/* --------------------------------------------------------------
 viewport.js 2016-06-14
 Gambio GmbH
 http://www.gambio.de
 Copyright (c) 2016 Gambio GmbH
 Released under the GNU General Public License (Version 2)
 [http://www.gnu.org/licenses/gpl-2.0.html]
 --------------------------------------------------------------
 */

gx.controllers.module('viewport', [], function (data) {

    'use strict';

    // ------------------------------------------------------------------------
    // VARIABLES
    // ------------------------------------------------------------------------

    /**
     * Module Selector
     *
     * @type {jQuery}
     */
    const $this = $(this);

    /**
     * Module Instance
     *
     * @type {Object}
     */
    const module = {};

    /**
     * Info Row
     *
     * @type {jQuery}
     */
    const $infoRow = $('#main-footer .info.row');


    // ------------------------------------------------------------------------
    // FUNCTIONS
    // ------------------------------------------------------------------------

    /**
     * Checks if the provided dropdown is out of the vertical viewport.
     *
     * @param {jQuery} $dropDownMenu
     *
     * @returns {boolean}
     */
    function _isDropDownOutOfVerticalView($dropDownMenu) {
        const infoRowTopPosition = $infoRow.offset().top;
        const dropDownMenuTopPosition = $dropDownMenu.height() + $dropDownMenu.siblings('.dropdown-toggle').offset().top

        return dropDownMenuTopPosition > infoRowTopPosition;
    }

    /**
     * Checks if the provided dropdown is out of the horizontal viewport.
     *
     * @param {jQuery} $dropDownMenu
     *
     * @returns {boolean}
     */
    function _isDropDownOutOfHorizontalView($dropDownMenu) {
        const viewportWidth = $('body').width();
        const dropDownMenuLeftPosition = $dropDownMenu.width() + $dropDownMenu.siblings('.dropdown-toggle')
            .prev()
            .offset().left;

        return dropDownMenuLeftPosition > viewportWidth;
    }

    /**
     * Adjust the dropdown position, depending on the current viewport.
     */
    function _adjustDropDownPosition() {

        const $target = $(this);

        let $dropDownMenu = $target.find('.dropdown-menu');

        // Put the dropdown menu above the clicked target,
        // if the menu would touch or even be larger than the info row in the main footer.
        if (_isDropDownOutOfVerticalView($dropDownMenu)) {
            $target.addClass('dropup');
            $target.removeClass('dropdown');
            $target.find('.caret').addClass('caret-reversed');
        } else if ($target.hasClass('dropup')) {
            $target.removeClass('dropup');
            $target.addClass('dropdown');
            $target.find('.caret').removeClass('caret-reversed');
        }

        if (_isDropDownOutOfHorizontalView($dropDownMenu)) {
            $dropDownMenu.addClass('dropdown-menu-right');
        } else if ($target.hasClass('dropdown-menu-right')) {
            $target.removeClass('dropdown-menu-right');
        }
    }

    // ------------------------------------------------------------------------
    // INITIALIZATION
    // ------------------------------------------------------------------------

    module.init = function (done) {
        $('body').on('show.bs.dropdown', '.btn-group.dropdown, .btn-group.dropup', _adjustDropDownPosition);

        done();
    };

    return module;
});