/***********************************************
 *  CS2510 Fall 2011 
 *  Lecture #7.1
 *  Interfaces, Classes, and Abstractions
 ***********************************************/
import tester.*;

/** Components of Design Recipe
 * 
 * 1. Purpose statements for each method
 * 2. Template with Fields and Methods for each Class
 * 3. Examples
 * 4. Tests
 * 5. Code
 */




/**
 *  We start with the following class hierarchy
 * 
 *              +-------------+
 *              |   IPerson   |
 *              +------+------+
 *                    / \
 *                   +-+-+
 *            +--------|-----------+-------------------+
 *            |                    |                   |
 *  +---------+-------+   +--------+-------+   +-------+---------+
 *  |      Faculty    |   |      Staff     |   |      Student    |
 *  +-----------------+   +----------------+   +-----------------+
 *  | String   name   |   | String  name   |   | String  name    |
 *  | int      id     |   | int     id     |   | int     id      |
 *  | boolean  tenure |   | double  salary |   | int     credits |
 *  +-----------------+   +----------------+   +-----------------+
 *  
 *  But when we write the definitions, and possibly some methods, we
 *  notice that their is lots and lots of repeat code.
 *  
 *  So we Abstract!
 */

/**
 *  We end up with an "abstract" class that has the "name" and "id"
 *  fields, and our "concrete" classes "extend" the abstract class.
 *  Note that we use the same arrow for both "implements" and "extends".
 *  
 *  We refer to Faculty as a "subclass" of APerson, and APerson as the
 *  "superclass" of Faculty (also Staff and Student) 
 * 
 *              +------------------+
 *              |   IPerson        |
 *              +------------------+
 *              | String nameTag() |
 *              +------+-----------+
 *                    / \
 *                   +-+-+
 *                     |
 *              +------+-------+
 *              |   APerson    |
 *              +--------------+
 *              | String  name |
 *              | int     id   |
 *              +------+-------+
 *                    / \
 *                   +-+-+
 *            +--------|-----------+------------------+
 *            |                    |                  |
 *  +---------+-------+   +--------+-------+   +------+-------+
 *  |      Faculty    |   |      Staff     |   |   Student    |
 *  +-----------------+   +----------------+   +--------------+
 *  | boolean  tenure |   | double  salary |   | int  credits |
 *  +-----------------+   +----------------+   +--------------+
 *
 */


// Represents a Person at Northeastern
interface IPerson{
    String nameTag();
}

// Represents a Person with a name/id at Northeastern
abstract class APerson implements IPerson{
    String name;
    int id;

    APerson(String name, int id) {
        this.name = name;
        this.id = id;
    }
    
    public String nameTag() {
        return name + ": " + id; 
    }
    
}

// Represents Northeastern Faculty
class Faculty extends APerson{
    boolean tenure;

    Faculty(String name, int id, boolean tenure) {
        super(name, id);
        this.tenure = tenure;
    }
    
    // Creates a specialized name tag for Faculty
    // with PhD appended
    public String nameTag() {
        return super.nameTag() + " PhD";
    }
}

// Represents Northeastern Staff
class Staff extends APerson{
    double salary;

    Staff(String name, int id, double salary) {
        super(name, id);
        this.salary = salary;
    }
}

// Represents Northeastern Students
class Student extends APerson{
    int credits;
    
    Student(String name, int id, int credits) {
        super(name, id);
        this.credits = credits;
    }
} 

// Examples/Tests for Person class hierarchy 
class PersonExamples{
    IPerson spenc = new Student("Spencer", 1234, 120);
    IPerson clerk = new Staff("Clerk Clark", 7896, 31000);
    IPerson bryan = new Faculty("Bryan", 4321, false);
    
    boolean testNameTag(Tester t) {
        return (t.checkExpect(spenc.nameTag(),"Spencer: 1234") &&
                t.checkExpect(clerk.nameTag(), "Clerk Clark: 7896") &&
                t.checkExpect(bryan.nameTag(),"Bryan: 4321 PhD"));
    }
    
}