package horstmann.ch02_mail;
/**
   A mailbox contains messages that can be listed, kept or discarded.
 */
public class Mailbox
{
  /**
      Creates Mailbox object.
      @param aPasscode passcode number
      @param aGreeting greeting string
   */
  public Mailbox(String aPasscode, String aGreeting)
  {
    passcode = aPasscode;
    greeting = aGreeting;
    newMessages = new MessageQueue();
    keptMessages = new MessageQueue();
  }

  /**
      Check if the passcode is correct.
      @param aPasscode a passcode to check
      @return true if the supplied passcode matches the mailbox passcode
   */
  public boolean checkPasscode(String aPasscode)
  {
    return aPasscode.equals(passcode);
  }

  /**
      Add a message to the mailbox.
      @param aMessage the message to be added
   */
  public void addMessage(Message aMessage)
  {
    newMessages.add(aMessage);
  }

  /**
      Get the current message.
      @return the current message
   */
  public Message getCurrentMessage()
  {
    if (newMessages.size() > 0)
      return newMessages.peek();
    else if (keptMessages.size() > 0)
      return keptMessages.peek();
    else
      return null;
  }

  /**
      Remove the current message from the mailbox.
      @return the message that has just been removed
   */
  public Message removeCurrentMessage()
  {
    if (newMessages.size() > 0)
      return newMessages.remove();
    else if (keptMessages.size() > 0)
      return keptMessages.remove();
    else
      return null;
  }

  /**
      Save the current message
   */
  public void saveCurrentMessage()
  {
    Message m = removeCurrentMessage();
    if (m != null)
      keptMessages.add(m);
  }

  /**
      Change mailbox's greeting.
      @param newGreeting the new greeting string
   */
  public void setGreeting(String newGreeting)
  {
    greeting = newGreeting;
  }

  /**
      Change mailbox's passcode.
      @param newPasscode the new passcode
   */
  public void setPasscode(String newPasscode)
  {
    passcode = newPasscode;
  }

  /**
      Get the mailbox's greeting.
      @return the greeting
   */
  public String getGreeting()
  {
    return greeting;
  }

  private MessageQueue newMessages;
  private MessageQueue keptMessages;
  private String greeting;
  private String passcode;
}