#include <iostream>
#include <vector>
#include <new>
#include <string>
#include <fstream>
#include <sstream>
using namespace std;
int authorization(string username,string password)
{
    ifstream file("password.txt");
    if(!file.is_open())
    {
        cerr << "FAILED TO OPEN FILE" <<  endl;
    }
    string s_username,s_password;
    while(file >> s_username >> s_password)
    {
        if(s_username == username && s_password == password)
        {
            cout << "Login Succesfull" <<  endl;
            return 0;
        }          
    }
    cout  << "Invalid credentials" << endl;
            return 1;
}
string a_lowercase(string str)
{
    for (char &c : str)
    {
        c = tolower(c); 
    }
    return str;
}
string a_uppercase(string str)
{
    for (char &c : str)
    {
        c = toupper(c); 
    }
    return str;
}
void save_record()
{
    ofstream outfile("s_record.txt",ios::app);
    if(!outfile)
    {
        cerr << "FAILED TO OPEN FILE" <<  endl;
        return ;
    }
    outfile.seekp(0,ios::end);
    if(outfile.tellp() == 0)
    {
        outfile << "STUDENT NAME\tMAT NO\tCOS201\tCOS212\tMATH231\tGST201\tGPA\n";
        outfile << "----------------------------------------------------------\n";
    }
    string name,matric;
    int cos1,cos2,mth,gst;
    float gpa;
    cout << "\nEnter Student Name\t";
    cin.ignore();
    getline(cin,name);
    name = a_uppercase(name);
    cout << "\nEnter Student's Matric Number\t";
    cin.ignore();
    getline(cin, matric);
    cout << "\nGrades\nCOS 201\t";
    cin  >> cos1;
    cout << "\nCOS 212\t";
    cin  >> cos2;
    cout << "\nMATH231\t";
    cin  >> mth;
    cout << "\nGST201\t";
    cin  >> gst;
    cout << "\nGPA\t";
    cin  >> gpa;
    
    outfile << name << "\t" << matric << "\t" << cos1 << "\t" << cos2 << "\t" << mth << "\t" << gst << "\t" << gpa << "\t";
    outfile.close();
    cout << "DATA ENTERED SUCCESSFULLY\n" << endl;
}
void search_record(string search)
{
    ifstream infile("s_record.txt");
    
    if(!infile)
    {
        cerr << "FAILED TO OPEN FILE" <<  endl;
        return ;
    }
    string line;
    bool found = false;
    while(getline(infile,line))
    {
        if(line.find("STUDENT NAME") != string::npos || line.find("--------") != string::npos)
        {
            continue;
        }
        string name,matric,line;
        int cos1,cos2,mth,gst;
        float gpa;
        stringstream iss(line);
        getline(iss,name,'\t');
        getline(iss,matric,'\t');
        iss >> cos1 >> cos2 >> mth >> gst >> gpa;
        if(search == matric)
        {
            cout << "\nSTUDENT FOUND: \n";
            cout << "Name: " << name << endl;
            cout << "Matric Number: " << matric << endl;
            cout << "COS 201: " << cos1 << endl;
            cout << "COS 212: " << cos2 << endl;
            cout << "MATH 231: " << mth << endl;
            cout << "GST 201: " << gst << endl;
            cout << "GPA: " << gpa << endl;
            found = true;
            break;
        }
    }
    if(!found)
        {
            cout << "NO AVAILABLE MATRIC NUMBER FOUND\n" << endl;
        }
    infile.close();  
}
int main()
{
    int begin;
    int authenticator;
    string username,password,input;
    bool valid = false;
    string search;
    cout << "        PAU RESULT MANAGEMNT SYSTEM         "  << endl;
    
    do
    {
    cout << "Do You Want TO Enter Your Credentials ?(1/2)\n";
    cin  >> begin;
       if(begin == 1)
       {
          do
          {
            cout << "Enter username : ";
            cin  >> username;
            cout << "Enter password for "  << username << ":";
            cin  >> password;
            authenticator = authorization(username,password);
          }while(authenticator != 0);
          
          if(authenticator == 0)
          {
            do
            {
                cout << "\tMAIN MENU\nTO SEARCH FOR STUDENTS RESULT ENTER Q\nTO UPDATE A STUDENTS RESULT ENTER U\nTO SAVE A STUDENT RESULT TO A FILE ENTER P\nTO VIEW ALL RESULT ENTER A\nTO EXIT THE PROGRAM ENTER E\nENTER AN OPTION\n";
                cin  >> input;
                if(input == "p")
                {
                    cout << "PRINT RESULT FILE" << endl;
                    save_record();
                }
                else if(input == "q" || input == "Q")
                {
                    cout << "SEARCH RECORD" << endl;
                    cout << "ENTE STUDENTS MATRIC NUMBER\n";
                    cin.ignore();
                    getline(cin, search);
                    search_record(search);
                }
                else if(input == "e")
                {
                    break;
                }
            }while(input != "e");
          }
       }
       else if(begin == 2)
       {
       cout << "Program is coming to an end " << endl;
       }
       else
       {
       cout << "Wrong character entered\nEnter the proper character" << endl;
       }
    }while(begin != 2);
    
    return 0;
}