//--------------------------------------------------------------------
//Programmed by: Mark Cruz
// Date: 11/12/02
//  Laboratory 6, Prelab Ex. 3, Application test        testloan.cpp
//
//--------------------------------------------------------------------

// Displays a loan schedule for a fully amortized loan.

#include <iostream.h>
#include <iomanip.h>
#include <math.h>
#include <fstream.h>

// Function prototypes
double monthlyPayment ( double principal, double annualRate,
                        int numYears                         );

void loanSchedule ( double principal, double annualRate,
                    int numYears                         );


void main ()
{
    double principal,     // Amount borrowed (in dollars)
           interestRate;  // Annual interest rate (as a % of 1.0)
    int numYears;         // Length of the loan (in years)

    // Prompt the user and read in the amount borrowed, interest
    // rate, and length of the loan.
    cout << endl << "Enter the amount borrowed: ";
    cin >> principal;
    cout << "Enter the annual interest rate (as a % of 1.0): ";
    cin >> interestRate;
    cout << "Enter the length of the loan (in years): ";
    cin >> numYears;

    // Output the monthly payment.
    cout << "Monthly payment : $"
         << monthlyPayment(principal,interestRate,numYears) << endl;

    // Output the loan schedule.
    loanSchedule(principal,interestRate,numYears);
}

//--------------------------------------------------------------------
// Insert your function implementations here.
//--------------------------------------------------------------------
double monthlyPayment ( double principal, double annualRate,
                        int numYears   )
{ 

	
	double months = numYears*12;
	double mpr = annualRate/12;
		cout.setf(ios::fixed, ios::floatfield);
	cout.setf(ios::showpoint);
	cout << setprecision (2);
	double monthlyPayment = mpr*((principal)/(1-(1/(pow (1 + mpr,months)))));
	
	return monthlyPayment;
		
}


void loanSchedule (double principal, double annualRate,
                    int numYears                         )

{
	
	int month = 0;
	double mpr, ipay, balance, mp, ppay;

	ofstream outfile ("loan.txt");
	mpr = annualRate/12;

	mp = monthlyPayment(principal,annualRate,numYears);

	
	outfile << "Month" << setw(20) << "Interest Paid" << setw(25) << "Principal Paid" << setw(25) 
		<< "Remaining Balance" <<setw(25) << endl;

	balance = principal;
while (month <numYears *12)
{
	month ++;
	ipay = mpr * balance;
	ppay = mp - ipay;
	balance = balance - ppay;
	
	
	outfile.setf(ios::fixed,ios::floatfield);
	outfile.setf(ios::showpoint);
	outfile <<setprecision (2);
	outfile.setf(ios::right);

	outfile << setw(5) << month <<setw (20)<<  ipay <<setw(20) <<
	ppay <<setw(20) <<fabs(balance) <<setw(20) <<endl;
}

}
	
/*

Enter the amount borrowed: 5000
Enter the annual interest rate (as a % of 1.0): .05
Enter the length of the loan (in years): 2
Monthly payment : $219.36
Press any key to continue

*/