/*
 * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.sun.nio.zipfs;

import java.nio.file.DirectoryStream;
import java.nio.file.ClosedDirectoryStreamException;
import java.nio.file.NotDirectoryException;
import java.nio.file.Path;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.io.IOException;

/**
 *
 * @author  Xueming Shen, Rajendra Gutupalli, Jaya Hangal
 */

public class ZipDirectoryStream implements DirectoryStream<Path> {

    private final ZipFileSystem zipfs;
    private final byte[] path;
    private final DirectoryStream.Filter<? super Path> filter;
    private volatile boolean isClosed;
    private volatile Iterator<Path> itr;

    ZipDirectoryStream(ZipPath zipPath,
                       DirectoryStream.Filter<? super java.nio.file.Path> filter)
        throws IOException
    {
        this.zipfs = zipPath.getFileSystem();
        this.path = zipPath.getResolvedPath();
        this.filter = filter;
        // sanity check
        if (!zipfs.isDirectory(path))
            throw new NotDirectoryException(zipPath.toString());
    }

    @Override
    public synchronized Iterator<Path> iterator() {
        if (isClosed)
            throw new ClosedDirectoryStreamException();
        if (itr != null)
            throw new IllegalStateException("Iterator has already been returned");

        try {
            itr = zipfs.iteratorOf(path, filter);
        } catch (IOException e) {
            throw new IllegalStateException(e);
        }
        return new Iterator<Path>() {
            private Path next;
            @Override
            public boolean hasNext() {
                if (isClosed)
                    return false;
                return itr.hasNext();
            }

            @Override
            public synchronized Path next() {
                if (isClosed)
                    throw new NoSuchElementException();
                return itr.next();
            }

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

    @Override
    public synchronized void close() throws IOException {
        isClosed = true;
    }


}
