/*

 * Copyright (c) 2012, 2013, 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.

 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * Copyright (c) 2011-2012, Stephen Colebourne & Michael Nascimento Santos

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *

 *  * Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 *

 *  * Neither the name of JSR-310 nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

package java.time.zone;

import java.io.DataInput;

import java.io.DataOutput;

import java.io.Externalizable;

import java.io.IOException;

import java.io.InvalidClassException;

import java.io.ObjectInput;

import java.io.ObjectOutput;

import java.io.StreamCorruptedException;

import java.time.ZoneOffset;

/**

 * The shared serialization delegate for this package.

 *

 * This class is mutable and should be created once per serialization.

 *

 * @serial include

 * @since 1.8

 */

final class Ser implements Externalizable {

    /**

     * Serialization version.

     */

    private static final long serialVersionUID = -8885321777449118786L;

    /** Type for ZoneRules. */

    static final byte ZRULES = 1;

    /** Type for ZoneOffsetTransition. */

    static final byte ZOT = 2;

    /** Type for ZoneOffsetTransition. */

    static final byte ZOTRULE = 3;

    /** The type being serialized. */

    private byte type;

    /** The object being serialized. */

    private Object object;

    /**

     * Constructor for deserialization.

     */

    public Ser() {

    }

    /**

     * Creates an instance for serialization.

     *

     * @param type  the type

     * @param object  the object

     */

    Ser(byte type, Object object) {

        this.type = type;

        this.object = object;

    }

    //-----------------------------------------------------------------------

    /**

     * Implements the {@code Externalizable} interface to write the object.

     *

     * @param out  the data stream to write to, not null

     */

    public void writeExternal(ObjectOutput out) throws IOException {

        writeInternal(type, object, out);

    }

    static void write(Object object, DataOutput out) throws IOException {

        writeInternal(ZRULES, object, out);

    }

    private static void writeInternal(byte type, Object object, DataOutput out) throws IOException {

        out.writeByte(type);

        switch (type) {

            case ZRULES:

                ((ZoneRules) object).writeExternal(out);

                break;

            case ZOT:

                ((ZoneOffsetTransition) object).writeExternal(out);

                break;

            case ZOTRULE:

                ((ZoneOffsetTransitionRule) object).writeExternal(out);

                break;

            default:

                throw new InvalidClassException("Unknown serialized type");

        }

    }

    //-----------------------------------------------------------------------

    /**

     * Implements the {@code Externalizable} interface to read the object.

     *

     * @param in  the data to read, not null

     */

    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {

        type = in.readByte();

        object = readInternal(type, in);

    }

    static Object read(DataInput in) throws IOException, ClassNotFoundException {

        byte type = in.readByte();

        return readInternal(type, in);

    }

    private static Object readInternal(byte type, DataInput in) throws IOException, ClassNotFoundException {

        switch (type) {

            case ZRULES:

                return ZoneRules.readExternal(in);

            case ZOT:

                return ZoneOffsetTransition.readExternal(in);

            case ZOTRULE:

                return ZoneOffsetTransitionRule.readExternal(in);

            default:

                throw new StreamCorruptedException("Unknown serialized type");

        }

    }

    /**

     * Returns the object that will replace this one.

     *

     * @return the read object, should never be null

     */

    private Object readResolve() {

         return object;

    }

    //-----------------------------------------------------------------------

    /**

     * Writes the state to the stream.

     *

     * @param offset  the offset, not null

     * @param out  the output stream, not null

     * @throws IOException if an error occurs

     */

    static void writeOffset(ZoneOffset offset, DataOutput out) throws IOException {

        final int offsetSecs = offset.getTotalSeconds();

        int offsetByte = offsetSecs % 900 == 0 ? offsetSecs / 900 : 127;  // compress to -72 to +72

        out.writeByte(offsetByte);

        if (offsetByte == 127) {

            out.writeInt(offsetSecs);

        }

    }

    /**

     * Reads the state from the stream.

     *

     * @param in  the input stream, not null

     * @return the created object, not null

     * @throws IOException if an error occurs

     */

    static ZoneOffset readOffset(DataInput in) throws IOException {

        int offsetByte = in.readByte();

        return (offsetByte == 127 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(offsetByte * 900));

    }

    //-----------------------------------------------------------------------

    /**

     * Writes the state to the stream.

     *

     * @param epochSec  the epoch seconds, not null

     * @param out  the output stream, not null

     * @throws IOException if an error occurs

     */

    static void writeEpochSec(long epochSec, DataOutput out) throws IOException {

        if (epochSec >= -4575744000L && epochSec < 10413792000L && epochSec % 900 == 0) {  // quarter hours between 1825 and 2300

            int store = (int) ((epochSec + 4575744000L) / 900);

            out.writeByte((store >>> 16) & 255);

            out.writeByte((store >>> 8) & 255);

            out.writeByte(store & 255);

        } else {

            out.writeByte(255);

            out.writeLong(epochSec);

        }

    }

    /**

     * Reads the state from the stream.

     *

     * @param in  the input stream, not null

     * @return the epoch seconds, not null

     * @throws IOException if an error occurs

     */

    static long readEpochSec(DataInput in) throws IOException {

        int hiByte = in.readByte() & 255;

        if (hiByte == 255) {

            return in.readLong();

        } else {

            int midByte = in.readByte() & 255;

            int loByte = in.readByte() & 255;

            long tot = ((hiByte << 16) + (midByte << 8) + loByte);

            return (tot * 900) - 4575744000L;

        }

    }

}