/***********************************************
 *                                             *
 *                                             *
 *              CSCI 1470, Fall 2005           *
 *              Machine Problem: MP8ab         *
 *     Purpose:Annuities with menu             *
 ***********************************************/

#include <iostream>
#include <iomanip>
#include<cmath>

//display menu
void menu();

//calculate future annuity
void fuvannuity();

//calculate present annuity
void pvannuity();

//show ammortization schedule
void amschedule();


using namespace std;

int main(void)
{

	menu();

	return 0;


}//end of function main

//This function displays the menu
void menu()
{
	int menu_select;

	cout << "1. Future Value of an Annuity" << endl;
	cout << "2. Present Value of an Annuity" << endl;
	cout << "3. Monthly Payment of a Loan and Amortization Schedule" << endl;
	cout << "4. Exit" << endl << endl;
	cout << "Please enter your selection: ";
	cin >> menu_select;

	if (menu_select < 5)

	switch (menu_select)
	{
		case 1:
			fuvannuity();
			break;
		case 2:
			pvannuity();
			break;
		case 3:
			amschedule();
			break;
		case 4:
			return;
	}

	return;

}//end of function menu

//Calculate and display the future value of an annuity
void fuvannuity()
{
	double fv, pmt, i;
	int n;

	cout << "Enter the fixed periodic payment: ";
	cin >> pmt;
	cout << endl << "Enter the periodic interest rate: ";
	cin >> i;
	cout << endl << "Enter the number of periods: ";
	cin >> n;

	fv = pmt * (((pow((1 + i),n)) - 1) / i);

	cout << endl << endl << "The Future Value of the Annuity is " << fv << endl << endl;

	return;

}//end of function fuvannuity

//Calculate and display the present value of an annuity
void pvannuity()
{
	double pv, pmt, i;
	int n;
	
	cout << "Enter the fixed periodic payment: ";
	cin >> pmt;
	cout << endl << "Enter the periodic interest rate: ";
	cin >> i;
	cout << endl << "Enter the number of periods: ";
	cin >> n;

	pv = pmt * ((1 - pow((1 + i),-n)) / i);

	cout << endl << endl << "The Present Value of the Annuity is " << pv << endl << endl;

	return;
}//end of function pvannuity

//Calculate and display the monthly payment of a loan and display the ammortization schedule
void amschedule()
{
	double pmt, pv, i, remain;
	int n;

	cout << "Enter the present value of the annuity: ";
	cin >> pv;
	cout << endl << "Enter the periodic interest rate: ";
	cin >> i;
	cout << endl << "Enter the number of years: ";
	cin >> n;

	//changes n from years to months
	n = n * 12;
	remain = pv;
	
	cout << setw(5) << "Payment#" << setw(20) << "Monthly Payment" << setw(23) << "Interest" << setw(26) << "Remaining Loan" << endl;
	cout << setw(5) << "--------" << setw(20) << "---------------" << setw(23) << "--------" << setw(26) << "--------------" << endl;

	
	double i_dec;

	i_dec = i / 1200;

	pmt = (pv * i_dec) / (1 - pow((1 + i_dec),-n));

	for (int j=0; j<n; j++)
	{
		remain = (remain + (remain * i_dec)) - pmt;

		cout << setw(5) << j+1 << setw(20) << setprecision(3) << fixed << showpoint << pmt << setw(23) << i << setw(26) << remain << endl;

		
		
	}

	return;

}//end of function amschedule