/*

 * Copyright (c) 2001, 2018, 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.ch;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.DatagramSocketImpl;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.NetworkInterface;

import java.net.SocketAddress;

import java.net.SocketException;

import java.net.SocketOption;

import java.net.SocketTimeoutException;

import java.net.StandardSocketOptions;

import java.nio.ByteBuffer;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.DatagramChannel;

import java.nio.channels.IllegalBlockingModeException;

import java.util.Objects;

// Make a datagram-socket channel look like a datagram socket.

//

// The methods in this class are defined in exactly the same order as in

// java.net.DatagramSocket so as to simplify tracking future changes to that

// class.

//

public class DatagramSocketAdaptor

    extends DatagramSocket

{

    // The channel being adapted

    private final DatagramChannelImpl dc;

    // Timeout "option" value for receives

    private volatile int timeout;

    // ## super will create a useless impl

    private DatagramSocketAdaptor(DatagramChannelImpl dc) throws IOException {

        // Invoke the DatagramSocketAdaptor(SocketAddress) constructor,

        // passing a dummy DatagramSocketImpl object to avoid any native

        // resource allocation in super class and invoking our bind method

        // before the dc field is initialized.

        super(dummyDatagramSocket);

        this.dc = dc;

    }

    public static DatagramSocket create(DatagramChannelImpl dc) {

        try {

            return new DatagramSocketAdaptor(dc);

        } catch (IOException x) {

            throw new Error(x);

        }

    }

    private void connectInternal(SocketAddress remote)

        throws SocketException

    {

        InetSocketAddress isa = Net.asInetSocketAddress(remote);

        int port = isa.getPort();

        if (port < 0 || port > 0xFFFF)

            throw new IllegalArgumentException("connect: " + port);

        if (remote == null)

            throw new IllegalArgumentException("connect: null address");

        try {

            dc.connect(remote);

        } catch (ClosedChannelException e) {

            // ignore

        } catch (Exception x) {

            Net.translateToSocketException(x);

        }

    }

    public void bind(SocketAddress local) throws SocketException {

        try {

            if (local == null)

                local = new InetSocketAddress(0);

            dc.bind(local);

        } catch (Exception x) {

            Net.translateToSocketException(x);

        }

    }

    public void connect(InetAddress address, int port) {

        try {

            connectInternal(new InetSocketAddress(address, port));

        } catch (SocketException x) {

            // Yes, j.n.DatagramSocket really does this

        }

    }

    public void connect(SocketAddress remote) throws SocketException {

        Objects.requireNonNull(remote, "Address can't be null");

        connectInternal(remote);

    }

    public void disconnect() {

        try {

            dc.disconnect();

        } catch (IOException x) {

            throw new Error(x);

        }

    }

    public boolean isBound() {

        return dc.localAddress() != null;

    }

    public boolean isConnected() {

        return dc.remoteAddress() != null;

    }

    public InetAddress getInetAddress() {

        InetSocketAddress remote = dc.remoteAddress();

        return (remote != null) ? remote.getAddress() : null;

    }

    public int getPort() {

        InetSocketAddress remote = dc.remoteAddress();

        return (remote != null) ? remote.getPort() : -1;

    }

    public void send(DatagramPacket p) throws IOException {

        synchronized (dc.blockingLock()) {

            if (!dc.isBlocking())

                throw new IllegalBlockingModeException();

            try {

                synchronized (p) {

                    ByteBuffer bb = ByteBuffer.wrap(p.getData(),

                                                    p.getOffset(),

                                                    p.getLength());

                    if (dc.isConnected()) {

                        if (p.getAddress() == null) {

                            // Legacy DatagramSocket will send in this case

                            // and set address and port of the packet

                            InetSocketAddress isa = dc.remoteAddress();

                            p.setPort(isa.getPort());

                            p.setAddress(isa.getAddress());

                            dc.write(bb);

                        } else {

                            // Target address may not match connected address

                            dc.send(bb, p.getSocketAddress());

                        }

                    } else {

                        // Not connected so address must be valid or throw

                        dc.send(bb, p.getSocketAddress());

                    }

                }

            } catch (IOException x) {

                Net.translateException(x);

            }

        }

    }

    private SocketAddress receive(ByteBuffer bb) throws IOException {

        assert Thread.holdsLock(dc.blockingLock()) && dc.isBlocking();

        long to = this.timeout;

        if (to == 0) {

            return dc.receive(bb);

        } else {

            for (;;) {

                if (!dc.isOpen())

                    throw new ClosedChannelException();

                long st = System.currentTimeMillis();

                if (dc.pollRead(to)) {

                    return dc.receive(bb);

                }

                to -= System.currentTimeMillis() - st;

                if (to <= 0)

                    throw new SocketTimeoutException();

            }

        }

    }

    public void receive(DatagramPacket p) throws IOException {

        synchronized (dc.blockingLock()) {

            if (!dc.isBlocking())

                throw new IllegalBlockingModeException();

            try {

                synchronized (p) {

                    ByteBuffer bb = ByteBuffer.wrap(p.getData(),

                                                    p.getOffset(),

                                                    p.getLength());

                    SocketAddress sender = receive(bb);

                    p.setSocketAddress(sender);

                    p.setLength(bb.position() - p.getOffset());

                }

            } catch (IOException x) {

                Net.translateException(x);

            }

        }

    }

    public InetAddress getLocalAddress() {

        if (isClosed())

            return null;

        InetSocketAddress local = dc.localAddress();

        if (local == null)

            local = new InetSocketAddress(0);

        InetAddress result = local.getAddress();

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            try {

                sm.checkConnect(result.getHostAddress(), -1);

            } catch (SecurityException x) {

                return new InetSocketAddress(0).getAddress();

            }

        }

        return result;

    }

    public int getLocalPort() {

        if (isClosed())

            return -1;

        try {

            InetSocketAddress local = dc.localAddress();

            if (local != null) {

                return local.getPort();

            }

        } catch (Exception x) {

        }

        return 0;

    }

    public void setSoTimeout(int timeout) throws SocketException {

        this.timeout = timeout;

    }

    public int getSoTimeout() throws SocketException {

        return timeout;

    }

    private void setBooleanOption(SocketOption<Boolean> name, boolean value)

        throws SocketException

    {

        try {

            dc.setOption(name, value);

        } catch (IOException x) {

            Net.translateToSocketException(x);

        }

    }

    private void setIntOption(SocketOption<Integer> name, int value)

        throws SocketException

    {

        try {

            dc.setOption(name, value);

        } catch (IOException x) {

            Net.translateToSocketException(x);

        }

    }

    private boolean getBooleanOption(SocketOption<Boolean> name) throws SocketException {

        try {

            return dc.getOption(name).booleanValue();

        } catch (IOException x) {

            Net.translateToSocketException(x);

            return false;       // keep compiler happy

        }

    }

    private int getIntOption(SocketOption<Integer> name) throws SocketException {

        try {

            return dc.getOption(name).intValue();

        } catch (IOException x) {

            Net.translateToSocketException(x);

            return -1;          // keep compiler happy

        }

    }

    public void setSendBufferSize(int size) throws SocketException {

        if (size <= 0)

            throw new IllegalArgumentException("Invalid send size");

        setIntOption(StandardSocketOptions.SO_SNDBUF, size);

    }

    public int getSendBufferSize() throws SocketException {

        return getIntOption(StandardSocketOptions.SO_SNDBUF);

    }

    public void setReceiveBufferSize(int size) throws SocketException {

        if (size <= 0)

            throw new IllegalArgumentException("Invalid receive size");

        setIntOption(StandardSocketOptions.SO_RCVBUF, size);

    }

    public int getReceiveBufferSize() throws SocketException {

        return getIntOption(StandardSocketOptions.SO_RCVBUF);

    }

    public void setReuseAddress(boolean on) throws SocketException {

        setBooleanOption(StandardSocketOptions.SO_REUSEADDR, on);

    }

    public boolean getReuseAddress() throws SocketException {

        return getBooleanOption(StandardSocketOptions.SO_REUSEADDR);

    }

    public void setBroadcast(boolean on) throws SocketException {

        setBooleanOption(StandardSocketOptions.SO_BROADCAST, on);

    }

    public boolean getBroadcast() throws SocketException {

        return getBooleanOption(StandardSocketOptions.SO_BROADCAST);

    }

    public void setTrafficClass(int tc) throws SocketException {

        setIntOption(StandardSocketOptions.IP_TOS, tc);

    }

    public int getTrafficClass() throws SocketException {

        return getIntOption(StandardSocketOptions.IP_TOS);

    }

    public void close() {

        try {

            dc.close();

        } catch (IOException x) {

            throw new Error(x);

        }

    }

    public boolean isClosed() {

        return !dc.isOpen();

    }

    public DatagramChannel getChannel() {

        return dc;

    }

   /*

    * A dummy implementation of DatagramSocketImpl that can be passed to the

    * DatagramSocket constructor so that no native resources are allocated in

    * super class.

    */

   private static final DatagramSocketImpl dummyDatagramSocket

       = new DatagramSocketImpl()

   {

       protected void create() throws SocketException {}

       protected void bind(int lport, InetAddress laddr) throws SocketException {}

       protected void send(DatagramPacket p) throws IOException {}

       protected int peek(InetAddress i) throws IOException { return 0; }

       protected int peekData(DatagramPacket p) throws IOException { return 0; }

       protected void receive(DatagramPacket p) throws IOException {}

       @Deprecated

       protected void setTTL(byte ttl) throws IOException {}

       @Deprecated

       protected byte getTTL() throws IOException { return 0; }

       protected void setTimeToLive(int ttl) throws IOException {}

       protected int getTimeToLive() throws IOException { return 0;}

       protected void join(InetAddress inetaddr) throws IOException {}

       protected void leave(InetAddress inetaddr) throws IOException {}

       protected void joinGroup(SocketAddress mcastaddr,

                                 NetworkInterface netIf) throws IOException {}

       protected void leaveGroup(SocketAddress mcastaddr,

                                 NetworkInterface netIf) throws IOException {}

       protected void close() {}

       public Object getOption(int optID) throws SocketException { return null;}

       public void setOption(int optID, Object value) throws SocketException {}

   };

}