/**
 * A class to model a simple email client. The client is run by a
 * particular user, and sends and retrieves mail via a particular server.
 *
 * Exercise 3.52
 * Add a subject line.
 *
 * @author David J. Barnes and Michael Kölling
 * @version 2016.02.29
 */
public class MailClient
{
    // The server used for sending and receiving.
    private MailServer server;
    // The user running this client.
    private String user;

    /**
     * Create a mail client run by user and attached to the given server.
     */
    public MailClient(MailServer server, String user)
    {
        this.server = server;
        this.user = user;
    }

    /**
     * Return the next mail item (if any) for this user.
     */
    public MailItem getNextMailItem()
    {
        return server.getNextMailItem(user);
    }

    /**
     * Print the next mail item (if any) for this user to the text
     * terminal.
     */
    public void printNextMailItem()
    {
        MailItem item = server.getNextMailItem(user);
        if(item == null) {
            System.out.println("No new mail.");
        }
        else {
            item.print();
        }
    }

    /**
     * Send the given message to the given recipient via
     * the attached mail server.
     * @param to The intended recipient.
     * @param message The text of the message to be sent.
     */
    public void sendMailItem(String to, String subject, String message)
    {
        MailItem item = new MailItem(user, to, subject, message);
        server.post(item);
    }
}

/**
 * A class to model a simple mail item. The item has sender and recipient
 * addresses and a message string.
 *
 * Exercise 3.54
 * Add a subject line to print out
 *
 * @author David J. Barnes and Michael Kölling
 * @version 2016.02.29
 */
public class MailItem
{
    // The sender of the item.
    private String from;
    // The intended recipient.
    private String to;
    // The text of the message.
    private String message;
    // The subject of the message.
    private String subject;

    /**
     * Create a mail item from sender to the given recipient,
     * containing the given message.
     * @param from The sender of this item.
     * @param to The intended recipient of this item.
     * @param message The text of the message to be sent.
     */
    public MailItem(String from, String to, String message, String subject)
    {
        this.from = from;
        this.to = to;
        this.message = message;
        this.subject = subject;
    }

    /**
     * @return The sender of this message.
     */
    public String getFrom()
    {
        return from;
    }

    /**
     * @return The intended recipient of this message.
     */
    public String getTo()
    {
        return to;
    }

    /**
     * @return The text of the message.
     */
    public String getMessage()
    {
        return message;
    }

    /**
     * Print this mail message to the text terminal.
     */
    public void print()
    {
        System.out.println("From: " + from);
        System.out.println("To: " + to);
        System.out.println("Subject: " + subject);
        System.out.println("Message: " + message);
    }
}