//////////////////////////////////////////////////
//
//  the stringifier is based on
//    http://json.org/json.js as of 2006-04-28 from json.org
//  the parser is based on 
//    http://osteele.com/sources/openlaszlo/json
//


rison = {};

/**
 *  rules for an uri encoder that is more tolerant than encodeURIComponent
 *
 *  encodeURIComponent passes  ~!*()-_.'
 *
 *  we also allow              ,:@$/
 *
 */
rison.uri_ok = {  // ok in url paths and in form query args
            '~': true,  '!': true,  '*': true,  '(': true,  ')': true,
            '-': true,  '_': true,  '.': true,  ',': true,
            ':': true,  '@': true,  '$': true,
            "'": true,  '/': true
};

/*
 * we divide the uri-safe glyphs into three sets
 *   <rison> - used by rison                         ' ! : ( ) ,
 *   <identifier> - common in strings                - _ . / ~
 *   <reserved> - not common in strings, reserved    * @ $
 */

/**
 * characters that are illegal inside ids.
 * <rison> and <reserved> classes are illegal in ids.
 */
rison.not_idchar  = "'!:(),*@$";

/**
 * characters that are illegal as the start of an id
 * this is so ids can't look like numbers.
 */
rison.not_idstart = "-0123456789";


(function () {
    var idrx = '[^' + rison.not_idstart + rison.not_idchar + 
               '][^' + rison.not_idchar + ']*';

    rison.id_ok = new RegExp('^' + idrx + '$');

    // regexp to find the end of an id when parsing
    // g flag on the regexp is necessary for iterative regexp.exec()
    rison.next_id = new RegExp(idrx, 'g');
})();


/**
 * uri-encode a string, using a tolerant url encoder.
 *
 * @see rison.uri_ok
 */
rison.quote = function (x) {
    // speedups todo:
    //   regex match exact set of uri_ok chars.
    //   chunking series of unsafe chars rather than encoding char-by-char
    var ok = rison.uri_ok;

    if (/^[A-Za-z0-9_-]*$/.test(x))  // XXX add more safe chars
        return x;

    x = x.replace(/([^A-Za-z0-9_-])/g, function(a, b) {
        var c = ok[b];
        if (c) return b;

        return encodeURIComponent(b);
    });
    return x.replace(/%20/g, '+');
};


//
//  based on json.js 2006-04-28 from json.org
//  license: http://www.json.org/license.html
//
//  hacked by nix for use in uris.
//

(function () {
    var sq = { // url-ok but quoted in strings
               "'": true,  '!': true
    },
    s = {
            array: function (x) {
                var a = ['!('], b, f, i, l = x.length, v;
                for (i = 0; i < l; i += 1) {
                    v = x[i];
                    f = s[typeof v];
                    if (f) {
                        v = f(v);
                        if (typeof v == 'string') {
                            if (b) {
                                a[a.length] = ',';
                            }
                            a[a.length] = v;
                            b = true;
                        }
                    }
                }
                a[a.length] = ')';
                return a.join('');
            },
            'boolean': function (x) {
                if (x)
                    return '!t';
                return '!f'
            },
            'null': function (x) {
                return "!n";
            },
            number: function (x) {
                if (!isFinite(x))
                    return '!n';
                // strip '+' out of exponent, '-' is ok though
                return String(x).replace(/\+/,'');
            },
            object: function (x) {
                if (x) {
                    if (x instanceof Array) {
                        return s.array(x);
                    }
                    if (typeof x.__prototype__ === 'object' && typeof x.__prototype__.encode_rison !== 'undefined')
                        return x.encode_rison();

                    var a = ['('], b, f, i, v, ki, ks=[];
                    for (i in x)
                        ks[ks.length] = i;
                    ks.sort();
                    for (ki = 0; ki < ks.length; ki++) {
                        i = ks[ki];
                        v = x[i];
                        f = s[typeof v];
                        if (f) {
                            v = f(v);
                            if (typeof v == 'string') {
                                if (b) {
                                    a[a.length] = ',';
                                }
                                a.push(s.string(i), ':', v);
                                b = true;
                            }
                        }
                    }
                    a[a.length] = ')';
                    return a.join('');
                }
                return '!n';
            },
            string: function (x) {
                if (x == '')
                    return "''";

                if (rison.id_ok.test(x))
                    return x;

                x = x.replace(/(['!])/g, function(a, b) {
                    if (sq[b]) return '!'+b;
                    return b;
                });
                return "'" + x + "'";
            },
            undefined: function (x) {
                throw new Error("rison can't encode the undefined value");
            }
        };


    /**
     * rison-encode a javascript structure
     *
     *  implemementation based on Douglas Crockford's json.js:
     *    http://json.org/json.js as of 2006-04-28 from json.org
     *
     */
    rison.encode = function (v) {
        return s[typeof v](v);
    };

    /**
     * rison-encode and uri-encode a javascript structure
     *
     */
    rison.encode_uri = function (v) {
        return rison.quote(s[typeof v](v));
    };

})();




//
// based on openlaszlo-json and hacked by nix for use in uris.
//
// Author: Oliver Steele
// Copyright: Copyright 2006 Oliver Steele.  All rights reserved.
// Homepage: http://osteele.com/sources/openlaszlo/json
// License: MIT License.
// Version: 1.0


/**
 * parse a rison string into a javascript structure
 *
 * this is the simplest decoder entry point.
 *
 *  based on Oliver Steele's OpenLaszlo-JSON
 *     http://osteele.com/sources/openlaszlo/json
 */
rison.decode = function(r) {
    var errcb = function(e) { alert('rison decoder error: ' + e); };
    var p = new rison.parser(errcb);
    return p.parse(r);
};


/**
 * construct a new parser object for reuse
 *
 * @see rison.decode
 */
rison.parser = function (errcb) {
    this.errorHandler = errcb;
};

/**
 * string containing acceptable whitespace characters
 * by default the rison decoder tolerates no whitespace.
 * to accept whitespace set rison.parser.WHITESPACE = " \t\n\r\f";
 */
rison.parser.WHITESPACE = "";

// expose this as-is?
rison.parser.prototype.setOptions = function (options) {
    if (options['errorHandler'])
        this.errorHandler = options.errorHandler;
};

/**
 * parse a rison string into a javascript structure
 */
rison.parser.prototype.parse = function (str) {
    this.string = str;
    this.index = 0;
    this.message = null;
    var value = this.readValue();
    if (!this.message && this.next())
        value = this.error("extra characters at the end of the string");
    if (this.message && this.errorHandler)
        this.errorHandler(this.message, this.index);
    return value;
};

rison.parser.prototype.error = function (message) {
    if (typeof(console) != 'undefined')
        mjt.log('rison parser error: ', message);
    this.message = message;
    return undefined;
}
    
rison.parser.prototype.readValue = function () {
    var c = this.next();
    var fn = c && this.table[c];

    if (fn)
        return fn.apply(this);

    // fell through table, parse as an id

    var s = this.string;
    var i = this.index-1;

    // Regexp.lastIndex may not work right in IE before 5.5?
    // g flag on the regexp is also necessary
    rison.next_id.lastIndex = i;
    var m = rison.next_id.exec(s);

    // mjt.log('matched id', i, r.lastIndex);

    if (m.length > 0) {
        var id = m[0];
        this.index = i+id.length;
        return id;  // a string
    }

    if (c) return this.error("invalid character: '" + c + "'");
    return this.error("empty expression");
}

rison.parser.parse_array = function (parser) {
    var ar = [];
    var c;
    while ((c = parser.next()) != ')') {
        if (!c) return parser.error("unmatched '!('");
        if (ar.length) {
            if (c != ',')
                parser.error("missing ','");
        } else if (c == ',') {
            return parser.error("extra ','");
        } else
            --parser.index;
        var n = parser.readValue();
        if (typeof n == "undefined") return undefined;
        ar.push(n);
    }
    return ar;
};

rison.parser.bangs = {
    t: true,
    f: false,
    n: null,
    '(': rison.parser.parse_array
}

rison.parser.prototype.table = {
    '!': function () {
        var s = this.string;
        var c = s.charAt(this.index++);
        if (!c) return this.error('"!" at end of input');
        var x = rison.parser.bangs[c];
        if (typeof(x) == 'function') {
            return x.call(null, this);
        } else if (typeof(x) == 'undefined') {
            return this.error('unknown literal: "!' + c + '"');
        }
        return x;
    },
    '(': function () {
        var o = {};
        var c;
        var count = 0;
        while ((c = this.next()) != ')') {
            if (count) {
                if (c != ',')
                    this.error("missing ','");
            } else if (c == ',') {
                return this.error("extra ','");
            } else
                --this.index;
            var k = this.readValue();
            if (typeof k == "undefined") return undefined;
            if (this.next() != ':') return this.error("missing ':'");
            var v = this.readValue();
            if (typeof v == "undefined") return undefined;
            o[k] = v;
            count++;
        }
        return o;
    },
    "'": function () {
        var s = this.string;
        var i = this.index;
        var start = i;
        var segments = [];
        var c;
        while ((c = s.charAt(i++)) != "'") {
            //if (i == s.length) return this.error('unmatched "\'"');
            if (!c) return this.error('unmatched "\'"');
            if (c == '!') {
                if (start < i-1)
                    segments.push(s.slice(start, i-1));
                c = s.charAt(i++);
                if ("!'".indexOf(c) >= 0) {
                    segments.push(c);
                } else {
                    return this.error('invalid string escape: "!'+c+'"');
                }
                start = i;
            }
        }
        if (start < i-1)
            segments.push(s.slice(start, i-1));
        this.index = i;
        return segments.length == 1 ? segments[0] : segments.join('');
    },
    // Also any digit.  The statement that follows this table
    // definition fills in the digits.
    '-': function () {
        var s = this.string;
        var i = this.index;
        var start = i-1;
        var state = 'int';
        var permittedSigns = '-';
        var transitions = {
            'int+.': 'frac',
            'int+e': 'exp',
            'frac+e': 'exp'
        };
        do {
            var c = s.charAt(i++);
            if (!c) break;
            if ('0' <= c && c <= '9') continue;
            if (permittedSigns.indexOf(c) >= 0) {
                permittedSigns = '';
                continue;
            }
            state = transitions[state+'+'+c.toLowerCase()];
            if (state == 'exp') permittedSigns = '-';
        } while (state);
        this.index = --i;
        s = s.slice(start, i)
        if (s == '-') return this.error("invalid number");
        return Number(s);
    }
};
// copy table['-'] to each of table[i] | i <- '0'..'9':
(function (table) {
    for (var i = 0; i <= 9; i++)
        table[String(i)] = table['-'];
})(rison.parser.prototype.table);

// return the next non-whitespace character, or undefined
rison.parser.prototype.next = function () {
    var s = this.string;
    var i = this.index;
    do {
        if (i == s.length) return undefined;
        var c = s.charAt(i++);
    } while (rison.parser.WHITESPACE.indexOf(c) >= 0);
    this.index = i;
    return c;
};