/*******************************************************************************
   * 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.
   *******************************************************************************/
  
  import java.applet.Applet;
  import java.applet.AppletContext;
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.io.UnsupportedEncodingException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.net.URLConnection;
  import java.net.URLEncoder;
  import java.util.Map;
  import java.util.Set;
  
  import javolution.util.FastMap;
  
  import org.ofbiz.base.util.UtilValidate;
  
  /**
   * Control Applet - Client applet for page pushing and (future) chat
   */
  @SuppressWarnings("serial")
  public class ControlApplet extends Applet implements Runnable {
  
      private static String pushUrl = "/commonapp/control/pushapplet";
      private static String pullUrl = "/commonapp/control/pullapplet";
  
      protected AppletContext ctx = null;
  
      protected String sessionId = null;
      protected String visitId = null;
      protected String serverUrl = null;
      protected String timeoutUrl = null;
      protected String currentPage = null;
      protected String debug = null;
  
      protected int waitTime = 1500;
      protected int timeout = 300000;
  
      protected boolean isRunning = false;
      protected boolean stopped = true;
  
      protected Thread thread = null;
  
      @Override
      public void init() {
          ctx = this.getAppletContext();
          this.sessionId = this.getParameter("sessionId");
          this.visitId = this.getParameter("visitId");
          this.serverUrl = this.getParameter("serverUrl");
          this.timeoutUrl = this.getParameter("timeoutUrl");
          this.currentPage = this.getParameter("currentPage");
          this.debug = this.getParameter("debug");
  
          // see if we override the integer values
          try {
              int waitInt = Integer.parseInt(this.getParameter("waitTime"));
              if (waitInt > 0)
                  waitTime = waitInt;
          } catch (NumberFormatException e) {
          }
          try {
              int outInt = Integer.parseInt(this.getParameter("timeout"));
              if (outInt > 0)
                  timeout = outInt;
          } catch (NumberFormatException e) {
          }
  
          if (serverUrl != null) {
              boolean sessionOkay = false;
              boolean visitOkay = false;
              boolean pageOkay = false;
  
              if (UtilValidate.isNotEmpty(sessionId))
                  sessionOkay = true;
              if (UtilValidate.isNotEmpty(visitId))
                  visitOkay = true;
              if (UtilValidate.isNotEmpty(currentPage))
                  pageOkay = true;
  
              if (sessionOkay && visitOkay && pageOkay) {
                  // tell the host about our current page (mainly for followers)
                  this.push();
              }
  
              // start the polling thread
              this.isRunning = true;
              this.stopped = false;
              thread = new Thread(this);
              thread.setDaemon(false);
              thread.start();
          }
      }
  
      @Override
      public void destroy() {
          this.stopped = true;
      }
  
      // poll the servlet for page request
      public void run() {
          while (isRunning && !stopped) {
              this.pull();
              try {
                  Thread.sleep(waitTime);
              } catch (InterruptedException e) {
                  this.stopped = true;
                  this.isRunning = false;
              }
          }
          if (debug != null && debug.equalsIgnoreCase("true"))
              System.out.println("Polling finished.");
      }
  
      protected void pull() {
          Map<String, Object> params = FastMap.newInstance();
          params.put("sessionId", this.sessionId.trim());
          params.put("visitId", this.visitId.trim());
  
          String pullResp = null;
          URL callPullUrl = null;
          try {
              callPullUrl = new URL(serverUrl + pullUrl);
          } catch (MalformedURLException e) {
          }
  
          if (callPullUrl != null) {
              try {
                  pullResp = callServer(callPullUrl, params);
              } catch (IOException e) {
              }
          }
  
          if (UtilValidate.isNotEmpty(pullResp)) {
              URL docUrl = null;
              try {
                  docUrl = new URL(pullResp);
              } catch (MalformedURLException e) {
              }
              if (docUrl != null)
                  ctx.showDocument(docUrl, "appletWindow");
          }
      }
  
      protected void push() {
          Map<String, Object> params = FastMap.newInstance();
          params.put("sessionId", this.sessionId.trim());
          params.put("visitId", this.visitId.trim());
          params.put("currentPage", this.currentPage.trim());
  
          URL callPushUrl = null;
          try {
              callPushUrl = new URL(serverUrl + pushUrl);
          } catch (MalformedURLException e) {
          }
  
          if (callPushUrl != null) {
              try {
                  callServer(callPushUrl, params);
              } catch (IOException e) {
              }
          }
      }
  
      private String callServer(URL serverUrl, Map<String, Object> parms) throws IOException {
          // send the request
          String parameters = this.encodeArgs(parms);
          if (debug != null && debug.equalsIgnoreCase("true")) {
              System.out.println("Sending parameters: " + parameters);
          }
          URLConnection uc = serverUrl.openConnection();
          uc.setDoOutput(true);
          uc.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
          PrintWriter pw = new PrintWriter(uc.getOutputStream());
          pw.println(parameters);
          pw.close();
  
          // read the response
          BufferedReader in = new BufferedReader(new InputStreamReader(uc.getInputStream()));
          String responseStr = in.readLine();
          in.close();
          if (responseStr != null) {
              responseStr = responseStr.trim();
          }
          if (debug != null && debug.equalsIgnoreCase("true")) {
              System.out.println("Receive response: " + responseStr);
          }
          return responseStr;
      }
  
      public String encodeArgs(Map<String, Object> args) {
          StringBuffer buf = new StringBuffer();
          if (args != null) {
              Set<Map.Entry<String, Object>> entrySet = args.entrySet();
              for (Map.Entry<String, Object> entry : entrySet) {
                  String name = entry.getKey();
                  Object value = entry.getValue();
                  String valueStr = null;
                  if (name != null && value != null) {
                      if (value instanceof String) {
                          valueStr = (String) value;
                      } else {
                          valueStr = value.toString();
                      }
  
                      if (UtilValidate.isNotEmpty(valueStr)) {
                          if (buf.length() > 0) buf.append('&');
                          try {
                              buf.append(URLEncoder.encode(name, "UTF-8"));
                          } catch (UnsupportedEncodingException e) {
                              e.printStackTrace();
                          }
                          buf.append('=');
                          try {
                              buf.append(URLEncoder.encode(valueStr, "UTF-8"));
                          } catch (UnsupportedEncodingException e) {
                              e.printStackTrace();
                          }
                      }
                  }
              }
          }
          return buf.toString();
      }
  }