Milana

package midq1;

import java.util.Scanner;

public class PlayASong {

	public static void main(String[] args) {
		Artist artistob = new Artist("Pablo Albo","pablo@gmail.com","pop",2);
		artistob.enterSongDetails();
		artistob.printDetails();
		Operator operatorob = new Operator("Simon","simon@playasong.com","123","accountant");
		operatorob.printDetails();
		operatorob.calculateRevenue(artistob);
	}
}

abstract class User{
	Scanner ob  = new Scanner(System.in);
	protected String obname;
	protected String obemail;

	public User(String pname, String pemail) {
		this.obname = pname;
		this.obemail = pemail;
	}

	public User(User newUser) {
		this.obname = newUser.obname;
		this.obemail = newUser.obemail;
	}

	abstract public void printDetails();
}

interface Calculation{
	void calculateRevenue(Artist artistob);
}

class Operator extends User implements Calculation{

	private String obempNumber;
	private String objob;

	public Operator(String nname, String nemail, String nempno, String njob) {
		super(nname, nemail);
		this.obempNumber = nempno;
		this.objob = njob;
	}

	public void printDetails() {
		System.out.println("Operator name is "+ this.obname);
		System.out.println("Operator email is "+this.obemail);
		System.out.println("Operator employee number is "+this.obempNumber);
		System.out.println("Operator designation is "+this.objob);
		System.out.println("\n");
	}

	public void calculateRevenue(Artist artistObject) {
		System.out.print("Enter number of downloads: ");
		int album = ob.nextInt();
		System.out.println("\n");
		System.out.println("Artist: "+artistObject.obname);
		double revenue = artistObject.calcRateAverage() * album;
		System.out.printf("Album revenue is LKR %.2f",revenue);

	}
}

class Artist extends User{

	private String obgenre;
	private int obnumSongs;
	private String obsongList[][];

	public Artist(String nname, String nemail, String ngenre, int nnumSongs) {
		super(nname, nemail);
		this.obgenre = ngenre;
		this.obnumSongs = nnumSongs;
	}

	public void enterSongDetails() {
		String songrate = null;
		this.obsongList = new String[this.obnumSongs][2];
		for (int i = 0;i < obsongList.length; ++i) {
			System.out.println("Enter song:");
			this.obsongList[i][0] = ob.nextLine();
			try {
				System.out.println("Enter rate:");
				songrate = ob.nextLine();
				Double.parseDouble(songrate);
			} catch(NumberFormatException e) {
				System.out.print("Please enter a number for song rate: ");
				songrate = ob.nextLine();
			} finally {
				this.obsongList[i][1] = songrate;
				System.out.println("\n");
			}
		}
	}

	public void printDetails() {
		System.out.println("Artist's name is "+this.obname);
		System.out.println("Artist's email is "+this.obemail);
		System.out.println("Artist's genre is "+this.obgenre);
		System.out.println("Number of songs is "+this.obnumSongs);
		System.out.println("Song list is:");

		for (int c = 0;c < this.obnumSongs; ++c) {
			System.out.println(this.obsongList[c][0]+"\t"+this.obsongList[c][1]);
		}
		System.out.println("\n");
	}
	public double calcRateAverage() {
		double songavg = 0.00;
		for (int s = 0; s < obsongList.length; ++s) {
			songavg = songavg + Double.parseDouble(this.obsongList[s][1]);
		}
		songavg = songavg / obsongList.length;
		return songavg;
	}
}