/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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 org.apache.dubbo.remoting.transport.netty;

import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.Version;
import org.apache.dubbo.common.logger.ErrorTypeAwareLogger;
import org.apache.dubbo.common.logger.LoggerFactory;
import org.apache.dubbo.common.utils.NamedThreadFactory;
import org.apache.dubbo.common.utils.NetUtils;
import org.apache.dubbo.remoting.ChannelHandler;
import org.apache.dubbo.remoting.Constants;
import org.apache.dubbo.remoting.RemotingException;
import org.apache.dubbo.remoting.transport.AbstractClient;

import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFactory;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;

import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static org.apache.dubbo.common.constants.LoggerCodeConstants.TRANSPORT_CLIENT_CONNECT_TIMEOUT;
import static org.apache.dubbo.common.constants.LoggerCodeConstants.TRANSPORT_FAILED_CONNECT_PROVIDER;
import static org.apache.dubbo.common.constants.LoggerCodeConstants.TRANSPORT_FAILED_DISCONNECT_PROVIDER;

/**
 * NettyClient.
 */
public class NettyClient extends AbstractClient {

    private static final ErrorTypeAwareLogger logger = LoggerFactory.getErrorTypeAwareLogger(NettyClient.class);

    // ChannelFactory's closure has a DirectMemory leak, using static to avoid
    // https://issues.jboss.org/browse/NETTY-424
    private static final ChannelFactory CHANNEL_FACTORY = new NioClientSocketChannelFactory(Executors.newCachedThreadPool(new NamedThreadFactory("NettyClientBoss", true)),
        Executors.newCachedThreadPool(new NamedThreadFactory("NettyClientWorker", true)),
        Constants.DEFAULT_IO_THREADS);
    private ClientBootstrap bootstrap;

    private volatile Channel channel; // volatile, please copy reference to use

    public NettyClient(final URL url, final ChannelHandler handler) throws RemotingException {
        super(url, wrapChannelHandler(url, handler));
    }

    @Override
    protected void doOpen() throws Throwable {
        NettyHelper.setNettyLoggerFactory();
        bootstrap = new ClientBootstrap(CHANNEL_FACTORY);
        // config
        // @see org.jboss.netty.channel.socket.SocketChannelConfig
        bootstrap.setOption("keepAlive", true);
        bootstrap.setOption("tcpNoDelay", true);
        bootstrap.setOption("connectTimeoutMillis", getConnectTimeout());
        final NettyHandler nettyHandler = new NettyHandler(getUrl(), this);
        bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
            @Override
            public ChannelPipeline getPipeline() {
                NettyCodecAdapter adapter = new NettyCodecAdapter(getCodec(), getUrl(), NettyClient.this);
                ChannelPipeline pipeline = Channels.pipeline();
                pipeline.addLast("decoder", adapter.getDecoder());
                pipeline.addLast("encoder", adapter.getEncoder());
                pipeline.addLast("handler", nettyHandler);
                return pipeline;
            }
        });
    }

    @Override
    protected void doConnect() throws Throwable {
        long start = System.currentTimeMillis();
        ChannelFuture future = bootstrap.connect(getConnectAddress());
        try {
            boolean ret = future.awaitUninterruptibly(getConnectTimeout(), TimeUnit.MILLISECONDS);

            if (ret && future.isSuccess()) {
                Channel newChannel = future.getChannel();
                newChannel.setInterestOps(Channel.OP_READ_WRITE);
                try {
                    // Close old channel
                    Channel oldChannel = NettyClient.this.channel; // copy reference
                    if (oldChannel != null) {
                        try {
                            if (logger.isInfoEnabled()) {
                                logger.info("Close old netty channel " + oldChannel + " on create new netty channel " + newChannel);
                            }
                            oldChannel.close();
                        } finally {
                            NettyChannel.removeChannelIfDisconnected(oldChannel);
                        }
                    }
                } finally {
                    if (NettyClient.this.isClosed()) {
                        try {
                            if (logger.isInfoEnabled()) {
                                logger.info("Close new netty channel " + newChannel + ", because the client closed.");
                            }
                            newChannel.close();
                        } finally {
                            NettyClient.this.channel = null;
                            NettyChannel.removeChannelIfDisconnected(newChannel);
                        }
                    } else {
                        NettyClient.this.channel = newChannel;
                    }
                }
            } else if (future.getCause() != null) {
                Throwable cause = future.getCause();

                RemotingException remotingException = new RemotingException(this, "client(url: " + getUrl() + ") failed to connect to server "
                    + getRemoteAddress() + ", error message is:" + cause.getMessage(), cause);

                // 6-1 - Failed to connect to provider server by other reason.
                logger.error(TRANSPORT_FAILED_CONNECT_PROVIDER, "network disconnected", "", "Failed to connect to provider server by other reason.", cause);

                throw remotingException;
            } else {

                RemotingException remotingException = new RemotingException(this, "client(url: " + getUrl() + ") failed to connect to server "
                    + getRemoteAddress() + " client-side timeout "
                    + getConnectTimeout() + "ms (elapsed: " + (System.currentTimeMillis() - start) + "ms) from netty client "
                    + NetUtils.getLocalHost() + " using dubbo version " + Version.getVersion());

                // 6-2 - Client-side timeout.
                logger.error(TRANSPORT_CLIENT_CONNECT_TIMEOUT, "provider crash", "", "Client-side timeout.", remotingException);

                throw remotingException;
            }
        } finally {
            if (!isConnected()) {
                future.cancel();
            }
        }
    }

    @Override
    protected void doDisConnect() throws Throwable {
        try {
            NettyChannel.removeChannelIfDisconnected(channel);
        } catch (Throwable t) {
            logger.warn(TRANSPORT_FAILED_DISCONNECT_PROVIDER, "", "", t.getMessage());
        }
    }

    @Override
    protected void doClose() throws Throwable {
        /*try {
            bootstrap.releaseExternalResources();
        } catch (Throwable t) {
            logger.warn(t.getMessage());
        }*/
    }

    @Override
    protected org.apache.dubbo.remoting.Channel getChannel() {
        Channel c = channel;
        if (c == null || !c.isConnected()) {
            return null;
        }
        return NettyChannel.getOrAddChannel(c, getUrl(), this);
    }

    Channel getNettyChannel() {
        return channel;
    }

}
