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

const char FILE_NAME[] = "list.csv";

struct Student {
    int num;
    char* name;
    Student* next;
};

void addItemToList(Student* &theList, Student* theNewStudent){
    //(*theNewStudent).next = theList;
    theNewStudent->next = theList;
    theList = theNewStudent;

}

Student* createStudent(int num, char name[]){
    Student* newItem = new Student;
    newItem->num = num;
    newItem->name = new char[256];
    strcpy(newItem->name, name);
    newItem->next = nullptr;
    return newItem;
}

void printList(Student* theList){
    Student* it = theList;
    while (it != nullptr){
        cout << it->num << ": " << it->name << endl;
        it = it->next;
    }
}

Student* inputItem(){
    int num;
    char name[256];

    cout << "Type the number: ";
    cin >> num;

    cout << "Type the name: ";
    cin >> name;

    return createStudent(num, name);
}

void saveList(Student* theList){
    ofstream out;
    out.open(FILE_NAME);

    Student* it = theList;
    while (it != nullptr){
        out << '"' << it->num << "\";\"" << it->name << '"' << endl;
        //out << it->num << " " << it->name << endl;
        it = it->next;
    }

    out.close();

    cout << "List saved as " << FILE_NAME << ".\n";
}

void loadList(Student* &ourList){
    ifstream in;
    in.open(FILE_NAME);

    char line[4096];
    while (in.getline(line, 4096)){
        char* a = &(line[1]);
        int num = 0;
        while (*a != '"'){
            num += *a - '0';
            a++;

            if (*a != '"'){
                num *= 10;
            }
        }

        char name[256];
        a += 3;
        int pos = 0;
        while (*a != '"'){
            name[pos] = *a;
            pos++;
            *a++;
        }
        name[pos] = '\0';

        addItemToList(ourList, createStudent(num, name));

    }



    in.close();

}

int main(){
    Student* ourList = nullptr;

    unsigned ans = 1;

    while (true){
        cout << " \n------------------------------------------\n\n";
        cout << "Select an option: \n";
        cout << " [1] - Display List\n";
        cout << " [2] - Insert Item\n";
        cout << " [3] - Save List\n";
        cout << " [4] - Load List\n";
        cout << " [0] - Exit\n\n";
        cout << "Choice: ";
        cin >> ans;
        cout << endl;

        switch (ans){
        case 1:
            printList(ourList);
            break;

        case 2:
            addItemToList(ourList, inputItem());
            break;

        case 3:
            saveList(ourList);
            break;

        case 4:
            loadList(ourList);
            break;

        case 0:
            return 0;
            break;

        default:
            cout << "Command not supported.\n\n\n";
        }
    }
}