package lettergame.model;

import java.util.*;

/**
 * Wraps a list so that any changes can be observed.
 * Changes made through an iterator also result in
 * notification of observers;
 * @author kjg
 * @param <T>
 */
public class ObservableList<T>
	extends Observable implements List<T> {
	private List<T> list;  // the wrapped list
	
	public ObservableList(List<T> list) {
		this.list = list;
	}
	
	private void mutated() {
		setChanged();
		notifyObservers();
	}

	public void add(int arg0, T arg1) {
		list.add(arg0, arg1);
		mutated();
	}

	public boolean add(T arg0) {
		boolean result = list.add(arg0);
		mutated();
		return result;
	}

	public boolean addAll(Collection<? extends T> arg0) {
		boolean result = list.addAll(arg0);
		mutated();
		return result;
	}

	public boolean addAll(int arg0, Collection<? extends T> arg1) {
		boolean result = list.addAll(arg0, arg1);
		mutated();
		return result;
	}

	public void clear() {
		list.clear();
		mutated();
	}

	public boolean contains(Object arg0) {
		return list.contains(arg0);
	}

	public boolean containsAll(Collection<?> arg0) {
		return list.containsAll(arg0);
	}

	public boolean equals(Object arg0) {
		return list.equals(arg0);
	}

	public T get(int arg0) {
		return list.get(arg0);
	}

	public int hashCode() {
		return list.hashCode();
	}

	public int indexOf(Object arg0) {
		return list.indexOf(arg0);
	}

	public boolean isEmpty() {
		return list.isEmpty();
	}

	public Iterator<T> iterator() {
		return new NotifyingIterator<T>(list.listIterator());
	}

	public int lastIndexOf(Object arg0) {
		return list.lastIndexOf(arg0);
	}

	public ListIterator<T> listIterator() {
		return new NotifyingIterator<T>(list.listIterator());
	}

	public ListIterator<T> listIterator(int arg0) {
		return new NotifyingIterator<T>(list.listIterator(arg0));
	}
	
	/**
	 * Moves the object from indexA to the position indexB.
	 * @param indexA
	 * @param indexB
	 */
	public void move(int indexA, int indexB) {
		if (indexA != indexB) {
			try {
				list.add(indexB, list.remove(indexA));
			} finally {
				mutated();
			}
		}
	}

	public T remove(int arg0) {
		T result = list.remove(arg0);
		mutated();
		return result;
	}

	public boolean remove(Object arg0) {
		boolean result = list.remove(arg0);
		mutated();
		return result;
	}

	public boolean removeAll(Collection<?> arg0) {
		boolean result = list.removeAll(arg0);
		mutated();
		return result;
	}

	public boolean retainAll(Collection<?> arg0) {
		boolean result = list.retainAll(arg0);
		mutated();
		return result;
	}

	public T set(int arg0, T arg1) {
		T result = list.set(arg0, arg1);
		mutated();
		return result;
	}

	public int size() {
		return list.size();
	}

	public List<T> subList(int arg0, int arg1) {
		return list.subList(arg0, arg1);
	}

	public Object[] toArray() {
		return list.toArray();
	}

	public <X> X[] toArray(X[] arg0) {
		return list.toArray(arg0);
	}
	
	public String toString() {
		return list.toString();
	}
	
	class NotifyingIterator<T> implements ListIterator<T> {
		private ListIterator<T> it; // the wrapped iterator
		NotifyingIterator(ListIterator<T> it) {
			this.it = it;
		}
		public void add(T arg0) {
			it.add(arg0);
			mutated();
		}
		public boolean hasNext() {
			return it.hasNext();
		}
		public boolean hasPrevious() {
			return it.hasPrevious();
		}
		public T next() {
			return it.next();
		}
		public int nextIndex() {
			return it.nextIndex();
		}
		public T previous() {
			return it.previous();
		}
		public int previousIndex() {
			return it.previousIndex();
		}
		public void remove() {
			it.remove();
			mutated();
		}
		public void set(T arg0) {
			it.set(arg0);
			mutated();
		}
	}
	
	// Test program illustrating creating a list and adding
	// an observer that reacts to changes.
	public static void main(String[] args) {
		List<String> model = new LinkedList<String>();
		final ObservableList<String> l
			= new ObservableList<String>(model);
		l.addObserver(new Observer() {
			public void update(Observable arg0, Object arg1) {
				System.out.println(l);
			}
		});
		l.add("hello");
		l.add("there");
		l.remove(1);
		l.clear();
		l.add("world");
		l.add("peace");
		l.move(1,0);
		l.move(0,1);
		Iterator<String> it = l.iterator();
		while (it.hasNext()) {
			it.next();
			it.remove();
		}
		
	}
}