/******************************************************************************
 *                              GROUP PROJECT                                 *
 * LEADER: Jared Cabrera                                                      *
 * MEMBERS : Jezreel Salinas, Franco Miranda, Mauricio Alvarez                *
                Arturo Morales, Dennis De Jesus                               *
 * @Date: November 16, 2017                                                   *
 ******************************************************************************
*/
#include <iostream>
#include <iomanip>
#include <cmath>
#include <cstdlib>
#include <windows.h>

using namespace std;
void loadmenu();
int checkChoice(int&);
void printPay(double&,double&,double&,double&,double&);
void inputLoanAmount(double&);
void inputInterest (double&);
void inputMonthlyPayments (double&);
void numPayments (double, double, double, int&);
void loanPayments(double&, double&, double&, double&);

int main()
{
    int choice;
    double A, B, C, D, E;
    int F;

    HANDLE screen = GetStdHandle(STD_OUTPUT_HANDLE);
    SetConsoleTextAttribute(screen, 10);
    cout << "$$\\       $$$$$$\\   $$$$$$\\  $$\\   $$\\  $$$$$$\\  " << endl;
    cout << "$$ |     $$  __$$\\ $$  __$$\\ $$$\\  $$ |$$  __$$\\" << endl;
    cout << "$$ |     $$ /  $$ |$$ /  $$ |$$$$\\ $$ |$$ /  \\__|" << endl;
    cout << "$$ |     $$ |  $$ |$$  __$$ |$$ \\$$$$ | \\____$$\\ " << endl;
    cout << "$$ |     $$ |  $$ |$$ |  $$ |$$ |\\$$$ |$$\\   $$ |" << endl;
    cout << "$$$$$$$$\\ $$$$$$  |$$ |  $$ |$$ | \\$$ |\\$$$$$$  |" << endl;
    cout << "\\________|\\______/ \\__|  \\__|\\__|  \\__| \\______/ " << endl;

    SetConsoleTextAttribute(screen, 15);
    cin.get();

    do{
    cout << "\n\n" << endl;
    loadmenu();
    cout << setw(10) << " " << "Enter your choice: ";
    cin >> choice;
    checkChoice(choice);

    switch(choice){
        case 1: {
            loanPayments(A,B,C,D);
            cout << setw(10) << " ";
            system("pause");
            system("cls");
            break;

        }
        case 2: {
            printPay(A, B, C, D, E);
            cout << setw(10) << " ";
            system("pause");
            system("cls");
            break;
        }
        case 3: {
            inputLoanAmount(A);
            inputInterest(B);
            inputMonthlyPayments(C);
            numPayments(A, B, C, F);
            cout << setw(10) << " ";
            system("pause");
            system("cls");
            break;
        }
        case 4: {
            cout << setw(10) << " " << "Thank You For Using Me" << endl;
            exit(1);
            break;
        }
    }
    }while(choice != 4);
    return 0;
}

/******************************************************************************
 *                           loadmenu() function                              *
 * - This function loads and prints up the main menu                          *
 *                                                                            *
 ******************************************************************************
*/
void loadmenu(){

    cout << setw(10) << " " << "__________________________________" << endl;
    cout << setw(10) << " " << "     LOAN AND SAVINGS PROGRAM     " << endl;
    cout << setw(10) << " " << "__________________________________" << endl;
    cout << endl;
    cout << setw(10) << " " << "1. Find Monthly Loan Payments" << endl;
    cout << setw(10) << " " << "2. Print out a Loan Payback List" << endl;
    cout << setw(10) << " " << "3. Number of Payments" << endl;
    cout << setw(10) << " " << "4. EXIT Program" << endl;
    cout << setw(10) << " " << "__________________________________" << endl;
    cout << endl;

}

/******************************************************************************
 *                          checkChoice() function                            *
 * - This function check if the input choice is not less than 1 or 4          *
 *                                                                            *
 ******************************************************************************
*/
int checkChoice(int &choice){

    while (choice < 1 || choice > 4){
            cout << setw(10) << " " << "Re-Enter a Number 1-4: ";
            cin >> choice;
    }

    return (choice);
}



/******************************************************************************
 *                           printPay() function                              *
 * - This function print out a loan progression showing how much you have     *
 *  paid and what's left on the loan.                                         *
 ******************************************************************************
*/
void printPay(double &L, double &yInt,double &n,
              double &monthlyPayment, double &balance)
{
    double mInt;
    cout << setw(10) << " " <<"Enter Loan Amount: ";
    cin >> L;
    cout << setw(10) << " " << "Enter Yearly Interest-Rate: ";
    cin >> yInt;
    cout << setw(10) << " " << "Enter the Number of Monthly Payments: ";
    cin >> n;
    cout << setw(10) << " " << "Enter Monthly Payment: ";
    cin >> monthlyPayment;


    cout << setw(10) << " " << "----------------------"
    << "---------------------------" << endl;
    cout << setw(10) << " " << "Payment No." << setw(4)
    << " " << "Total Paid" << setw(6) << " " << "Left to Pay" << endl;
    cout << endl;
    cout << setw(10) << " " << "----------------------"
    << "---------------------------" << endl;

    mInt = (yInt/100)/12;
    cout << fixed << setprecision(2);
    for(int i = 1; i <= n; i++){
        balance = (L*pow(1 + mInt, i)) - (monthlyPayment / mInt)
        *(pow(1 + mInt, i) - 1);


        cout << setw(13) << i << ":" << setw(18) << right
             << monthlyPayment*i  << setw(18) << balance << endl;
    }
    cout << endl;
}

/******************************************************************************
 *                        inputLoanAmount() function                          *
 * - This function  out a loan progression showing how much you have     *
 *  paid and what's left on the loan.                                         *
 ******************************************************************************
*/
void inputLoanAmount(double& loanAmount){
    cout << setw(10) << " " << "Enter Loan Amount: ";
    cin >> loanAmount;

    while (loanAmount < 0){
        cout << setw(10) << " " << "Enter Loan Amount: ";
        cin >> loanAmount;
    }
}
void inputInterest(double& interest){
    cout << setw(10) << " " <<  "Enter Monthly Interest: ";
    cin >> interest;

    while (interest < 0){
        cout << setw(10) << " " << "Enter Monthly Interest: ";
        cin >> interest;
    }
    interest = (interest / 100) / 12;

}
void inputMonthlyPayments(double& monthlyPayments){
    cout << setw(10) << " " << "Enter Monthly Payments: ";
    cin >> monthlyPayments;

    while (monthlyPayments < 0){
        cout << "Enter Monthly Payments: ";
        cin >> monthlyPayments;
    }
}
void numPayments(double A, double B, double C, int& F){
    cout << endl;
    F = (- log(1 - ((B * A) / C))) / (log(1 + B));
    cout <<  fixed << setprecision(2);
    cout << setw(10) << " " << "$" << C << " Requires " << F
        << " Payments" << endl;
}

void loanPayments(double& A, double& B, double& C, double& D)
{
    cout << setw(10) << " " << "Enter Loan Amount: ";
    cin >> A;
    cout << setw(10) << " " << "Enter Interest Rate: ";
    cin >> C;
    cout << setw(10) << " " << "Enter Number of Payments: ";
    cin >> B;

    C = C / 100;

    D = ((C/12)*A)/(1-pow((1+C/12),-B));
    cout << setw(10) << " " << "Monthly Payment: $" << D << endl;

    cout << endl;
}