/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *                               ***
 *
 *   Community License: GPL 3.0
 *
 *   This file is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published
 *   by the Free Software Foundation, either version 3 of the License,
 *   or (at your option) any later version.
 *
 *   This file is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 *                               ***
 *
 *   Available Commercial License: GraniteDS SLA 1.0
 *
 *   This is the appropriate option if you are creating proprietary
 *   applications and you are not prepared to distribute and share the
 *   source code of your application under the GPL v3 license.
 *
 *   Please visit http://www.granitedataservices.com/license for more
 *   details.
 */
package org.granite.client.collection;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

import org.granite.client.collection.CollectionChangeListener;
import org.granite.client.collection.CollectionChangeSupport;
import org.granite.client.collection.ObservableCollection;
import org.granite.client.collection.CollectionChangeEvent.Kind;

/**
 * @author William DRAI
 */
public class ObservableList<E> implements List<E>, ObservableCollection {
        
        protected CollectionChangeSupport ccs = new CollectionChangeSupport(this);
        private final List<E> wrappedList;
        
        public ObservableList(List<E> list) {
                this.wrappedList = list;
        }
        
        protected List<E> getWrappedList() {
                return wrappedList;
        }
        
        public void addCollectionChangeListener(CollectionChangeListener listener) {
                ccs.addCollectionChangeListener(listener);
        }
        
        public void removeCollectionChangeListener(CollectionChangeListener listener) {
                ccs.removeCollectionChangeListener(listener);
        }

        @Override
        public boolean add(E element) {
                int index = wrappedList.size();
                boolean added = wrappedList.add(element);
                if (added) {
                        ccs.fireCollectionChangeEvent(Kind.ADD, index, new Object[] { element });
                        trackElement(element);
                }
                return added;
        }

        @Override
        public void add(int index, E element) {
                wrappedList.add(index, element);
                ccs.fireCollectionChangeEvent(Kind.ADD, index, new Object[] { element });
                trackElement(element);
        }
        
        @Override
        public boolean addAll(Collection<? extends E> elements) {
                int index = wrappedList.size();
                boolean added = wrappedList.addAll(elements);
                if (added)
                        ccs.fireCollectionChangeEvent(Kind.ADD, index, elements.toArray());
                return added;
        }

        @Override
        public boolean addAll(int index, Collection<? extends E> elements) {
                boolean added = wrappedList.addAll(index, elements);
                if (added) {
                        ccs.fireCollectionChangeEvent(Kind.ADD, index, elements.toArray());
                        for (Object element : elements)
                                trackElement(element);
                }
                return added;
        }

        @Override
        public E remove(int index) {
                E element = wrappedList.remove(index);
                ccs.fireCollectionChangeEvent(Kind.REMOVE, index, new Object[] { element });
                untrackElement(element);
                return element;
        }

        @Override
        public boolean remove(Object element) {
                int index = wrappedList.indexOf(element);
                boolean removed = wrappedList.remove(element);
                if (removed) {
                        ccs.fireCollectionChangeEvent(Kind.REMOVE, index, new Object[] { element });
                        untrackElement(element);
                }
                return removed;
        }

        @Override
        public boolean removeAll(Collection<?> collection) {
                boolean removed = false;
                List<Object> removedElements = new ArrayList<Object>();
                int index = 0;
                for (Object element : collection) {
                        if (remove(element)) {
                                removed = true;
                                removedElements.add(element);
                                ccs.fireCollectionChangeEvent(Kind.REMOVE, index, new Object[] { element });
                                untrackElement(element);
                        }
                        index++;
                }
                return removed;
        }

        @Override
        public boolean retainAll(Collection<?> collection) {
                boolean changed = false;
                int index = 0;
                for (Object element : collection) {
                        if (!wrappedList.contains(element) && remove(element)) {
                                changed = true;
                                ccs.fireCollectionChangeEvent(Kind.REMOVE, index, new Object[] { element });
                                untrackElement(element);
                        }
                        index++;
                }
                return changed;
        }

        @Override
        public E set(int index, E element) {
                E oldElement = wrappedList.set(index, element);
                if (element != oldElement) {
                        ccs.fireCollectionChangeEvent(Kind.REPLACE, index, new Object[] { oldElement, element });
                        untrackElement(oldElement);
                        trackElement(element);
                }
                return oldElement;
        }
        
        @Override
        public void clear() {
                if (wrappedList.size() == 0)
                        return;
                Object[] elements = wrappedList.toArray();
                wrappedList.clear();
                ccs.fireCollectionChangeEvent(Kind.CLEAR, null, elements);
                for (Object element : elements)
                        untrackElement(element);
        }

        @Override
        public boolean contains(Object element) {
                return wrappedList.contains(element);
        }

        @Override
        public boolean containsAll(Collection<?> collection) {
                return wrappedList.containsAll(collection);
        }

        @Override
        public E get(int index) {
                return wrappedList.get(index);
        }

        @Override
        public int indexOf(Object element) {
                return wrappedList.indexOf(element);
        }

        @Override
        public int lastIndexOf(Object element) {
                return wrappedList.lastIndexOf(element);
        }

        @Override
        public boolean isEmpty() {
                return wrappedList.isEmpty();
        }

        @Override
        public int size() {
                return wrappedList.size();
        }

        @Override
        public Object[] toArray() {
                return wrappedList.toArray();
        }

        @Override
        public <T> T[] toArray(T[] array) {
                return wrappedList.toArray(array);
        }

        @Override
        public List<E> subList(int start, int end) {
                return new ObservableList<E>(wrappedList.subList(start, end));
        }
        
        @Override
        public Iterator<E> iterator() {
                return new IteratorWrapper(wrappedList.iterator());
        }

        @Override
        public ListIterator<E> listIterator() {
                return new ListIteratorWrapper(wrappedList.listIterator());
        }

        @Override
        public ListIterator<E> listIterator(int index) {
                return new ListIteratorWrapper(wrappedList.listIterator(index), index);
        }
        
        
        private class IteratorWrapper implements Iterator<E> {
                
                private final Iterator<E> wrappedIterator;
                private int index = -1;
                private E element;
                
                public IteratorWrapper(Iterator<E> iterator) {
                        this.wrappedIterator = iterator;
                }

                public boolean hasNext() {
                        return wrappedIterator.hasNext();
                }

                public E next() {
                        index++;
                        element = wrappedIterator.next();
                        return element;
                }

                public void remove() {
                        wrappedIterator.remove();
                        ccs.fireCollectionChangeEvent(Kind.REMOVE, index, new Object[] { element });
                }
        }
        
        private class ListIteratorWrapper implements ListIterator<E> {
                
                private final ListIterator<E> wrappedIterator;
                private int index = -1;
                private E element;
                
                public ListIteratorWrapper(ListIterator<E> iterator) {
                        this.wrappedIterator = iterator;
                }

                public ListIteratorWrapper(ListIterator<E> iterator, int index) {
                        this.wrappedIterator = iterator;
                        this.index = index;                     
                }
                
                public void add(E element) {
                        wrappedIterator.add(element);
                        ccs.fireCollectionChangeEvent(Kind.ADD, index, new Object[] { element });
                }

                public void remove() {
                        wrappedIterator.remove();
                        ccs.fireCollectionChangeEvent(Kind.REMOVE, index, new Object[] { element });
                }

                public void set(E element) {
                        Object oldElement = this.element;
                        wrappedIterator.set(element);
                        if (element != oldElement)
                                ccs.fireCollectionChangeEvent(Kind.REPLACE, index, new Object[] { oldElement, element });
                }

                public boolean hasNext() {
                        return wrappedIterator.hasNext();
                }

                public boolean hasPrevious() {
                        return wrappedIterator.hasPrevious();
                }

                public E next() {
                        index++;
                        element = wrappedIterator.next();
                        return element;
                }

                public int nextIndex() {
                        return wrappedIterator.nextIndex();
                }

                public E previous() {
                        index--;
                        element = wrappedIterator.previous();
                        return element;
                }

                public int previousIndex() {
                        return wrappedIterator.previousIndex();
                }               
        }
        
        
        private PropertyChangeListener trackingListener = new PropertyChangeListener() {
                public void propertyChange(PropertyChangeEvent event) {
                        ccs.fireCollectionChangeEvent(Kind.UPDATE, null, new Object[] { event });
                }
        };
        
        private void trackElement(Object obj) {
                if (obj == null)
                        return;
                try {
                        Method m = obj.getClass().getMethod("addPropertyChangeListener", PropertyChangeListener.class);
                        m.invoke(obj, trackingListener);
                }
                catch (Exception e) {
                }
        }
        
        private void untrackElement(Object obj) {
                if (obj == null)
                        return;
                try {
                        Method m = obj.getClass().getMethod("removePropertyChangeListener", PropertyChangeListener.class);
                        m.invoke(obj, trackingListener);
                }
                catch (Exception e) {
                }
        }
}