/*

 * Copyright (c) 2009, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.nio.zipfs;

import java.io.IOException;

import java.nio.file.ClosedDirectoryStreamException;

import java.nio.file.DirectoryIteratorException;

import java.nio.file.DirectoryStream;

import java.nio.file.NotDirectoryException;

import java.nio.file.Path;

import java.util.Iterator;

import java.util.NoSuchElementException;

/**

 *

 * @author Xueming Shen, Rajendra Gutupalli, Jaya Hangal

 */

class ZipDirectoryStream implements DirectoryStream<Path> {

    private final ZipFileSystem zipfs;

    private final ZipPath dir;

    private final DirectoryStream.Filter<? super Path> filter;

    private volatile boolean isClosed;

    private volatile Iterator<Path> itr;

    ZipDirectoryStream(ZipPath dir,

                       DirectoryStream.Filter<? super java.nio.file.Path> filter)

        throws IOException

    {

        this.zipfs = dir.getFileSystem();

        this.dir = dir;

        this.filter = filter;

        // sanity check

        if (!zipfs.isDirectory(dir.getResolvedPath()))

            throw new NotDirectoryException(dir.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(dir, filter);

        } catch (IOException e) {

            throw new DirectoryIteratorException(e);

        }

        return new Iterator<Path>() {

            @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;

    }

}