Code for my required assignment for Study.com CS 112. A HRMS implemented in C++

Study.com - CS112 Final Project - HR Information System

/* 
* Study.com - CS 112 Intro to Programming in C++ Assignment - HR Resource Manager.cpp : This file contains the 'main' function.Program execution begins and ends there.
* by Kyle Spillane - spillman@gmail.com
* 
* This program implements a HR Information System as requested by the assignment prompt.
* 
* Main Program Operation:
* 
* When launched, the program will first check if erm_data.txt exists in the working directory.
* If not, it will prompt the user to login with a master administrator password
* 
* Master Administrator Password is : 4dm1n
* 
* This is onlly done if the file does not exist, or if the file does exist, but no users are defined in the file.
* If an admin login is done, the program will prompt the user to generate an initial user, who will be set as HR.
* After the user is generated and saved to the file, the user is prompted to login as a valid user, and the csv data
* file is read and each row (employee object) is loaded into vector<Employee> employees. User interactions simply
* manipulate the objects in the vector, which is fully written back to the file after each manipulation.
* 
* Once logged in, the user will have access to main functions, based on their user type, as descriped by the assignment prompt.
*
* Custom Classes and General Program Structure:
* 
* Employee data is stored in a csv file, each row an employee, each field an object member.
* Employee data is stored using the Employee class as a container to organize the data members.
*
* The UserInteraction class handles the interaction betwene the user and the program. To keep things simple, the program's main
* loop is implemented in the UserInteraction class constructor.
* 
* TODOs (for program improvement, outside of the scope of the assignment):
* 
* 1. Hash password data - Currently user passwords are stored in the clear. I considered using the openssl
*    libraries to implement a SHA2 hasing function, but that is probably outside the scope of this class.
*
* 2. Use something other than csv file to hold data. If we get say 100 employees, this program will bog down.
*    I'd use either some sort of RDBMS or at least sqlite to handle it. If we used SQL, we coudl simplify
*    many program functions, since searching, modifying, and viewing records is included in SQL. Again, beyons the scope here.
*
* 3. Since ther was no requirements for storing the data, the data is primary fields, so it is possible
*    that two records could be identical. Using SQL with primary keys would help resolve this, or adding extra
*    code to check for this would be do-able, but it wasn't mentioned in the prompt, so I am not going to do it.
* 
* 4. There lots of room for reducing code redundancy, I think I have a reasonable amount for what was asked, but
*    table and meny generating codes could be rolled into their own functions and called just to format output.
* 
* NOTE ABOUT THE STUDENT:
* 
* My background is mostly in interpreted languages like Bash, Powershell, and Python, although I did have to
* take a course in x86 assembly when I was an engineering student. This is the most I have ever done
* in a C family language, and while I feel I could have done this in half the time if I was writing in in Python
* that's simply due to lack of experience.
*
* Overall, I enjoyed this project and am proud of it. I might try to pick up some knowledge in C#!
* 
*/

// Libraries used
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <cctype>
#include <limits>

using namespace std;

//Enumerated User Type, to keep it easy to read
enum UserType {
    HR,
    Management,
    Individual
};

//Converts string to UserType datatype
UserType stringToUserType(const std::string& input) {
   
    if (input == "0") return UserType::HR;
    else if (input == "1") return UserType::Management;
    else if (input == "2") return UserType::Individual;
    else return UserType::Individual;  // Return least priv. type as the default value

}

//Employee class holds employee object data
class Employee {
public:

    string firstname;
    string lastname;
    string id;
    UserType role;
    string login;
    string password;
};

//UserInteraction class handles
//the events of the user interacting
//with the program.
class UserInteraction {

    //This class members indicate which user
    //is currently logged in to the system
    UserType active_user;
    string active_user_name;
    string active_user_id;

    //Master employee list
    vector<Employee> employees;

    //open_file checks for existence of te data file
    //creates it if it is not present
    //if it is present, reads data out of it
    //and loads data into master Employee list, employees
    void open_file() {
        fstream file;
        file.open("erm_data.txt", ios::in);
        if (!file.is_open()) {
            cout << "No data file found! Attempting to create one." << endl;
            
            ofstream newfile("erm_data.txt"); //Create the data file
            newfile.close();
            file.open("erm_data.txt", ios::in);
            if (!file.is_open()) {
                //If we are here, the file couldn't be created. Probably a permissions issue
                cout << "There was a problem creating the data file!" << endl << "This program will now exit." << endl << endl;
                cout << "Press any key to exit...";

                exit(1);
            };
            string user_pass;
            cout << "Since there are no valid users, you must login as an admin to create a new HR user." << endl;
            cout << "Enter Administrator Password: ";
            getline(cin, user_pass);
            //Prompt for master admin login
            if (user_pass != "4dm1n") {
                cout << "You have entered an incorrect administrator password." << endl;
                cout << "Please refer to head comments in source code for the default." << endl;
                cout << "Press any key to exit..." << endl;
                cin;
                exit(1);
            };

            //Initial user setup and force user to be HR
            Employee initial_user = create_user();
            initial_user.role = HR;
            employees.push_back(initial_user);
            if (save_data()) {
                cout << "Data File Initialized" << endl;
             };
  
            return;
          
        };

        Employee datain; //Temp employee object to be used for passing data from file to master vector
        
        string line;
        //Read the data file
        while (getline(file, line)) {
            stringstream s(line);
            string field;

            //Break each row into a stream of comma seperated values, and load each field into a member
            getline(s, field, ',');
            datain.firstname = field;
            getline(s, field, ',');
            datain.lastname = field;
            getline(s, field, ',');
            datain.id = field;
            getline(s, field, ',');
            datain.role = stringToUserType(field); //Converts from string to custom type
            getline(s, field, ',');
            datain.login = field;
            getline(s, field);
            datain.password = field;

            //Load the new Employee type into the master employee list
            employees.push_back(datain);
        };

        file.close();
        if (employees.size() < 1) {
            // The file is present, but there's no users in it, for some reason, create one
            cout << "There are no employees in the data. You must login as administrator and create one who will be the HR user." << endl;
            string user_pass;
            cout << "Enter Administrator Password: ";
            getline(cin, user_pass);
            if (user_pass != "4dm1n") {
                cout << "You have entered an incorrect administrator password." << endl;
                cout << "Please refer to head comments in source code for the default." << endl;
                cout << "Press any key to exit..." << endl;
                cin;
                exit(1);
            };

            Employee initial_user = create_user();
            initial_user.role = HR;
            employees.push_back(initial_user);
            if (save_data()) {
                cout << "Data File Initialized" << endl;
            };

            return;

        }

        return;

    };

    //This function saves the current master employee vector back to the data file
    bool save_data() {
        static const char* const outfile = "erm_data.txt";
        ofstream fout;
        fout.open(outfile);
        cout << "Saving data file to disk." << endl;
        if (!fout) {
            cout << "There was a problem opening the file for writing!" << endl << "This program will now exit." << endl << endl;
            cout << "Press any key to exit...";

            exit(1);
        }

        //Iterate through each object in the vector
        for (const auto& items : employees) {
            //Write each object member to file as comma serpated fields, one per tow
            fout << items.firstname << ',' << items.lastname << ',' << items.id << ',' << items.role << ',' << items.login << ',' << items.password << '\n';
        }
        cout << "Data file saved." << endl;

        return 1;
    };

    //This function creates a new user and rerturns the user object
    Employee create_user() {
        Employee user; // Temp object to pass entered data to the employees vector
        string linein;

        cout << endl << "Enter Employee Information" << endl;
        cout << "Enter Employee First Name: ";
        getline(cin, user.firstname);
        cout << "Enter Employee Last Name: ";
        getline(cin, user.lastname);
        cout << "Enter employee ID: ";
        getline(cin, user.id);
        string input;
        do {
            cout << "Enter employee role (1 for HR, 2 for Manager, 3 for Individual Contributor): ";
            
            getline(cin, input);
            
        } while (input != "1" && input != "2" && input != "3");
        //do...while to ensure role entry is valid

        switch (stoi(input))
        {
        case 1:
            user.role = HR;
            break;
        case 2:
            user.role = Management;
            break;
        case 3:
            user.role = Individual;
            break;
        default:
            break;
        }
        cout << "Enter Username for login: ";
        getline(cin, user.login);
        cout << "Enter Password for login: ";
        getline(cin, user.password);

        return user;
    }

    //This function handles user logins
    void user_login() {

        string user_login, user_pass;

        cout << "This is a restricted system. Only authorized users may login" << endl;
        cout << "" << endl;
        cout << "Enter User Login: ";
        getline(cin, user_login);
        cout << "Enter Password: ";
        getline(cin, user_pass);

        //This loop iterates through the vector
        //looking for a matching login
        //if one is found, we know who is currently
        //using the program
        for (const auto& items : employees) {
            if (items.login == user_login) { //We have a valid user login
                if (items.password == user_pass) { //Password matches
                    active_user = items.role; //Get the logged in user's role type and hold it
                    active_user_name = items.firstname + " " + items.lastname;
                    active_user_id = items.id;

                    return;
                }
            }
        }

        cout << "The entered login information is not correct." << endl << "The program will now exit." << endl;
        exit(1);

    }

    //This function allows any employee to view their own employee record
    void view_Self() {

        //Iterate through employee records until we find the right one.
        for (const auto& items : employees) {
            if (items.id == active_user_id) { 
               //We have found the logged in user
                cout << "\033c" << endl;
                cout << "Here is your employee information : " << endl;
               cout << left << setw(15) << "First Name" << left << setw(15) << "Last Name" << left << setw(5) << "ID" << left << setw(15) << "Role" << left << setw(15) << "Login" << left << setw(15) << "Password\n" << endl;
                cout << left << setw(15) << items.firstname << left << setw(15) << items.lastname << left << setw(5) << items.id << left << setw(15) << displayUserType(items.role) << left << setw(15) << items.login << left << setw(15) << items.password << endl;
                cout << "\nPress ENTER to return to the main menu..." << endl;
                getchar();

               return;
            
            }
        }

    }

    //Function to handle employee deletion
    void delete_Employee() {

        int i = 0;
        string input;
        cout << "\033c" << endl;
        cout << "Employee Master List: \n" << endl;
        //Build the list of employees
        cout << left << setw(15) << "First Name" << left << setw(15) << "Last Name" << left << setw(5) << "ID" << left << setw(15) << "Role" << left << setw(15) << "Login" << left << setw(15) << "Password\n" << endl;
        for (const auto& items : employees) {
            i++; // Added to begining of each line, to indicate the index of employee we want to delete
            cout << i << ")\t" << left << setw(15) << items.firstname << left << setw(15) << items.lastname << left << setw(5) << items.id << left << setw(15) << displayUserType(items.role) << left << setw(15) << items.login << left << setw(15) << items.password << endl;
        }

        cout << "\nSelect the number of the employee you wish to delete" << endl;
        cout << "or enter a letter to cancel delete." << endl;
        cout << "Entry: ";
        cin >> input;

        if (stoi(input) <= i) {
            confirmDelete(stoi(input));
        }

        return;
    }

    //This function verifies a deletion of employee record, and handles the deletion
    void confirmDelete(int index) {
        index--; //Vector index starts at 0, but row counts starts at 1
        string input;

        cout << "\nAre you sure you want to delete employee id " << employees[index].id << " with name " << employees[index].firstname << ' ' << employees[index].lastname << "?" << endl;
        cout << "Confirm by entering the employee id : ";
        getline(cin, input); // Verify we really want to do this
        if (input == employees[index].id) {
            employees.erase(employees.begin() + index); //Delete the object at the selected index
            cout << "Employee removed from Master List." << endl;
            save_data();
            cout << "\nPress ENTER to return to the main menu" << endl;
            getchar();
        }
        else {
            cout << "Incorrect Employee ID - User Not Deleted" << endl;
            cout << "Press ENTER to return to the main menu." << endl;
            getchar();
        }

    }

    //This funcrtion allows HR or Management to view all employee data
    void view_All() {

        cout << "\033c" << endl;
        cout << "\n\nEmployee Master List: \n" << endl;
        cout << left << setw(15) << "First Name" << left << setw(15) << "Last Name" << left << setw(5) << "ID" << left << setw(15) << "Role" << left << setw(15) << "Login" << left << setw(15) << "Password\n" << endl;
        
        //Display each vector object on a line
        for (const auto& items : employees) {
            cout << left << setw(15) << items.firstname << left << setw(15) << items.lastname << left << setw(5) << items.id << left << setw(15) << displayUserType(items.role) << left << setw(15) << items.login << left << setw(15) << items.password << endl;
        }  
            cout << "\nPress ENTER to return to the main menu..." << endl;
            getchar();

        return;
    }

    // This function allows HR to modify an employee record
    void modify_User() {
       
        int i = 0;
        string input;
        cout << "\033c" << endl;
        cout << "Employee Master List: \n" << endl;
        cout << left << setw(15) << "First Name" << left << setw(15) << "Last Name" << left << setw(5) << "ID" << left << setw(15) << "Role" << left << setw(15) << "Login" << left << setw(15) << "Password\n" << endl;
        for (const auto& items : employees) {
            i++; //effectively i is the index for current item, effectively employees[i]
            cout << i << ")" << left << setw(15) << items.firstname << left << setw(15) << items.lastname << left << setw(5) << items.id << left << setw(15) << displayUserType(items.role) << left << setw(15) << items.login << left << setw(15) << items.password << endl;
        }

        cout << "\nSelect the number of the employee you wish to modify." << endl;
        cout << "Entry: ";
        cin >> input;

        if (stoi(input) <= i) {
            confirmModify(stoi(input));
        }

        return;
    }

    // Thius function actually handles the employee data modification
    void confirmModify(int index) {
        index--; // Because base index in the vector is 0
        Employee user;

        cout << "\nYou are modifying employee id " << employees[index].id << " with name " << employees[index].firstname << ' ' << employees[index].lastname << "?" << endl;
        cout << "Simply press enter to use the current data [] for a field." << endl;
        cout << endl << "Enter Employee Information" << endl;
        cout << "Enter Employee First Name: [ " << employees[index].firstname << " ]: ";
        
        cin.ignore(numeric_limits<streamsize>::max(), '\n'); //Clear the newline out of the inout buffer
        getline(cin, user.firstname);
        cout << "Enter Employee Last Name: [ " << employees[index].lastname << " ]: ";
        getline(cin, user.lastname);
        cout << "Enter employee ID: [ " << employees[index].id << " ]: ";
        getline(cin, user.id);
        string input;
        do {
            cout << "Enter employee role (1 for HR, 2 for Manager, 3 for Individual Contributor) [ " << employees[index].role << " ]: ";

            getline(cin, input);
            if (input == "") { break; }

        } while (input != "1" && input != "2" && input != "3");
        if (input != "") { // Don't update role if nothing was entered
            switch (stoi(input))
            {
            case 1:
                user.role = HR;
                break;
            case 2:
                user.role = Management;
                break;
            case 3:
                user.role = Individual;
                break;
            default:
                break;
            }
        }

        cout << "Enter Username for login: [ " << employees[index].login << " ]: ";
        getline(cin, user.login);
        cout << "Enter Password for login: [ " << employees[index].password << " ]: ";
        getline(cin, user.password);

        //These if blocks are checking to see if no info was entered
        //to the responses. If not, don't update, thus keeping the current value
        if (user.firstname != "") {
            employees[index].firstname = user.firstname;
        }

        if (user.firstname != "") {
            employees[index].firstname = user.firstname;
        }

        if (user.id != "") {
            employees[index].id = user.id;
        }

        if (user.login != "") {
            employees[index].login = user.login;
        }

        if (user.password != "") {
            employees[index].password = user.password;
        }

        cout << "Employee record updated." << endl;
        save_data();
        cout << "\nPress ENTER to return to the main menu" << endl;
        cin;
    
    }

    // This function allows a user to search for user by name or id
    void search_User() {
        string search;

        cout << "\033c" << endl;
        cout << "You can search for employee records by name or id." << endl;
        cout << "\nEnter EITHER an employee's full first OR last name, OR an employee id number.";
        cout << endl << "Entry: ";
        getline(cin, search);
        transform(search.begin(), search.end(), search.begin(), ::tolower); //Convert input to lowercase for case insensitive searching
        cout << "\n\nEmployee Search Results List: \n" << endl;
        cout << left << setw(15) << "First Name" << left << setw(15) << "Last Name" << left << setw(5) << "ID" << left << setw(15) << "Role" << left << setw(15) << "Login" << left << setw(15) << "Password\n" << endl;
        
        //Iterate through the items in the array, checking the search term against firstname, lastname, or id data members
        for (const auto& items : employees) {
            
            //This section converts  the id/firstname values to lower case so we can search case insensityive
            string id = items.id;
            transform(id.begin(), id.end(), id.begin(), ::tolower);
            string firstname = items.firstname;
            transform(firstname.begin(), firstname.end(), firstname.begin(), ::tolower);
            string lastname = items.lastname;
            transform(lastname.begin(), lastname.end(), lastname.begin(), ::tolower);
            
            //Display the record if the search term is a subset of id or name fields - for matching partials - Thanks Stack Overflow!
            if (id.find(search) != string::npos || firstname.find(search) != string::npos || lastname.find(search) != string::npos) {
                cout << left << setw(15) << items.firstname << left << setw(15) << items.lastname << left << setw(5) << items.id << left << setw(15) << displayUserType(items.role) << left << setw(15) << items.login << left << setw(15) << items.password << endl;
            }
        }
        cout << "\nPress ENTER to return to the main menu..." << endl;
        getchar();

    }
    
    // This functions generates the main menu
    void run_menu() {
        string input;
        do
        {
            cout << "\033c"; //This escapre sequence clears the console and resets the cursor to top-left
            cout << "You are logged in as " + active_user_name + " - Role type: " << displayUserType() << endl;
            cout << "You have the following options available, please make a selection" << endl << endl;
            cout << "1) View your own employee record." << endl;
            
            //The following conditionals are used to restrict meny view by user role
            if (active_user != Individual) { //HR & Manager Only
                cout << "2) View All Employees" << endl;
                cout << "3) Search for an employee." << endl;
                if (active_user != Management) { // HR Only
                    cout << "4) Modify an existing employee record" << endl;
                    cout << "5) Add a new employee record" << endl;
                    cout << "6) Delete an employee record" << endl;
                }
            }
            cout << "\n8) Switch User" << endl;
            cout << "9) Quit Program" << endl;

            cout << endl << "Please enter a selection: ";
            getline(cin, input);
            
            //Menu option handler
            //We verify permissions here, not showing the options isnt enough security
            switch (stoi(input)) {
            case 1:
                view_Self();
                break;
            case 2:
                if (active_user == Management || active_user == HR) {
                    view_All();
                }
                break;
            case 3:
                if (active_user == Management || active_user == HR) {
                    search_User();
                }
                break;
            case 4:
                if(active_user == HR) {
                    modify_User();
                }
                break;
            case 5:
                if (active_user == HR) {
                    employees.push_back(create_user());
                    save_data();
                    cout << endl << "New employee record added and saved." << endl;
                    cout << "Press ENTER to return to the main manu..." << endl;
                    getchar();
                }
                break;
            case 6:
                if (active_user == HR) {
                    delete_Employee();
                }
                break;
            case 8:
                user_login(); // Re-login as a different user
                break;
            case 9: //Return out of constructor, thus exiting the program
                return;
            default: //Go back to the meny display loop if they didnt hit a correct option
                break;
            }
        } while (true); //Infinite Loop to kepe the menu up
    }

public:

    //Class constructor handles the main program loop
    UserInteraction() {
        open_file();   //Open and read, or create new, file
        user_login();  //Handle user login
        run_menu();    //Generate the menu and loop it
    }

    // This function effectively converts the current user enumerated type to a string
    string displayUserType(UserType u) {
        switch (u)
        {
        case HR:
            return "HR";
            break;
        case Management:
            return "Manager";
            break;
        case Individual:
            return "Individual";
            break;
        default:
            return "Unknown User Type";
            break;
        }
    }

    //Overload function, to show just the current user role type
    string displayUserType() {
        switch (active_user)
        {
        case HR:
            return "HR";
            break;
        case Management:
            return "Manager";
            break;
        case Individual:
            return "Individual";
            break;
        default:
            return "Unknown User Type";
            break;
        }
    }

};
    
    int main() {
        //main program function, creates UserInteraction object
        //which handles main program loop and functions

        UserInteraction user; //Create user interaction object, which handles the main program interaction
        return 0;
    };