package headfirst.composite.menuiterator;


import java.util.Iterator;
import java.util.Stack;

@SuppressWarnings("rawtypes")
public class CompositeIterator implements Iterator {
        Stack<Object> stack = new Stack<Object>();

        public CompositeIterator(Iterator iterator) {
                stack.push(iterator);
        }

        public Object next() {
                if (hasNext()) {
                        Iterator iterator = (Iterator) stack.peek();
                        MenuComponent component = (MenuComponent) iterator.next();
                        if (component instanceof Menu) {
                                stack.push(component.createIterator());
                        }
                        return component;
                } else {
                        return null;
                }
        }

        public boolean hasNext() {
                if (stack.empty()) {
                        return false;
                } else {
                        Iterator iterator = (Iterator) stack.peek();
                        if (!iterator.hasNext()) {
                                stack.pop();
                                return hasNext();
                        } else {
                                return true;
                        }
                }
        }

        public void remove() {
                throw new UnsupportedOperationException();
        }
}