var TwuixeDB = function() {

    var db = window.google && google.gears;
    
    if(db) {
        db = google.gears.factory.create('beta.database');
        db.open('twuixe-0.1');
        db.execute('create table if not exists Users (username text primary key, password text)');
    }
    
    return {
        hasGears: function() {
            return db ? true : false;  
        },
        createUser: function(username, password) {
            if(db) {
                db.execute('insert into Users values (?, ?)', [username, password]);
            }
        },
        deleteUser: function(username) {
            if(db) {
                db.execute('delete from Users where username = ?', [username]);
            }
        },
        editUser: function(username, password) {
            if(db) {
                db.execute('update Users set username = ?, password = ? where username = ?', [username, password, username]);
            }
        },
        getUsers: function() {            
            var users = [];
            if(db) {
                var rs = db.execute('select * from Users');
                while (rs.isValidRow()) {
                    users[users.length] = {
                        username: rs.field(0),
                        password: rs.field(1)
                    };
                    rs.next();
                }
                rs.close();
            }
            return users;
        }
    }
}();