/*
 * 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.rpc.protocol.webservice;

import org.apache.dubbo.common.URL;
import org.apache.dubbo.remoting.Constants;
import org.apache.dubbo.remoting.http.HttpBinder;
import org.apache.dubbo.remoting.http.HttpHandler;
import org.apache.dubbo.remoting.http.HttpServer;
import org.apache.dubbo.remoting.http.servlet.DispatcherServlet;
import org.apache.dubbo.rpc.RpcContext;
import org.apache.dubbo.rpc.RpcException;
import org.apache.dubbo.rpc.protocol.AbstractProxyProtocol;

import org.apache.cxf.bus.extension.ExtensionManagerBus;
import org.apache.cxf.endpoint.Client;
import org.apache.cxf.frontend.ClientProxy;
import org.apache.cxf.frontend.ClientProxyFactoryBean;
import org.apache.cxf.frontend.ServerFactoryBean;
import org.apache.cxf.interceptor.Fault;
import org.apache.cxf.transport.http.HTTPConduit;
import org.apache.cxf.transport.http.HTTPTransportFactory;
import org.apache.cxf.transport.http.HttpDestinationFactory;
import org.apache.cxf.transport.servlet.ServletController;
import org.apache.cxf.transport.servlet.ServletDestinationFactory;
import org.apache.cxf.transports.http.configuration.HTTPClientPolicy;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.SocketTimeoutException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import static org.apache.dubbo.common.constants.CommonConstants.DEFAULT_TIMEOUT;
import static org.apache.dubbo.common.constants.CommonConstants.TIMEOUT_KEY;

/**
 * WebServiceProtocol.
 */
public class WebServiceProtocol extends AbstractProxyProtocol {

    public static final int DEFAULT_PORT = 80;

    private final Map<String, HttpServer> serverMap = new ConcurrentHashMap<String, HttpServer>();

    private final ExtensionManagerBus bus = new ExtensionManagerBus();

    private final HTTPTransportFactory transportFactory = new HTTPTransportFactory();

    private HttpBinder httpBinder;

    public WebServiceProtocol() {
        super(Fault.class);
        bus.setExtension(new ServletDestinationFactory(), HttpDestinationFactory.class);
    }

    public void setHttpBinder(HttpBinder httpBinder) {
        this.httpBinder = httpBinder;
    }

    @Override
    public int getDefaultPort() {
        return DEFAULT_PORT;
    }

    @Override
    protected <T> Runnable doExport(T impl, Class<T> type, URL url) throws RpcException {
        String addr = getAddr(url);
        HttpServer httpServer = serverMap.get(addr);
        if (httpServer == null) {
            httpServer = httpBinder.bind(url, new WebServiceHandler());
            serverMap.put(addr, httpServer);
        }
        final ServerFactoryBean serverFactoryBean = new ServerFactoryBean();
        serverFactoryBean.setAddress(url.getAbsolutePath());
        serverFactoryBean.setServiceClass(type);
        serverFactoryBean.setServiceBean(impl);
        serverFactoryBean.setBus(bus);
        serverFactoryBean.setDestinationFactory(transportFactory);
        serverFactoryBean.create();
        return new Runnable() {
            @Override
            public void run() {
                if(serverFactoryBean.getServer()!= null) {
                    serverFactoryBean.getServer().destroy();
                }
                if(serverFactoryBean.getBus()!=null) {
                    serverFactoryBean.getBus().shutdown(true);
                }
            }
        };
    }

    @Override
    @SuppressWarnings("unchecked")
    protected <T> T doRefer(final Class<T> serviceType, final URL url) throws RpcException {
        ClientProxyFactoryBean proxyFactoryBean = new ClientProxyFactoryBean();
        proxyFactoryBean.setAddress(url.setProtocol("http").toIdentityString());
        proxyFactoryBean.setServiceClass(serviceType);
        proxyFactoryBean.setBus(bus);
        T ref = (T) proxyFactoryBean.create();
        Client proxy = ClientProxy.getClient(ref);
        HTTPConduit conduit = (HTTPConduit) proxy.getConduit();
        HTTPClientPolicy policy = new HTTPClientPolicy();
        policy.setConnectionTimeout(url.getParameter(Constants.CONNECT_TIMEOUT_KEY, Constants.DEFAULT_CONNECT_TIMEOUT));
        policy.setReceiveTimeout(url.getParameter(TIMEOUT_KEY, DEFAULT_TIMEOUT));
        conduit.setClient(policy);
        return ref;
    }

    @Override
    protected int getErrorCode(Throwable e) {
        if (e instanceof Fault) {
            e = e.getCause();
        }
        if (e instanceof SocketTimeoutException) {
            return RpcException.TIMEOUT_EXCEPTION;
        } else if (e instanceof IOException) {
            return RpcException.NETWORK_EXCEPTION;
        }
        return super.getErrorCode(e);
    }

    private class WebServiceHandler implements HttpHandler {

        private volatile ServletController servletController;

        @Override
        public void handle(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
            if (servletController == null) {
                HttpServlet httpServlet = DispatcherServlet.getInstance();
                if (httpServlet == null) {
                    response.sendError(500, "No such DispatcherServlet instance.");
                    return;
                }
                synchronized (this) {
                    if (servletController == null) {
                        servletController = new ServletController(transportFactory.getRegistry(), httpServlet.getServletConfig(), httpServlet);
                    }
                }
            }
            RpcContext.getContext().setRemoteAddress(request.getRemoteAddr(), request.getRemotePort());
            servletController.invoke(request, response);
        }

    }

}
