// JavaScript Document
function utf8_decode ( str_data ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Webtoolkit.info (http://www.webtoolkit.info/)
    // +      input by: Aman Gupta
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Norman "zEh" Fuchs
    // +   bugfixed by: hitwork
    // +   bugfixed by: Onno Marsman
    // +      input by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // *     example 1: utf8_decode('Kevin van Zonneveld');
    // *     returns 1: 'Kevin van Zonneveld'

    var tmp_arr = [], i = 0, ac = 0, c1 = 0, c2 = 0, c3 = 0;
    
    str_data += '';
    
    while ( i < str_data.length ) {
        c1 = str_data.charCodeAt(i);
        if (c1 < 128) {
            tmp_arr[ac++] = String.fromCharCode(c1);
            i++;
        } else if ((c1 > 191) && (c1 < 224)) {
            c2 = str_data.charCodeAt(i+1);
            tmp_arr[ac++] = String.fromCharCode(((c1 & 31) << 6) | (c2 & 63));
            i += 2;
        } else {
            c2 = str_data.charCodeAt(i+1);
            c3 = str_data.charCodeAt(i+2);
            tmp_arr[ac++] = String.fromCharCode(((c1 & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
            i += 3;
        }
    }

    return tmp_arr.join('');
}




function unserialize (data) {
    // http://kevin.vanzonneveld.net
    // +     original by: Arpad Ray (mailto:arpad@php.net)
    // +     improved by: Pedro Tainha (http://www.pedrotainha.com)
    // +     bugfixed by: dptr1988
    // +      revised by: d3x
    // +     improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +        input by: Brett Zamir (http://brett-zamir.me)
    // +     improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +     improved by: Chris
    // +     improved by: James
    // +        input by: Martin (http://www.erlenwiese.de/)
    // +     bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +     improved by: Le Torbi
    // +     input by: kilops
    // +     bugfixed by: Brett Zamir (http://brett-zamir.me)
    // -      depends on: utf8_decode
    // %            note: We feel the main purpose of this function should be to ease the transport of data between php & js
    // %            note: Aiming for PHP-compatibility, we have to translate objects to arrays
    // *       example 1: unserialize('a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}');
    // *       returns 1: ['Kevin', 'van', 'Zonneveld']
    // *       example 2: unserialize('a:3:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";s:7:"surName";s:9:"Zonneveld";}');
    // *       returns 2: {firstName: 'Kevin', midName: 'van', surName: 'Zonneveld'}

    var that = this;
    var utf8Overhead = function(chr) {
        // http://phpjs.org/functions/unserialize:571#comment_95906
        var code = chr.charCodeAt(0);
        if (code < 0x0080) {
            return 0;
        }
        if (code < 0x0800) {
             return 1;
        }
        return 2;
    };


    var error = function (type, msg, filename, line){throw new that.window[type](msg, filename, line);};
    var read_until = function (data, offset, stopchr){
        var buf = [];
        var chr = data.slice(offset, offset + 1);
        var i = 2;
        while (chr != stopchr) {
            if ((i+offset) > data.length) {
                error('Error', 'Invalid');
            }
            buf.push(chr);
            chr = data.slice(offset + (i - 1),offset + i);
            i += 1;
        }
        return [buf.length, buf.join('')];
    };
    var read_chrs = function (data, offset, length){
        var buf;

        buf = [];
        for (var i = 0;i < length;i++){
            var chr = data.slice(offset + (i - 1),offset + i);
            buf.push(chr);
            length -= utf8Overhead(chr); 
        }
        return [buf.length, buf.join('')];
    };
    var _unserialize = function (data, offset){
        var readdata;
        var readData;
        var chrs = 0;
        var ccount;
        var stringlength;
        var keyandchrs;
        var keys;

        if (!offset) {offset = 0;}
        var dtype = (data.slice(offset, offset + 1)).toLowerCase();

        var dataoffset = offset + 2;
        var typeconvert = function(x) {return x;};

        switch (dtype){
            case 'i':
                typeconvert = function (x) {return parseInt(x, 10);};
                readData = read_until(data, dataoffset, ';');
                chrs = readData[0];
                readdata = readData[1];
                dataoffset += chrs + 1;
            break;
            case 'b':
                typeconvert = function (x) {return parseInt(x, 10) !== 0;};
                readData = read_until(data, dataoffset, ';');
                chrs = readData[0];
                readdata = readData[1];
                dataoffset += chrs + 1;
            break;
            case 'd':
                typeconvert = function (x) {return parseFloat(x);};
                readData = read_until(data, dataoffset, ';');
                chrs = readData[0];
                readdata = readData[1];
                dataoffset += chrs + 1;
            break;
            case 'n':
                readdata = null;
            break;
            case 's':
                ccount = read_until(data, dataoffset, ':');
                chrs = ccount[0];
                stringlength = ccount[1];
                dataoffset += chrs + 2;

                readData = read_chrs(data, dataoffset+1, parseInt(stringlength, 10));
                chrs = readData[0];
                readdata = readData[1];
                dataoffset += chrs + 2;
                if (chrs != parseInt(stringlength, 10) && chrs != readdata.length){
                    error('SyntaxError', 'String length mismatch');
                }

                // Length was calculated on an utf-8 encoded string
                // so wait with decoding
                readdata = that.utf8_decode(readdata);
            break;
            case 'a':
                readdata = {};

                keyandchrs = read_until(data, dataoffset, ':');
                chrs = keyandchrs[0];
                keys = keyandchrs[1];
                dataoffset += chrs + 2;

                for (var i = 0; i < parseInt(keys, 10); i++){
                    var kprops = _unserialize(data, dataoffset);
                    var kchrs = kprops[1];
                    var key = kprops[2];
                    dataoffset += kchrs;

                    var vprops = _unserialize(data, dataoffset);
                    var vchrs = vprops[1];
                    var value = vprops[2];
                    dataoffset += vchrs;

                    readdata[key] = value;
                }

                dataoffset += 1;
            break;
            default:
                error('SyntaxError', 'Unknown / Unhandled data type(s): ' + dtype);
            break;
        }
        return [dtype, dataoffset - offset, typeconvert(readdata)];
    };
    
    return _unserialize((data+''), 0)[2];
}
