function StateMapper(subjects,states) {
    var self = this;
    self.states = states || [];
    self.subjects = subjects || [];

    self.encode = function(z) {
        z = z.toString();
        var x = "0123456789";
        var u = "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM!?";
        var s = x.length;
        var d = u.length;
        var v = 0;
        var n = z.length;
        for (var i = 0; i < n; i++) {
            v = v * s + x.indexOf(z.charAt(i));
        }
        if (v < 0) return 0;
        var r = v % d;
        var c = u.charAt(r);
        var q = Math.floor(v / d);
        while (q) {
            r = q % d; q = Math.floor(q / d); c = u.charAt(r) + c;
        }
        return c;
    };

    self.decode = function(z) {
        z = z.toString();
        var u = "0123456789";
        var x = "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM!?";
        var s = x.length;
        var d = u.length;
        var v = 0;
        var n = z.length;
        for (var i = 0; i < n; i++) {
            v = v * s + x.indexOf(z.charAt(i));
        }
        if (v < 0) return 0;
        var r = v % d;
        var c = u.charAt(r);
        var q = Math.floor(v / d);
        while (q) {
            r = q % d; q = Math.floor(q / d); c = u.charAt(r) + c;
        }
        return c;
    };

    self.compress = function (data) {
        var str = "";
        for (var k in data) {
            var v = data[k];
            if (!self.states.includes(v)) {
                self.states.push(v);
            }
            self.subjects.push(k);
            str += self.encode(self.states.indexOf(v));
        }
        return self.code = self.encode(str);
    };

    self.decompress = function (code) {
        code = code || self.code;
        if (!code) return ;
        var states = self.decode(code);
        if (states.length < self.subjects.length) {
            var l = self.subjects.length - states.length;
            for (var i = 0; i < l; i++) {
                states = "0" + states;
            }
        }
        states = states.split("");
        var out = {};
        states.forEach(function(state,index){
            out[self.subjects[index]] = self.states[parseInt(state)];
        });
        return out;
    };
}

/*
var sm = new StateMapper(["bob","joe","billy","boe"],["happy","sad","mad"]);
sm.compress({ bob: "happy", joe: "sad", billy: "mad", boe: "happy" }); // "1X"
sm.decompress("1X");

*/