PA 7 - Phone Bill (updated)

// Christian Ballard
// COSC 1336 - 001
// 4/21/15
// Should take customer information and display their bill.

#include <iostream>
#include <string>
#include <ctime>
#include <iomanip>

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);

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

        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);
        }
        // END LOOP

        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);
}

// Character validation
char getChoice(string prompt, char char1, char char2)
{
        char someChar;
        bool valid = false;

        do
        {
                // Prompts the user to enter a valid service type
                cout << prompt << " (" << char1 << " or " << char2 << "): ";
                cin >> someChar;
                someChar = tolower(someChar);

                // Determining valid service type
                valid = (someChar == char1 || someChar == char2);

                // If the input is false, it clears the screen and prompts re-entry
                if (!valid || !isspace(cin.peek())) {
                        cout << "Error!" << endl;
                        cout << prompt << " must be " << char1 << " or " << char2 << endl;
                        cout << "Try Again: ";
                        cin.clear(); // Clearing the fail state
                        cin.ignore(numeric_limits<streamsize>::max(), '\n');

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

        // Ignores following invalid data if it's correct
        cin.ignore(100, '\n');

        return someChar;
}

// 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
                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 for aesthetic appeal
        system("CLS");
        cout << "(type EXIT to close program)" << endl;
}