/*global jQuery */
/*!
 * jQuery siteDarts
 * Examples and documentation at: http://elfsternberg.com/projects/sitedarts/
 * Copyright (c) 2011 E. M. Sternberg
 * Version: 0.9
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 * Requires: jQuery v1.3.2 or later
 */
 
;(function($) {
	$.fn.siteDarts = function(options) {
		return this.each(() => {
            options = $.extend(true, {}, $.fn.siteDarts.defaults, options);
            var names = $('a[name]');
            
            var reposition = () => {
                var prop = $(window).height();
                var doch = $(document).height();
                
                names.each(function(dex) {
                    var n = $(this).attr('name');
                    var d = $(this).offset().top;
                    $("li." + options.markitem + ' a[href="#' + n + '"]')
                        .parent()
                        .animate({top: prop * (d / doch) - dex * 7});
                });
            };
            
            var buildDarts = () => {
                if ($('#' + options.marklist)) {
                    $('#' + options.marklist).remove();
                }
                var l = $('<ul id="' + options.marklist + '"></ul>').appendTo('body');
                names.each(function() {
                    var o = $('<li class="' + options.markitem + '"><a href="#' + 
                              $(this).attr('name') + '">' + $(this).text() + '</a></li>').appendTo(l);
                    
                    $('a', o).click(function(event) {
                        event.preventDefault();
                        var target = $(event.target).attr('href').replace('#', '');
                        var targetOffset = $('a[name="' + target  + '"]').offset().top;
                        $('html body').animate(
                            {
                                scrollTop: targetOffset
                            }, 
                            {
                                duration: 800, 
                                easing: options.easing,
                                complete: function() {
                                    window.location.hash = target;
                                }
                            });
                    });
                });
            };
            buildDarts();
            reposition();
		});
	};
	
	$.fn.siteDarts.defaults = {
        marklist: 'marklist',
        markitem: 'marklistitem',
        easing: 'easeOutQuint'
    };

})(jQuery);