/* --------------------------------------------------------------
 page_nav_tabs.js 2016-07-13
 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]
 --------------------------------------------------------------
 */

/**
 * ## Page Navigation Tabs
 *
 * This module will convert old table-style navigation to the new theme navigation tabs for
 * every page. It searches for specific HTML patterns and creates new markup for the page
 * navigation.
 *
 * **Important!** If you need to exclude an old navigation table from being converted you must add
 * the "exclude-page-nav" class to its table tag as in the following example.
 *
 * ```html
 * <table class="exclude-page-nav"> ... </table>
 * ```
 *
 * @module Compatibility/page_nav_tabs
 */
gx.compatibility.module(
    'page_nav_tabs',

    [],

    /**  @lends module:Compatibility/page_nav_tabs */

    function (data) {

        'use strict';

        // ------------------------------------------------------------------------
        // VARIABLES DEFINITION
        // ------------------------------------------------------------------------

        var
            /**
             * Module Selector
             *
             * @var {object}
             */
            $this = $(this),

            /**
             * Default Options
             *
             * @type {object}
             */
            defaults = {
                EXCLUDE_CLASS: 'exclude-page-nav',
                CONVERT_CLASS: 'convert-to-tabs'
            },

            /**
             * Final Options
             *
             * @var {object}
             */
            options = $.extend(true, {}, defaults, data),

            /**
             * Module Object
             *
             * @type {object}
             */
            module = {},

            /**
             * The original position of the tab navigation
             *
             * @type int
             */
            originalPosition = 0,

            /**
             * The last scroll position
             *
             * @type int
             */
            scrollPosition = $(window).scrollTop(),

            /**
             * The original left position of the pageHeading
             *
             * @type {number}
             */
            originalLeft = 0,

            /**
             * Tells if the tab navigation is within the view port
             *
             * @type boolean
             */
            isOut = true;

        // ------------------------------------------------------------------------
        // PRIVATE METHODS
        // ------------------------------------------------------------------------

        /**
         * Change the first .pageHeading HTML to contain the ".page-nav-title" class.
         */
        var _fixPageHeading = function () {
            var $pageHeading = $('.pageHeading:first-child');
            $pageHeading.html('<div class="page-nav-title">' + $pageHeading.html() + '</div>');

            $pageHeading.wrap('<div class="pageHeadingWrapper"></div>');
            $('.pageHeadingWrapper').height($pageHeading.height() + 1);
            originalLeft = $('.pageHeading').length ? $('.pageHeading').offset().left : 0;
        };

        /**
         * Checks if the page has the old table-style navigation system.
         *
         * @return {string} Returns Returns the selector that matches the string or null if none was found.
         */
        var _detectHtmlPattern = function () {
            var patterns = [
                    '.main table .dataTableHeadingRow .dataTableHeadingContentText a',
                    '.pdf_menu tr td.dataTableHeadingContent',
                    '.boxCenter table tr td.dataTableHeadingContent a'
                ],
                selector = null;

            $.each(patterns, function () {
                if ($this.find(this).length > 0 && !$this.find(this).closest('table').hasClass(options.EXCLUDE_CLASS)) {
                    selector = this;
                    return false; // exit loop
                }
            });

            return selector;
        };

        /**
         * Performs the conversion of the old style to the new navigation HTML.
         *
         * It will also hide the old navigation markup. Styling for the new HTML is located in the
         * "_compatibility.scss".
         *
         * @param {string} selector The selector string to be used for selecting the old table td cells.
         */
        var _convertNavigationTabs = function (selector) {
            var $selector = $this.find(selector),
                $table = $selector.closest('table'),
                $pageHeading = $('.pageHeading:first-child'),
                $pageNavTabs = $('<div class="page-nav-tabs"></div>');

            $table.find('tr td').each(function () {
                var $navTab = $('<div class="nav-tab">' + $(this).html() + '</div>');

                // Style current page tabs.
                if ($navTab.find('a').length === 0) {
                    $navTab.addClass('no-link');
                }

                $navTab.appendTo($pageNavTabs);
            });

            $pageNavTabs.appendTo($pageHeading);

            $table.hide();
        };

        /**
         * Quick Return Check
         *
         * Reset the page navigation frame to the original position if the user scrolls directly
         * to top.
         */
        var _quickReturn = function () {
            var newScrollPosition = $(window).scrollTop();
            var isScrollDown = scrollPosition - newScrollPosition < 0;
            var isScrollUp = scrollPosition - newScrollPosition > 0;
            originalPosition = $('.main-top-header').height();
            _setPageHeadingLeftAbsolute();

            var scrolledToTop = _checkScrolledToTop();

            if (!scrolledToTop) {
                if (isScrollDown && !isScrollUp && !isOut) {
                    _rollOut();
                } else if (!isScrollDown && isScrollUp && isOut) {
                    _rollIn();
                }
            }

            scrollPosition = newScrollPosition;
        };

        /**
         * Roll-in Animation Function
         */
        var _rollIn = function () {
            isOut = false;
            $('.pageHeading').css({
                top: '0px',
                position: 'fixed'
            });

            $('.pageHeading').animate(
                {
                    top: originalPosition + 'px'
                },
                {
                    complete: _checkScrolledToTop
                },
                'fast');
        };

        /**
         * Sets the left position of the pageHeading absolute
         */
        var _setPageHeadingLeftAbsolute = function () {
            var contentHeaderLeft = originalLeft - $(window).scrollLeft();
            var menuWidth = $('.columnLeft2').outerWidth();
            $('.pageHeading').css('left', (contentHeaderLeft < menuWidth ? menuWidth : contentHeaderLeft) + 'px');
        };

        /**
         * Roll-out Animation Function
         */
        var _rollOut = function () {
            isOut = true;
            $('.pageHeading').animate({
                top: '0px'
            }, 'fast', 'swing', function () {
                $('.pageHeading').css({
                    top: originalPosition + 'px',
                    position: 'static'
                });
            });
        };

        /**
         * Check if user has scrolled to top of the page.
         *
         * @returns {bool} Returns the check result.
         */
        var _checkScrolledToTop = function () {
            if ($(window).scrollTop() === 0) {
                $('.pageHeading').css({
                    top: originalPosition + 'px',
                    position: 'static'
                });

                return true;
            }

            return false;
        };

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

        module.init = function (done) {
            setTimeout(function () {
                _fixPageHeading(); // must be executed for every page

                // Convert only the pages that have a recognizable table navigation style.
                var selector = _detectHtmlPattern();

                if (selector !== null) {
                    _convertNavigationTabs(selector);
                }

                $(window).on('scroll', _quickReturn);

                // Set height for parent element of the page heading bar to avoid that the main content moves up when
                // the heading bar switches into sticky mode
                $('.pageHeading').parent().height($('.pageHeading').parent().height());

                done();
            }, 300);
        };

        return module;
    });