di->index();
                if ($did) {
                    // Save it to db.
                    $tbl_se_ref = Database::get_main_table(TABLE_MAIN_SEARCH_ENGINE_REF);
                    $sql = 'INSERT INTO %s (id, course_code, tool_id, ref_id_high_level, search_did)
                        VALUES (NULL , \'%s\', \'%s\', %s, %s)';
                    $sql = sprintf($sql, $tbl_se_ref, $courseid, TOOL_LINK, $link_id, $did);
                    Database::query($sql);
                }
            }

            unset($urllink, $title, $description, $selectcategory);

            Display::display_confirmation_message(get_lang('LinkAdded'));
        }
    } elseif ($type == 'category') {
        $tbl_categories = Database :: get_course_table(TABLE_LINK_CATEGORY);

        $category_title = trim($_POST['category_title']);
        $description = trim($_POST['description']);

        if (empty($category_title)) {
            $msgErr = get_lang('GiveCategoryName');
            Display::display_error_message(get_lang('GiveCategoryName'));
            $ok = false;
        } else {
            // Looking for the largest order number for this category.
            $result = Database::query("SELECT MAX(display_order) FROM  ".$tbl_categories);
            list($orderMax) = Database::fetch_row($result);
            $order = $orderMax + 1;

            $session_id = api_get_session_id();

            $sql = "INSERT INTO ".$tbl_categories." (category_title, description, display_order, session_id) VALUES ('".Security::remove_XSS($category_title)."','".Security::remove_XSS($description)."', '$order', '$session_id')";
            Database::query($sql);

            $catlinkstatus = get_lang('CategoryAdded');
            unset($category_title, $description);
            Display::display_confirmation_message(get_lang('CategoryAdded'));
        }
    }

    // "WHAT'S NEW" notification : update last tool Edit.
    if ($type == 'link') {
        global $_user;
        global $_course;
        global $nameTools;

        api_item_property_update($_course, TOOL_LINK, $link_id, 'LinkAdded', $_user['user_id']);
    }

    return $ok;
}

/**
 * Used to delete a link or a category
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function deletelinkcategory($type) {

    global $catlinkstatus;
    global $_course;
    global $_user;
    $tbl_link = Database :: get_course_table(TABLE_LINK);
    $tbl_categories = Database :: get_course_table(TABLE_LINK_CATEGORY);
    $TABLE_ITEM_PROPERTY = Database :: get_course_table(TABLE_ITEM_PROPERTY);

    if ($type == 'link') {

        global $id;
        // -> Items are no longer fysically deleted, but the visibility is set to 2 (in item_property).
        // This will make a restore function possible for the platform administrator.
        if (isset($_GET['id']) && $_GET['id'] == strval(intval($_GET['id']))) {
            $sql = "UPDATE $tbl_link SET on_homepage='0' WHERE id='".Database::escape_string($_GET['id'])."'";
            Database::query($sql);
        }

        api_item_property_update($_course, TOOL_LINK, $id, 'delete', $_user['user_id']);
        delete_link_from_search_engine(api_get_course_id(), $id);
        $catlinkstatus = get_lang('LinkDeleted');
        unset ($id);

        Display::display_confirmation_message(get_lang('LinkDeleted'));
    }

    if ($type == 'category') {
        global $id;
        if (isset($_GET['id']) && !empty($_GET['id'])) {
            // First we delete the category itself and afterwards all the links of this category.
            $sql = "DELETE FROM ".$tbl_categories." WHERE id='".intval($_GET['id'])."'";
            Database::query($sql);
            $sql = "DELETE FROM ".$tbl_link." WHERE category_id='".intval($_GET['id'])."'";
            $catlinkstatus = get_lang('CategoryDeleted');
            unset ($id);
            Database::query($sql);

            Display::display_confirmation_message(get_lang('CategoryDeleted'));
        }
    }
}

/**
 * Removes a link from search engine database
 *
 * @param string $course_id Course code
 * @param int $document_id Document id to delete
 */
function delete_link_from_search_engine($course_id, $link_id) {
    // Remove from search engine if enabled.
    if (api_get_setting('search_enabled') == 'true') {
        $tbl_se_ref = Database::get_main_table(TABLE_MAIN_SEARCH_ENGINE_REF);
        $sql = 'SELECT * FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_high_level=%s LIMIT 1';
        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_LINK, $link_id);
        $res = Database::query($sql);
        if (Database::num_rows($res) > 0) {
            $row = Database::fetch_array($res);
            require_once api_get_path(LIBRARY_PATH).'search/DokeosIndexer.class.php';
            $di = new DokeosIndexer();
            $di->remove_document((int)$row['search_did']);
        }
        $sql = 'DELETE FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_high_level=%s LIMIT 1';
        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_LINK, $link_id);
        Database::query($sql);

        // Remove terms from db.
        require_once(api_get_path(LIBRARY_PATH) .'specific_fields_manager.lib.php');
        delete_all_values_for_item($course_id, TOOL_DOCUMENT, $link_id);
    }
}

/**
 * Used to edit a link or a category
 * @todo Rewrite the whole links tool because it is becoming completely cluttered,
 *       code does not follow the coding conventions, does not use html_quickform, ...
 *       Some features were patched in.
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 * @todo replace the globals with the appropriate $_POST or $_GET values
 */
function editlinkcategory($type) {

    global $catlinkstatus;
    global $id;
    global $submit_link;
    global $submit_category;
    global $_user;
    global $_course;
    global $nameTools;
    global $urllink;
    global $title;
    global $description;
    global $category;
    global $selectcategory;
    global $description;
    global $category_title;
    global $onhomepage;
    global $target_link;

    $tbl_link       = Database :: get_course_table(TABLE_LINK);
    $tbl_categories = Database :: get_course_table(TABLE_LINK_CATEGORY);

    if ($type == 'link') {

        // This is used to populate the link-form with the info found in the database.
        if (!empty($_GET['id'])) {
            $sql = "SELECT * FROM ".$tbl_link." WHERE id='".intval($_GET['id'])."'";
            $result = Database::query($sql);
            if ($myrow = Database::fetch_array($result)) {
                $urllink = $myrow['url'];
                $title = $myrow['title'];
                $description = $myrow['description'];
                $category = $myrow['category_id'];
                if ($myrow['on_homepage'] != 0) {
                    $onhomepage = 'checked';
                }
                $target_link = $myrow['target'];
            }
        }

        // This is used to put the modified info of the link-form into the database.
        if ($_POST['submitLink']) {

            // Ivan, 13-OCT-2010: It is a litle bit messy code below, just in case I added some extra-security checks here.
            $_POST['urllink'] = trim(Security::remove_XSS($_POST['urllink']));
            $_POST['title'] = trim(Security::remove_XSS(stripslashes($_POST['title'])));
            $_POST['description'] = trim(Security::remove_XSS(stripslashes($_POST['description'])));
            $_POST['selectcategory'] = intval($_POST['selectcategory']);
            $_POST['id'] = intval($_POST['id']);

            // We ensure URL to be absolute.
            if (strpos($_POST['urllink'], '://') === false) {
                $_POST['urllink'] = 'http://'.$_POST['urllink'];
            }

            // If the title is empty, we use the URL as title.
            if ($_POST['title'] == '') {
                $_POST['title'] = $_POST['urllink'];
            }

            // If the URL is invalid, an error occurs.
            // Ivan, 13-OCT-2010, Chamilo 1.8.8: Let us still tolerate PHP 5.1.x and avoid a specific bug in filter_var(), see http://bugs.php.net/51192
            //if (!filter_var($urllink, FILTER_VALIDATE_URL)) {
            if (!api_valid_url($urllink, true)) { // A check against an absolute URL.
                $msgErr = get_lang('GiveURL');
                Display::display_error_message(get_lang('GiveURL'));
                return false;
            }

            $onhomepage = Security::remove_XSS($_POST['onhomepage']);
            $target = Security::remove_XSS($_POST['target_link']);
            if (empty($mytarget)) { $mytarget = '_self'; }
            $mytarget = ",target='".$target."'";

            // Finding the old category_id.
            $sql = "SELECT * FROM ".$tbl_link." WHERE id='".intval($_POST['id'])."'";
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
            $category_id = $row['category_id'];

            if ($category_id != $_POST['selectcategory']) {
                $sql = "SELECT MAX(display_order) FROM ".$tbl_link." WHERE category_id='".intval($_POST['selectcategory'])."'";
                $result = Database::query($sql);
                list ($max_display_order) = Database::fetch_row($result);
                $max_display_order ++;
            } else {
                $max_display_order = $row['display_order'];
            }

            $sql = "UPDATE ".$tbl_link." SET " .
                    "url='".Database::escape_string($_POST['urllink'])."', " .
                    "title='".Database::escape_string($_POST['title'])."', " .
                    "description='".Database::escape_string($_POST['description'])."', " .
                    "category_id='".Database::escape_string($_POST['selectcategory'])."', " .
                    "display_order='".$max_display_order."', " .
                    "on_homepage='".Database::escape_string($onhomepage)." ' $mytarget " .
                    " WHERE id='".Database::escape_string($_POST['id'])."'";
            Database::query($sql);

            // Update search enchine and its values table if enabled.
            if (api_get_setting('search_enabled') == 'true') {
                $link_id = intval($_POST['id']);
                $course_id = api_get_course_id();
                $link_url = Database::escape_string($_POST['urllink']);
                $link_title = Database::escape_string($_POST['title']);
                $link_description = Database::escape_string($_POST['description']);

                // Actually, it consists on delete terms from db, insert new ones, create a new search engine document, and remove the old one.
                // Get search_did.
                $tbl_se_ref = Database::get_main_table(TABLE_MAIN_SEARCH_ENGINE_REF);
                $sql = 'SELECT * FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_high_level=%s LIMIT 1';
                $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_LINK, $link_id);
                $res = Database::query($sql);

                if (Database::num_rows($res) > 0) {
                    require_once api_get_path(LIBRARY_PATH).'search/DokeosIndexer.class.php';
                    require_once api_get_path(LIBRARY_PATH).'search/IndexableChunk.class.php';
                    require_once api_get_path(LIBRARY_PATH).'specific_fields_manager.lib.php';

                    $se_ref = Database::fetch_array($res);
                    $specific_fields = get_specific_field_list();
                    $ic_slide = new IndexableChunk();

                    $all_specific_terms = '';
                    foreach ($specific_fields as $specific_field) {
                        delete_all_specific_field_value($course_id, $specific_field['id'], TOOL_LINK, $link_id);
                        if (isset($_REQUEST[$specific_field['code']])) {
                            $sterms = trim($_REQUEST[$specific_field['code']]);
                            if (!empty($sterms)) {
                                $all_specific_terms .= ' '. $sterms;
                                $sterms = explode(',', $sterms);
                                foreach ($sterms as $sterm) {
                                    $ic_slide->addTerm(trim($sterm), $specific_field['code']);
                                    add_specific_field_value($specific_field['id'], $course_id, TOOL_LINK, $link_id, $sterm);
                                }
                            }
                        }
                    }

                    // Build the chunk to index.
                    $ic_slide->addValue("title", $link_title);
                    $ic_slide->addCourseId($course_id);
                    $ic_slide->addToolId(TOOL_LINK);
                    $xapian_data = array(
                        SE_COURSE_ID => $course_id,
                        SE_TOOL_ID => TOOL_LINK,
                        SE_DATA => array('link_id' => (int)$link_id),
                        SE_USER => (int)api_get_user_id(),
                    );
                    $ic_slide->xapian_data = serialize($xapian_data);
                    $link_description = $all_specific_terms .' '. $link_description;
                    $ic_slide->addValue('content', $link_description);

                    // Add category name if set.
                    if (isset($_POST['selectcategory']) && $selectcategory > 0) {
                        $table_link_category = Database::get_course_table(TABLE_LINK_CATEGORY);
                        $sql_cat = 'SELECT * FROM %s WHERE id=%d LIMIT 1';
                        $sql_cat = sprintf($sql_cat, $table_link_category, (int)$selectcategory);
                        $result = Database::query($sql_cat);
                        if (Database::num_rows($result) == 1) {
                            $row = Database::fetch_array($result);
                            $ic_slide->addValue('category', $row['category_title']);
                        }
                    }

                    $di = new DokeosIndexer();
                    isset($_POST['language'])? $lang = Database::escape_string($_POST['language']): $lang = 'english';
                    $di->connectDb(NULL, NULL, $lang);
                    $di->remove_document((int)$se_ref['search_did']);
                    $di->addChunk($ic_slide);

                    // Index and return search engine document id.
                    $did = $di->index();
                    if ($did) {
                        // Save it to db.
                        $sql = 'DELETE FROM %s WHERE course_code=\'%s\' AND tool_id=\'%s\' AND ref_id_high_level=\'%s\'';
                        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_LINK, $link_id);
                        Database::query($sql);
                        $sql = 'INSERT INTO %s (id, course_code, tool_id, ref_id_high_level, search_did)
                            VALUES (NULL , \'%s\', \'%s\', %s, %s)';
                        $sql = sprintf($sql, $tbl_se_ref, $course_id, TOOL_LINK, $link_id, $did);
                        Database::query($sql);
                    }
                }
            }

            // "WHAT'S NEW" notification: update table last_toolEdit.
            api_item_property_update($_course, TOOL_LINK, $_POST['id'], 'LinkUpdated', $_user['user_id']);

            Display::display_confirmation_message(get_lang('LinkModded'));
        }
    }

    if ($type == 'category') {

        // This is used to populate the category-form with the info found in the database.
        if (!$submit_category) {
            $sql = "SELECT * FROM ".$tbl_categories." WHERE id='".intval($_GET['id'])."'";
            $result = Database::query($sql);
            if ($myrow = Database::fetch_array($result)) {
                $category_title = $myrow['category_title'];
                $description = $myrow['description'];
            }
        }

        // This is used to put the modified info of the category-form into the database.
        if ($submit_category) {
            $sql = "UPDATE ".$tbl_categories." set category_title='".Database::escape_string($_POST['category_title'])."', description='".Database::escape_string($_POST['description'])."' WHERE id='".Database::escape_string($_POST['id'])."'";
            Database::query($sql);
            Display::display_confirmation_message(get_lang('CategoryModded'));
        }

    }

    return true; // On errors before this statement, exit from this function by returning false value.
}

/**
 * Creates a correct $view for in the URL
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function makedefaultviewcode($locatie) {
    global $aantalcategories, $view;
    for ($j = 0; $j <= $aantalcategories -1; $j ++) {
        $view[$j] = 0;
    }
    $view[intval($locatie)] = '1';
}

/**
 * Changes the visibility of a link
 * @todo add the changing of the visibility of a course
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function change_visibility($id, $scope) {
    global $_course, $_user;
    if ($scope == 'link') {
        api_item_property_update($_course, TOOL_LINK, $id, $_GET['action'], $_user['user_id']);
        Display::display_confirmation_message(get_lang('VisibilityChanged'));
    }
}

/**
 * Displays all the links of a given category.
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function showlinksofcategory($catid) {
    global $is_allowed, $charset, $urlview, $up, $down, $_user;

    $tbl_link = Database :: get_course_table(TABLE_LINK);
    $TABLE_ITEM_PROPERTY = Database :: get_course_table(TABLE_ITEM_PROPERTY);

    // Condition for the session.
    $session_id = api_get_session_id();
    $condition_session = api_get_session_condition($session_id, true, true);

    $sqlLinks = "SELECT * FROM ".$tbl_link." link, ".$TABLE_ITEM_PROPERTY." itemproperties WHERE itemproperties.tool='".TOOL_LINK."' AND link.id=itemproperties.ref AND link.category_id='".$catid."' AND (itemproperties.visibility='0' OR itemproperties.visibility='1') $condition_session ORDER BY link.display_order DESC";
    $result = Database::query($sqlLinks);
    $numberoflinks = Database::num_rows($result);

    echo '<table class="data_table" width="100%">';
    $i = 1;
    while ($myrow = Database::fetch_array($result)) {

        // Validacion when belongs to a session.
        $session_img = api_get_session_image($myrow['session_id'], $_user['status']);

        $css_class = $i%2 == 0 ? $css_class = 'row_odd' : $css_class = 'row_even';

        $myrow[3] = text_filter($myrow[3]);
        if ($myrow['visibility'] == '1') {
            echo '<tr class="', $css_class, '"><td align="center" valign="middle" width="15"><a href="link_goto.php?', api_get_cidreq(), '&amp;link_id=', $myrow[0], '&amp;link_url=', urlencode($myrow[1]), '" target="_blank"><img src="../../main/img/link.gif" border="0" alt="', get_lang('Link'), '"/></a></td><td width="80%" valign="top"><a href="link_goto.php?', api_get_cidreq(), '&amp;link_id=', $myrow[0], '&amp;link_url=', urlencode($myrow[1]), '" target="',$myrow['target'],'">', Security::remove_XSS($myrow[2]), '</a>', $session_img, '<br />', $myrow[3];
        } else {
            if (api_is_allowed_to_edit(null, true)) {
                echo '<tr class="', $css_class, '"><td align="center" valign="middle" width="15"><a href="link_goto.php?', api_get_cidreq(), '&amp;link_id=', $myrow[0], "&amp;link_url=", urlencode($myrow[1]), '" target="_blank" class="invisible">', Display::return_icon('link_na.gif', get_lang('Link')), '</a></td><td width="80%" valign="top"><a href="link_goto.php?', api_get_cidreq(), '&amp;link_id=', $myrow[0], '&amp;link_url=', urlencode($myrow[1]), '" target="',$myrow['target'],'"  class="invisible">', Security::remove_XSS($myrow[2]), "</a>\n", $session_img, '<br />', $myrow[3];
            }
        }

        echo '<td style="text-align:center;">';
        if (api_is_allowed_to_edit(null, true)) {
            if ($session_id == $myrow['session_id']) {

                echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;action=editlink&amp;category='.(!empty($category) ? $category : '').'&amp;id='.$myrow[0].'&amp;urlview='.$urlview.'" title="'.get_lang('Modify').'"><img src="../img/edit.gif" border="0" alt="', get_lang('Modify'), '" /></a>';
                echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;action=deletelink&amp;id=', $myrow[0], '&amp;urlview=', $urlview, "\" onclick=\"javascript: if(!confirm('".get_lang('LinkDelconfirm')."')) return false;\" title=\"".get_lang('Delete').'"><img src="../img/delete.gif" border="0" alt="', get_lang('Delete'), '" /></a>';
                // DISPLAY MOVE UP COMMAND only if it is not the top link.
                if ($i != 1) {
                    echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;urlview='.$urlview.'&amp;up=', $myrow[0], '" title="'.get_lang('Up').'"><img src="../img/up.gif" border="0" alt="'.get_lang('Up').'"/>', "</a>\n";
                } else {
                    echo '<img src="'.api_get_path(WEB_IMG_PATH).'up_na.gif" border="0" alt="'.get_lang('Up').'"/>';
                }

                // DISPLAY MOVE DOWN COMMAND only if it is not the bottom link.
                if ($i < $numberoflinks) {
                    echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;urlview='.$urlview.'&amp;down='.$myrow[0].'" title="'.get_lang('Down').'"><img src="../img/down.gif" border="0" alt="'.get_lang('Down').'"/>', "</a>\n";
                } else {
                    echo '<img src="'.api_get_path(WEB_IMG_PATH).'down_na.gif" border="0" alt="'.get_lang('Down').'"/>';
                }

                if ($myrow['visibility'] == '1') {
                    echo '<a href="link.php?'.api_get_cidreq().'&amp;action=invisible&amp;id='.$myrow[0].'&amp;scope=link&amp;urlview='.$urlview.'" title="'.get_lang('Hide').'"><img src="../img/visible.gif" border="0" /></a>';
                }
                if ($myrow['visibility'] == '0') {
                     echo '<a href="link.php?'.api_get_cidreq().'&amp;action=visible&amp;id='.$myrow[0].'&amp;scope=link&amp;urlview='.$urlview.'" title="'.get_lang('Show').'"><img src="../img/invisible.gif" border="0" /></a>';
                }
            } else {
                echo get_lang('EditionNotAvailableFromSession');
            }
        }
        echo '</td></tr>';
        $i++;
    }
    echo '</table>';
}

/**
 * Displays the edit, delete and move icons
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function showcategoryadmintools($categoryid) {

    global $urlview;
    global $aantalcategories;
    global $catcounter;
    echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;action=editcategory&amp;id='.$categoryid.'&amp;urlview='.$urlview.'" title='.get_lang('Modify').'"><img src="../img/edit.gif" border="0" alt="'.get_lang('Modify').'"/></a>';
    echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;action=deletecategory&amp;id=', $categoryid, "&amp;urlview=$urlview\" onclick=\"javascript: if(!confirm('".get_lang('CategoryDelconfirm')."')) return false;\">", '<img src="../img/delete.gif" border="0" alt="', get_lang('Delete'), '"/></a>';

    // DISPLAY MOVE UP COMMAND only if it is not the top link.
    if ($catcounter != 1) {
        echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;catmove=true&amp;up=', $categoryid, '&amp;urlview='.$urlview.'" title="'.get_lang('Up').'"><img src="../img/up.gif" border="0" alt="'.get_lang('Up').'"/>', "</a>\n";
    } else {
        echo '<img src="'.api_get_path(WEB_IMG_PATH).'up_na.gif" border="0" alt="'.get_lang('Up').'"/>';
    }

    // DISPLAY MOVE DOWN COMMAND only if it is not the bottom link.
    if ($catcounter < $aantalcategories) {
        echo '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;catmove=true&amp;down='.$categoryid.'&amp;urlview='.$urlview.'"><img src="../img/down.gif" border="0" alt="'.get_lang('Down').'"/>', "</a>\n";
    } else {
        echo '<img src="'.api_get_path(WEB_IMG_PATH).'down_na.gif" border="0" alt="'.get_lang('Down').'"/>';
    }
    $catcounter ++;
}

/**
 * move a link or a linkcategory up or down
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function movecatlink($catlinkid) {

    global $catmove;
    global $up;
    global $down;
    $tbl_link = Database :: get_course_table(TABLE_LINK);
    $tbl_categories = Database :: get_course_table(TABLE_LINK_CATEGORY);

    if (!empty($down)) {
        $thiscatlinkId = intval($down);
        $sortDirection = 'DESC';
    }
    if (!empty($up)) {
        $thiscatlinkId = intval($up);
        $sortDirection = 'ASC';
    }

    // We check if it is a category we are moving or a link. If it is a category, a querystring catmove = true is present in the url.
    if ($catmove == 'true') {
        $movetable = $tbl_categories;
        $catid = $catlinkid;
    } else {
        $movetable = $tbl_link;
        // Getting the category of the link.
        if (!empty($thiscatlinkId)) {
            $sql = "SELECT category_id from ".$movetable." WHERE id='$thiscatlinkId'";
            $result = Database::query($sql);
            $catid = Database::fetch_array($result);
        }
    }

    // This code is copied and modified from announcements.php.
    if (!empty($sortDirection)) {
        if (!in_array(trim(strtoupper($sortDirection)), array ('ASC', 'DESC')))
            die('Bad sort direction used.'); // Sanity check of sortDirection var.
        if ($catmove == 'true') {
            $sqlcatlinks = "SELECT id, display_order FROM ".$movetable." ORDER BY display_order $sortDirection";
        } else {
            $sqlcatlinks = "SELECT id, display_order FROM ".$movetable." WHERE category_id='".$catid[0]."' ORDER BY display_order $sortDirection";
        }
        $linkresult = Database::query($sqlcatlinks);
        while ($sortrow = Database::fetch_array($linkresult)) {
            // STEP 2 : FOUND THE NEXT ANNOUNCEMENT ID AND ORDER, COMMIT SWAP
            // This part seems unlogic, but it isn't . We first look for the current link with the querystring ID
            // and we know the next iteration of the while loop is the next one. These should be swapped.
            if (isset ($thislinkFound) && $thislinkFound) {
                $nextlinkId = $sortrow['id'];
                $nextlinkOrdre = $sortrow['display_order'];

                Database::query("UPDATE ".$movetable."
                                         SET display_order = '$nextlinkOrdre'
                                         WHERE id =  '$thiscatlinkId'");

                Database::query("UPDATE ".$movetable."
                                         SET display_order = '$thislinkOrdre'
                                         WHERE id =  '$nextlinkId'");

                break;
            }

            if ($sortrow['id'] == $thiscatlinkId) {
                $thislinkOrdre = $sortrow['display_order'];
                $thislinkFound = true;
            }
        }
    }

    Display::display_confirmation_message(get_lang('LinkMoved'));
}

/**
 * CSV file import functions
 * @author René Haentjens , Ghent University
 */
function get_cat($catname) {
    // Get category id (existing or make new).
    $tbl_categories = Database :: get_course_table(TABLE_LINK_CATEGORY);
    $result = Database::query("SELECT `id` FROM ".$tbl_categories." WHERE `category_title`='".addslashes($catname)."'");
    if (Database::num_rows($result) >= 1 && ($row = Database::fetch_array($result))) {
        return $row['id']; // Several categories with same name: take the first.
    }

    $result = Database::query("SELECT MAX(display_order) FROM ".$tbl_categories);
    list ($max_order) = Database::fetch_row($result);
    Database::query("INSERT INTO ".$tbl_categories." (category_title, description, display_order) VALUES ('".addslashes($catname)."','','". ($max_order +1)."')");
    return Database::insert_id();
}

/**
 * CSV file import functions
 * @author René Haentjens , Ghent University
 */
function put_link($url, $cat, $title, $description, $on_homepage, $hidden) {
    $tbl_link = Database :: get_course_table(TABLE_LINK);

    $urleq = "url='".Database::escape_string($url)."'";
    $cateq = "category_id=".intval($cat);

    $result = Database::query("SELECT id FROM $tbl_link WHERE ".$urleq.' AND '.$cateq);

    if (Database::num_rows($result) >= 1 && ($row = Database::fetch_array($result))) {
        Database::query("UPDATE $tbl_link set title='".Database::escape_string($title)."', description='".Database::escape_string($description)."' WHERE id='".Database::escape_string($row['id'])."'");

        $lang_link = get_lang('update_link');
        $ipu = 'LinkUpdated';
        $rv = 1; // 1 = upd
    } else {
        // Add new link
        $result = Database::query("SELECT MAX(display_order) FROM  $tbl_link WHERE category_id='".intval($cat)."'");
        list ($max_order) = Database::fetch_row($result);

        Database::query("INSERT INTO $tbl_link (url, title, description, category_id, display_order, on_homepage) VALUES ('".Database::escape_string($url)."','".Database::escape_string($title)."','".Database::escape_string($description)."','".intval($cat)."','". (intval($max_order) +1)."','".intval($on_homepage)."')");

        $id = Database::insert_id();
        $lang_link = get_lang('new_link');
        $ipu = 'LinkAdded';
        $rv = 2; // 2 = new
    }

    global $_course, $nameTools, $_user;
    api_item_property_update($_course, TOOL_LINK, $id, $ipu, $_user['user_id']);

    if ($hidden && $ipu == 'LinkAdded') {
        api_item_property_update($_course, TOOL_LINK, $id, 'invisible', $_user['user_id']);
    }
    return $rv;
}

/**
 * CSV file import functions
 * @author René Haentjens , Ghent University
 */
function import_link($linkdata) {
    // url, category_id, title, description, ...

    // Field names used in the uploaded file
    $known_fields = array('url', 'category', 'title', 'description', 'on_homepage', 'hidden');
    $hide_fields = array('kw', 'kwd', 'kwds', 'keyword', 'keywords');

    // All other fields are added to description, as "name:value".

    // Only one hide_field is assumed to be present, <> is removed from value.

    if (!($url = trim($linkdata['url'])) || !($title = trim($linkdata['title']))) {
        return 0; // 0 = fail
    }

    $cat = ($catname = trim($linkdata['category'])) ? get_cat($catname) : 0;

    $regs = array(); // Will be passed to ereg()
    foreach ($linkdata as $key => $value)
        if (!in_array($key, $known_fields))
            if (in_array($key, $hide_fields) && ereg('^<?([^>]*)>?$', $value, $regs)) // possibly in <...>
                if (($kwlist = trim($regs[1])) != '')
                    $kw = '<i kw="'.htmlspecialchars($kwlist).'">';
                else
                    $kw = '';
    // i.e. assume only one of the $hide_fields will be present
    // and if found, hide the value as expando property of an <i> tag
    elseif (trim($value)) {
        $d .= ', '.$key.':'.$value;
    }
    if ($d) {
        $d = substr($d, 2).' - ';
    }

    return put_link($url, $cat, $title, $kw.ereg_replace('\[((/?(b|big|i|small|sub|sup|u))|br/)\]', '<\\1>', htmlspecialchars($d.$linkdata['description'])). ($kw ? '</i>' : ''), $linkdata['on_homepage'] ? '1' : '0', $linkdata['hidden'] ? '1' : '0');
    // i.e. allow some BBcode tags, e.g. [b]...[/b]
}

/**
 * CSV file import functions
 * @author René Haentjens , Ghent University
 */
function import_csvfile() {

    global $catlinkstatus; // Feedback message to user.

    if (is_uploaded_file($filespec = $_FILES['import_file']['tmp_name']) && filesize($filespec) && ($myFile = @ fopen($filespec, 'r'))) {
        // read first line of file (column names) and find ',' or ';'
        $listsep = strpos($colnames = trim(fgets($myFile)), ',') !== false ? ',' : (strpos($colnames, ';') !== false ? ';' : '');

        if ($listsep) {
            $columns = array_map('strtolower', explode($listsep, $colnames));

            if (in_array('url', $columns) && in_array('title', $columns)) {
                $stats = array (0, 0, 0); // fails, updates, inserts

                // Modified by Ivan Tcholakov, 01-FEB-2010.
                //while (($data = fgetcsv($myFile, 32768, $listsep))) {
                while (($data = api_fgetcsv($myFile, null, $listsep))) {
                //
                    foreach ($data as $i => & $text) {
                        $linkdata[$columns[$i]] = $text;
                    }

                    $stats[import_link($linkdata)]++;
                    unset($linkdata);
                }

                $catlinkstatus = '';

                if ($stats[0]) {
                    $catlinkstatus .= $stats[0].' '.get_lang('CsvLinesFailed');
                }
                if ($stats[1]) {
                    $catlinkstatus .= $stats[1].' '.get_lang('CsvLinesOld');
                }
                if ($stats[2]) {
                    $catlinkstatus .= $stats[2].' '.get_lang('CsvLinesNew');
                }
            } else {
                $catlinkstatus = get_lang('CsvFileNoURL'). ($colnames ? get_lang('CsvFileLine1').htmlspecialchars(substr($colnames, 0, 200)).'...' : '');
            }
        } else {
            $catlinkstatus = get_lang('CsvFileNoSeps'). ($colnames ? get_lang('CsvFileLine1').htmlspecialchars(substr($colnames, 0, 200)).'...' : '');
        }
        fclose($myFile);
    } else {
        $catlinkstatus = get_lang('CsvFileNotFound');
    }
}