/**
 * UsingVehicles.java
 *
 * A program that illustrates concepts related to inheritance and polymorphism.
 * It is a client program of the classes in our hierarchy of vehicle classes.
 *
 * Computer Science S-111
 */

import java.util.*;

public class UsingVehicles {
    // obtains the current year -- you don't need to understand how this works!
    public static final int CURRENT_YEAR = (new GregorianCalendar()).get(GregorianCalendar.YEAR);

    /**
     * printFleet - prints the vehicles in the array of Vehicles that is passed
     * in as a parameter
     */
    public static void printFleet(Vehicle[] fleet) {
        // Print each Vehicle in the array.
        // Thanks to dynamic binding, the correct
        // version of the toString() method will
        // be invoked for each vehicle.
        for (int i = 0; i < fleet.length; i++) {
            System.out.println(fleet[i]);
        }
    }
 
    /**
     * computeAverageAge - computes and returns the average age of the
     * vehicles in the array passed in as a parameter
     */
    public static double computeAverageAge(Vehicle[] fleet) {
        int totalAge = 0;

        // We can invoke the getYear() method on each object in the fleet,
        // because they are all subclasses of Vehicle, and the getYear()
        // method is defined in Vehicle.
        for (int i = 0; i < fleet.length; i++) {
            int age = CURRENT_YEAR - fleet[i].getYear();
            totalAge += age;
        }
        
        double averageAge = (double)totalAge / fleet.length; 
        return averageAge;
    }
 
    /**
     * computeAverageAge - computes and returns the average mileage of the
     * vehicles in the array passed in as a parameter
     */
    public static double computeAverageMileage(Vehicle[] fleet) {
        int totalMileage = 0;

        // We can invoke the getMileage() method on each object in the
        // fleet, because they are all subclasses of Vehicle, and the
        // getMileage() method is defined in Vehicle.
        for (int i = 0; i < fleet.length; i++) {
            totalMileage += fleet[i].getMileage();
        }
  
        double averageMileage = (double)totalMileage / fleet.length; 
        return averageMileage;
    }
 
    public static void main(String[] args) {
        Vehicle[] fleet = new Vehicle[5];
        fleet[0] = new Automobile("Honda", "Civic", 2005);
        fleet[1] = new Motorcycle("Harley", "Sportster", 2007);
  
        //
        // In order to call the setIsSleeper() method, we need
        // to use a variable of type TractorTrailer, because
        // the method is defined in that class.
        //
        // We can't do
        //    fleet[2].setIsSleeper(); 
        // because setIsSleeper() is not defined in Vehicle.
        //
        TractorTrailer t = new TractorTrailer("Mack", "Vision", 2003, 10); 
        t.setIsSleeper(true);
        fleet[2] = t;
  
        fleet[3] = new Taxi("Ford", "Tempo", 1999, "12345");
        fleet[4] = new Truck("Dodge", "Durango", 2007, 4);
  
        printFleet(fleet);
        
        double averageAge = computeAverageAge(fleet);
        System.out.println("\naverage age = " + averageAge);
 
        // We can use the array elements when calling
        // setMileage(), because that method is defined
        // in the Vehicle class.
        fleet[0].setMileage(120000);
        fleet[1].setMileage(65000);
        fleet[2].setMileage(83125);
        fleet[3].setMileage(220000);
        fleet[4].setMileage(15000);
        double averageMileage = computeAverageMileage(fleet);
        System.out.println("average mileage = " + averageMileage);
        System.out.println();
  
        // To call the getNumAxles() method on the two
        // trucks in the fleet, we need to use casting,
        // because that method is defined in the Truck class.
        // Thanks to dynamic binding, the correct version of
        // getNumAxles() will be called.
        Truck mackTruck = (Truck)fleet[2];
        Truck durango = (Truck)fleet[4];
        System.out.println("The " + mackTruck.getMake() + " has " +
          mackTruck.getNumWheels() + " wheels and " +  
          mackTruck.getNumAxles() + " axles.");
        System.out.println("The " + durango.getMake() + " has " + 
          durango.getNumWheels() + " wheels and " +  
          durango.getNumAxles() + " axles.");
    }
}