/**
 * Collapsed Topics Information
 *
 * A topic based format that solves the issue of the 'Scroll of Death' when a course has many topics. All topics
 * except zero have a toggle that displays that topic. One or more topics can be displayed at any given time.
 * Toggles are persistent on a per browser session per course basis but can be made to persist longer by a small
 * code change. Full installation instructions, code adaptions and credits are included in the 'Readme.txt' file.
 *
 * @package    format_topcoll
 * @version    See the value of '$plugin->version' in version.php.
 * @copyright  © 2012-onwards G J Barnard in respect to modifications of standard topics format.
 * @author     G J Barnard - gjbarnard at gmail dot com and {@link http://moodle.org/user/profile.php?id=442195}
 * @link       http://docs.moodle.org/en/Collapsed_Topics_course_format
 * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License
 *
 * 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/>.
 */

M.course = M.course || {};
M.course.format = M.course.format || {};

/**
 * Get sections config for this format
 *
 * The section structure is:
 * <ul class="ctopics">
 *  <li class="section">...</li>
 *  <li class="section">...</li>
 *   ...
 * </ul>
 *
 * @return {object} section list configuration
 */
M.course.format.get_config = function() {
    return {
        container_node : 'ul',
        container_class : 'ctopics',
        section_node : 'li',
        section_class : 'section'
    };
};

/**
 * Swap section
 *
 * @param {YUI} Y YUI3 instance.
 * @param {string} node1 node to swap to.
 * @param {string} node2 node to swap with.
 * @return {NodeList} section list.
 */
M.course.format.swap_sections = function(Y, node1, node2) {
    var CSS = {
        COURSECONTENT : '.course-content',
        SECTIONADDMENUS : '.section_add_menus'
    };

    var sectionlist = Y.Node.all(CSS.COURSECONTENT + ' ' + M.course.format.get_section_selector(Y));
    // Swap menus.
    sectionlist.item(node1).one(CSS.SECTIONADDMENUS).swap(sectionlist.item(node2).one(CSS.SECTIONADDMENUS));
};

/**
 * Process sections after ajax response
 *
 * @param {YUI} Y YUI3 instance
 * @param {array} response ajax response
 * @param {string} sectionfrom first affected section
 * @param {string} sectionto last affected section
 * @return void
 */
M.course.format.process_sections = function(Y, sectionlist, response, sectionfrom, sectionto) {
    var CSS = {
        SECTIONNAME     : 'the_toggle h3'
    },
    SELECTORS = {
        LEFTCONTENT     : '.left .cps_centre',
        SECTIONLEFTSIDE : '.left .section-handle .icon'
    };

    if (response.action == 'move') {
        if (sectionfrom > sectionto) { // MDL-34798.
            var temp = sectionto;
            sectionto = sectionfrom;
            sectionfrom = temp;
        }

        // Update titles and move icons in all affected sections.
        var leftcontent, ele, str, stridx, newstr;

        for (var i = sectionfrom; i <= sectionto; i++) {
            // Update section title.
            var content = Y.Node.create('<span>' + response.sectiontitles[i] + '</span>');
            sectionlist.item(i).all('.' + CSS.SECTIONNAME).setHTML(content);
            // If the left content section number exists, then set it.
            leftcontent = sectionlist.item(i).one(SELECTORS.LEFTCONTENT);
            if (leftcontent) { // Only set if the section number is shown otherwise JS crashes and stops working.
                leftcontent.setContent(i);
            }
            // Update move icon.  MDL-37901.
            ele = sectionlist.item(i).one(SELECTORS.SECTIONLEFTSIDE);
            str = ele.getAttribute('alt');
            stridx = str.lastIndexOf(' ');
            newstr = str.substr(0, stridx + 1) + i;
            ele.setAttribute('alt', newstr);
            ele.setAttribute('title', newstr); // For FireFox as 'alt' is not refreshed.

            if (response.current !== -1) {
                if (sectionlist.item(i).hasClass('current')) {
                    // Remove the current class as section has been moved.  MDL-33546.
                    sectionlist.item(i).removeClass('current');
                }
            }
        }
        // If there is a current section, apply corresponding class in order to highlight it.  MDL-33546.
        if (response.current !== -1) {
            // Add current class to the required section.
            sectionlist.item(response.current).addClass('current');
        }
    }
};