import java.util.*;     // access class ArrayList
/**
 * CompactDisc describes the contents of a Compact disk consisting of
 * zero or more songs.  CSE142 Su01 lecture example.
 * 
 * @author Hal Perkins
 * @version 7/15/01
 */
public class CompactDisc {
    // instance variables
    private String      title;          // CD title
    private ArrayList   songs;          // songs on this CD in order
    private int         totalSeconds;   // total length of songs on this CD in seconds

    /**
     * Construct an empty CompactDisc with the given title
     * @param title CD title
     */
    public CompactDisc(String title) {
        this.songs = new ArrayList();
        this.title = title;
        this.totalSeconds = 0;
    }

    /**
     * Add a new song at the end of the list of songs in this CompactDisc
     * @param song new song to be added
     */
    public void add(Song song) {
        this.songs.add(song);
        this.totalSeconds = this.totalSeconds + song.getSeconds();
    }

    /** 
     * Return Song at given position in this CompactDisc
     * @param pos Song position in CompactDisc (numbered from 0)
     * @return Song at the specified position
     */
    public Song get(int pos) {
        return (Song)this.songs.get(pos);
    }

    /**
     * Return title of this CompactDisc
     * @return CompactDisc title
     */
    public String getTitle() {
        return this.title;
    }

    /**
     * Return total length of the songs in this CompactDisc
     * @return total length of songs in seconds
     */
    public int getSeconds() {
        return this.totalSeconds;
    }

    /**
     * Print the titles of the songs on this CompactDisc on System.out
     */
    public void printTitles() {
        Iterator songIter = this.songs.iterator();
        while (songIter.hasNext()) {
            Song currentSong = (Song)songIter.next();
            System.out.println(currentSong.getTitle());
        }
    }

    /**
     * Return String description of this CompactDisc
     * @return String containing CompactDisc title, number of songs,
     * and total time in seconds
     */
    public String toString() {
        return "CompactDisc: title = " + this.title + " with " +
                this.songs.size() + " songs with total time of " +
                this.totalSeconds + " seconds.";
    }

}