package org.gcube.data.streams.adapters;

import java.io.Closeable;
import java.io.IOException;
import java.net.URI;
import java.util.Iterator;

/**
 * An adaptation strategy for {@link IteratorStream}.
 * 
 * @author Fabio Simeoni
 * @see IteratorStream
 *
 */
public class IteratorAdapter<E> implements Closeable {

	private final Iterator<E> iterator;
	
	/**
	 * Creates an instance from a given {@link Iterator}.
	 * @param iterator the iterator
	 */
	public IteratorAdapter(Iterator<E> iterator) {
		this.iterator=iterator;
	}
	
	/**
	 * Returns the underlying iterator.
	 * @return the iterator
	 */
	final Iterator<E> iterator() {
		return iterator;
	}
	
	/**
	 * Returns a locator for the underlying iterator.
	 * <p>
	 * By default it returns a locator of the form {@code local:<toString()>}, where {@code <toString()>} is the string
	 * obtained by invoking {@link #toString()} on the iterator.
	 * @return the locator
	 */
	public URI locator() {
		return URI.create("local://"+iterator);
	}
	
	/**
	 * Closes the underlying iterator.
	 * <p>
	 * By defaults it has no effect except when the iterator implements the {@link Closeable} interface. In this 
	 * case, it simply delegates to the iterator.
	 */
	@Override
	public void close() throws IOException {
		if (iterator instanceof Closeable)
			((Closeable) iterator).close();
	};
	
	
}