#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
using namespace std;
void rgs();
void Menu();
void Login();

int ans1;
string charname, pw, user, pass;


int main()
{
    ifstream inFile;
    inFile.open("users.txt");
    string userset, passset;
    if (!inFile.is_open())
    {
        cout << "There is an error." << endl;
    }
    else
    {
	Menu();
	system("CLS");
	if (ans1==1)
	{
		Login();
	}
	else if (ans1==2)
	{
		rgs();
	}
	else
	{
		cout<<"You have entered an invalid option"<<endl;
	}
	system ("pause");
	return 0;
	}
}
void Login()
{
	ifstream inFile;
	inFile.open("users.txt");
	if (!inFile)
	{
		cout<<"Unable to load the database"<<endl;
	}
	else
	{
		cout << "Please enter your username: ";
		cin>> user;
		cout << "Please enter your password: ";
		cin >> pass;

		inFile>>charname>>pw;
		if (inFile.fail())
		{
			cout<<"Error"<<endl;
		}
		else if (charname==user && pw==pass)
		{
			cout<<"You have log on successfully."<<endl;
		}
		else
		{
			cout<<"You have entered the wrong username/password"<<endl;
		}
	}

}


void Menu()
{
	cout<<"Welcome to dungeon hunter!"<<endl;
	cout<<"Choose a choice below."<<endl;
	cout<<"1. Login"<<endl;
	cout<<"2. Register a new account"<<endl;
	cout<<"Please enter your option: ";
	cin>>ans1;
}

void rgs()
{
    ifstream inFile;
    ofstream newuser;
    string username, password, passwordconfirm;
    inFile.open("users.txt", ios::app);
    newuser.open("users.txt", ios::app);
    bool uservalid=false;
    while (!uservalid)
    {
        cout << "Username: ";
        cin >> username;
        cout << "Password: ";
        cin >> password;
        cout << "Confirm password: ";
        cin >> passwordconfirm;
        int m=0;
        int k=0;
        while (inFile >> user >> pass)
        {
            m++;
            if (username!=user)
                k++;
        }
        if (m==k && password==passwordconfirm)
            uservalid=true;
        else if (m!=k)
            cout << "There is already a user with this username." << endl;
        else
            cout << "The passwords given do not match." << endl;
    }
    newuser << username << " " << password << endl;;
    inFile.close();
    newuser.close();
}