#include <iostream>
#include <fstream>
#include <stdlib.h>
using namespace std;

//-------------------------------------------------------------------------------------------------------------------------------
// Function Prototypes and declarations
//-------------------------------------------------------------------------------------------------------------------------------
ifstream inputFromFile;
ofstream outputToFile;

void loginChoice();
void administratorLogin();
void memberChoice();
void lecturerLogin();
void studentLogin();
void administratorMenu();
void lecturerMenu();
void studentMenu();

//-------------------------------------------------------------------------------------------------------------------------------
// Function to open and write a file
//-------------------------------------------------------------------------------------------------------------------------------
void openWriteFile(const string filename)
{
  outputToFile.clear();  
  outputToFile.open(filename.c_str(),ios::in);
  if (!outputToFile) 
      cout << "There was an error opening the file" << endl;      
}    

//-------------------------------------------------------------------------------------------------------------------------------
// Function to close a written file
//-------------------------------------------------------------------------------------------------------------------------------
void closeWriteFile()
{
   outputToFile.close();
}    

//-------------------------------------------------------------------------------------------------------------------------------
// Function to open and read a file
//-------------------------------------------------------------------------------------------------------------------------------
int openReadFile(const string filename)
{
  inputFromFile.clear();  
  inputFromFile.open(filename.c_str(),ios::in);
  if (!inputFromFile) 
      cout << "There was an error opening the file" << endl;      
}    

//-------------------------------------------------------------------------------------------------------------------------------
// Function to close a read file
//-------------------------------------------------------------------------------------------------------------------------------
int closeReadFile()
{
   inputFromFile.close();
}    

//-------------------------------------------------------------------------------------------------------------------------------
// The Main Function
//-------------------------------------------------------------------------------------------------------------------------------
int main(int argc, char *argv[])
{
  loginChoice();
  return 0;
}

//-------------------------------------------------------------------------------------------------------------------------------
// Login Choice
//-------------------------------------------------------------------------------------------------------------------------------
void loginChoice()
{
   int choice; 
    
    cout <<" ||------------------------------||"<<endl;             
    cout <<" ||Multimedia Room Booking System||"<<endl;
    cout <<" ||------------------------------||"<<endl;
    cout <<" || Please choose:               ||"<<endl;
    cout <<" ||                              ||"<<endl;
    cout <<" || '1' for administrators       ||"<<endl;
    cout <<" || '2' for members              ||"<<endl;
    cout <<" || '3' to exit program          ||"<<endl;
    cout <<" ||------------------------------||"<<endl<<endl<<endl;
    
    cout <<  "Your choice is: ";
    cin >> choice ;

    if (choice == 1)
    {
        system ("cls");
        administratorLogin();
    }        
    else if (choice == 2)
    {
        system ("cls");
        memberChoice();        
    }        
    else if (choice == 3)
    {
        // will exit
    }        
    else 
    {
        cout <<endl<<"Please choose from the list above"<<endl;
        system ("PAUSE");
        system ("cls");
        loginChoice();
    }
}

//-------------------------------------------------------------------------------------------------------------------------------
// Administrator Login
//-------------------------------------------------------------------------------------------------------------------------------
void administratorLogin()
{
 int a, ID_number = 0;
 string password, b;
      
 cout<<"                ID number :  "; 
 cin>>ID_number;
 cout<<"                   |    "<<endl;
 cout<<"                Password  :   ";
 cin>>password;
 system("cls");
 
 openReadFile("AdministratorPassword.txt");
 while(!inputFromFile.eof())
 {
  inputFromFile>>a>>b;
  if(!inputFromFile.fail())
  {
   if((a==ID_number)&&(b==password))
   {
    closeReadFile();
    administratorMenu();
   }
  }
 }
 if((a!=ID_number)||(b!=password))
  {
  cout<<"Your ID number or password is invalid "<<endl;
  closeReadFile();
  system ("PAUSE");
  system ("cls");
  loginChoice();
  }
}

//-------------------------------------------------------------------------------------------------------------------------------
// Administrator Menu
//-------------------------------------------------------------------------------------------------------------------------------
void administratorMenu()
{
    cout <<"there will be a menu here";
    system ("PAUSE");
    system ("cls");
    loginChoice();
}


//-------------------------------------------------------------------------------------------------------------------------------
// Member Type Choice
//-------------------------------------------------------------------------------------------------------------------------------
void memberChoice()
{
   int choice;
     
    cout <<" ||------------------------------||"<<endl;
    cout <<" || Members Login                ||"<<endl;
    cout <<" ||------------------------------||"<<endl;
    cout <<" || Please press:                ||"<<endl;
    cout <<" ||                              ||"<<endl;
    cout <<" || '1' for lecturers            ||"<<endl;
    cout <<" || '2' for students             ||"<<endl;
    cout <<" || '3' back to first menu       ||"<<endl;
    cout <<" || '4' to exit program          ||"<<endl;
    cout <<" ||------------------------------||"<<endl<<endl<<endl;
    
    cout <<  "Your choice is: ";
    cin >> choice ;

    if (choice == 1)
    {
        system("cls");
        lecturerLogin();
    }
    else if (choice == 2)
    {
        system("cls");
        studentLogin();
    }
    else if (choice == 3)
    {
        system("cls");
        loginChoice();
    }
    else if (choice == 4)
    {
        //will exit
    }
    else
    {
        cout <<endl<<"Please choose from the list above"<<endl;
        system ("PAUSE");
        system ("cls");
        memberChoice();
    }
}

//-------------------------------------------------------------------------------------------------------------------------------
// Lecturer Login
//-------------------------------------------------------------------------------------------------------------------------------
void lecturerLogin()
{
 int a, ID_number = 0;
 string password, b;
      
 cout<<"                ID number :  "; 
 cin>>ID_number;
 cout<<"                   |    "<<endl;
 cout<<"                Password  :   ";
 cin>>password;
 system("cls");
 
 openReadFile("LecturerPassword.txt");
 while(!inputFromFile.eof())
 {
  inputFromFile>>a>>b;
  if(!inputFromFile.fail())
  {
   if((a==ID_number)&&(b==password))
   {
    closeReadFile();
    lecturerMenu();
   }
  }
 }
 if((a!=ID_number)||(b!=password))
  {
  cout<<"Your ID number or password is invalid "<<endl;
  closeReadFile();
  system ("PAUSE");
  system ("cls");
  memberChoice();
  }
}

//-------------------------------------------------------------------------------------------------------------------------------
// Lecturer Menu
//-------------------------------------------------------------------------------------------------------------------------------
void lecturerMenu()
{
    cout <<"there will be a menu here";
    system ("PAUSE");
    system ("cls");
    memberChoice();
}

//-------------------------------------------------------------------------------------------------------------------------------
// Student Login
//-------------------------------------------------------------------------------------------------------------------------------
void studentLogin()
{
 int a, ID_number = 0;
 string password, b;
      
 cout<<"                ID number :  "; 
 cin>>ID_number;
 cout<<"                   |    "<<endl;
 cout<<"                Password  :   ";
 cin>>password;
 system("cls");
 
 openReadFile("StudentPassword.txt");
 while(!inputFromFile.eof())
 {
  inputFromFile>>a>>b;
  if(!inputFromFile.fail())
  {
   if((a==ID_number)&&(b==password))
   {
    closeReadFile();
    studentMenu();
   }
  }
 }
 if((a!=ID_number)||(b!=password))
  {
  cout<<"Your ID number or password is invalid "<<endl;
  closeReadFile();
  system ("PAUSE");
  system ("cls");
  memberChoice();
  }
}

//-------------------------------------------------------------------------------------------------------------------------------
// Student Menu
//-------------------------------------------------------------------------------------------------------------------------------
void studentMenu()
{
    cout <<"there will be a menu here";
    system ("PAUSE");
    system ("cls");
    memberChoice();
}

int a;

while(true)
{
    cout << "enter the value of a:";
 
    if(cin >> a)    //this test will fail if you recieved input other than the type of a
    {
         while(cin.get() != '\n');    //after a was filled, this will eat up the rest of the line
                                      //until it finds \n, which is when the user pressed 'enter'
         break; //stop getting input
    }
    cin.clear();   //cin failed...this will clear that fail bit
    while(cin.get() != '\n');    // same reason as above
}

...
int main()
{
     int choice;
     cout<<"Enter a Number between 1 and 5: ";     //'a' is entered
     cin>>choice;     //infinite loop
     if(choice<static_cast<char>(1+'0')  ||  choice>static_cast<char>(5+'0'))
          cout<<"That is not a Valid Choice";
}

...
int main()
{
     char choice;
     cout<<"Enter a Number between 1 and 5: ";     //'a' is entered
     cin>>choice;     //accepts ANY keyboard input
     if(choice<static_cast<char>(1+'0')  ||  choice>static_cast<char>(5+'0'))  //not what it wanted
          cout<<"That is not a Valid Choice";     //no infinite loop here - just a message and the program is under control
}