/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 * 
 *    (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
 *    
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library 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
 *    Lesser General Public License for more details.
 */
package org.geotools.data.memory;

import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.TreeMap;

import org.geotools.feature.collection.AbstractFeatureCollection;
import org.geotools.feature.collection.RandomFeatureAccess;
import org.geotools.feature.visitor.BoundsVisitor;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.util.NullProgressListener;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

/**
 * Implement a SimpleFeatureCollection by burning memory!
 * <p>
 * Contents are maintained in a sorted TreeMap by FID, this serves as a reference implementation
 * when exploring the SimpleFeatureCollection api.
 * </p>
 * <p>
 * This is similar to DefaultFeatureCollection, although additional methods are supported and test
 * cases have been written. Unlike DefaultFeatureCollection the type information must be known at
 * construction time.
 * </p>
 * 
 * @author Jody Garnett, Refractions Research
 *
 * @source $URL$
 *         http://svn.osgeo.org/geotools/trunk/modules/library/main/src/main/java/org/geotools/
 *         data/memory/MemoryFeatureCollection.java $
 */
public class MemoryFeatureCollection extends AbstractFeatureCollection implements
        RandomFeatureAccess {
    TreeMap contents = new TreeMap();

    public MemoryFeatureCollection(SimpleFeatureType schema) {
        super(schema);
    }

    public boolean add(SimpleFeature o) {
        SimpleFeature feature = (SimpleFeature) o;
        contents.put(feature.getID(), feature);
        return true;
    }

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

    public Iterator openIterator() {
        return new MemoryIterator(contents.values().iterator());
    }

    public void closeIterator(Iterator close) {
        if (close == null)
            return;

        MemoryIterator it = (MemoryIterator) close;
        it.close();
    }

    class MemoryIterator implements Iterator {
        Iterator it;

        MemoryIterator(Iterator iterator) {
            it = iterator;
        }

        public void close() {
            it = null;
        }

        public boolean hasNext() {
            if (it == null) {
                throw new IllegalStateException();
            }
            return it.hasNext();
        }

        public Object next() {
            if (it == null) {
                throw new IllegalStateException();
            }
            return it.next();
        }

        public void remove() {
            it.remove();
        }
    }

    //
    // RandomFeatureAccess
    //
    public SimpleFeature getFeatureMember(String id) throws NoSuchElementException {
        if (contents.containsKey(id)) {
            return (SimpleFeature) contents.get(id);
        }
        throw new NoSuchElementException(id);
    }

    public SimpleFeature removeFeatureMember(String id) {
        if (contents.containsKey(id)) {
            SimpleFeature old = (SimpleFeature) contents.get(id);
            contents.remove(id);
            return old;
        }
        return null;
    };

    /**
     * Calculates the bounds of the features without caching.
     */
    @Override
    public ReferencedEnvelope getBounds() {
        BoundsVisitor bounds = new BoundsVisitor();
        accepts(bounds, new NullProgressListener());
        return bounds.getBounds();
    }

}