//  File: InputDemo.java

//  A Purchase class object has the number of items purchased, a one-word 
//  description of the item, and the price of the item. 

//  Test class InputDemo uses the Scanner class to read data for a Purchase.

//  (Program also shows a defined constant and formatted output using "third
//   party" class Align)

import java.util.Scanner ; 			// for input

/**
 * A class to represent a purchase - number of items, description, and price
 * per item
 */
class Purchase 
{
	// instance vars
	private int quantity ;			// number of each item purchased
    private String item ;			// description of the item
    private double unitPrice ;		// price per item
    private double cost ;			// total cost:  quantity * unitPrice
    
    private static final double TAX_RATE = 0.065 ;	// 6.5% (a constant)

	/**
	 * Creates a purchase object
	 * @param quantity number of items bought
	 * @param item one-word description of item
	 * @param unitPrice price per item
	 */
	public Purchase(int quantity, String item, double unitPrice) 
	{
		this.quantity = quantity ;
		this.item = item ;
		this.unitPrice = unitPrice ;
		// compute cost of purchase
		cost = quantity * unitPrice ;	
	}
	
	/**
	 * Return the cost of a purchase.
	 * @return the cost of a purchase
	 */
    public double getCost()
	{
		return cost ;					
	}
	
	/**
	 * Returns a String containing the input data for a purchase
	 * @return the quantity, description, and price per item as a String
	 * Example:	"5 widget(s) @ $1.23
	 */
    public String data() 
	{
		return  quantity + " " + item + "(s) @ $" + unitPrice ;
		// example:	"5 widget(s) @ $1.23
	}

	/**
	 * Compute and return the tax on a purchase.
	 * @return the tax on a purchase
	 */
    public double getTax()
	{
		double tax = cost * TAX_RATE ;		// tax on purchase
		return tax ;					
	}

	/**
	 * Compute and return total cost of a purchase, including tax
	 * @return the total cost of a purchase, tax included
	 */
    public double getTotal()
	{
		// call getTax() to compute the tax, and add to cost
		return getTax() + cost ;
	}
	
} // end of Purchase class definition ========================================

/**
 * Test class for Purchase class
 */
public class InputDemo3
{
  	public static void main(String[] args)  
  	{
		Scanner input = new Scanner(System.in) ;

		// prompt user
		System.out.println("Enter quantity, description, and price of item " +
		                   "(separated by spaces):") ;
                       	   
    	int quantity = input.nextInt() ; 	// first token is an int
		
		String item = input.next() ;		// next is a String
		
		double price = input.nextDouble() ;	// last is a double
      	    
   	    // construct a Purchase object, using input data
   	    Purchase current = new Purchase(quantity, item, price) ;
      	    
    	// print purchase, tax, and total cost
    	System.out.println("\nYour purchase:\n") ;
    	System.out.println(Align.right( current.data(),25 ) + " = " +
    	                    Align.currency( current.getCost(), 8) ) ;
    	System.out.println(Align.right( "Tax",25 ) + " = " +    
    	                   Align.currency( current.getTax(), 8) ) ;
        System.out.println(Align.right( "Total cost",25 ) + " = " +    
    	                   Align.currency( current.getTotal(), 8) ) ;
	}
} 

/*  sample output:

Enter quantity, description, and price of item (separated by spaces):
8 hockeypuck 4.37

Your purchase:

  8 hockeypuck(s) @ $4.37 = $34.96
                      Tax = $ 2.27
               Total cost = $37.23
*/