/*

 * Copyright (c) 2016, 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.  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

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 */

package sun.nio.fs;

import java.nio.file.CopyOption;

import java.nio.file.OpenOption;

import java.nio.file.WatchEvent;

import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

/**

 * Provides support for handling JDK-specific OpenOption, CopyOption and

 * WatchEvent.Modifier types.

 */

public final class ExtendedOptions {

    // maps InternalOption to ExternalOption

    private static final Map<InternalOption<?>, Wrapper<?>> internalToExternal

        = new ConcurrentHashMap<>();

    /**

     * Wraps an option or modifier.

     */

    private static final class Wrapper<T> {

        private final Object option;

        private final T param;

        Wrapper(Object option, T param) {

            this.option = option;

            this.param = param;

        }

        T parameter() {

            return param;

        }

    }

    /**

     * The internal version of a JDK-specific OpenOption, CopyOption or

     * WatchEvent.Modifier.

     */

    public static final class InternalOption<T> {

        InternalOption() { }

        private void registerInternal(Object option, T param) {

            Wrapper<T> wrapper = new Wrapper<T>(option, param);

            internalToExternal.put(this, wrapper);

        }

        /**

         * Register this internal option as a OpenOption.

         */

        public void register(OpenOption option) {

            registerInternal(option, null);

        }

        /**

         * Register this internal option as a CopyOption.

         */

        public void register(CopyOption option) {

            registerInternal(option, null);

        }

        /**

         * Register this internal option as a WatchEvent.Modifier.

         */

        public void register(WatchEvent.Modifier option) {

            registerInternal(option, null);

        }

        /**

         * Register this internal option as a WatchEvent.Modifier with the

         * given parameter.

         */

        public void register(WatchEvent.Modifier option, T param) {

            registerInternal(option, param);

        }

        /**

         * Returns true if the given option (or modifier) maps to this internal

         * option.

         */

        public boolean matches(Object option) {

            Wrapper <?> wrapper = internalToExternal.get(this);

            if (wrapper == null)

                return false;

            else

                return option == wrapper.option;

        }

        /**

         * Returns the parameter object associated with this internal option.

         */

        @SuppressWarnings("unchecked")

        public T parameter() {

            Wrapper<?> wrapper = internalToExternal.get(this);

            if (wrapper == null)

                return null;

            else

                return (T) wrapper.parameter();

        }

    }

    // Internal equivalents of the options and modifiers defined in

    // package com.sun.nio.file

    public static final InternalOption<Void> INTERRUPTIBLE = new InternalOption<>();

    public static final InternalOption<Void> NOSHARE_READ = new InternalOption<>();

    public static final InternalOption<Void> NOSHARE_WRITE = new InternalOption<>();

    public static final InternalOption<Void> NOSHARE_DELETE = new InternalOption<>();

    public static final InternalOption<Void> FILE_TREE = new InternalOption<>();

    public static final InternalOption<Void> DIRECT = new InternalOption<>();

    public static final InternalOption<Integer> SENSITIVITY_HIGH = new InternalOption<>();

    public static final InternalOption<Integer> SENSITIVITY_MEDIUM = new InternalOption<>();

    public static final InternalOption<Integer> SENSITIVITY_LOW = new InternalOption<>();

}