#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;

        return 1;

    }

    string s_username, s_password;

    while (file >> s_username >> s_password) {

        if (s_username == username && s_password == password) {

            cout << "Login Successful" << 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(const string search) {

    ifstream infile("s_record.txt");

    if (!infile) {

        cerr << "FAILED TO OPEN FILE" << endl;

        return;

    }

    ofstream outfile("save.txt");

    if (!outfile) {

        cerr << "FAILED TO OPEN OUTPUT FILE" << endl;

        return;

    }

    string line;

    bool found = false;

    // Write the header to save.txt

    while (getline(infile, line)) {

        if (line.find("STUDENT NAME") != string::npos || line.find("--------") != string::npos) {

            outfile << line << endl;  // Copy header and separator

            continue;

        }

        stringstream iss(line);

        string name, matric;

        int cos1, cos2, mth, gst;

        float gpa;

        // Extract name and the rest of the line

        size_t tabPos = line.find('\t');

        if (tabPos != string::npos) {

            name = line.substr(0, tabPos);

            line = line.substr(tabPos + 1);  // Remove name part from line

        }

        stringstream rest(line);

        if (getline(rest, matric, '\t') && (rest >> cos1) && (rest >> cos2) && (rest >> mth) && (rest >> gst) && (rest >> 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;

                // Save this specific record to the new file

                outfile << line << endl;

                found = true;

                break;

            }

        }

    }

    if (!found) {

        cout << "NO AVAILABLE MATRIC NUMBER FOUND\n" << endl;

    }

    infile.close();

    outfile.close();

}

void search_record(const 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;

        }

        stringstream iss(line);

        string name, matric;

        int cos1, cos2, mth, gst;

        float gpa;

        // Read the entire name (including spaces) up to the tab character

        size_t tabPos = line.find('\t');

        if (tabPos != string::npos) {

            name = line.substr(0, tabPos);

            line = line.substr(tabPos + 1); // Remove the name and tab from the line

        }

        // Use a new stringstream to parse the rest of the line

        stringstream rest(line);

        if (getline(rest, matric, '\t') && (rest >> cos1) && (rest >> cos2) && (rest >> mth) && (rest >> gst) && (rest >> 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();

}

void update_record() {

    string search;

    cout << "ENTER STUDENT'S MATRIC NUMBER TO UPDATE: ";

    cin >> search;

    ifstream infile("s_record.txt");

    if (!infile) {

        cerr << "FAILED TO OPEN FILE" << endl;

        return;

    }

    // we pasted the entire record to a place in memory using vec

    vector<string> lines;

    string line;

    while (getline(infile, line)) {

        lines.push_back(line);

    }

    infile.close();

    bool found = false;

    // Open the file for writing (truncate the file)

    ofstream outfile("s_record.txt");

    if (!outfile) {

        cerr << "FAILED TO OPEN FILE FOR WRITING" << endl;

        return;

    }

    // Rewrite the file with updated records

    for (size_t i = 0; i < lines.size(); i++) {

        line = lines[i];

        // Skip header and separator lines

        if (line.find("STUDENT NAME") != string::npos || line.find("--------") != string::npos) {

            outfile << line << endl;

            continue;

        }

        stringstream iss(line);

        string name, matric;

        int cos1, cos2, mth, gst;

        float gpa;

        

        //i used AI to learn more on including spaces as i was getting error

        size_t tabPos = line.find('\t');

        if (tabPos != string::npos) {

            name = line.substr(0, tabPos);

            line = line.substr(tabPos + 1); // Remove the name and tab from the line

        }

        

        stringstream rest(line);

        if (getline(rest, matric, '\t') && (rest >> cos1) && (rest >> cos2) && (rest >> mth) && (rest >> gst) && (rest >> gpa)) {

            if (search == matric) {

                found = true;

                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;

                

                cout << "\nENTER NEW GRADES:\n";

                cout << "COS 201: ";

                cin >> cos1;

                cout << "COS 212: ";

                cin >> cos2;

                cout << "MATH 231: ";

                cin >> mth;

                cout << "GST 201: ";

                cin >> gst;

                cout << "GPA: ";

                cin >> gpa;

                

                outfile << name << "\t" << matric << "\t" << cos1 << "\t" << cos2 << "\t" << mth << "\t" << gst << "\t" << gpa << endl;

                cout << "RECORD UPDATED SUCCESSFULLY!\n";

            } else {

                

                

                outfile << name << "\t" << matric << "\t" << cos1 << "\t" << cos2 << "\t" << mth << "\t" << gst << "\t" << gpa << endl;

            }

        }

    }

    if (!found) {

        cout << "NO AVAILABLE MATRIC NUMBER FOUND\n" << endl;

    }

    outfile.close();

}

void display_all() {

    ifstream infile("s_record.txt");

    if (!infile) {

        cerr << "FAILED TO OPEN FILE" << endl;

        return;

    }

    string line;

    bool firstLine = true;

    cout << "\nDISPLAYING ALL STUDENT RECORDS:\n";

    cout << "--------------------------------------------\n";

    while (getline(infile, line)) {

        

        

        if (line.find("STUDENT NAME") != string::npos || line.find("--------") != string::npos) {

            if (firstLine) {

                cout << line << endl; 

                firstLine = false;

            }

            continue;

        }

        

        if (line.empty()) {

            continue;

        }

        stringstream iss(line);

        string name, matric;

        int cos1, cos2, mth, gst;

        float gpa;

        //Borrowed the search function and pasted to search and update

        size_t tabPos = line.find('\t');

        if (tabPos != string::npos) {

            name = line.substr(0, tabPos);

            line = line.substr(tabPos + 1); 

        }

        stringstream rest(line);

        if (getline(rest, matric, '\t') && (rest >> cos1) && (rest >> cos2) && (rest >> mth) && (rest >> gst) && (rest >> gpa)) {

            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;

            cout << "--------------------------------------------\n";

        } 

    }

    infile.close();

}

int main() {

    int authenticator;

    string username, password, input;

    string search;

    cout << "--------------------------------------------" << endl;

    cout << "  PAU RESULT MANAGEMENT SYSTEM (GROUP 2!)   " << endl;

    cout << "--------------------------------------------" << endl;

    while (true) {

        cout << "\n\nEnter your credentials? (y/n)";

        string start;

        getline(cin, start);

        if (start == "n" || start == "N") {

            cout << "Program is coming to an end " << endl;

            return 0;

        } else if (start == "y" || start == "Y") {

            system("cls");

            cout << "Lets proceed!\n\n\n";

            break;

        } else {

            cout << "Please enter a valid input y or n" << endl;

        }

    }

    do {

        cout << "Enter username : ";

        getline(cin, username);

        cout << "Enter password for " << username << ":";

        getline(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;

            cin.ignore();  // Clear the newline character left in the input buffer

           if (input == "p")

           {

               cout << "SEARCH FOR A STUDENT TO SAVE THEIR RECORD\n";

               cout << "ENTER STUDENT'S MATRIC NUMBER: ";

               cin.ignore(); // Clear input buffer

               getline(cin, search);  // Get the matric number to search

               save_record(search);  // Save the specific record to save.txt

           }

            else if (input == "q" || input == "Q") {

                cout << "SEARCH RECORD" << endl;

                cout << "ENTER STUDENTS MATRIC NUMBER\n";

                cin >> search;

                search_record(search);

            } else if (input == "a" || input == "A") {

                display_all();

            } else if (input == "u" || input == "U") {

                update_record();

            } else if (input == "e") {

                break;

            }

    }

			while (input != "e");

    return 0;

}}