/**
 * Name:		Team Orange		<br />
 * Course:		4010-361-03		<br />
 * Assignment:	Project 		<br />
 * Date:		2/19/07			<br />
 * <br />
 * Class:	TeacherList.java	<br />
 * Purpose:	This class provides the means by which to store several Teacher objects.
 * <br />
 * @author Zack
 */

package dataObject;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;

public class TeacherList implements Serializable {
	
	/**
	 * Refer to the Java API for a good explanation of this constant.
	 * Essentially, it is maintained so that Java can be sure that it's
	 * deserializing to the right version of an object.  It should be modified
	 * when changes to the structure of the object are made.
	 */	
	private static final long serialVersionUID = 1L;
	
	/**
	 * The Singleton object.
	 */
	private static TeacherList thisList;
	
	/**
	 * The list of teachers managed by this class.
	 */
	private ArrayList<Teacher> teachers;
	
	/**
	 * Default constructor.
	 * @author - Zack
	 */
	private TeacherList() {
		this.teachers = new ArrayList<Teacher>();
	}
	
	/**
	 * The singleton control method
	 * @author Zack
	 * <br />
	 * @return the singleton of this class
	 */
	public TeacherList getInstance() {
		TeacherList aList = thisList;
		
		if( thisList == null ) {
			aList = new TeacherList();
		}
		
		return aList;
	}
	
	public void writeObject( ObjectOutputStream out ) throws IOException {
		out.writeObject(this);
		out.close();
	}

	public static void readObject( ObjectInputStream in ) throws IOException, ClassNotFoundException {
		thisList = (TeacherList)in.readObject();
		in.close();
	}

	/**
	 * Method to add a new teacher to this list.
	 * @author - Zack
	 * <br />
	 * @param newTeacher the teacher to add
	 */
	public void addTeacher( Teacher newTeacher ) {
		this.teachers.add( newTeacher );
	}

	/**
	 * Method to delete a teacher from this list.
	 * @author - Zack
	 * <br />
	 * @param teacherToRemove the teacher to be removed
	 */
	public void deleteTeacher( Teacher teacherToRemove ){
		this.teachers.remove( teacherToRemove );
	}
	
	/**
	 * Method to update a teacher in this list.
	 * @author - Zack
	 * <br />
	 * @param oldTeacher the teacher to be modified
	 * @param newTeacher the newly modified teacher object
	 */
	public void updateTeacher( Teacher oldTeacher, Teacher newTeacher ) {
		this.deleteTeacher( oldTeacher );
		this.addTeacher( newTeacher );
	}

	/**
	 * Method to retrieve a teacher based on the teacher's name.
	 * @author - Zack
	 * <br />
	 * @param teacherName the name of the teacher to be retrieved contained in a 
	 * 			two-element array [firstname,lastname]
	 * @return the Teacher object associated with that name
	 */
	public Teacher retrieveTeacher( String[] teacherName ) {
		Iterator iter = this.teachers.iterator();
		
		while( iter.hasNext() ) {
			Teacher currTeacher = (Teacher)iter.next();
			
			if( currTeacher.getName().equals( teacherName ) ) {
				return currTeacher;
			}
		}
		
		return null;
	}
	
	/**
	 * Method to return the entire list of teachers.
	 * @author - Zack
	 * <br />
	 * @return the list of teachers 
	 */
	public ArrayList<Teacher> retrieveAllTeachers() {
		return this.teachers;
	}
}