/*
 * Copyright 2011 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.channel.sctp.nio;

import com.sun.nio.sctp.SctpChannel;
import com.sun.nio.sctp.SctpServerChannel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.channel.ChannelPromise;
import io.netty.channel.nio.AbstractNioMessageChannel;
import io.netty.channel.sctp.DefaultSctpServerChannelConfig;
import io.netty.channel.sctp.SctpServerChannelConfig;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.nio.channels.SelectionKey;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

SctpServerChannel implementation which use non-blocking mode to accept new connections and create the NioSctpChannel for them. Be aware that not all operations systems support SCTP. Please refer to the documentation of your operation system, to understand what you need to do to use it. Also this feature is only supported on Java 7+. /**
 * {@link io.netty.channel.sctp.SctpServerChannel} implementation which use non-blocking mode to accept new
 * connections and create the {@link NioSctpChannel} for them.
 *
 * Be aware that not all operations systems support SCTP. Please refer to the documentation of your operation system,
 * to understand what you need to do to use it. Also this feature is only supported on Java 7+.
 */
public class NioSctpServerChannel extends AbstractNioMessageChannel
        implements io.netty.channel.sctp.SctpServerChannel {
    private static final ChannelMetadata METADATA = new ChannelMetadata(false, 16);

    private static SctpServerChannel newSocket() {
        try {
            return SctpServerChannel.open();
        } catch (IOException e) {
            throw new ChannelException(
                    "Failed to open a server socket.", e);
        }
    }

    private final SctpServerChannelConfig config;

    
Create a new instance
/**
     * Create a new instance
     */
    public NioSctpServerChannel() {
        super(null, newSocket(), SelectionKey.OP_ACCEPT);
        config = new NioSctpServerChannelConfig(this, javaChannel());
    }

    @Override
    public ChannelMetadata metadata() {
        return METADATA;
    }

    @Override
    public Set<InetSocketAddress> allLocalAddresses() {
        try {
            final Set<SocketAddress> allLocalAddresses = javaChannel().getAllLocalAddresses();
            final Set<InetSocketAddress> addresses = new LinkedHashSet<InetSocketAddress>(allLocalAddresses.size());
            for (SocketAddress socketAddress : allLocalAddresses) {
                addresses.add((InetSocketAddress) socketAddress);
            }
            return addresses;
        } catch (Throwable ignored) {
            return Collections.emptySet();
        }
    }

    @Override
    public SctpServerChannelConfig config() {
        return config;
    }

    @Override
    public boolean isActive() {
        return isOpen() && !allLocalAddresses().isEmpty();
    }

    @Override
    public InetSocketAddress remoteAddress() {
        return null;
    }

    @Override
    public InetSocketAddress localAddress() {
        return (InetSocketAddress) super.localAddress();
    }

    @Override
    protected SctpServerChannel javaChannel() {
        return (SctpServerChannel) super.javaChannel();
    }

    @Override
    protected SocketAddress localAddress0() {
        try {
            Iterator<SocketAddress> i = javaChannel().getAllLocalAddresses().iterator();
            if (i.hasNext()) {
                return i.next();
            }
        } catch (IOException e) {
            // ignore
        }
        return null;
    }

    @Override
    protected void doBind(SocketAddress localAddress) throws Exception {
        javaChannel().bind(localAddress, config.getBacklog());
    }

    @Override
    protected void doClose() throws Exception {
        javaChannel().close();
    }

    @Override
    protected int doReadMessages(List<Object> buf) throws Exception {
        SctpChannel ch = javaChannel().accept();
        if (ch == null) {
            return 0;
        }
        buf.add(new NioSctpChannel(this, ch));
        return 1;
    }

    @Override
    public ChannelFuture bindAddress(InetAddress localAddress) {
        return bindAddress(localAddress, newPromise());
    }

    @Override
    public ChannelFuture bindAddress(final InetAddress localAddress, final ChannelPromise promise) {
        if (eventLoop().inEventLoop()) {
            try {
                javaChannel().bindAddress(localAddress);
                promise.setSuccess();
            } catch (Throwable t) {
                promise.setFailure(t);
            }
        } else {
            eventLoop().execute(new Runnable() {
                @Override
                public void run() {
                    bindAddress(localAddress, promise);
                }
            });
        }
        return promise;
    }

    @Override
    public ChannelFuture unbindAddress(InetAddress localAddress) {
        return unbindAddress(localAddress, newPromise());
    }

    @Override
    public ChannelFuture unbindAddress(final InetAddress localAddress, final ChannelPromise promise) {
        if (eventLoop().inEventLoop()) {
            try {
                javaChannel().unbindAddress(localAddress);
                promise.setSuccess();
            } catch (Throwable t) {
                promise.setFailure(t);
            }
        } else {
            eventLoop().execute(new Runnable() {
                @Override
                public void run() {
                    unbindAddress(localAddress, promise);
                }
            });
        }
        return promise;
    }

    // Unnecessary stuff
    @Override
    protected boolean doConnect(
            SocketAddress remoteAddress, SocketAddress localAddress) throws Exception {
        throw new UnsupportedOperationException();
    }

    @Override
    protected void doFinishConnect() throws Exception {
        throw new UnsupportedOperationException();
    }

    @Override
    protected SocketAddress remoteAddress0() {
        return null;
    }

    @Override
    protected void doDisconnect() throws Exception {
        throw new UnsupportedOperationException();
    }

    @Override
    protected boolean doWriteMessage(Object msg, ChannelOutboundBuffer in) throws Exception {
        throw new UnsupportedOperationException();
    }

    @Override
    protected Object filterOutboundMessage(Object msg) throws Exception {
        throw new UnsupportedOperationException();
    }

    private final class NioSctpServerChannelConfig extends DefaultSctpServerChannelConfig {
        private NioSctpServerChannelConfig(NioSctpServerChannel channel, SctpServerChannel javaChannel) {
            super(channel, javaChannel);
        }

        @Override
        protected void autoReadCleared() {
            clearReadPending();
        }
    }
}