/*
 * jquery json plugin
 * version: 1.0 (2008-04-17)
 *
 * this document is licensed as free software under the terms of the
 * mit license: http://www.opensource.org/licenses/mit-license.php
 *
 * brantley harris technically wrote this plugin, but it is based somewhat
 * on the json.org website's http://www.json.org/json2.js, which proclaims:
 * "no warranty expressed or implied. use at your own risk.", a sentiment that
 * i uphold.  i really just cleaned it up.
 *
 * it is also based heavily on mochikit's serializejson, which is 
 * copywrited 2005 by bob ippolito.
 */
 
(function($) {   
    function tointegersatlease(n) 
    // format integers to have at least two digits.
    {    
        return n < 10 ? '0' + n : n;
    }

    date.prototype.tojson = function(date)
    // yes, it polutes the date namespace, but we'll allow it here, as
    // it's damned usefull.
    {
        return this.getutcfullyear()   + '-' +
             tointegersatlease(this.getutcmonth()) + '-' +
             tointegersatlease(this.getutcdate());
    };

    var escapeable = /["\\\x00-\x1f\x7f-\x9f]/g;
    var meta = {    // table of character substitutions
            '\b': '\\b',
            '\t': '\\t',
            '\n': '\\n',
            '\f': '\\f',
            '\r': '\\r',
            '"' : '\\"',
            '\\': '\\\\'
        };
        
    $.quotestring = function(string)
    // places quotes around a string, inteligently.
    // if the string contains no control characters, no quote characters, and no
    // backslash characters, then we can safely slap some quotes around it.
    // otherwise we must also replace the offending characters with safe escape
    // sequences.
    {
        if (escapeable.test(string))
        {
            return '"' + string.replace(escapeable, function (a) 
            {
                var c = meta[a];
                if (typeof c === 'string') {
                    return c;
                }
                c = a.charcodeat();
                return '\\u00' + math.floor(c / 16).tostring(16) + (c % 16).tostring(16);
            }) + '"';
        }
        return '"' + string + '"';
    };
    
    $.tojson = function(o)
    {
        var type = typeof(o);
		
        if (type == "undefined")
            return "undefined";
        else if (type == "number" || type == "boolean")
            return o + "";
        else if (o === null)
            return "null";
        
        // is it a string?
        if (type == "string") 
        {
            return $.quotestring(o);
        }
        
        // does it have a .tojson function?
        if (type == "object" && typeof o.tojson == "function") 
            return o.tojson();
        
        // is it an array?
        if (type != "function" && typeof(o.length) == "number") 
        {
            var ret = [];
            for (var i = 0; i < o.length; i++) {
                ret.push( $.tojson(o[i]) );
            }
            return "[" + ret.join(",") + "]";
        }
        
        // if it's a function, we have to warn somebody!
        if (type == "function") {
            throw new typeerror("unable to convert object of type 'function' to json.");
        }
        
        // it's probably an object, then.
        var ret = [];
        for (var k in o) {
            var name;
            type = typeof(k);
            
            if (type == "number")
                name = '"' + k + '"';
            else if (type == "string")
                name = $.quotestring(k);
            else
                continue;  //skip non-string or number keys
            
            var val = $.tojson(o[k]);
            if (typeof(val) != "string") {
                // skip non-serializable values
                continue;
            }
            
            ret.push(name + ":" + val);
        }
        return "{" + ret.join(",") + "}";
    };
    
    $.compactjson = function(o)
    {
        return $.tojson(o, true);
    };
    
    $.evaljson = function(src)
    // evals json that we know to be safe.
    {
        return eval("(" + src + ")");
    };
    
    $.secureevaljson = function(src)
    // evals json in a way that is *more* secure.
    {
        var filtered = src;
        filtered = filtered.replace(/\\["\\\/bfnrtu]/g, '@');
        filtered = filtered.replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[ee][+\-]?\d+)?/g, ']');
        filtered = filtered.replace(/(?:^|:|,)(?:\s*\[)+/g, '');
        
        if (/^[\],:{}\s]*$/.test(filtered))
            return eval("(" + src + ")");
        else
            throw new syntaxerror("error parsing json, source is not valid.");
    };
})(jquery);