/*
 * Fabtabulous! Simple tabs using Prototype
 * http://tetlaw.id.au/view/blog/fabtabulous-simple-tabs-using-prototype/
 * Andrew Tetlaw
 * version 2 2008-08-10
 * http://creativecommons.org/licenses/by-sa/2.5/
 */
var Fabtabs = Class.create({
    initialize: function(element, options) {
        var parent = this.element = $(element);
        this.options = Object.extend({
            hover: false,
            remotehover: false,
            anchorpolicy: 'allow-initial'
            // 'protect', 'allow', 'allow initial', 'disable'
        }, options || {});

        this.menu = this.element.select('a');
        this.hrefs = this.menu.map(function(elm) {
            return elm.href.match(/#(\w.+)/) ? RegExp.$1: null;
        }).compact();

        this.activate(this.getInitialTab());

        var onLocal = function(event) {
            if (this.options.anchorpolicy !== 'allow') {
                event.stop();
            }
            var elm = event.findElement("a");
						if (elm)
						{
	            this.activate(elm);
	            if (this.options.anchorpolicy === 'protect') {
	                window.location.hash = '.' + this.tabID(elm);
	            }
						}
        };

        var onRemote = function(event) {
            if (this.options.anchorpolicy !== 'allow') {
                event.stop();
            }
            var trig = event.findElement("a");
            this.activate(this.tabID(trig));
            if (this.options.anchorpolicy === 'protect') {
                window.location.hash = '.' + this.tabID(elm);
            }
        }
        
				this.element.observe('click', onLocal.bindAsEventListener(this));
        
				if (this.options.hover) {
            this.menu.each(function(elm) {
                elm.observe('mouseover', onLocal.bindAsEventListener(this))
            }.bind(this));
        }

        var triggers = [];
        this.hrefs.each(function(id) {
            $$('a[href="#' + id + '"]').reject(function(elm) {
                return elm.descendantOf(parent)
            }).each(function(trig) {
                triggers.push(trig);
            });
        })
        triggers.each(function(elm) {
            elm.observe('click', onRemote.bindAsEventListener(this));
            if (this.options.remotehover) {
                elm.observe('mouseover', onRemote.bindAsEventListener(this));
            }
        }.bind(this));
    },

    activate: function(elm) {
        if (typeof elm == 'string') {
            elm = this.element.select('a[href="#' + elm + '"]')[0];
        }
        this.on(elm);
        this.menu.without(elm).each(this.off.bind(this));
				if (this.options.onchange)
				{
					this.options.onchange($(this.tabID(elm)));
				}
    },

    off: function(elm) {
	    if (!elm)	return;
      $(elm).removeClassName('active-tab');
      $(this.tabID(elm)).hide();
    },

    on: function(elm) {
      if (!elm)	return;
      $(elm).addClassName('active-tab');
      $(this.tabID(elm)).show();
    },

    tabID: function(elm) {
        return elm.href.match(this.re)[1];
    },

    getInitialTab: function() {
        if (this.options.anchorpolicy !== 'disable' && document.location.href.match(this.re)) {
            var hash = RegExp.$1;
            if (hash.substring(0, 1) == ".") {
                hash = hash.substring(1);
            }
            return this.element.select('a[href="#' + hash + '"]')[0];
        } else {
            return this.menu.first();
        }
    },

    re: /#(\.?\w.+)/
});

document.observe('dom:loaded', function() {
	if (!document.location.hash && $('tab') && $('tab').value)
	{
		document.location.hash = $('tab').value;
	}

	if ($('tabs'))
	{
  	new Fabtabs('tabs', {onchange: function(el) {
  		if ($('tab')) $('tab').value = el.id;
  	}});
  }
})