#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;

const int MAX_ENROLLMENTS=5;

struct Course{
    string courseID;
    int enrolDate;
    int fine;
};

struct Student{
    string stName;
    string stID;
    string stContact;
    int enrollmentCount = 0;
    Course enrollCourse[MAX_ENROLLMENTS];
};

//functions prototypes
void displayMenu();
void addStudent(Student Detail[], int&stCount);
void displayDetails(Student Detail[], int stCount);
void enrollInCourse(Student Detail[], int studentCount);
void displayenrollments(Student Detail[], int stCount);
void displayfines(Student Detail[], int stCount);
void displayoptionstoload(Student Detail[], int&stCount);
void displayoptionstosave(Student Detail[], int stCount);
void addStudentfromfile(Student Detail[], int&stCount);
void enrollInCoursefromfile(Student Detail[], int studentCount);
void displayDetailsinFile(Student Detail[], int stCount);
void displayenrollmentsinFile(Student Detail[], int stCount);
void displayfinesinFile(Student Detail[], int stCount);
void instructions();

int main(){
    cout<< "\t\t============Welcome to The Admin Portal============"<<endl;

    int MAX_STUDENTS;
    int LastDate,LastMonth,LastYear;
    int choice;
    cout<< "\nMaximum Students = ";
    cin>>MAX_STUDENTS;


    Student stDetail[MAX_STUDENTS];


    int studentCount = 0;

    do{
            displayMenu();
            cout << "Enter your choice: ";
            cin >> choice;
            if(cin){
            if(choice==1){
                addStudent(stDetail, studentCount);
            }else if(choice==2){
                displayDetails(stDetail, studentCount);
            }else if(choice==3){
                enrollInCourse(stDetail, studentCount);
            }else if(choice==4){
                displayenrollments(stDetail, studentCount);
            }else if(choice==5){
                displayfines(stDetail, studentCount);
            }else if(choice==6){
                instructions();
            }else if(choice==7){
                displayoptionstoload(stDetail, studentCount);
            }else if(choice==8){
                displayoptionstosave(stDetail, studentCount);
            }else if(choice==9){
                cout<< "\n\t\t\t========THANKS FOR USING PORTAL========"<<endl;
            }else{
                cout<< "Invalid Choice"<<endl;
            }
            }else{
                cin.clear();
                cin.ignore();
                cout<< "Invalid DataType"<<endl;
            }


    }while(choice!=9);



    return 0;
}

//display function
void displayMenu(){

    cout<< "\n\t=============== Student Registration System Menu ===============\n\n";
    cout<<left<<setw(50)<< "1 => Add new student"<<left<<setw(50)<< "2 => Display all students"<<endl;
    cout<<left<<setw(50)<< "3 => Enroll in a course" <<left<<setw(50)<< "4 => Display all enrollments"<<endl;
    cout<<left<<setw(50)<< "5 => Display all fines" <<left<<setw(50)<<"6 => Instructions"<<endl;
    cout<<left<<setw(50)<< "7 => Load data from file" <<left<<setw(50)<< "8 => Save data to file"<<endl;
    cout<<left<<setw(50)<< "9 => Exit"<<endl;
}


void addStudent(Student Detail[], int&stCount){
    string name,id,contact;
    bool duplicate=false;
    cout<< "\n\t\t=============== Register New Student ===============\n\n";
    cout<<"Enter Student Name = ";
    cin.ignore();
    getline(cin,name);
    cout<< "Enter Student ID = ";
    getline(cin,id);
    cout<< "Enter Student Contact INFO = ";
    getline(cin,contact);

    for (int i = 0; i < stCount; ++i) {
        if (Detail[i].stID == id) {
            cout<< "THIS STUDENT IS ALREADY PRESENT IN DTATABASE!!!"<<endl;
            duplicate=true;
            break;
        }
    }
    if(duplicate==0){
        Detail[stCount].stName= name;
        Detail[stCount].stID= id;
        Detail[stCount].stContact= contact;
        stCount++;
        cout<< "New Student is Enrolled SUCCESSFULY"<<endl;

    }
}

void displayDetails(Student Detail[], int stCount){
    cout<< "\n\t\t=============== Already Registered Students ===============\n\n";
     if (stCount == 0) {
        cout << "No students registered yet.\n";
    }else{
        cout<<left<<setw(10)<<"sr no."<<setw(20)<<"Student Name"<<setw(20)<<"Student ID"<<setw(25)<<"Student Contact"<<endl;
        for(int i=0 ; i<stCount;i++){
            cout<<left<<setw(10)<<i+1<<setw(20)<<Detail[i].stName<<setw(20)<<Detail[i].stID<<setw(25)<<Detail[i].stContact<<endl;
        }
    }
}


void enrollInCourse(Student Detail[], int studentCount) {
    string studentID;
    string courseID;

    cout << "Enter student ID: ";
    cin >> studentID;

    // Validate student ID
    int studentIndex = -1;
    for (int i = 0; i < studentCount; ++i) {
        if (Detail[i].stID == studentID) {
            studentIndex = i;
            break;
        }
    }

    if (studentIndex == -1) {
        cout << "Student not found. Please register the student first.\n";
        return;
    }

    if(Detail[studentIndex].enrollmentCount>=5){
        cout << "Maximum no. of courses Enrolled of that Student"<<endl;
        return;
    }

    cout << "Enter course ID: ";
    cin >> courseID;
    int j= Detail[studentIndex].enrollmentCount;
    // Validate course ID

    int d,m,y;

    cout << "Enter Enrollment Date (DD MM YYYY): ";
    cin >> d>>m>>y;
    if((d>0&&d<=31)&&(m==01||m==1)&&(y==2024)){

    // Get current date and time

            Detail[studentIndex].enrollCourse[j].enrolDate=d;

    // Enroll the student in the course

            Detail[studentIndex].enrollCourse[j].courseID = courseID;

            cout << "Enrollment successful.\n";

    // Increment enrollment count
            Detail[studentIndex].enrollmentCount++;

    //fine calculate
            if(d>0&&d<11){
                Detail[studentIndex].enrollCourse[j].fine=0;
            }else{
                int daysfine=d-10;
                Detail[studentIndex].enrollCourse[j].fine=500*daysfine;
            }
    }else{
        cout<< "Invalid Date"<<endl;
    }
}

void displayenrollments(Student Detail[], int stCount){
    cout<< "\n\t\t=============== Already Registered Courses ===============\n\n";
     if (stCount == 0) {
        cout << "No students registered yet.\n";
    }else{
        cout<<left<<setw(10)<<"sr no."<<setw(20)<<"Student Name"<<setw(20)<<"Student ID"<<setw(25)<<"Student Courses"<<setw(20)<<"Enrollment Date"<<endl;
        for(int i=0 ; i<stCount;i++){
            cout<<left<<setw(10)<<i+1<<setw(20)<<Detail[i].stName<<setw(20)<<Detail[i].stID;
            if(Detail[i].enrollmentCount>=1){
                for(int j=0; j<Detail[i].enrollmentCount; j++){
                    if(j==0){
                        cout<<setw(25)<< Detail[i].enrollCourse[j].courseID<< Detail[i].enrollCourse[j].enrolDate<<"/01/2024" <<endl;
                    }else{
                        cout<<setw(50)<<" "<<setw(25)<< Detail[i].enrollCourse[j].courseID << Detail[i].enrollCourse[j].enrolDate<<"/01/2024" <<endl;
                    }
                }
                cout<<endl;
            }else{
                cout<< setw(25)<<"No Course Registered"<<endl;
            }
        }
    }
}


void displayfines(Student Detail[], int stCount){
    cout<< "\n\t\t=============== Student Fine List ===============\n\n";
     if (stCount == 0) {
        cout << "No students registered yet.\n";
    }else{
        cout<<left<<setw(10)<<"sr no."<<setw(20)<<"Student Names"<<setw(20)<<"Student IDs"<<setw(25)<<"No. of Courses"<<setw(20)<<"Fines"<<endl;
        for(int i=0 ; i<stCount;i++){
                int sum=0;
            cout<<left<<setw(10)<<i+1<<setw(20)<<Detail[i].stName<<setw(20)<<Detail[i].stID;
            if(Detail[i].enrollmentCount>=1){
                for(int j=0; j<Detail[i].enrollmentCount; j++){
                        sum+=Detail[i].enrollCourse[j].fine;
                }
                cout<<setw(25)<< Detail[i].enrollmentCount<< sum<<endl;
            }else{
                cout<< setw(25)<<"No Course Registered"<<endl;
            }
        }
    }
}

void displayoptionstosave(Student Detail[], int stCount){

    cout<< "\n\t=============== Student Registration System Menu ===============\n\n";
    cout<<left<<setw(50)<< "1 => Display all students"<<endl;
    cout<<left<<setw(50)<< "2 => Display all enrollments"<<endl;
    cout<<left<<setw(50)<< "3 => Display all fines"<<endl;
    cout<<left<<setw(50)<< "4 => Exit"<<endl;
    cout << "Enter your choice : ";
    char choice;
    cin>>choice;
    switch(choice){
    case '1':
        displayDetailsinFile(Detail, stCount);
        break;
    case '2':
        displayenrollmentsinFile(Detail, stCount);
        break;
    case '3':
        displayfinesinFile(Detail, stCount);
        break;
    case '4':
        break;
    default:
        cout<<"invalid choice";
    }

}


void displayoptionstoload(Student Detail[], int&stCount){

    cout<< "\n\t=============== Student Registration System Menu ===============\n\n";
    cout<<left<<setw(50)<< "1 => Load students Data from f\File"<<endl;
    cout<<left<<setw(50)<< "2 => Load enrollments Data from File"<<endl;
    cout<<left<<setw(50)<< "3 => Exit"<<endl;
    cout << "Enter your choice : ";
    char choice;
    cin>>choice;
    switch(choice){
    case '1':
        addStudentfromfile(Detail, stCount);
        break;
    case '2':
        enrollInCoursefromfile(Detail, stCount);
        break;
    case '3':
        break;
    default:
        cout<<"invalid choice";
    }

}

void addStudentfromfile(Student Detail[], int&stCount){
    string name,id,contact;
    ifstream inFile;
    inFile.open("StudentData.txt");

     if (!inFile) {
        cout << "No previous data found.\n";
        return;
    }
    while(inFile>>name>>id>>contact){
        Detail[stCount].stName= name;
        Detail[stCount].stID= id;
        Detail[stCount].stContact= contact;
        stCount++;
    }

       cout<< "New Students is Enrolled SUCCESSFULY"<<endl;

       inFile.close();
}

void enrollInCoursefromfile(Student Detail[], int studentCount) {
    string studentID;
    string courseID;
    ifstream inFile;
    inFile.open("EnrollmentCourseData.txt");
    while(inFile>>studentID){

    // Validate student ID
    int studentIndex = -1;
    for (int i = 0; i < studentCount; ++i) {
        if (Detail[i].stID == studentID) {
            studentIndex = i;
            break;
        }
    }

    inFile >> courseID;
    int j= Detail[studentIndex].enrollmentCount;
    // Validate course ID

    int d,m,y;

    inFile >> d>>m>>y;
    if((d>0&&d<=31)&&(m==01||m==1)&&(y==2024)){

    // Get current date and time

            Detail[studentIndex].enrollCourse[j].enrolDate=d;

    // Enroll the student in the course

            Detail[studentIndex].enrollCourse[j].courseID = courseID;

    // Increment enrollment count
            Detail[studentIndex].enrollmentCount++;

    //fine calculate
            if(d>0&&d<11){
                Detail[studentIndex].enrollCourse[j].fine=0;
            }else{
                int daysfine=d-10;
                Detail[studentIndex].enrollCourse[j].fine=500*daysfine;
            }
    }

    }
      cout << "Enrollment successful.\n";
      inFile.close();
}


void displayenrollmentsinFile(Student Detail[], int stCount){
    ofstream outFile;
    outFile.open("DisplayEnrollments.txt");

    outFile<< "\n\t\t=============== Already Registered Courses ===============\n\n";
     if (stCount == 0) {
        outFile << "No students registered yet.\n";
    }else{
        outFile<<left<<setw(10)<<"sr no."<<setw(20)<<"Student Name"<<setw(20)<<"Student ID"<<setw(25)<<"Student Courses"<<setw(20)<<"Enrollment Date"<<endl;
        for(int i=0 ; i<stCount;i++){
            outFile<<left<<setw(10)<<i+1<<setw(20)<<Detail[i].stName<<setw(20)<<Detail[i].stID;
            if(Detail[i].enrollmentCount>=1){
                for(int j=0; j<Detail[i].enrollmentCount; j++){
                    if(j==0){
                        outFile<<setw(25)<< Detail[i].enrollCourse[j].courseID<< Detail[i].enrollCourse[j].enrolDate<<"/01/2024" <<endl;
                    }else{
                        outFile<<setw(50)<<" "<<setw(25)<< Detail[i].enrollCourse[j].courseID << Detail[i].enrollCourse[j].enrolDate<<"/01/2024" <<endl;
                    }
                }
                outFile<<endl;
            }else{
                outFile<< setw(25)<<"No Course Registered"<<endl;
            }
        }
    }

    outFile.close();
}


void displayfinesinFile(Student Detail[], int stCount){
    ofstream outFile;
    outFile.open("DisplayFInes.txt");

    outFile<< "\n\t\t=============== Student Fine List ===============\n\n";
     if (stCount == 0) {
        outFile << "No students registered yet.\n";
    }else{
        outFile<<left<<setw(10)<<"sr no."<<setw(20)<<"Student Names"<<setw(20)<<"Student IDs"<<setw(25)<<"No. of Courses"<<setw(20)<<"Fines"<<endl;
        for(int i=0 ; i<stCount;i++){
                int sum=0;
            outFile<<left<<setw(10)<<i+1<<setw(20)<<Detail[i].stName<<setw(20)<<Detail[i].stID;
            if(Detail[i].enrollmentCount>=1){
                for(int j=0; j<Detail[i].enrollmentCount; j++){
                        sum+=Detail[i].enrollCourse[j].fine;
                }
                outFile<<setw(25)<< Detail[i].enrollmentCount<< sum<<endl;
            }else{
                outFile<< setw(25)<<"No Course Registered"<<endl;
            }
        }
    }
    outFile.close();
}

void displayDetailsinFile(Student Detail[], int stCount){
    ofstream outFile;
    outFile.open("DisplayStdentDetails.txt");


    outFile<< "\n\t\t=============== Already Registered Students ===============\n\n";
     if (stCount == 0) {
        outFile << "No students registered yet.\n";
    }else{
        outFile<<left<<setw(10)<<"sr no."<<setw(20)<<"Student Name"<<setw(20)<<"Student ID"<<setw(25)<<"Student Contact"<<endl;
        for(int i=0 ; i<stCount;i++){
            outFile<<left<<setw(13)<<i+1<<setw(20)<<Detail[i].stName<<setw(25)<<Detail[i].stID<<setw(25)<<Detail[i].stContact<<endl;
        }
    }
    outFile.close();
}

void instructions(){
    cout<<"\t==============Student Registration System - Instructions and Policy==============\n\n";
    cout<< "HOW TO USE???\n\n1.  Adding a New Student:\n\t- Choose option 1 from the main menu.\n\t- Enter the student's name, ID, and contact information.\n\t- The system checks for duplicate IDs before enrolling a new student."<<endl<<endl;
    cout<< "2. Displaying All Students:\n\t- Choose option 2 from the main menu.\n\t- View a list of all currently registered students with their names, IDs, and contact information."<<endl<<endl;
    cout<< "3. Enrolling in a Course:\n\t- Choose option 3 from the main menu.\n\t- Enter the student ID.\n\t - Enter the course ID, enrollment date (DD MM YYYY), and validate the date.\n\t- The system checks for maximum course enrollments (up to 5) and calculates fines if applicable."<<endl<<endl;
    cout<< "4. Displaying All Enrollments:\n\t- Choose option 4 from the main menu.\n\t- View a list of all enrolled courses for each student, along with enrollment dates."<<endl<<endl;
    cout<< "5. Displaying All Fines:\n\t- Choose option 5 from the main menu.\n\t- View a list of fines for each student based on their course enrollments."<<endl<<endl;
    cout<< "6. Loading and Saving Data:\n\t- Choose options 7 and 8 from the main menu to load from and save data to files, respectively.\n\t- For loading, you can load both student and enrollment data from separate text files."<<endl<<endl;
    cout<< "7. Exiting the Program:\n\t- Choose option 9 to exit the program."<<endl<<endl;
    cout<< "\nPOLICY\n\t- The program is designed for managing student registrations, enrollments, and fines.\n\t- Respect the maximum limit of 5 enrollments per student.\n\t- Follow the specified format for input data, especially for dates (DD MM YYYY).\n\t- Be cautious to avoid duplicate student IDs during registration.\n\t- Save and load data using the provided options to maintain records.\n\t- The program calculates fines for late enrollments based on a fixed rate."<<endl<<endl;
    cout<< "\nThank you for using the Student Registration System! If you have any questions or encounter issues, refer to the instructions or contact the administrator for assistance."<<endl<<endl;

}