/*

 * Copyright (c) 2011, 2012, 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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 * questions.

 */

package sun.security.krb5;

import java.io.IOException;

import java.util.Collection;

import java.util.Hashtable;

import java.util.Vector;

public class SCDynamicStoreConfig {

    private static native void installNotificationCallback();

    private static native Hashtable<String, Object> getKerberosConfig();

    private static boolean DEBUG = sun.security.krb5.internal.Krb5.DEBUG;

    static {

        boolean isMac = java.security.AccessController.doPrivileged(

            new java.security.PrivilegedAction<Boolean>() {

                public Boolean run() {

                    String osname = System.getProperty("os.name");

                    if (osname.contains("OS X")) {

                        System.loadLibrary("osxkrb5");

                        return true;

                    }

                    return false;

                }

            });

        if (isMac) installNotificationCallback();

    }

    private static Vector<String> unwrapHost(

            Collection<Hashtable<String, String>> c) {

        Vector<String> vector = new Vector<String>();

        for (Hashtable<String, String> m : c) {

            vector.add(m.get("host"));

        }

        return vector;

    }

    /**

     * convertRealmConfigs: Maps the Object graph that we get from JNI to the

     * object graph that Config expects. Also the items inside the kdc array

     * are wrapped inside Hashtables

     */

    @SuppressWarnings("unchecked")

    private static Hashtable<String, Object>

            convertRealmConfigs(Hashtable<String, ?> configs) {

        Hashtable<String, Object> realmsTable = new Hashtable<String, Object>();

        for (String realm : configs.keySet()) {

            // get the kdc

            Hashtable<String, Collection<?>> map =

                    (Hashtable<String, Collection<?>>) configs.get(realm);

            Hashtable<String, Vector<String>> realmMap =

                    new Hashtable<String, Vector<String>>();

            // put the kdc into the realmMap

            Collection<Hashtable<String, String>> kdc =

                    (Collection<Hashtable<String, String>>) map.get("kdc");

            if (kdc != null) realmMap.put("kdc", unwrapHost(kdc));

            // put the admin server into the realmMap

            Collection<Hashtable<String, String>> kadmin =

                    (Collection<Hashtable<String, String>>) map.get("kadmin");

            if (kadmin != null) realmMap.put("admin_server", unwrapHost(kadmin));

            // add the full entry to the realmTable

            realmsTable.put(realm, realmMap);

        }

        return realmsTable;

    }

    /**

     * Calls down to JNI to get the raw Kerberos Config and maps the object

     * graph to the one that Kerberos Config in Java expects

     *

     * @return

     * @throws IOException

     */

    public static Hashtable<String, Object> getConfig() throws IOException {

        Hashtable<String, Object> stanzaTable = getKerberosConfig();

        if (stanzaTable == null) {

            throw new IOException(

                    "Could not load configuration from SCDynamicStore");

        }

        if (DEBUG) System.out.println("Raw map from JNI: " + stanzaTable);

        return convertNativeConfig(stanzaTable);

    }

    @SuppressWarnings("unchecked")

    private static Hashtable<String, Object> convertNativeConfig(

            Hashtable<String, Object> stanzaTable) throws IOException {

        // convert SCDynamicStore realm structure to Java realm structure

        Hashtable<String, ?> realms =

                (Hashtable<String, ?>) stanzaTable.get("realms");

        if (realms == null || realms.isEmpty()) {

            throw new IOException(

                    "SCDynamicStore contains an empty Kerberos setting");

        }

        stanzaTable.remove("realms");

        Hashtable<String, Object> realmsTable = convertRealmConfigs(realms);

        stanzaTable.put("realms", realmsTable);

        WrapAllStringInVector(stanzaTable);

        if (DEBUG) System.out.println("stanzaTable : " + stanzaTable);

        return stanzaTable;

    }

    @SuppressWarnings("unchecked")

    private static void WrapAllStringInVector(

            Hashtable<String, Object> stanzaTable) {

        for (String s: stanzaTable.keySet()) {

            Object v = stanzaTable.get(s);

            if (v instanceof Hashtable) {

                WrapAllStringInVector((Hashtable<String,Object>)v);

            } else if (v instanceof String) {

                Vector<String> vec = new Vector<>();

                vec.add((String)v);

                stanzaTable.put(s, vec);

            }

        }

    }

}