/*

 * Copyright (c) 2017, 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.

 *

 * 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.tools.jaotc.collect;

import java.io.IOException;

import java.nio.file.attribute.BasicFileAttributes;

import java.util.ArrayList;

import java.util.Iterator;

/**

 * {@link FileVisitor} implementation to find class files recursively.

 */

public final class FileSystemFinder extends SimpleFileVisitor<Path> implements Iterable<Path> {

    private final ArrayList<Path> fileNames = new ArrayList<>();

    private final PathMatcher filter;

    public FileSystemFinder(Path combinedPath, PathMatcher filter) {

        this.filter = filter;

        try {

            Files.walkFileTree(combinedPath, this);

        } catch (IOException e) {

            throw new InternalError(e);

        }

    }

    /**

     * Compares the glob pattern against the file name.

     */

    private void find(Path file) {

        Path name = file.getFileName();

        if (name != null && filter.matches(name)) {

            fileNames.add(file);

        }

    }

    @Override

    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {

        find(file);

        return CONTINUE;

    }

    @Override

    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {

        find(dir);

        return CONTINUE;

    }

    @Override

    public Iterator<Path> iterator() {

        return fileNames.iterator();

    }

}