/*
 * Created on 15-Sep-2005
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package org.vamsas.client;

import java.beans.EventHandler;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.lang.reflect.Field;
import java.util.Hashtable;
import java.util.Vector;

import org.exolab.castor.xml.IDResolver;
import org.exolab.castor.xml.MarshalException;
import org.exolab.castor.xml.Marshaller;
import org.exolab.castor.xml.UnmarshalListener;
import org.exolab.castor.xml.Unmarshaller;
import org.exolab.castor.xml.ValidationException;
import org.vamsas.objects.core.VamsasDocument;

/**
 * @author jimp
 */
public class SimpleClient implements IClient {

  UserHandle user = null;

  SessionHandle session = null;

  ClientHandle client = null;
  
  /*
   * (non-Javadoc)
   * TODO: check that build substitution variables are correct
   * @see org.vamsas.client.IClient#getAbout()
   */
  public String getAbout() {
    return new String("VORBA SimpleClient version $version$ build $build$");
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#getSessionUrn()
   */
  public String getSessionUrn() {
    return session.getSessionUrn();
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#getSessionHandle()
   */
  public SessionHandle getSessionHandle() {
    return session;
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#getClientHandle()
   */
  public ClientHandle getClientHandle() {
    return client;
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#getUserHandle()
   */
  public UserHandle getUserHandle() {
    return user;
  }

  private Hashtable handlers = initHandlers();

  private Vector listeners = new Vector();

  /**
   * make all the PropertyChangeSupport objects for the
   * events described in org.vamsas.client.Event
   * @return
   */
  private static Hashtable initHandlers() {
    Hashtable events = new Hashtable();
    java.util.Iterator evt = Events.EventList.iterator();
    while (evt.hasNext()) {
      Object ths = evt.next();
      events.put(ths, (Object) new PropertyChangeSupport(ths));
    }
    return events;
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#addDocumentUpdateHandler(java.util.EventListener)
   */
  public void addDocumentUpdateHandler(PropertyChangeListener evt) {
    if (handlers.containsKey(Events.DOCUMENT_UPDATE)) {
      Object handler;
      ((PropertyChangeSupport) (handler = handlers.get(Events.DOCUMENT_UPDATE)))
          .addPropertyChangeListener(evt);
      listeners.add(handler);
      listeners.add((Object) evt);
    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#finalizeClient()
   */
  public void finalizeClient() {
    // TODO: determine if this is last client in session
    // TODO: raise events like : ((lst_client && document.request.to.close), (client_finalization), (
    
    // if (handlers.containsKey(Events.))
    // if (handlers.containsKey(Events.CLIENT_FINALIZATION))
    // deregister listeners.
    // mark this instance as finalized
  }

  /**
   * writes the VamsasDocument to the given stream.
   * TODO: ensure that (at least) default provenance entries are written for objects.
   * @param outstream
   * @param doc
   * @throws IOException
   * @throws MarshalException
   * @throws ValidationException
   */
  private static void setVamsasDocument(Writer outstream, VamsasDocument doc)
      throws IOException, MarshalException, ValidationException {
    Marshaller marshaller = new Marshaller(outstream);
    marshaller.marshal(doc);
  }

  /**
   * Unmarshals a vamsasDocument object from a stream, registers
   * unregistered objects, records existing VorbaIds, and completes 
   * the org.vamsas.client.object housekeeping fields.
   * For a valid unmarshalling, the array of returned objects also includes
   * a <return>sync</return> parameter which is true if new VorbaIds
   * were created. If sync is false, then the caller should ensure that the
   * vamsasDocument is written back to disk to propagate the new VorbaIds.
   *  TODO: ensure that provenance is correct for newly registered objects
   * @param instream - the XML input stream 
   * @param factory - the SimpleClient's properly configured VorbaId factory to make new references.
   * @return null or {(Object) VamsasDocument object, (Object) Hashtable of object references, (Object) Boolean(sync) }
   */
private static Object[] getVamsasDocument(Reader instream,
      IVorbaIdFactory factory) {
    Unmarshaller unmarshaller = new Unmarshaller(instream);
    unmarshaller.setIDResolver(new IDResolver() {
      public Object resolve(String id) {
        System.err.println("Warning - id " + id
            + " is not found in the VamsasDocument!");
        return null;
      }
    });
    Hashtable refbase = new Hashtable();
    Vector unrefed = new Vector();
    final Hashtable objrefs = refbase;
    final IVorbaIdFactory vorbafactory = factory;
    final Vector unrefedObj =  unrefed;
    unmarshaller.setUnmarshalListener(new UnmarshalListener() {

      /*
       * (non-Javadoc)
       * 
       * @see org.exolab.castor.xml.UnmarshalListener#attributesProcessed(java.lang.Object)
       */
      public void attributesProcessed(Object object) {
      }

      /*
       * (non-Javadoc)
       * 
       * @see org.exolab.castor.xml.UnmarshalListener#fieldAdded(java.lang.String,
       *      java.lang.Object, java.lang.Object)
       */
      public void fieldAdded(String fieldName, Object parent, Object child) {
      }

      /*
       * (non-Javadoc)
       * 
       * @see org.exolab.castor.xml.UnmarshalListener#initialized(java.lang.Object)
       */
      public void initialized(Object object) {
      }

      /*
       * Check if the object has an 'id' field - if it does, copy the value into
       * the VorbaId field of object, and add the object to the VorbaId hash.
       * 
       * @see org.exolab.castor.xml.UnmarshalListener#unmarshalled(java.lang.Object)
       */
      public void unmarshalled(Object newobj) {
        if (newobj instanceof object) {
          object nobj = (object) newobj;
          nobj.set__stored_in_document(true);
          Field fd = null;
          try {
            if (nobj.isRegisterable()) {
              // look for the id field (should be an NCName string)
              nobj.__vorba = vorbafactory;
              fd = nobj.getClass().getField("id");
              String idstring;
              if (fd.get(nobj) != null) {
                idstring = (String) fd.get(nobj);
                if (idstring.length() > 0) {
                  if (!objrefs.containsKey(idstring)) {
                    objrefs.put(idstring, nobj);
                    nobj.setVorbaId(VorbaId.newId(idstring));
                  } else {
                    System.err.println("Serious problem : duplicate id '"+idstring+"' found! expect badness.");
                    // TODO: HANDLE duplicate XML ids correctly
                  }
                } else {
                  // add to list of objects without a valid vorbaId
                  unrefedObj.add(nobj);
                }
              } else {
                // add to list of objects without a valid vorbaId
                unrefedObj.add(nobj);
              }
              
            nobj.doHash();
          }
          } catch (Exception e) {
            return;
          };
          
        }
      }

    });
    // Call the unmarshaller.
    try {
      while (instream.ready()) {
        Object obj = unmarshaller.unmarshal(instream);
        boolean sync=true;
        if (obj instanceof VamsasDocument) {
          if (unrefed.size()>0) {
            sync=false; // document is out of sync - ids have been created.
            java.util.Iterator newobj = unrefed.listIterator();
            while (newobj.hasNext()) {
              object o = (object) newobj.next();
              // forces registration and id field update.
              VorbaId id = o.getVorbaId();
              if (!objrefs.containsKey(id)) {
                objrefs.put(id.id, o);
              } else {
                throw new Error("Serious! Duplicate reference made by vorbaIdFactory!");
              }
            }
          }
          return new Object[] { obj, objrefs, new Boolean(sync)};
        }
      }
    } catch (MarshalException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (ValidationException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    return null;
  }
  /**
   * extract data appropriate for client, session and user
   * from vamsas document.
   * @return application's byte array
   */
  private byte[] getApplicationData() {
    // TODO: extract correct byte object from Jar and return it to application.
    return null;
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#getClientDocument()
   */
  public IClientDocument getClientDocument() {
    Object[] vdoc;//  TODO: = getVamsasDocument(new Reader());
    // ClientDocument cdoc = new ClientDocument(getApplicationData(),
        // ((VamsasDocument) vdoc[0]).getVAMSAS(), (Hashtable) vdoc[1], this);
    // 
    return null;
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#updateDocument(org.vamsas.client.IClientDocument)
   */
  public void updateDocument(IClientDocument newdoc) {
    // TODO Auto-generated method stub
    // 
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#storeDocument(java.io.File)
   */
  public void storeDocument(File location) {
    // TODO Auto-generated method stub

  }

  /*
   * (non-Javadoc)
   * 
   * @see org.vamsas.client.IClient#addVorbaEventHandler(java.lang.String,
   *      java.beans.PropertyChangeListener)
   */
  public void addVorbaEventHandler(String EventChain, PropertyChangeListener evt) {
    if (handlers.containsKey(EventChain)) {
      Object handler;
      ((PropertyChangeSupport) (handler = handlers.get(EventChain)))
          .addPropertyChangeListener(evt);
      listeners.add(handler);
      listeners.add((Object) evt);
    }
  }

  /* (non-Javadoc)
   * @see org.vamsas.client.IClient#pollUpdate()
   */
  public void pollUpdate() {
    // TODO wake up UpdateWatcher thread to check for updates.

  }

  public static void main(String[] args) {
  }

  /* (non-Javadoc)
   * @see org.vamsas.client.IClient#joinSession()
   */
  public void joinSession() throws Exception {
    // TODO Auto-generated method stub
    
  }
}