/*

 * Copyright (c) 1997, 2015, 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

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 */

package java.security;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.ObjectStreamField;

import java.util.*;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.CopyOnWriteArrayList;

/**

 * A UnresolvedPermissionCollection stores a collection

 * of UnresolvedPermission permissions.

 *

 * @see java.security.Permission

 * @see java.security.Permissions

 * @see java.security.UnresolvedPermission

 *

 *

 * @author Roland Schemers

 * @since 1.2

 *

 * @serial include

 */

final class UnresolvedPermissionCollection

extends PermissionCollection

implements java.io.Serializable

{

    /**

     * Key is permission type, value is a list of the UnresolvedPermissions

     * of the same type.

     * Not serialized; see serialization section at end of class.

     */

    private transient ConcurrentHashMap<String, List<UnresolvedPermission>> perms;

    /**

     * Create an empty UnresolvedPermissionCollection object.

     *

     */

    public UnresolvedPermissionCollection() {

        perms = new ConcurrentHashMap<>(11);

    }

    /**

     * Adds a permission to this UnresolvedPermissionCollection.

     * The key for the hash is the unresolved permission's type (class) name.

     *

     * @param permission the Permission object to add.

     */

    @Override

    public void add(Permission permission) {

        if (! (permission instanceof UnresolvedPermission))

            throw new IllegalArgumentException("invalid permission: "+

                                               permission);

        UnresolvedPermission up = (UnresolvedPermission) permission;

        // Add permission to map. NOTE: cannot use lambda for

        // remappingFunction parameter until JDK-8076596 is fixed.

        perms.compute(up.getName(),

            new java.util.function.BiFunction<>() {

                @Override

                public List<UnresolvedPermission> apply(String key,

                                        List<UnresolvedPermission> oldValue) {

                    if (oldValue == null) {

                        List<UnresolvedPermission> v =

                            new CopyOnWriteArrayList<>();

                        v.add(up);

                        return v;

                    } else {

                        oldValue.add(up);

                        return oldValue;

                    }

                }

            }

        );

    }

    /**

     * get any unresolved permissions of the same type as p,

     * and return the List containing them.

     */

    List<UnresolvedPermission> getUnresolvedPermissions(Permission p) {

        return perms.get(p.getClass().getName());

    }

    /**

     * always returns false for unresolved permissions

     *

     */

    @Override

    public boolean implies(Permission permission) {

        return false;

    }

    /**

     * Returns an enumeration of all the UnresolvedPermission lists in the

     * container.

     *

     * @return an enumeration of all the UnresolvedPermission objects.

     */

    @Override

    public Enumeration<Permission> elements() {

        List<Permission> results =

            new ArrayList<>(); // where results are stored

        // Get iterator of Map values (which are lists of permissions)

        for (List<UnresolvedPermission> l : perms.values()) {

            results.addAll(l);

        }

        return Collections.enumeration(results);

    }

    private static final long serialVersionUID = -7176153071733132400L;

    // Need to maintain serialization interoperability with earlier releases,

    // which had the serializable field:

    // private Hashtable permissions; // keyed on type

    /**

     * @serialField permissions java.util.Hashtable

     *     A table of the UnresolvedPermissions keyed on type, value is Vector

     *     of permissions

     */

    private static final ObjectStreamField[] serialPersistentFields = {

        new ObjectStreamField("permissions", Hashtable.class),

    };

    /**

     * @serialData Default field.

     */

    /*

     * Writes the contents of the perms field out as a Hashtable

     * in which the values are Vectors for

     * serialization compatibility with earlier releases.

     */

    private void writeObject(ObjectOutputStream out) throws IOException {

        // Don't call out.defaultWriteObject()

        // Copy perms into a Hashtable

        Hashtable<String, Vector<UnresolvedPermission>> permissions =

            new Hashtable<>(perms.size()*2);

        // Convert each entry (List) into a Vector

        Set<Map.Entry<String, List<UnresolvedPermission>>> set = perms.entrySet();

        for (Map.Entry<String, List<UnresolvedPermission>> e : set) {

            // Convert list into Vector

            List<UnresolvedPermission> list = e.getValue();

            Vector<UnresolvedPermission> vec = new Vector<>(list);

            // Add to Hashtable being serialized

            permissions.put(e.getKey(), vec);

        }

        // Write out serializable fields

        ObjectOutputStream.PutField pfields = out.putFields();

        pfields.put("permissions", permissions);

        out.writeFields();

    }

    /*

     * Reads in a Hashtable in which the values are Vectors of

     * UnresolvedPermissions and saves them in the perms field.

     */

    private void readObject(ObjectInputStream in) throws IOException,

    ClassNotFoundException {

        // Don't call defaultReadObject()

        // Read in serialized fields

        ObjectInputStream.GetField gfields = in.readFields();

        // Get permissions

        @SuppressWarnings("unchecked")

        // writeObject writes a Hashtable<String, Vector<UnresolvedPermission>>

        // for the permissions key, so this cast is safe, unless the data is corrupt.

        Hashtable<String, Vector<UnresolvedPermission>> permissions =

                (Hashtable<String, Vector<UnresolvedPermission>>)

                gfields.get("permissions", null);

        perms = new ConcurrentHashMap<>(permissions.size()*2);

        // Convert each entry (Vector) into a List

        Set<Map.Entry<String, Vector<UnresolvedPermission>>> set = permissions.entrySet();

        for (Map.Entry<String, Vector<UnresolvedPermission>> e : set) {

            // Convert Vector into ArrayList

            Vector<UnresolvedPermission> vec = e.getValue();

            List<UnresolvedPermission> list = new CopyOnWriteArrayList<>(vec);

            // Add to Hashtable being serialized

            perms.put(e.getKey(), list);

        }

    }

}