(function($) {

		$.fn.StickySidebar = function(options) {
			var defaults = {
				'containerSelector': '',
				'additionalMarginTop': 0,
				'additionalMarginBottom': 0,
				'updateSidebarHeight': true,
				'minWidth': 0,
				'disableOnResponsiveLayouts': true,
				'sidebarBehavior': 'modern'
			};
			options = $.extend(defaults, options);

			// Validate options
			options.additionalMarginTop = parseInt(options.additionalMarginTop) || 0;
			options.additionalMarginBottom = parseInt(options.additionalMarginBottom) || 0;

			tryInitOrHookIntoEvents(options, this);

			// Try doing init, otherwise hook into window.resize and document.scroll and try again then.
			function tryInitOrHookIntoEvents(options, $that) {
				var success = tryInit(options, $that);

				if (!success) {
					console.log('TST: Body width smaller than options.minWidth. Init is delayed.');

					$(document).scroll(function(options, $that) {
						return function(evt) {
							var success = tryInit(options, $that);

							if (success) {
								$(this).unbind(evt);
							}
						};
					}(options, $that));
					$(window).resize(function(options, $that) {
						return function(evt) {
							var success = tryInit(options, $that);

							if (success) {
								$(this).unbind(evt);
							}
						};
					}(options, $that))
				}
			}

			// Try doing init if proper conditions are met.
			function tryInit(options, $that) {
				if (options.initialized === true) {
					return true;
				}

				if ($('body').width() < options.minWidth) {
					return false;
				}

				init(options, $that);

				return true;
			}

			// Init the sticky sidebar(s).
			function init(options, $that) {
				options.initialized = true;

				// Add CSS
				$('head').append($('<style>.StickySidebar:after {content: ""; display: table; clear: both;}</style>'));

				$that.each(function() {
					var o = {};

					o.sidebar = $(this);

					// Save options
					o.options = options || {};

					// Get container
					o.container = $(o.options.containerSelector);
					if (o.container.length == 0) {
						o.container = o.sidebar.parent();
					}

					// Create sticky sidebar
					o.sidebar.parents().css('-webkit-transform', 'none'); // Fix for WebKit bug - https://code.google.com/p/chromium/issues/detail?id=20574
					o.sidebar.css({
						'position': 'relative',
						'overflow': 'visible',
						// The "box-sizing" must be set to "content-box" because we set a fixed height to this element when the sticky sidebar has a fixed position.
						'-webkit-box-sizing': 'border-box',
						'-moz-box-sizing': 'border-box',
						'box-sizing': 'border-box'
					});

					// Get the sticky sidebar element. If none has been found, then create one.
					o.stickySidebar = o.sidebar.find('.StickySidebar');
					if (o.stickySidebar.length == 0) {
						o.sidebar.find('script').remove(); // Remove <script> tags, otherwise they will be run again on the next line.
						o.stickySidebar = $('<div>').addClass('StickySidebar').append(o.sidebar.children());
						o.sidebar.append(o.stickySidebar);
					}

					// Get existing top and bottom margins and paddings
					o.marginTop = parseInt(o.sidebar.css('margin-top'));
					o.marginBottom = parseInt(o.sidebar.css('margin-bottom'));
					o.paddingTop = parseInt(o.sidebar.css('padding-top'));
					o.paddingBottom = parseInt(o.sidebar.css('padding-bottom'));

					// Add a temporary padding rule to check for collapsable margins.
					var collapsedTopHeight = o.stickySidebar.offset().top;
					var collapsedBottomHeight = o.stickySidebar.outerHeight();
					o.stickySidebar.css('padding-top', 1);
					o.stickySidebar.css('padding-bottom', 1);
					collapsedTopHeight -= o.stickySidebar.offset().top;
					collapsedBottomHeight = o.stickySidebar.outerHeight() - collapsedBottomHeight - collapsedTopHeight;
					if (collapsedTopHeight == 0) {
						o.stickySidebar.css('padding-top', 0);
						o.stickySidebarPaddingTop = 0;
					} else {
						o.stickySidebarPaddingTop = 1;
					}

					if (collapsedBottomHeight == 0) {
						o.stickySidebar.css('padding-bottom', 0);
						o.stickySidebarPaddingBottom = 0;
					} else {
						o.stickySidebarPaddingBottom = 1;
					}

					// We use this to know whether the user is scrolling up or down.
					o.previousScrollTop = null;

					// Scroll top (value) when the sidebar has fixed position.
					o.fixedScrollTop = 0;

					// Set sidebar to default values.
					resetSidebar();

					o.onScroll = function(o) {
						// Stop if the sidebar isn't visible.
						if (!o.stickySidebar.is(":visible")) {
							return;
						}

						// Stop if the window is too small.
						if ($('body').width() < o.options.minWidth) {
							resetSidebar();
							return;
						}

						// Stop if the sidebar width is larger than the container width (e.g. the theme is responsive and the sidebar is now below the content)
						if (o.options.disableOnResponsiveLayouts) {
							var sidebarWidth = o.sidebar.outerWidth(o.sidebar.css('float') == 'none');

							if (sidebarWidth + 50 > o.container.width()) {
								resetSidebar();
								return;
							}
						}

						var scrollTop = $(document).scrollTop();
						var position = 'static';

						// If the user has scrolled down enough for the sidebar to be clipped at the top, then we can consider changing its position.
						if (scrollTop >= o.container.offset().top + (o.paddingTop + o.marginTop - o.options.additionalMarginTop)) {
							// The top and bottom offsets, used in various calculations.
							var offsetTop = o.paddingTop + o.marginTop + options.additionalMarginTop;
							var offsetBottom = o.paddingBottom + o.marginBottom + options.additionalMarginBottom;

							// All top and bottom positions are relative to the window, not to the parent elemnts.
							var containerTop = o.container.offset().top;
							var containerBottom = o.container.offset().top + getClearedHeight(o.container);

							// The top and bottom offsets relative to the window screen top (zero) and bottom (window height).
							var windowOffsetTop = 0 + options.additionalMarginTop;
							var windowOffsetBottom;

							var sidebarSmallerThanWindow = (o.stickySidebar.outerHeight() + offsetTop + offsetBottom) < $(window).height();
							if (sidebarSmallerThanWindow) {
								windowOffsetBottom = windowOffsetTop + o.stickySidebar.outerHeight();
							} else {
								windowOffsetBottom = $(window).height() - o.marginBottom - o.paddingBottom - options.additionalMarginBottom;
							}

							var staticLimitTop = containerTop - scrollTop + o.paddingTop + o.marginTop;
							var staticLimitBottom = containerBottom - scrollTop - o.paddingBottom - o.marginBottom;

							var top = o.stickySidebar.offset().top - scrollTop;
							var scrollTopDiff = o.previousScrollTop - scrollTop;

							// If the sidebar position is fixed, then it won't move up or down by itself. So, we manually adjust the top coordinate.
							if (o.stickySidebar.css('position') == 'fixed') {
								if (o.options.sidebarBehavior == 'modern') {
									top += scrollTopDiff;
								}
							}

							if (o.options.sidebarBehavior == 'stick-to-top') {
								top = options.additionalMarginTop;
							}

							if (o.options.sidebarBehavior == 'stick-to-bottom') {
								top = windowOffsetBottom - o.stickySidebar.outerHeight();
							}

							if (scrollTopDiff > 0) { // If the user is scrolling up.
								top = Math.min(top, windowOffsetTop);
							} else { // If the user is scrolling down.
								top = Math.max(top, windowOffsetBottom - o.stickySidebar.outerHeight());
							}

							top = Math.max(top, staticLimitTop);

							top = Math.min(top, staticLimitBottom - o.stickySidebar.outerHeight());

							// If the sidebar is the same height as the container, we won't use fixed positioning.
							var sidebarSameHeightAsContainer = o.container.height() == o.stickySidebar.outerHeight();

							if (!sidebarSameHeightAsContainer && top == windowOffsetTop) {
								position = 'fixed';
							} else if (!sidebarSameHeightAsContainer && top == windowOffsetBottom - o.stickySidebar.outerHeight()) {
								position = 'fixed';
							} else if (scrollTop + top - o.sidebar.offset().top - o.paddingTop <= options.additionalMarginTop) {
								// Stuck to the top of the page. No special behavior. 
								position = 'absolute';
							} else {
								// Stuck to the bottom of the page.
								position = 'absolute';
							}
						}

						/*
						 * Performance notice: It's OK to set these CSS values at each resize/scroll, even if they don't change.
						 * It's way slower to first check if the values have changed.
						 */
						if (position == 'fixed') {
							o.stickySidebar.css({
								'position': 'fixed',
								'width': o.sidebar.width(),
								'top': top,
								'left': o.sidebar.offset().left + parseInt(o.sidebar.css('padding-left'))
							});
						} else if (position == 'absolute') {
							var css = {};

							if (o.stickySidebar.css('position') != 'absolute') {
								css.position = 'absolute';
								css.top = scrollTop + top - o.sidebar.offset().top - o.stickySidebarPaddingTop - o.stickySidebarPaddingBottom;
							}

							css.width = o.sidebar.width();
							css.left = '';

							o.stickySidebar.css(css);
						} else if (position == 'static') {
							resetSidebar();
						}

						if (position != 'static') {
							if (o.options.updateSidebarHeight == true) {
								o.sidebar.css({
									'min-height': o.stickySidebar.outerHeight() + o.stickySidebar.offset().top - o.sidebar.offset().top + o.paddingBottom
								});
							}
						}

						o.previousScrollTop = scrollTop;
					};

					// Initialize the sidebar's position.
					o.onScroll(o);

					// Recalculate the sidebar's position on every scroll and resize.
					$(document).scroll(function(o) {
						return function() {
							o.onScroll(o);
						};
					}(o));
					$(window).resize(function(o) {
						return function() {
							o.stickySidebar.css({
								'position': 'static'
							});
							o.onScroll(o);
						};
					}(o));

					// Reset the sidebar to its default state
					function resetSidebar() {
						o.fixedScrollTop = 0;
						o.sidebar.css({
							'min-height': '1px'
						});
						o.stickySidebar.css({
							'position': 'static',
							'width': ''
						});
					}

					// Get the height of a div as if its floated children were cleared. Note that this function fails if the floats are more than one level deep.
					function getClearedHeight(e) {
						var height = e.height();

						e.children().each(function() {
							height = Math.max(height, $(this).height());
						});

						return height;
					}
				});
			}
		}
	})(jQuery);