package cn.com.chinabank.shared.protocol.learn;

import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.Parameters;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import com.alibaba.dubbo.common.utils.NetUtils;
import com.alibaba.dubbo.remoting.ChannelHandler;
import com.alibaba.dubbo.remoting.RemotingException;
import com.alibaba.dubbo.remoting.exchange.ExchangeClient;
import com.alibaba.dubbo.remoting.exchange.ExchangeHandler;
import com.alibaba.dubbo.remoting.exchange.Exchangers;
import com.alibaba.dubbo.remoting.exchange.ResponseFuture;

import java.net.InetSocketAddress;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Created with IntelliJ IDEA.
 * User: baowp
 * Date: 1/10/14
 * Time: 3:29 PM
 */
final class LazyConnectExchangeClient implements ExchangeClient {

    private final static Logger logger = LoggerFactory.getLogger(LazyConnectExchangeClient.class);

    private final URL url;
    private final ExchangeHandler requestHandler;
    private volatile ExchangeClient       client;
    private final Lock connectLock = new ReentrantLock();
    //lazy connect 如果没有初始化时的连接状态
    private final boolean                 initialState ;

    protected final  boolean requestWithWarning;

    //当调用时warning，出现这个warning，表示程序可能存在bug.
    static final  String REQUEST_WITH_WARNING_KEY = "lazyclient_request_with_warning";

    private AtomicLong warningcount = new AtomicLong(0);

    public LazyConnectExchangeClient(URL url, ExchangeHandler requestHandler) {
        //lazy connect ,need set send.reconnect = true, to avoid channel bad status.
        this.url = url.addParameter(Constants.SEND_RECONNECT_KEY, Boolean.TRUE.toString());
        this.requestHandler = requestHandler;
        this.initialState = url.getParameter(Constants.LAZY_CONNECT_INITIAL_STATE_KEY,Constants.DEFAULT_LAZY_CONNECT_INITIAL_STATE);
        this.requestWithWarning = url.getParameter(REQUEST_WITH_WARNING_KEY, false);
    }


    private void initClient() throws RemotingException {
        if (client != null )
            return;
        if (logger.isInfoEnabled()) {
            logger.info("Lazy connect to " + url);
        }
        connectLock.lock();
        try {
            if (client != null)
                return;
            this.client = Exchangers.connect(url, requestHandler);
        } finally {
            connectLock.unlock();
        }
    }

    public ResponseFuture request(Object request) throws RemotingException {
        warning(request);
        initClient();
        return client.request(request);
    }

    public URL getUrl() {
        return url;
    }

    public InetSocketAddress getRemoteAddress() {
        if (client == null){
            return InetSocketAddress.createUnresolved(url.getHost(), url.getPort());
        } else {
            return client.getRemoteAddress();
        }
    }
    public ResponseFuture request(Object request, int timeout) throws RemotingException {
        warning(request);
        initClient();
        return client.request(request, timeout);
    }

    /**
     * 如果配置了调用warning，则每调用5000次warning一次.
     * @param request
     */
    private void warning(Object request){
        if (requestWithWarning ){
            if (warningcount.get() % 5000 == 0){
                logger.warn(new IllegalStateException("safe guard client , should not be called ,must have a bug."));
            }
            warningcount.incrementAndGet() ;
        }
    }

    public ChannelHandler getChannelHandler() {
        checkClient();
        return client.getChannelHandler();
    }

    public boolean isConnected() {
        if (client == null) {
            return initialState;
        } else {
            return client.isConnected();
        }
    }

    public InetSocketAddress getLocalAddress() {
        if (client == null){
            return InetSocketAddress.createUnresolved(NetUtils.getLocalHost(), 0);
        } else {
            return client.getLocalAddress();
        }
    }

    public ExchangeHandler getExchangeHandler() {
        return requestHandler;
    }

    public void send(Object message) throws RemotingException {
        initClient();
        client.send(message);
    }

    public void send(Object message, boolean sent) throws RemotingException {
        initClient();
        client.send(message, sent);
    }

    public boolean isClosed() {
        if (client != null)
            return client.isClosed();
        else
            return true;
    }

    public void close() {
        if (client != null)
            client.close();
    }

    public void close(int timeout) {
        if (client != null)
            client.close(timeout);
    }

    public void reset(URL url) {
        checkClient();
        client.reset(url);
    }

    @Deprecated
    public void reset(Parameters parameters){
        reset(getUrl().addParameters(parameters.getParameters()));
    }

    public void reconnect() throws RemotingException {
        checkClient();
        client.reconnect();
    }

    public Object getAttribute(String key) {
        if (client == null){
            return null;
        } else {
            return client.getAttribute(key);
        }
    }

    public void setAttribute(String key, Object value) {
        checkClient();
        client.setAttribute(key, value);
    }

    public void removeAttribute(String key) {
        checkClient();
        client.removeAttribute(key);
    }

    public boolean hasAttribute(String key) {
        if (client == null){
            return false;
        } else {
            return client.hasAttribute(key);
        }
    }

    private void checkClient() {
        if (client == null) {
            throw new IllegalStateException(
                    "LazyConnectExchangeClient state error. the client has not be init .url:" + url);
        }
    }
}
