module addressbook;

import  java.util.Hashtable;
import  java.util.Enumeration;

//  Address book implementation taken from CORBA examples 
//  in Sun's Java CORBA Tutorial.
//
//
// AddressBook
//
// This behavior is responsible for implementing
// three message handlers
//
//   * String getEmail ( String email );
//   * String getName ( String name  );
//   * boolean addUser ( String name, String email ); 
//
//

behavior AddressBook
{
    private Hashtable name2email;

    AddressBook()
    {
	// Create a new hashtable to store name & email
	name2email = new Hashtable();
    }

    // Get the name of this email user
    String getName( String email ) 
    {
	if (name2email.contains(email))
	{
 	    // Begin search for that name
	    for (Enumeration e = name2email.keys(); 
                 e.hasMoreElements();)
	    {
		String name = (String) e.nextElement();
		String e_mail = (String) name2email.get(name);

		// Match on email ?
		if (email.compareTo(e_mail) == 0)
		{
			return name;
		}
	    }
	}

         return new String("Unknown user");
    }

    // Get the email of this person
    String getEmail ( String name  ) 
    {
	// If user exists
	if (name2email.containsKey(name))
	{
		// Return email address
		return (String) name2email.get(name);
	}

	// User doesn't exist
	return new String("Unknown user");
    }

    // Add a new user to the system, returns success
    boolean addUser ( String name, String email )
    {
	// Is the user already listed
	if (name2email.containsKey( name ) ||
	    name2email.contains( email ) )
	{
		// If so, return false
		return false;
	}

	// Add to our hash table
	name2email.put (name, email);
             return true;
    }

   void act(String args[]){
      
      if (args.length != 2) {
         standardOutput<-println( "Usage: java addressbook.AddressBook <UAN> <UAL>" );

         return;
      }

      bind( args[0], args[1] );

  }
}