/**
 * @author Bruno Bornsztein <bruno@missingmethod.com>
 * @copyright 2007 Curbly LLC
 * @package Glider
 * @license MIT
 * @url http://www.missingmethod.com/projects/glider/
 * @version 0.0.4
 * @dependencies prototype.js 1.5.1+, effects.js
 */

/*  Thanks to Andrew Dupont for refactoring help and code cleanup - http://andrewdupont.net/  */

Glider = Class.create();
Object.extend(Object.extend(Glider.prototype, Abstract.prototype), {
	initialize: function(wrapper, options) {
		this.scrolling = false;
		this.wrapper = $(wrapper);
		this.scroller = this.wrapper.down('div.scroller');
		this.sections = this.wrapper.getElementsBySelector('div.section');
		this.options = Object.extend({controlsEvent: 'click', duration: 1.0, frequency: 3}, options || {});
		this.direction = 1;
		this.isDebug = true;

		this.sections.each(function(section, index) {
			section._index = index;
		});

		this.events = {
			click: this.click.bind(this)
		};

		this.addObservers();

		if (this.options.initialSection) {
			this.moveTo(this.options.initialSection, this.scroller, {duration: this.options.duration});
			// initialSection should be the id of the section you want to show up on load
		} else {
			var initialIndex = (this.current) ? this.current._index: 0;
			this.toggleControls(initialIndex);
		}

		if (this.options.autoGlide)
			this.start();
	},

	addObservers: function() {
		this.controls = this.wrapper.getElementsBySelector('.controls a');
		this.controls.invoke('observe', this.options.controlsEvent, this.events.click);
	},

	click: function(event) {
		this.stop();
		var element = Event.findElement(event, 'a');
		if (this.scrolling) {
			this.scrolling.cancel();
		}

		// moveTo = this.wrapper.down(''+element.href.split("#")[1])
		// this.moveTo(moveTo, this.scroller, { duration:this.options.duration });	 
		this.moveTo(element.href.split("#")[1], this.scroller, {
			duration: this.options.duration
		});
		Event.stop(event);
	},

	moveTo: function(element, container, options) {
		this.current = $(element);
		this.toggleControls(this.current._index);

		Position.prepare();
		var containerOffset = Position.cumulativeOffset(container),
		elementOffset = Position.cumulativeOffset($(element));

		this.scrolling = new Effect.SmoothScroll(container, {
			duration: options.duration,
			x: (elementOffset[0] - containerOffset[0]),
			y: (elementOffset[1] - containerOffset[1])
		});

		if (this.controls.length > 0) {
			this.controls.each(function(control) {
				// control.removeClassName("active")
				Element.removeClassName(control, "active")
			});
			var control = this.controls[this.current._index];
			// control.addClassName("active")
			Element.addClassName(control, "active")
		}

		return false;
	},

	next: function() {
		if (this.current) {
			var currentIndex = this.current._index;
			var nextIndex = (this.sections.length - 1 == currentIndex) ? 0: currentIndex + 1;
		} else {
			var nextIndex = 1;
		}

		this.moveTo(this.sections[nextIndex], this.scroller, {
			duration: this.options.duration
		});
	},

	previous: function() {
		if (this.current) {
			var currentIndex = this.current._index;
			var prevIndex = (currentIndex == 0) ? this.sections.length - 1: currentIndex - 1;
		} else {
			var prevIndex = this.sections.length - 1;
		}

		this.moveTo(this.sections[prevIndex], this.scroller, {
			duration: this.options.duration
		});
	},

	toggleControls: function(index) {
		var previous = (index > 0) ? true : false;
		var next = (index < (this.sections.length - 1)) ? true : false;

		if ((this.options.previous != null) && (this.options.previous != 'undefined')) {
			var control = $(this.options.previous);
			if (control != 'undefined') {
				control.style.visibility = (previous) ? 'visible': 'hidden';
			}
		}

		if ((this.options.next != null) && (this.options.next != 'undefined')) {
			var control = $(this.options.next);
			if (control != 'undefined') {
				control.style.visibility = (next) ? 'visible': 'hidden';
			}
		}
	},

	moveDirectionally: function() {
		if (this.current) {
			var currentIndex = this.current._index;
			var nextIndex = 0;
			if (this.direction == 1) {
				if ((this.sections.length - 1) == currentIndex) {
					nextIndex = currentIndex - 1;
					this.direction *= -1;
				} else {
					nextIndex = currentIndex + 1;
				}
			} else {
				if (currentIndex == 0) {
					nextIndex = currentIndex + 1;
					this.direction *= -1;
				} else {
					nextIndex = currentIndex - 1;
				}
			}
		} else {
			var nextIndex = (this.direction == 1) ? 1: this.sections.length - 1;
		}

		this.moveTo(this.sections[nextIndex], this.scroller, {
			duration: this.options.duration
		});
	},

	stop: function() {
		clearTimeout(this.timer);
	},

	start: function() {
		this.periodicallyUpdate();
	},

	periodicallyUpdate: function() {
		if (this.timer != null) {
			clearTimeout(this.timer);
			// this.next();
			this.moveDirectionally();
		}
		this.timer = setTimeout(this.periodicallyUpdate.bind(this), this.options.frequency * 1000);
	}

});

Effect.SmoothScroll = Class.create();
Object.extend(Object.extend(Effect.SmoothScroll.prototype, Effect.Base.prototype), {
	initialize: function(element) {
		this.element = $(element);
		var options = Object.extend({
			x: 0,
			y: 0,
			mode: 'absolute'
		}, arguments[1] || {});
		this.start(options);
	},
	setup: function() {
		if (this.options.continuous && !this.element._ext) {
			this.element.cleanWhitespace();
			this.element._ext = true;
			this.element.appendChild(this.element.firstChild);
		}

		this.originalLeft = this.element.scrollLeft;
		this.originalTop = this.element.scrollTop;

		if (this.options.mode == 'absolute') {
			this.options.x -= this.originalLeft;
			this.options.y -= this.originalTop;
		}
	},
	update: function(position) {
		this.element.scrollLeft = this.options.x * position + this.originalLeft;
		this.element.scrollTop = this.options.y * position + this.originalTop;
	}
});