writing to a file

// Christian Ballard
// COSC 1336 - 001
// 4/5/15
// Writing to an Output File

#include "genericCDB.h"
#include <iostream>
#include <string>
#include <ctime>
#include <iomanip>
#include <fstream>

using namespace std;

// Forward declarations
void getData(string&, int&, char&);
int readInt(string = "", int = INT_MIN, int = INT_MAX);
char getChoice(string, char char1, char char2);
double calculate(char serviceType);
void display(string name, int displayAccount, string displayServiceType, double displayServiceCharge);
void writeBillingInfoToFile(ofstream& fileOut, string custName, int acctNo, char servType);


int main()
{
    // Variable declarations
    string name;            // Collects the customer name
    int accountNum;         // Collects the customer account number
    char serviceType;       // Collects customer service type
    bool loop = true;       // Keeps the program indefinitely running until prompted to exit
    char sentinial;

    ofstream fout;                          // fout is a user-defined object of type ofstream
    fout.open("Phone Bill Records.txt");    // attach the file stream to the physical file
    if (fout.fail())                        // if the file is not opened successfully;
    {
        cout << "\nError opening file for writing.\n";
        return EXIT_FAILURE;    // terminate program from main with returned value of 1
    }

    cout << "Welcome! please type the customer name to continue, " << endl << "or type \"exit\" to end the program." << endl << endl;

    // BEGIN LOOP
    while (loop == true) {
        // Entering the program
        getData(name, accountNum, serviceType);
        sentinial = getChoice("Would you like to save the record to a file? ", 'Y', 'N');
        writeBillingInfoToFile(fout, name, accountNum, serviceType);
    }
    // END LOOP

    fout.close();


    return 0;
}

// Program body
void getData(string& name, int& account, char& service)
{
    cout << "Customer name: ";
    getline(cin, name);

    if (name == "Exit" || name == "exit" || name == "EXIT") {
        cout << "Program terminated by user, good-bye." << endl;
        system("PAUSE");
        exit(EXIT_SUCCESS);
        // Exits the program
    }

    // Data processing
    cout << "Enter account number: ";

    // Making sure the account number is between 0 and 9999
    account = readInt("Account number", 0, 9999);

    // Making sure the service type is either an R or a P
    service = getChoice("Service type", 'r', 'p');

    // Randomly generates minutes and calculates the total charge
    double serviceCharge = calculate(service);

    // Being passed into display function for aesthetic appeal
    string serviceName;

    if (service == 'p') {
        serviceName = "Premium";
    }
    else {
        serviceName = "Regular";
    }

    cout << endl;

    // Displays the final billing information for the customer
    display(name, account, serviceName, serviceCharge);
}


// Validates the account number
int readInt(string errorMsg, int min, int max)
{
    int someInt;
    bool valid = false;

    do
    {
        // User entering account number
        cin >> someInt;

        // Verifying the data is valid (0 to 9999)
        valid = (someInt >= min && someInt <= max);

        // Clearing out invalid data and prompting for re-entry
        if (cin.fail() || !valid || !isspace(cin.peek()))
        {
            cout << "Error! Invalid input." << endl;
            cout << errorMsg << " must be whole number between " << min << " and " << max << endl;
            cout << "Try Again: ";
            cin.clear(); // Clearing the fail state
            cin.ignore(numeric_limits<streamsize>::max(), '\n');

            valid = false;
        }
    } while (!valid);

    // Clears out following incorrect data once correct
    cin.ignore(100, '\n');

    return someInt;
}

// Generates minutes and calculates the final charges
double calculate(char serviceType)
{
    // Set amounts to be paid
    double payRegular = 10.0, payPremium = 25.0;
    int dayMinutes,         // Holds random day minutes
        nightMinutes;       // Holds random night minutes
    double  finalPay;       // Used to return final pay post-processing

    // seeding the random number generator
    srand(time(NULL));

    // Making sure decimals are displayed correctly
    cout << fixed << setprecision(2);

    // randomly generated minute range between 0 and 300. completely arbitrary ceiling
    dayMinutes = 0 + rand() % ((300 - 0) + 1);
    nightMinutes = 0 + rand() % ((300 - 0) + 1);

    // Checking and calculating Regular service
    if (serviceType == 'r') {

        // Day minutes used as standard minutes on regular service
        cout << "Minutes Used: " << dayMinutes << endl;

        if (dayMinutes > 50) {  // Checking if overcharge is necessary
            dayMinutes -= 50;       // Extracting amount to be charged

            // Applying fee
            payRegular = (dayMinutes * .2) + payRegular;

            // Finalizing payment due
            finalPay = payRegular;
        }
    }
    // Checking and calculating Premium service
    else if (serviceType == 'p') {

        cout << "Day Minutes: " << dayMinutes << endl;
        cout << "Night Minutes: " << nightMinutes << endl;

        if (dayMinutes > 75)    // Checking to see if overcharge is necessary
            dayMinutes -= 75;       // Pulls minutes to be charged overtime
        else
            dayMinutes = 0;         // Applies standard charge if minutes not exceeded
        if (nightMinutes > 100) // Checking if overcharge is necessary
            nightMinutes -= 100;      // Pulling minutes to be charged overtime

        // Calculating the final pay based on pre-determined charges depending
        // on using more minutes than allowed.
        // Bases off day cycle as well
        finalPay = (dayMinutes * 0.1) + (nightMinutes * 0.05) + payPremium;
    }

    return finalPay;
}

void display(string displayName, int displayAccount, string displayServiceType, double displayServiceCharge) {
    // Displaying final bill
    cout << "Customer Name: " << displayName << endl;
    cout << "Account Number: " << displayAccount << endl;
    cout << "Service Type: " << displayServiceType << endl;
    cout << "Service Charge: " << displayServiceCharge << endl << endl;
    system("PAUSE");

    // Clear screen
    system("CLS");
    cout << "(type EXIT to close program)" << endl;
}

void writeBillingInfoToFile(ofstream& fileOut, string custName, int acctNo, char servType)
{
    fileOut << custName << '\t' << acctNo << '\t' << servType << endl;

}