/**
 * jquery.scrollable 1.0.2. Put your HTML scroll.
 *
 * Copyright (c) 2009 Tero Piirainen
 * http://flowplayer.org/tools/scrollable.html
 *
 * Dual licensed under MIT and GPL 2+ licenses
 * http://www.opensource.org/licenses
 *
 * Launch  : March 2008
 * Version : 1.0.2 - Tue Feb 24 2009 10:52:08 GMT-0000 (GMT+00:00)
 */
(function($) {

	function fireEvent(opts, name, self, arg) {
		var fn = opts[name];

		if ($.isFunction(fn)) {
			try {
				return fn.call(self, arg);

			} catch (error) {
				if (opts.alert) {
					alert("Error calling scrollable." + name + ": " + error);
				} else {
					throw error;
				}
				return false;
			}
		}
		return true;
	}

	var current = null;


	// constructor
	function Scrollable(root, conf) {

		// current instance
		var self = this;
		if (!current) { current = self; }

		// horizontal flag
		var horizontal = !conf.vertical;


		// wrap (root elements for items)
		var wrap = $(conf.items, root);

		// current index
		var index = 0;


		// get handle to navigational elements
		var navi = root.siblings(conf.navi).eq(0);
		var prev = root.siblings(conf.prev).eq(0);
		var next = root.siblings(conf.next).eq(0);
		var prevPage = root.siblings(conf.prevPage).eq(0);
		var nextPage = root.siblings(conf.nextPage).eq(0);


		// methods
		$.extend(self, {

			getVersion: function() {
				return [1, 0, 1];
			},

			getIndex: function() {
				return index;
			},

			getConf: function() {
				return conf;
			},

			getSize: function() {
				return self.getItems().size();
			},

			getPageAmount: function() {
				return Math.ceil(this.getSize() / conf.size);
			},

			getPageIndex: function() {
				return Math.ceil(index / conf.size);
			},

			getRoot: function() {
				return root;
			},

			getItemWrap: function() {
				return wrap;
			},

			getItems: function() {
				return wrap.children();
			},

			/* all seeking functions depend on this */
			seekTo: function(i, time, fn) {

				// default speed
				time = time || conf.speed;

				// function given as second argument
				if ($.isFunction(time)) {
					fn = time;
					time = conf.speed;
				}

				if (i < 0) { i = 0; }
				if (i > self.getSize() - conf.size) { return self; }

				var item = self.getItems().eq(i);
				if (!item.length) { return self; }

				// onBeforeSeek
				if (fireEvent(conf, "onBeforeSeek", self, i) === false) {
					return self;
				}

				if (horizontal) {
					var left = -(item.outerWidth(true) * i);
					wrap.animate({left: left}, time, conf.easing, fn ? function() { fn.call(self); } : null);

				} else {
					var top = -(item.outerHeight(true) * i); // wrap.offset().top - item.offset().top;
					wrap.animate({top: top}, time, conf.easing, fn ? function() { fn.call(self); } : null);
				}


				// navi status update
				if (navi.length) {
					var klass = conf.activeClass;
					var page = Math.ceil(i / conf.size);
					page = Math.min(page, navi.children().length - 1);
					navi.children().removeClass(klass).eq(page).addClass(klass);
				}

				// prev buttons disabled flag
				if (i === 0) {
					prev.add(prevPage).addClass(conf.disabledClass);
				} else {
					prev.add(prevPage).removeClass(conf.disabledClass);
				}

				// next buttons disabled flag
				if (i >= self.getSize() - conf.size) {
					next.add(nextPage).addClass(conf.disabledClass);
				} else {
					next.add(nextPage).removeClass(conf.disabledClass);
				}

				current = self;
				index = i;

				// onSeek after index being updated
				fireEvent(conf, "onSeek", self, i);

				return self;

			},

			move: function(offset, time, fn) {
				var to = index + offset;
				if (conf.loop && to > (self.getSize() - conf.size)) {
					to = 0;
				}
				return this.seekTo(to, time, fn);
			},

			next: function(time, fn) {
				return this.move(1, time, fn);
			},

			prev: function(time, fn) {
				return this.move(-1, time, fn);
			},

			movePage: function(offset, time, fn) {
				return this.move(conf.size * offset, time, fn);
			},

			setPage: function(page, time, fn) {
				var size = conf.size;
				var index = size * page;
				var lastPage = index + size >= this.getSize();
				if (lastPage) {
					index = this.getSize() - conf.size;
				}
				return this.seekTo(index, time, fn);
			},

			prevPage: function(time, fn) {
				return this.setPage(this.getPageIndex() - 1, time, fn);
			},

			nextPage: function(time, fn) {
				return this.setPage(this.getPageIndex() + 1, time, fn);
			},

			begin: function(time, fn) {
				return this.seekTo(0, time, fn);
			},

			end: function(time, fn) {
				return this.seekTo(this.getSize() - conf.size, time, fn);
			},

			reload: function() {
				return load();
			},

			click: function(index, time, fn) {

				var item = self.getItems().eq(index);
				var klass = conf.activeClass;

				if (!item.hasClass(klass) && (index >= 0 || index < this.getSize())) {
					self.getItems().removeClass(klass);
					item.addClass(klass);
					var delta = Math.floor(conf.size / 2);
					var to = index - delta;

					// next to last item must work
					if (to > self.getSize() - conf.size) { to--;	}

					if (to !== index) {
						return this.seekTo(to, time, fn);
					}
				}

				return self;
			}

		});


		// mousewheel
		if ($.isFunction($.fn.mousewheel)) {
			root.bind("mousewheel.scrollable", function(e, delta)  {
				// opera goes to opposite direction
				var step = $.browser.opera ? 1 : -1;

				self.move(delta > 0 ? step : -step, 50);
				return false;
			});
		}

		// prev button
		prev.addClass(conf.disabledClass).click(function() {
			self.prev();
		});


		// next button
		next.click(function() {
			self.next();
		});

		// prev page button
		nextPage.click(function() {
			self.nextPage();
		});


		// next page button
		prevPage.addClass(conf.disabledClass).click(function() {
			self.prevPage();
		});


		// keyboard
		if (conf.keyboard) {

			// unfortunately window.keypress does not work on IE.
			$(window).unbind("keypress.scrollable").bind("keypress.scrollable", function(evt) {

				var el = current;
				if (!el) { return; }

				if (horizontal && (evt.keyCode == 37 || evt.keyCode == 39)) {
					el.move(evt.keyCode == 37 ? -1 : 1);
					return evt.preventDefault();
				}

				if (!horizontal && (evt.keyCode == 38 || evt.keyCode == 40)) {
					el.move(evt.keyCode == 38 ? -1 : 1);
					return evt.preventDefault();
				}

				return true;

			});
		}

		// navi
		function load() {

			navi.each(function() {

				var nav = $(this);

				// generate new entries
				if (nav.is(":empty") || nav.data("me") == self) {

					nav.empty();
					nav.data("me", self);

					for (var i = 0; i < self.getPageAmount(); i++) {

						var item = $("<" + conf.naviItem + "/>").attr("href", i).click(function(e) {
							var el = $(this);
							el.parent().children().removeClass(conf.activeClass);
							el.addClass(conf.activeClass);
							self.setPage(el.attr("href"));
							return e.preventDefault();
						});

						if (i === 0) { item.addClass(conf.activeClass); }
						nav.append(item);
					}

				// assign onClick events to existing entries
				} else {

					// find a entries first -> syntaxically correct
					var els = nav.children();

					els.each(function(i)  {
						var item = $(this);
						item.attr("href", i);
						if (i === 0) { item.addClass(conf.activeClass); }

						item.click(function() {
							nav.find("." + conf.activeClass).removeClass(conf.activeClass);
							item.addClass(conf.activeClass);
							self.setPage(item.attr("href"));
						});

					});
				}

			});


			// item.click()
			if (conf.clickable) {
				self.getItems().each(function(index, arg) {
					var el = $(this);
					if (!el.data("set")) {
						el.bind("click.scrollable", function() {
							self.click(index);
						});
						el.data("set", true);
					}
				});
			}


			// hover
			if (conf.hoverClass) {
				self.getItems().hover(function()  {
					$(this).addClass(conf.hoverClass);
				}, function() {
					$(this).removeClass(conf.hoverClass);
				});
			}

			return self;
		}

		load();


		// interval stuff
		var timer = null;

		function setTimer() {
			timer = setInterval(function()  {
				self.next();

			}, conf.interval);
		}

		if (conf.interval > 0) {

			root.hover(function() {
				clearInterval(timer);
			}, function() {
				setTimer();
			});

			setTimer();
		}

	}


	// jQuery plugin implementation
	jQuery.prototype.scrollable = function(conf) {

		// already constructed --> return API
		var api = this.eq(typeof conf == 'number' ? conf : 0).data("scrollable");
		if (api) { return api; }


		var opts = {

			// basics
			size: 5,
			vertical:false,
			clickable: true,
			loop: false,
			interval: 0,
			speed: 400,
			keyboard: true,

			// other
			activeClass:'active',
			disabledClass: 'disabled',
			hoverClass: null,
			easing: 'swing',

			// navigational elements
			items: '.items',
			prev: '.prev',
			next: '.next',
			prevPage: '.prevPage',
			nextPage: '.nextPage',
			navi: '.navi',
			naviItem: 'a',


			// callbacks
			onBeforeSeek: null,
			onSeek: null,
			alert: true
		};


		$.extend(opts, conf);

		this.each(function() {
			var el = new Scrollable($(this), opts);
			$(this).data("scrollable", el);
		});

		return this;

	};


})(jQuery);