package labtest1;

/**
 * This class represents a general.
 * There can be at most MAX_NUMBER generals (that is, at most
 * MAX_NUMBER General objects can be created).
 *
 * @author Franck van Breugel
 */
public class General
{
    private String name;
    private boolean retired;
    
    private static int number = 0; // number of created General objects
    
    /**
     * The maximum number of generals that can be created.
     */
    public static final int MAX_NUMBER = 5;

    /**
     * Initializes a general with the given name who is not retired.
     * 
     * @param name the name of this general.
     */
    private General(String name)
    {
	this.setName(name);
	this.setRetired(false);
	General.number++;
    }

    /**
     * Returns the name of this general.
     *
     * @return the name of this general.
     */
    public String getName()
    {
	return this.name;
    }

    /**
     * Sets the name of this general to the given name.
     *
     * @param name the new name of this general.
     */
    private void setName(String name)
    {
	this.name = name;
    }

    /**
     * Checks if this general is retired.
     *
     * @return true if this general is retired, false otherwise.
     */
    public boolean isRetired()
    {
	return this.retired;
    }

    /**
     * Sets the retired status of this general to the given status.
     *
     * @param retired the new retired status of this general.
     */
    private void setRetired(boolean retired)
    {
	this.retired = retired;
    }

    /**
     * Sets this general to be retired.
     */
    public void retire()
    {
	this.setRetired(true);
    }
    
    /**
     * Returns a general with the given name who is not retired if
     * the number of created generals has not reached MAX_NUMBER.
     * Returns null otherwise.
     * 
     * @param name the name of the general.
     * @return a general with the given name who is not retired if
     * the number of created generals has not reached MAX_NUMBER,
     * null otherwise.
     */
    public static General getInstance(String name)
    {
	General instance;
	if (General.number < General.MAX_NUMBER)
	{
	    instance = new General(name);
	}
	else
	{
	    instance = null;
	}
	return instance;
    }
    
    /**
     * Tests if this general is the same as the given object.
     * Two generals are the same if they have the same name.
     * Note that a general may not have a name (its name is null).
     * 
     * @param object an object.
     * @return true if this general is the same as the given object,
     * false otherwise.
     */
    public boolean equals(Object object)
    {
	boolean equal;
	if (object != null && this.getClass() == object.getClass())
	{
	    General other = (General) object;
	    equal = (this.getName() == null && other.getName() == null)
		|| (this.getName() != null && this.getName().equals(other.getName()));
	}
	else
	{
	    equal = false;
	}
	return equal;
    }
    
    /**
     * Returns the hashcode of this general.
     * Its hashcode is the hashcode of its name.
     * If the its name is null, its hashcode is zero.
     * 
     * @return the hashcode of this general.
     */
    public int hashCode()
    {
	int hashCode;
	if (this.getName() != null)
	{
	    hashCode = this.getName().hashCode();
	}
	else
	{
	    hashCode = 0;
	}
	return hashCode;
    }

    /**
     * Returns a string representation of this general.
     * This representation consists of two lines.  
     * The first line consists of the name of this general.
     * The second line either consists of 
     * "retired" or "not retired".
     * 
     * @return a string representation of this general.
     */
    public String toString()
    {
	return this.getName() + "\n" + (this.isRetired() ? "retired" : "not retired");
    }
}