/**
 * Accordion Effect for Script.aculo.us
 * Created by Lucas van Dijk
 * http://www.return1.net
 *
 * Copyright 2007 by Lucas van Dijk
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 */

var Accordion = Class.create();

Accordion.prototype = {

	initialize: function(handles, bodys, options) {
		this.options = this._set_options(options);		
		this.headers = $$(handles);
		this.bodys = $$(bodys);
		if(this.bodys.length != this.headers.length){
			throw Error('Number of headers/bodys does not match!');
		}		
		for(var i = 0; i < this.headers.length; i++) {		
			Event.observe(this.headers[i], this.options.event_trigger, this.show.bind(this, i));			
			this.headers[i].style.cursor = "pointer";			
			this.bodys[i].style.display = "none";
		}
    if (this.options.default_open >= this.headers.length) this.options.default_open = 0;
		this.bodys[this.options.default_open].id = "visible";
		this.show(this.options.default_open, true);
	},

	show: function(index, force) {
		if ((index >= this.length) || (index < 0)) {
			throw Error('Index out of range');
		}
		if (this.bodys[index].id == 'visible') {
			if (typeof force == "boolean") {
				this.options.OnStart(this.headers[index]);
				// Force display the visible object				
				for(var i = 0; i < this.bodys.length; i++) {
					if(this.bodys[i].style.display != 'none' && i != index) {
						new Effect.BlindUp(this.bodys[i], {duration:this.options.duration});
					}
				}
				new Effect.BlindDown(this.bodys[index], {duration:this.options.duration});
			}
		} else {
			this.options.OnStart(this.headers[this.default_open]);						
			// Normal change
			new Effect.Parallel([
        new Effect.Fade($('visible')),				
        new Effect.BlindUp($('visible')),
        new Effect.BlindDown(this.bodys[index]),
        new Effect.Appear(this.bodys[index])
      ], {
        duration: this.options.duration
      });
			$('visible').id = "";
			this.bodys[index].id = "visible";
		}
    this.default_open = index;
		this.options.OnFinish(this.headers[this.default_open]);
	},
	
	_default_options: {
		duration: 0.3,
		event_trigger: 'click',
		OnStart: function() { },
		OnFinish: function() { },
		default_open: 0
	},
	
	_set_options: function(options) {
		if(typeof options != "undefined") {
			var result = [];
			for(option in this._default_options) {
				if(typeof options[option] == "undefined") {
					result[option] = this._default_options[option];
				} else {
					result[option] = options[option];
				}
			}
			return result;
		} else {
			return this._default_options;
		}
	}
};

Effect.Accordion = Accordion;