import java.io.*;
import java.text.*;


public class MortgageCalculatorWK4{


private static BufferedReader stdin = new BufferedReader(
    new InputStreamReader (System.in));


public static void main(String[] args) throws IOException{
  //local objects
  MortgageCalculatorWK4 mortgageCalc = new MortgageCalculatorWK4();
  DecimalFormat df = new DecimalFormat("###,##0.00"); // to format the amount.
  DecimalFormat numDf = new DecimalFormat("000"); // to format the sequence number.

double principal = 0;
double annualInterest = 0.0;
int numOfYears = 0;

System.out.print("Please enter the amount borrowed:"); //prompt user input
String input = stdin.readLine(); //get user input
principal= Integer.parseInt(input); //convert string to int

System.out.print("Please enter the interest rate:");
String input2 = stdin.readLine();
  annualInterest = Integer.parseInt(input2);

System.out.print("Please enter the term of the loan in years:");
String input3 = stdin.readLine();
  numOfYears = Integer.parseInt(input3);

  //variables
  double monthlyInterest = annualInterest/(12*100);
  int totalNumOfMonths = numOfYears*12;


   System.out.println("Payment#   LoanBalance    InterestPaid");
   int monthCounter=1;
   for(; totalNumOfMonths>0; totalNumOfMonths--){
       //first get the monthly payment...
         double monthlyPayment = mortgageCalc.getMortgageAmount(principal,monthlyInterest,totalNumOfMonths);

      //now get the monthly principal in the payment...
         double monthlyPrincipal = mortgageCalc.getMonthlyPrincipal(monthlyPayment,monthlyInterest,principal);
         principal-=monthlyPrincipal;

         System.out.println(numDf.format(monthCounter) + "          " +df.format(principal)+ "          " +df.format((monthlyPayment-monthlyPrincipal)));
         monthCounter++;
         if(monthCounter%25==0)sleep(1000); // this will hesitate...


    }

}

public double getMortgageAmount(double principal, double monthlyInterest, int numOfMonths){
        // Monthly payment formula: M = P x (J/(1-(1+J)^-N));
        // M = P * ( J / (1 - (1 + J) ** -N));
       // source: http://www.hughchou.org/calc/formula.html
       double monthlyPayment = (double)(principal*(monthlyInterest / (1-(Math.pow((1+monthlyInterest),(numOfMonths*-1))))));
       return monthlyPayment;

     }

//calculate the monthly interst using simple interest.
public double getMonthlyPrincipal(double monthlyPayment, double monthlyInterest, double remainingPrincipal){
       return monthlyPayment - (remainingPrincipal * monthlyInterest);
}

// method to make the program sleep (hesitate) for a give time (in milliseconds)..
public static void sleep(long milliseconds){
     try{
          Thread.sleep(milliseconds);
     }catch(Exception e){
         //do nothing... for now...
     }
}

}

System.out.print("Please enter the amount borrowed:"); //prompt user input
String input = stdin.readLine(); //get user input

// Parse it to DOUBLE since your variable principal is a double datatype
// Using integer drops your decimal and can cause your problem.
principal = Double.parseDouble(input);