/*

  * Copyright 2006-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.ksb.messaging.serviceconnectors;

 import java.io.IOException;

 import java.net.SocketException;

 import java.net.SocketTimeoutException;

 import java.net.URL;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.Map;

 import java.util.Properties;

 import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;

 import org.apache.commons.httpclient.HostConfiguration;

 import org.apache.commons.httpclient.HttpClient;

 import org.apache.commons.httpclient.HttpMethod;

 import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;

 import org.apache.commons.httpclient.cookie.CookiePolicy;

 import org.apache.commons.httpclient.params.HttpClientParams;

 import org.apache.commons.httpclient.params.HttpConnectionManagerParams;

 import org.apache.commons.httpclient.params.HttpConnectionParams;

 import org.apache.commons.httpclient.params.HttpMethodParams;

 import org.apache.commons.httpclient.params.HttpParams;

 import org.apache.commons.httpclient.util.IdleConnectionTimeoutThread;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.config.property.ConfigContext;

 import org.kuali.rice.ksb.api.bus.support.JavaServiceConfiguration;

 import org.kuali.rice.ksb.messaging.HttpClientHelper;

 import org.kuali.rice.ksb.messaging.KSBHttpInvokerProxyFactoryBean;

 import org.kuali.rice.ksb.messaging.KSBHttpInvokerRequestExecutor;

 import org.kuali.rice.ksb.security.httpinvoker.AuthenticationCommonsHttpInvokerRequestExecutor;

 /**

  * @author Kuali Rice Team (rice.collab@kuali.org)

  * @since 0.9

  */

 public class HttpInvokerConnector extends AbstractServiceConnector {

         private static final Logger LOG = Logger.getLogger(HttpInvokerConnector.class);

         private HttpClientParams httpClientParams;

         private boolean httpClientInitialized = false;

         private static final String IDLE_CONNECTION_THREAD_INTERVAL_PROPERTY = "ksb.thinClient.idleConnectionThreadInterval";

         private static final String IDLE_CONNECTION_TIMEOUT_PROPERTY = "ksb.thinClient.idleConnectionTimeout";

         private static final String DEFAULT_IDLE_CONNECTION_THREAD_INTERVAL = "7500";

         private static final String DEFAULT_IDLE_CONNECTION_TIMEOUT = "5000";

         private static final String RETRY_SOCKET_EXCEPTION_PROPERTY = "ksb.thinClient.retrySocketException";

         private static IdleConnectionTimeoutThread ictt;

         public HttpInvokerConnector(final JavaServiceConfiguration serviceConfiguration, final URL alternateEndpointUrl) {

                 super(serviceConfiguration, alternateEndpointUrl);

                 initializeHttpClientParams();

         }

         protected JavaServiceConfiguration getJavaServiceConfiguration() {

                 return (JavaServiceConfiguration)getServiceConfiguration();

         }

         public Object getService() {

             LOG.debug("Getting connector for endpoint " + getActualEndpointUrl());

                 KSBHttpInvokerProxyFactoryBean client = new KSBHttpInvokerProxyFactoryBean();

                 client.setServiceUrl(getActualEndpointUrl().toExternalForm());

                 client.setServiceConfiguration(getJavaServiceConfiguration());

                 KSBHttpInvokerRequestExecutor executor;

                 if (getCredentialsSource() != null) {

                     executor = new AuthenticationCommonsHttpInvokerRequestExecutor(getHttpClient(), getCredentialsSource(), getJavaServiceConfiguration());

                 } else {

                     executor = new KSBHttpInvokerRequestExecutor(getHttpClient());

                 }

                 executor.setSecure(getJavaServiceConfiguration().getBusSecurity());

                 client.setHttpInvokerRequestExecutor(executor);        

                 client.afterPropertiesSet();

                 return getServiceProxyWithFailureMode(client.getObject(), getJavaServiceConfiguration());

         }

         /**

          * Creates a commons HttpClient for service invocation. Config parameters

          * that start with http.* are used to configure the client.

          * 

          * TODO we need to add support for other invocation protocols and

          * implementations, but for now...

          */

         public HttpClient getHttpClient() {

                 return new HttpClient(this.httpClientParams);

         }

         protected void initializeHttpClientParams() {

                 synchronized (HttpInvokerConnector.class) {

                 if (! this.httpClientInitialized) {

                     this.httpClientParams = new HttpClientParams();

                         configureDefaultHttpClientParams(this.httpClientParams);

                         Properties configProps = ConfigContext.getCurrentContextConfig().getProperties();

                         for (Iterator<Object> iterator = configProps.keySet().iterator(); iterator.hasNext();) {

                                 String paramName = (String) iterator.next();

                                 if (paramName.startsWith("http.")) {

                                         HttpClientHelper.setParameter(this.httpClientParams, paramName, (String) configProps.get(paramName));

                                 }

                         }

                                 runIdleConnectionTimeout();

                         this.httpClientInitialized = true;

                 }

         }

         }

         protected void configureDefaultHttpClientParams(HttpParams params) {

                 params.setParameter(HttpClientParams.CONNECTION_MANAGER_CLASS, MultiThreadedHttpConnectionManager.class);

                 params.setParameter(HttpMethodParams.COOKIE_POLICY, CookiePolicy.RFC_2109);

                 params.setLongParameter(HttpClientParams.CONNECTION_MANAGER_TIMEOUT, 10000);

                 Map<HostConfiguration, Integer> maxHostConnectionsMap = new HashMap<HostConfiguration, Integer>();

                 maxHostConnectionsMap.put(HostConfiguration.ANY_HOST_CONFIGURATION, new Integer(20));

                 params.setParameter(HttpConnectionManagerParams.MAX_HOST_CONNECTIONS, maxHostConnectionsMap);

                 params.setIntParameter(HttpConnectionManagerParams.MAX_TOTAL_CONNECTIONS, 20);

                 params.setIntParameter(HttpConnectionParams.CONNECTION_TIMEOUT, 10000);

                 params.setIntParameter(HttpConnectionParams.SO_TIMEOUT, 2*60*1000);

                 boolean retrySocketException = new Boolean(ConfigContext.getCurrentContextConfig().getProperty(RETRY_SOCKET_EXCEPTION_PROPERTY));

                 if (retrySocketException) {

                     LOG.info("Installing custom HTTP retry handler to retry requests in face of SocketExceptions");

                     params.setParameter(HttpMethodParams.RETRY_HANDLER, new CustomHttpMethodRetryHandler());

                 }

         }

         /**

          * Idle connection timeout thread added as a part of the fix for ensuring that 

          * threads that timed out need to be cleaned or and send back to the pool so that 

          * other clients can use it.

          *

          */

         private void runIdleConnectionTimeout() {

             if (ictt != null) {

                     String timeoutInterval = ConfigContext.getCurrentContextConfig().getProperty(IDLE_CONNECTION_THREAD_INTERVAL_PROPERTY);

                     if (StringUtils.isBlank(timeoutInterval)) {

                         timeoutInterval = DEFAULT_IDLE_CONNECTION_THREAD_INTERVAL;

                     }

                     String connectionTimeout = ConfigContext.getCurrentContextConfig().getProperty(IDLE_CONNECTION_TIMEOUT_PROPERTY);

                     if (StringUtils.isBlank(connectionTimeout)) {

                         connectionTimeout = DEFAULT_IDLE_CONNECTION_TIMEOUT;

                     }

                     ictt.addConnectionManager(getHttpClient().getHttpConnectionManager());

                     ictt.setTimeoutInterval(new Integer(timeoutInterval));

                     ictt.setConnectionTimeout(new Integer(connectionTimeout));

                     //start the thread

                     ictt.start();

             }

         }

         public static void shutdownIdleConnectionTimeout() {

                 if (ictt != null) {

                         try {

                                 ictt.shutdown();

                         } catch (Exception e) {

                                 LOG.error("Failed to shutdown idle connection thread.", e);

                         }

                 }

         }

         private static final class CustomHttpMethodRetryHandler extends DefaultHttpMethodRetryHandler {

                 private static final int MAX_RETRIES = 1;

                 public CustomHttpMethodRetryHandler() {

                         super(MAX_RETRIES, true);

         }

                 @Override

             public boolean retryMethod(HttpMethod method, IOException exception, int executionCount) {

                 boolean shouldRetry = super.retryMethod(method, exception, executionCount);

                 if (!shouldRetry && executionCount < MAX_RETRIES) {

                         if (exception instanceof SocketException) {

                                 LOG.warn("Retrying request because of SocketException!", exception);

                                 shouldRetry = true;

                         } else if (exception instanceof SocketTimeoutException) {

                                 LOG.warn("Retrying request because of SocketTimeoutException!", exception);

                                 shouldRetry = true;

                         }

                 }

                 return shouldRetry;

             }

         }

 }