package labtest1;

/**
 * This class represents a president.
 * There can be only a single president (singleton).
 * 
 * @author Franck van Breugel
 */
public class President
{
    private String firstName;
    private String lastName;
    private int numberOfYearsInOffice;
    
    private static President instance = null;
    
    /**
     * Initializes this president.
     * 
     * @param firstName the first name of this president.
     * @param lastName the last name of this president.
     * @param numberOfYearsInOffice the number of years in office
     * of this president.
     * @pre. numberOfYearsInOffice >= 0
     */
    private President(String firstName, String lastName, int numberOfYearsInOffice)
    {
	this.setFirstName(firstName);
	this.setLastName(lastName);
	this.setNumberOfYearsInOffice(numberOfYearsInOffice);
    }

    /**
     * Returns the first name of this president.
     *
     * @return the first name of this president.
     */
    public String getFirstName()
    {
	return this.firstName;
    }
    
    /**
     * Sets the first name of this president to the given first name.
     *
     * @param firstName the new first name of this president.
     */
    private void setFirstName(String firstName)
    {
	this.firstName = firstName;
    }
    
    /**
     * Returns the last name of this president.
     *
     * @return the last name of this president.
     */
    public String getLastName()
    {
	return this.lastName;
    }
    
    /**
     * Sets the last name of this president to the given last name.
     *
     * @param lastName the new last name of this president.
     */
    private void setLastName(String lastName)
    {
	this.lastName = lastName;
    }
    
    /**
     * Returns the number of years in office of this president.
     *
     * @return the number of years in office of this president.
     */
    public int getNumberOfYearsInOffice()
    {
	return this.numberOfYearsInOffice;
    }
    
    /**
     * Sets the number of years in office of this president to the 
     * given number of years in office.
     *
     * @param numberOfYearsInOffice the new number of years in office 
     * of this president.
     * @pre. numberOfYearsInOffice >= 0
     */
    public void setNumberOfYearsInOffice(int numberOfYearsInOffice)
    {
	this.numberOfYearsInOffice = numberOfYearsInOffice;
    }

    /**
     * Returns the name of this president.
     * The name consists of the first name followed by a single space
     * followed by the last name.
     * 
     * @return the name of this president.
     */
    public String getName()
    {
	return this.getFirstName() + " " + this.getLastName();
    }
    
    /**
     * Returns a president with the given first name, last name and
     * number of years in office.
     * 
     * @param firstName the first name of the president.
     * @param lastName the last name of the president.
     * @param numberOfYearsInOffice the number of years in office.
     * @pre. numberOfYearsInOffice >= 0
     * @return a president with the given first name, last name and
     * number of years in office.
     */
    public static President getInstance(String firstName, String lastName, int numberOfYearsInOffice)
    {
	if (President.instance == null)
	{
	    President.instance = new President(firstName, lastName, numberOfYearsInOffice);
	}
	else
	{
	    President.instance.setFirstName(firstName);
	    President.instance.setLastName(lastName);
	    President.instance.setNumberOfYearsInOffice(numberOfYearsInOffice);
	}
	return President.instance;
    }
    
    /**
     * Returns a president with the given first name, last name and
     * no years in office.
     * 
     * @param firstName the first name of the president.
     * @param lastName the last name of the president.
     * @return a president with the given first name, last name and
     * no years in office.
     */
    public static President getInstance(String firstName, String lastName)
    {
	return President.getInstance(firstName, lastName, 0);
    }
    
    /**
     * Returns a string representation of this president.
     * This representation consists of two lines.  
     * The first line consists of the name of this president.
     * The second line a * for each year this president is in office.
     * 
     * @return a string representation of this president.
     */
    public String toString()
    {
	StringBuffer representation = new StringBuffer();
	representation.append(this.getName());
	representation.append("\n");
	for (int i = 0; i < this.getNumberOfYearsInOffice(); i++)
	{
	    representation.append("*");
	}
	return representation.toString();
    }
}