/*

 * Copyright (c) 2000, 2019, 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.FileDescriptor;

import java.io.IOException;

import java.io.UncheckedIOException;

import java.net.ProtocolFamily;

import java.net.Socket;

import java.net.SocketAddress;

import java.net.SocketException;

import java.net.SocketOption;

import java.net.SocketTimeoutException;

import java.net.StandardProtocolFamily;

import java.net.StandardSocketOptions;

import java.nio.ByteBuffer;

import java.nio.channels.AlreadyBoundException;

import java.nio.channels.AlreadyConnectedException;

import java.nio.channels.AsynchronousCloseException;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.ConnectionPendingException;

import java.nio.channels.IllegalBlockingModeException;

import java.nio.channels.NoConnectionPendingException;

import java.nio.channels.NotYetConnectedException;

import java.nio.channels.SelectionKey;

import java.nio.channels.SocketChannel;

import java.nio.channels.UnixDomainSocketAddress;

import java.nio.channels.spi.SelectorProvider;

import java.security.AccessController;

import java.util.Collections;

import java.util.HashSet;

import java.util.Objects;

import java.util.Set;

import java.util.concurrent.locks.ReentrantLock;

import sun.net.ConnectionResetException;

import sun.net.NetHooks;

import sun.net.ext.ExtendedSocketOptions;

import sun.net.util.SocketExceptions;

/**

 * An implementation of SocketChannels

 */

public class UnixDomainSocketChannelImpl extends SocketChannelImpl

{

    public UnixDomainSocketChannelImpl(SelectorProvider sp, FileDescriptor fd, boolean bound)

        throws IOException

    {

        super(sp, fd);

        if (bound) {

            synchronized (stateLock) {

                this.localAddress = Net.localUnixAddress(fd);

            }

        }

    }

    // Constructor for sockets obtained from server sockets

    //

    UnixDomainSocketChannelImpl(SelectorProvider sp, FileDescriptor fd, SocketAddress isa)

        throws IOException

    {

        super(sp, fd);

        synchronized (stateLock) {

            this.localAddress = Net.localUnixAddress(fd);

            this.remoteAddress = isa;

            this.state = ST_CONNECTED;

        }

    }

    @Override

    public SocketAddress getLocalAddress() throws IOException {

        synchronized (stateLock) {

            ensureOpen();

            return localAddress; // TODO: revealed local address?

        }

    }

    @Override

    public SocketAddress getRemoteAddress() throws IOException {

        synchronized (stateLock) {

            ensureOpen();

            return remoteAddress;

        }

    }

    @Override

    public <T> SocketChannel setOption(SocketOption<T> name, T value)

        throws IOException

    {

        Objects.requireNonNull(name);

        if (!supportedOptions().contains(name))

            throw new UnsupportedOperationException("'" + name + "' not supported");

        if (!name.type().isInstance(value))

            throw new IllegalArgumentException("Invalid value '" + value + "'");

        synchronized (stateLock) {

            ensureOpen();

            // no options that require special handling

            Net.setSocketOption(fd, name, value);

            return this;

        }

    }

    @Override

    @SuppressWarnings("unchecked")

    public <T> T getOption(SocketOption<T> name)

        throws IOException

    {

        Objects.requireNonNull(name);

        if (!supportedOptions().contains(name))

            throw new UnsupportedOperationException("'" + name + "' not supported");

        synchronized (stateLock) {

            ensureOpen();

            // no options that require special handling

            return (T) Net.getSocketOption(fd, name); // AF_UNIX

        }

    }

    private static class DefaultOptionsHolder {

        static final Set<SocketOption<?>> defaultOptions = defaultOptions();

        private static Set<SocketOption<?>> defaultOptions() {

            HashSet<SocketOption<?>> set = new HashSet<>();

            set.add(StandardSocketOptions.SO_SNDBUF);

            set.add(StandardSocketOptions.SO_RCVBUF);

            set.add(StandardSocketOptions.SO_KEEPALIVE);

            set.add(StandardSocketOptions.SO_LINGER);

            return Collections.unmodifiableSet(set);

        }

    }

    @Override

    public final Set<SocketOption<?>> supportedOptions() {

        return DefaultOptionsHolder.defaultOptions;

    }

    @Override

    public SocketChannel bind(SocketAddress local) throws IOException {

        readLock.lock();

        try {

            writeLock.lock();

            try {

                synchronized (stateLock) {

                    ensureOpen();

                    if (state == ST_CONNECTIONPENDING)

                        throw new ConnectionPendingException();

                    if (localAddress != null)

                        throw new AlreadyBoundException();

                    if (local == null)

                        throw new NullPointerException(); // TODO: ??

                    UnixDomainSocketAddress usa = Net.checkUnixAddress(local);

                    Net.unixDomainBind(fd, usa);

                    localAddress = Net.localUnixAddress(fd);

                }

            } finally {

                writeLock.unlock();

            }

        } finally {

            readLock.unlock();

        }

        return this;

    }

    public Socket socket() {

        throw new UnsupportedOperationException("socket not supported");

    }

    /**

     * Checks the remote address to which this channel is to be connected.

     */

    @Override

    SocketAddress checkRemote(SocketAddress sa) throws IOException {

        SocketAddress isa = Net.checkUnixAddress(sa);

        return isa; // TODO

    }

    @Override

    int connectImpl(FileDescriptor fd, SocketAddress sa) throws IOException {

        UnixDomainSocketAddress isa = (UnixDomainSocketAddress)sa;

        return Net.unixDomainConnect(fd, isa);

    }

    @Override

    SocketAddress localAddressImpl(FileDescriptor fd) throws IOException {

        return Net.localUnixAddress(fd);

    }

    String getRevealedLocalAddressAsString(SocketAddress sa) {

        return sa.toString(); // TODO

    }

}