/*

uuid.js - Version 0.2
JavaScript Class to create a UUID like identifier
*/

// On creation of a UUID object, set it's initial value
function UUID() {
	this.id = this.createUUID();
}

// When asked what this Object is, lie and return it's value
UUID.prototype.valueOf = function () {
	return this.id;
}
UUID.prototype.toString = function () {
	return this.id;
}

//
// INSTANCE SPECIFIC METHODS
//

UUID.prototype.createUUID = function () {
	//
	// Loose interpretation of the specification DCE 1.1: Remote Procedure Call
	// described at http://www.opengroup.org/onlinepubs/009629399/apdxa.htm#tagtcjh_37
	// since JavaScript doesn't allow access to internal systems, the last 48 bits 
	// of the node section is made up using a series of random numbers (6 octets long).
	//  
	var dg = new Date(1582, 10, 15, 0, 0, 0, 0);
	var dc = new Date();
	var t = dc.getTime() - dg.getTime();
	var h = '-';
	var tl = UUID.getIntegerBits(t, 0, 31);
	var tm = UUID.getIntegerBits(t, 32, 47);
	var thv = UUID.getIntegerBits(t, 48, 59) + '1'; // version 1, security version is 2
	var csar = UUID.getIntegerBits(UUID.rand(4095), 0, 7);
	var csl = UUID.getIntegerBits(UUID.rand(4095), 0, 7);

	// since detection of anything about the machine/browser is far to buggy, 
	// include some more random numbers here
	// if NIC or an IP can be obtained reliably, that should be put in
	// here instead.
	var n = UUID.getIntegerBits(UUID.rand(8191), 0, 7) +
		UUID.getIntegerBits(UUID.rand(8191), 8, 15) +
		UUID.getIntegerBits(UUID.rand(8191), 0, 7) +
		UUID.getIntegerBits(UUID.rand(8191), 8, 15) +
		UUID.getIntegerBits(UUID.rand(8191), 0, 15); // this last number is two octets long
	return tl + h + tm + h + thv + h + csar + csl + h + n;
}


//
// GENERAL METHODS (Not instance specific)
//


// Pull out only certain bits from a very large integer, used to get the time
// code information for the first part of a UUID. Will return zero's if there 
// aren't enough bits to shift where it needs to.
UUID.getIntegerBits = function (val, start, end) {
	var base16 = UUID.returnBase(val, 16);
	var quadArray = new Array();
	var quadString = '';
	var i = 0;
	for (i = 0; i < base16.length; i++) {
		quadArray.push(base16.substring(i, i + 1));
	}
	for (i = Math.floor(start / 4); i <= Math.floor(end / 4); i++) {
		if (!quadArray[i] || quadArray[i] == '') quadString += '0';
		else quadString += quadArray[i];
	}
	return quadString;
}

// Numeric Base Conversion algorithm from irt.org
// In base 16: 0=0, 5=5, 10=A, 15=F
UUID.returnBase = function (number, base) {
	//
	// Copyright 1996-2006 irt.org, All Rights Reserved.	
	//
	// Downloaded from: http://www.irt.org/script/146.htm	
	// modified to work in this class by Erik Giberti
	var convert = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'];
	if (number < base) var output = convert[number];
	else {
		var MSD = '' + Math.floor(number / base);
		var LSD = number - MSD * base;
		if (MSD >= base) var output = this.returnBase(MSD, base) + convert[LSD];
		else var output = convert[MSD] + convert[LSD];
	}
	return output;
}

// pick a random number within a range of numbers
// int b rand(int a); where 0 <= b <= a
UUID.rand = function (max) {
	return Math.floor(Math.random() * max);
}

// end of UUID class file