/*!
Math.uuid.js (v1.4)
http://www.broofa.com
mailto:robert@broofa.com

Copyright (c) 2010 Robert Kieffer
Dual licensed under the MIT and GPL licenses.
*/

/*
* Generate a random uuid.
*
* USAGE: Math.uuid(length, radix)
*   length - the desired number of characters
*   radix  - the number of allowable values for each character.
*
* EXAMPLES:
*   // No arguments  - returns RFC4122, version 4 ID
*   >>> Math.uuid()
*   "92329D39-6F5C-4520-ABFC-AAB64544E172"
* 
*   // One argument - returns ID of the specified length
*   >>> Math.uuid(15)     // 15 character ID (default base=62)
*   "VcydxgltxrVZSTV"
*
*   // Two arguments - returns ID of the specified length, and radix. (Radix must be <= 62)
*   >>> Math.uuid(8, 2)  // 8 character ID (base=2)
*   "01001010"
*   >>> Math.uuid(8, 10) // 8 character ID (base=10)
*   "47473046"
*   >>> Math.uuid(8, 16) // 8 character ID (base=16)
*   "098F4D35"
*/
(function() {
    // Private array of chars to use
    var CHARS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');

    Math.uuid = function(len, radix) {
        var chars = CHARS, uuid = [];
        radix = radix || chars.length;

        if (len) {
            // Compact form
            for (var i = 0; i < len; i++) uuid[i] = chars[0 | Math.random() * radix];
        } else {
            // rfc4122, version 4 form
            var r;

            // rfc4122 requires these characters
            uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
            uuid[14] = '4';

            // Fill in random data.  At i==19 set the high bits of clock sequence as
            // per rfc4122, sec. 4.1.5
            for (var i = 0; i < 36; i++) {
                if (!uuid[i]) {
                    r = 0 | Math.random() * 16;
                    uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
                }
            }
        }

        return uuid.join('');
    };

    // A more performant, but slightly bulkier, RFC4122v4 solution.  We boost performance
    // by minimizing calls to random()
    Math.uuidFast = function() {
        var chars = CHARS, uuid = new Array(36), rnd = 0, r;
        for (var i = 0; i < 36; i++) {
            if (i == 8 || i == 13 || i == 18 || i == 23) {
                uuid[i] = '-';
            } else if (i == 14) {
                uuid[i] = '4';
            } else {
                if (rnd <= 0x02) rnd = 0x2000000 + (Math.random() * 0x1000000) | 0;
                r = rnd & 0xf;
                rnd = rnd >> 4;
                uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
            }
        }
        return uuid.join('');
    };

    // A more compact, but less performant, RFC4122v4 solution:
    Math.uuidCompact = function() {
        return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
            var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
            return v.toString(16);
        }).toUpperCase();
    };
})();