package org.votech.plastic.managers;
   
   import java.io.DataInputStream;
   import java.io.IOException;
   import java.net.URI;
   import java.net.URL;
   import java.util.Collection;
   import java.util.Iterator;
   import java.util.List;
  import java.util.Map;
  
  import org.votech.plastic.incoming.handlers.ExtendableHandler;
  import org.votech.plastic.incoming.handlers.StandardHandler;
  import org.votech.plastic.incoming.messages.votable.VOTableLoader;
  import org.votech.plastic.incoming.messages.votable.VotableLoadFromUrlMessageInvoker;
  import org.votech.plastic.managers.AbstractObservableManager.ManagerObserver;
  import org.votech.plastic.outgoing.messages.info.EchoMessage;
  import org.votech.plastic.outgoing.messages.info.GetDescriptionMessage;
  
  
  
  /**
   * This class is an example application that uses the {@link org.votech.plastic.managers.PlasticConnectionManager} class
   * to handle all things to do with Plastic.
   * It responds only to the core Plastic Messages to do with returning name, description etc. and the loadVOTable message.
   * When you run the main method it will attempt to connect the PlasticHub, and then execute a method
   * that lists the currently connected Plastic applications.  Finally it will send an ECHO message to each
   * application in turn.   The class implements two interfaces that allow it to register as a listener for Hub starting/stopping
   * and application registering/unregistering events.  To see a simpler example see {@link org.votech.plastic.managers.SimplestExampleApplication}.
   * @author jdt
   * @see #sendSomeMessages()
   * @see org.votech.plastic.managers.AbstractObservableManager.ManagerObserver
   * @see org.votech.plastic.managers.PlasticRegistryListener
   *
   */
  public class ExampleApplication implements ManagerObserver, PlasticRegistryListener {
  
      private static final String NAME = "Example";
      private static final String DESCRIPTION = "An example Plastic app showing the use of the PlasticManager";
      private static final String IVORN = "ivo://roe.ac.uk/plastic/jdt/example";
      private static final String LOGOURL = "";
      private PlasticConnectionManager manager;
      private PlasticRegistry registry;
  
      public ExampleApplication() {
          initPlastic();
      }
      /**
       * Set up the {@link PlasticConnectionManager} that is responsible for housekeeping tasks
       * such as keeping track of whether the hub is up or down, registering us, and responding
       * to common informational messages.
       *
       */
      private void initPlastic() {
          //Create a message handler for the core informational messages
          StandardHandler handler = new StandardHandler(NAME, DESCRIPTION, IVORN, LOGOURL);
          //Create another message handler for the loadVOTable message.  This type of handler can 
          //handle any number of different messages.
          ExtendableHandler exhandler = new ExtendableHandler();
          exhandler.addMessageInvoker(new VotableLoadFromUrlMessageInvoker(new VOTableLoader() {
              //A VOTable loader is something capable of loading a votable!  In this case, our
              //anon inner class just has a dummy method.
              public void loadVOTable(URI sender, String id, URL url) throws Exception {
                  System.out.println("Application "+sender+" has asked us to load a table from "+url+" and give it ID "+id);
              }
              
          }));
          //Handlers can be then chained together.  Some handlers "absorb" messages that they have dealt with, while
          //other types of handlers such as the LoggingHandler, deal with them and pass them on to the next handler.
          handler.appendHandler(exhandler);
          
          //Create the Plastic manager, tell it your name, the handler at the beginning of the chain, the fact
          //that we don't want to connect immediately, and that should we lose the hub we want to retry to
          //connect every 10 seconds.
          manager = new PlasticConnectionManagerImpl(NAME, handler, false, 10000 );
          
          //Register ourselves as being interested in the hub starting and stopping
          //See ManagerObserver interface
          manager.addObserver(this);
          
          //Instruct the manager to connect to the hub.
          manager.connect(); // Blocks waiting for connection.  See also manager.connectWhenReady()
          
          //While a PlasticConnectionManager keeps track of the hub, a PlasticRegistry keeps track of
          //other plastic applications.
          registry = new PlasticRegistry(manager);
          // Register ourselves as being interested in knowing when applications register and deregister
          registry.addListener(this);
          
      }
  
      
      /**
       * See who else is registered and get their metadata, if any.  
       * Send the ECHO message to each.
       * List all applications that understand the "getDescription" message.
       *
       */
      public void sendSomeMessages() {
         Collection apps =  registry.getPlasticApplications();
         Iterator it = apps.iterator();
         System.out.println("Registered applications-------");
         while (it.hasNext()) {
             PlasticApplication app = (PlasticApplication) it.next();
             System.out.println("Name: "+app.getName());
             System.out.println("Description: "+app.getDescription());
             System.out.println("Plastic version: "+app.getPlasticVersion());
             System.out.println("Icon URL: "+app.getIconUrl());
             System.out.println("IVORN: "+app.getIvorn());
             System.out.println("Plastic ID: "+app.getPlid());
             System.out.println("Supported messages:");
             List msgs = app.getSupportedMessageIds();
             for (int i=0;i<msgs.size();++i) {
                 System.out.println("\t"+msgs.get(i));
             }
             
             //Send an EchoMessage to the application, and convert the returned object to the correct class.
             //If you prefer to work with the raw message IDs, there's a method for that too.
             final Object rawResponse = app.sendMessage(new EchoMessage("Hello World"));
             //Most Message objects have a static convertReturn method that knows how to convert the returned Object
             //to something more appropriate.
             String response = EchoMessage.convertReturn(rawResponse);
             
             System.out.println("Sent an echo message, application returned: "+response);
             System.out.println();
         }
 
         //Broadcast a message to everyone.
         System.out.println("Broadcasting an echo message to everyone");
         Map responses = registry.broadcast(new EchoMessage("Goodbye cruel world"));
         Iterator respondingappsIt = responses.keySet().iterator();
         while (respondingappsIt.hasNext()) {
             PlasticApplication rApp = (PlasticApplication) respondingappsIt.next();
             System.out.println("Application "+rApp.getName()+" responded "+responses.get(rApp));
             
         }
         
         //The registry can also be used to get all the applications that support a particular message, for example
         //the getDescription message.
         Collection appsWithDescription = registry.getPlasticApplications(new GetDescriptionMessage().getURI());
         Iterator it2 = appsWithDescription.iterator();
         System.out.println("The following applications support the getDescription message");
         while (it2.hasNext()) {
             PlasticApplication app = (PlasticApplication) it2.next();
             System.out.println(app.getName());
         }
     }
 
     
     /**
      * Called when the hub goes down
      * @see org.votech.plastic.managers.AbstractObservableManager.ManagerObserver
      */
     public void down() {
         System.out.println("The hub has gone down - exiting");
         System.exit(0);
     }
     /**
      * Called when the hub comes up
      * @see org.votech.plastic.managers.AbstractObservableManager.ManagerObserver
      */
     public void up() {
         System.out.println("The hub is up");
         System.out.println("This hub's ID is "+manager.getHub().getHubId());
         System.out.println("My ID is "+ manager.getId());
     }
 
     /**
      * Called when an application registers or unregisters.
      * @see PlasticRegistryListener
      */
     public void applicationsChanged() {
         System.out.println("An application has registered/deregistered");
         
     }
 
     /**
      * Run me.
      * @param args
      * @throws IOException
      */
     public static void main(String[] args) throws IOException {
         
         ExampleApplication app = new ExampleApplication();
         
         
         //Wait for the user to hit return
         final DataInputStream dataInputStream = new DataInputStream(System.in);
         while (true) {
             app.sendSomeMessages();
             System.out.println("Hit return to go again, type q to exit");
             String stop = dataInputStream.readLine();
             if ("q".equalsIgnoreCase(stop)) System.exit(0);
         }
     }
 }