/**
 * @author Bruno Bornsztein <bruno@missingmethod.com>
 * @author Lee Horrocks <lee@58ninety.com>
 * @copyright 2007 Curbly LLC
 * @package Glider
 * @license MIT
 * @url http://missingmethod.com/projects/glider.html
 * @version 0.0.7
 * @dependencies prototype.js 1.5.1+, effects.js
 */
/*  Thanks to Andrew Dupont for refactoring help and code cleanup - http://andrewdupont.net/  */
/* 0.0.7 Changed Timer to Reset when user manually moves next/previous */
/* 0.0.6 Added Support for multiple sections on screen at the same time, and renaming the section div class*/
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.options = Object.extend({
            sectionClass: 'div.section',
            controlsEvent: 'click',
            duration: 0.5,
            frequency: 3,
            displayedElements: 1
        }, options || {});
        this.sections = this.wrapper.getElementsBySelector(this.options.sectionClass);
        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
        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();
        this.moveTo(element.href.split("#")[1], this.scroller, {
            duration: this.options.duration
        });
        Event.stop(event);
        this.controls.each(function(control) {
            if (control == element) {
                control.addClassName("active")
            } else {
                control.removeClassName("active")
            }
        });
    },
moveTo: function(element, container, options) {
        this.current = $(element);
        Position.prepare();
        var containerOffset = Position.cumulativeOffset(container),
        elementOffset = Position.cumulativeOffset($(element));
        this.scrolling = new Effect.SmoothScroll(container, 
        {
            duration: options.duration,
            x: (elementOffset[0] - containerOffset[0]),
            y: (elementOffset[1] - containerOffset[1])
        });
        return false;
    },
next: function() {
          if (this.options.autoGlide) { 
            clearTimeout(this.timer);
        } 
         
           if (this.current) {
            var currentIndex = this.current._index;
            var nextIndex = (this.sections.length - this.options.displayedElements == currentIndex) ? 0: currentIndex + 1;
        } else var nextIndex = 1;
        this.moveTo(this.sections[nextIndex], this.scroller, {
            duration: this.options.duration
        });
          if (this.options.autoGlide) { 
             this.timer = setTimeout(this.next.bind(this), this.options.frequency * 1000);
        }
    },
previous: function() {
          if (this.options.autoGlide) { 
            clearTimeout(this.timer);
        }
        
        if (this.current) {
            var currentIndex = this.current._index;
            var prevIndex = (currentIndex == 0) ? this.sections.length - this.options.displayedElements: currentIndex - 1;
        } else var prevIndex = this.sections.length - this.options.displayedElements;
        this.moveTo(this.sections[prevIndex], this.scroller, {
            duration: this.options.duration
        });
          if (this.options.autoGlide) { 
             this.timer = setTimeout(this.next.bind(this), this.options.frequency * 1000);
        }
    },
stop: function()
    {
        clearTimeout(this.timer);
    },
start: function()
    {
        this.periodicallyUpdate();
    },
periodicallyUpdate: function()
    {
        if (this.timer != null) {
            clearTimeout(this.timer);
        }
        this.timer = setTimeout(this.next.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;
    }
});