/*

 * Copyright (c) 2008, 2021, 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 sun.nio.fs;

import java.nio.ByteBuffer;

import java.nio.file.attribute.UserDefinedFileAttributeView;

import java.io.IOException;

import java.util.*;

/**

 * Base implementation of UserDefinedAttributeView

 */

abstract class AbstractUserDefinedFileAttributeView

    implements UserDefinedFileAttributeView, DynamicFileAttributeView

{

    protected AbstractUserDefinedFileAttributeView() { }

    protected void checkAccess(String file,

                               boolean checkRead,

                               boolean checkWrite)

    {

        assert checkRead || checkWrite;

        @SuppressWarnings("removal")

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            if (checkRead)

                sm.checkRead(file);

            if (checkWrite)

                sm.checkWrite(file);

            sm.checkPermission(new RuntimePermission("accessUserDefinedAttributes"));

        }

    }

    @Override

    public final String name() {

        return "user";

    }

    @Override

    public final void setAttribute(String attribute, Object value)

        throws IOException

    {

        ByteBuffer bb;

        if (value instanceof byte[]) {

            bb = ByteBuffer.wrap((byte[])value);

        } else {

            bb = (ByteBuffer)value;

        }

        write(attribute, bb);

    }

    @Override

    public final Map<String,Object> readAttributes(String[] attributes)

        throws IOException

    {

        // names of attributes to return

        List<String> names = new ArrayList<>();

        for (String name: attributes) {

            if (name.equals("*")) {

                names = list();

                break;

            } else {

                if (name.isEmpty())

                    throw new IllegalArgumentException();

                names.add(name);

            }

        }

        // read each value and return in map

        Map<String,Object> result = new HashMap<>();

        for (String name: names) {

            int size = size(name);

            byte[] buf = new byte[size];

            int n = read(name, ByteBuffer.wrap(buf));

            byte[] value = (n == size) ? buf : Arrays.copyOf(buf, n);

            result.put(name, value);

        }

        return result;

    }

}