main.cpp

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <fstream>

using namespace std;

typedef struct students{
    string student_id;
    string name;
    string cpf;
    struct students *next; 
} student_regist;


typedef struct subjects{
    string subj_id;
    string name;
    string teacher;
    float credits;
    struct subjects *next;
} subject_regist;


typedef struct periods{
    float period;
    vector<string> subjs_id;
    struct periods *next;
} period_schedule;


typedef struct student_subj{
    float period;
    string student_id;
    vector<string> subjs_id;
    struct student_subj *next;
} period_class;


subjects *lista=NULL;


struct subjects *busca_subjects (string id, struct subjects *lista, struct subjects **ant)
{
    struct subjects *aux=lista; 
    *ant = NULL;          

    while ( (aux != NULL) && (aux->subj_id != id))
    {
        *ant = aux;
        aux = aux->next;
    }
    return aux;
}


int inserir_subjects (string id, string name, string teacher, float credits, struct subjects **lista){
    struct subjects *aux=NULL;
    struct subjects *ant=NULL;
    
    aux = busca_subjects (id, *lista, &ant);
    
    if (aux != NULL)
        return 0;
    else
    {
        aux = new subjects;
        aux->subj_id = id;
        aux->name = name;
        aux->teacher = teacher;
        aux->credits = credits;
        aux->next = NULL;
        if (ant == NULL)
            *lista = aux;
        else
            ant->next = aux;
        return 1;
    }   
}


void print_subjects (subjects *lista)
{
    struct subjects *aux = lista;
    
    while (aux != NULL)
    {
        cout << aux -> subj_id << endl << aux->name << endl << aux->teacher << endl << aux->credits << endl;
        aux = aux->next;
    }
    cout << "\n";
}


int remove_subject (string id, struct subjects **lista)
{
    struct subjects *aux = NULL;
    struct subjects *ant = NULL;
    
    aux = busca_subjects (id, *lista, &ant);
    
    if (aux == NULL)
        return 0;
    else
    {
        if (ant == NULL)
        {
            *lista = aux->next;
            delete (aux);
            return 1;
        }
        else
        {
            ant->next = aux->next;
            delete (aux);
            return 1;
        }
    }
}


periods *listap=NULL;


struct periods *busca_periods (float period, struct periods *lista, struct periods **ant)
{
    struct periods *aux=lista; 
    *ant = NULL;          

    while ( (aux != NULL) && (aux->period != period))
    {
        *ant = aux;
        aux = aux->next;
    }
    return aux;
}


int inserir_periods (float period, vector<string> ids , struct periods **listap, subjects *lista){

    for (string id : ids) {
            subjects *ant;
            subjects *subject_aux = busca_subjects(id, lista, &ant);
            if (subject_aux == NULL) {
                cout << "subject " << id << " not found. Please register it" << endl;
                return 0;
            }
    }
        
    
    struct periods *aux=NULL;
    struct periods *ant=NULL;
    
    aux = busca_periods (period, *listap, &ant);
    
    if (aux != NULL)
        return 0;
    else
    {
        aux = new periods;
        aux->period = period;
        aux->subjs_id = ids;
        aux->next = NULL;
        if (ant == NULL)
            *listap = aux;
        else
            ant->next = aux;
        return 1;
    }   
}


void print_periods (periods *lista)
{
    struct periods *aux = lista;
    
    while (aux != NULL)
    {
        cout << aux->period << endl;
        for (string id : aux->subjs_id) {
            cout << id << " ";
        }
        cout << endl;
        aux = aux->next;
    }
    cout << "\n";

}


int remove_period (float period, struct periods **listap)
{
    struct periods *aux = NULL;
    struct periods *ant = NULL;
    
    aux = busca_periods (period, *listap, &ant);
    
    if (aux == NULL)
        return 0;
    else
    {
        if (ant == NULL) 
        {
            *listap = aux->next;
            delete (aux);
            return 1;
        }
        else
        {
            ant->next = aux->next;
            delete (aux);
            return 1;
        }
    }
}


void subjects_csv(subjects *lista) {
    ofstream arquivo("subjects.csv"); 
    
    if (arquivo.is_open()) { 
        subjects *aux = lista;
        while (aux != NULL) {
            arquivo << aux->subj_id << ",";
            arquivo << aux->name << ",";
            arquivo << aux->teacher << ",";
            arquivo << aux->credits << endl;
            aux = aux->next;
        }
        arquivo.close(); 
    } else {
        cout << "Erro ao abrir o arquivo 'assuntos.csv' para escrita." << endl;
    }
}


void periods_csv(periods *listap) {
    ofstream arquivo("periods.csv"); 
    
    if (arquivo.is_open()) { 
        periods *aux = listap;
        while (aux != NULL) {
            arquivo << aux->period << ",";
            for (size_t i = 0; i < aux->subjs_id.size(); ++i) {
                arquivo << aux->subjs_id[i];
                if (i != aux->subjs_id.size() - 1) {
                    arquivo << ",";
                }
            }
            arquivo << endl;
            aux = aux->next;
        }
        arquivo.close();
    } else {
        cout << "Erro ao abrir o arquivo 'periodos.csv' para escrita." << endl;
    }
}


void register_student(student_regist** rptr){
    //append a new student in the end of the struct
     
    student_regist *new_regist;
    students *it_ptr;
    it_ptr = *rptr;

    new_regist = new student_regist;
    cout << "Please insert students credentials \nID: ";
    cin >> (*new_regist).student_id;  
    cout << "\nName: ";
    cin >> (*new_regist).name;
    cout << "\nCPF: ";
    cin >> (*new_regist).cpf;

    while(it_ptr != NULL){
        if ((*it_ptr).student_id == (*new_regist).student_id){
            cout << "Student already registered with name " << (*it_ptr).name << " and CPF " << (*it_ptr).cpf; 
            return;
        }
    }

    it_ptr = (**rptr).next;

    if(*rptr == NULL){
        // Empty list
        *rptr = new_regist;
    }
    else{
        while((*it_ptr).next != NULL){
            it_ptr = (*it_ptr).next;
        }

        (*it_ptr).next = new_regist;
    }
}


void remove_student(student_regist** rptr){
    //remove student by its ID

    string removed_id;
    student_regist *it_ptr;
    student_regist *bin;
    it_ptr = (**rptr).next;
    int removed = 0;

    cout << "Please insert the ID you want to remove: ";
    cin >> removed_id;

    if((**rptr).student_id == removed_id){
        *rptr = (**rptr).next;
    }
    else{
        while((*it_ptr).next != NULL){
            bin = (*it_ptr).next;

            if((*bin).student_id == removed_id){
                (*it_ptr).next = (*bin).next;
                delete bin;
                removed = 1;
            }
            it_ptr = (*it_ptr).next;
        }
    }
    if (removed == 1){
        cout << "Student removed";
    }
    else{
        cout << "Student not found";
    }
}


void search_std_subj(student_subj** rptr, subjects **sptr){
    // search student's subject by its ID and its period

    string search_std_id;
    float search_period;
    student_subj *it_ptr = *rptr;
    subjects *sec_it_ptr = *sptr;
    int is_found = 0;

    cout << "Please insert the ID of the student: ";
    cin >>  search_std_id;
    cout << "Please insert the period you wan't to search for: ";
    cin >> search_period;

    if (rptr == NULL){
        // empty struct
        cout << "Empty database";
        return;
    }
    else{
        while(it_ptr != NULL){
            if (((*it_ptr).period == search_period) && ((*it_ptr).student_id == search_std_id)){
                is_found = 1;
                for(unsigned int i=0; i < (*it_ptr).subjs_id.size(); i++){
                    while(sec_it_ptr != NULL){
                        if ((*sec_it_ptr).subj_id == (*it_ptr).subjs_id[i]){
                            cout << (*sec_it_ptr).name << " -> " << (*sec_it_ptr).teacher << " -> " << (*sec_it_ptr).credits << "\n";
                        }
                        sec_it_ptr = (*sec_it_ptr).next;
                    }
                    sec_it_ptr = *sptr;
                }
            }
            it_ptr = (*it_ptr).next;
        }
        if (is_found == 0){
            cout << "Pair ID/period not found";
        }
    }
}


void search_subj_std(student_subj** rptr, students** sptr){
    // search students doing a subject

    float search_period;
    string search_subj_id;
    vector<string> student_list;
    student_subj* it_ptr = *rptr;
    students* sec_it_ptr = *sptr;
    int is_found = 0;

    cout << "Please insert the ID of the subject: ";
    cin >>  search_subj_id;
    cout << "Please insert the period you wan't to search for: ";
    cin >> search_period;

    if (rptr == NULL){
        // empty struct
        cout << "Empty database";
        return;
    }
    else{
        while(it_ptr != NULL){
            if (((*it_ptr).period == search_period) && (count((*it_ptr).subjs_id.begin(), (*it_ptr).subjs_id.end(), search_subj_id) >= 1)){
                student_list.push_back((*it_ptr).student_id);
                is_found = 1;
            }
            it_ptr = (*it_ptr).next;
        }
        for(unsigned int i=0; i < student_list.size(); i++){
            while(sec_it_ptr != NULL){
                if((*sec_it_ptr).student_id == student_list[i]){
                    cout << (*sec_it_ptr).name << " -> " << (*sec_it_ptr).cpf << "\n";
                }
                sec_it_ptr = (*sec_it_ptr).next;
            }
            sec_it_ptr = *sptr;
        }
        if (is_found == 0){
            cout << "There's no student registered for this subject";
        }
    }
}


void register_new_std_class(student_subj** rptr, subjects** sptr, students** stdptr){
    // register student's subject by period

    student_subj new_regist;
    student_subj* it_ptr = *rptr;
    student_subj* last_el_ptr;
    subjects* third_it_ptr = *sptr;
    students* sec_it_ptr = *stdptr;
    string subject;
    int is_found = 0;
    int is_std_regist = 0;
    int is_subj_regist = 0;

    cout << "Please insert the period you wan't to register: ";
    cin >> new_regist.period;
    cout << "Please insert the student's ID: ";
    cin >>  new_regist.student_id;
    cout << "Please insert the subjects you wan't register and when finished type done: ";

    while (cin >> subject && subject != "done") {
        new_regist.subjs_id.push_back(subject);
    }
    // first check if the subject ids are registered in the subjects LE
    // check it for the student id too

    while(sec_it_ptr != NULL){
        if ((*sec_it_ptr).student_id == new_regist.student_id){
            is_std_regist = 1;
        }
        sec_it_ptr = (*sec_it_ptr).next;
    }
    if (is_std_regist != 1){
        cout << "Student not found on the database. Please register it";
        return;
    }

    for (unsigned int i=0; i < new_regist.subjs_id.size(); i++){
        is_subj_regist = 0;
        while(third_it_ptr != NULL){
            if ((*third_it_ptr).subj_id == new_regist.subjs_id[i]){
                is_subj_regist = 1;
            }
            third_it_ptr = (*third_it_ptr).next;
        }
        if (is_subj_regist == 0){
            cout << "The following subject ID wasn't found: " << new_regist.subjs_id[i]; 
        }
    }

    if (is_subj_regist == 0){
        return;
    }

    // search for the period/std ID pair and append the current subject list if found
    // else just add the struct in the end of the database

    while(it_ptr != NULL){
        if (((*it_ptr).period == new_regist.period) && ((*it_ptr).student_id) == new_regist.student_id){
            (*it_ptr).subjs_id.insert((*it_ptr).subjs_id.end(), new_regist.subjs_id.begin(), new_regist.subjs_id.end());
            is_found = 1;
        }
        last_el_ptr = it_ptr;
        it_ptr = (*it_ptr).next;
    }
    if (is_found == 0){
        (*last_el_ptr).next = &new_regist;
    }
}


void remove_std_class(student_subj** rptr){
    string removed_std_id;
    float removed_std_period;
    student_subj* it_ptr = *rptr;
    student_subj* last_el = NULL;

    cout << "Please insert the ID you want to remove: ";
    cin >> removed_std_id;
    cout << "Please insert the period associated: ";
    cin >> removed_std_period;

    if(((**rptr).period == removed_std_period) && ((**rptr).student_id == removed_std_id)){
        *rptr = (**rptr).next;
    }
    else{
        while(it_ptr != NULL){
            if (((*it_ptr).student_id == removed_std_id) && ((*it_ptr).period == removed_std_period)){
                (*last_el).next = (*it_ptr).next;
            }
            else{
                last_el = it_ptr;
            }
            it_ptr = (*it_ptr).next;
        }
    }
}


int main(){
    /*
    inserir_subjects ("2411","Matematica discreta", "Veloso", 100, &lista);
    inserir_subjects ("2412","Sitemas Digitais", "Rotava", 100, &lista);
    inserir_subjects ("2321","Calculo 3", "Lima Vaz", 100, &lista);
    print_subjects(lista);
    inserir_periods (24.1,{"2411", "2412"} ,&listap, lista);
    inserir_periods (23.2,{"2321"} ,&listap, lista);
    print_periods(listap);
    periods_csv(listap);
    subjects_csv(lista);
    */
   int is_running = 1;
   int action;
   while(is_running == 1){
        cout << "Type the number in front of each option to choose an action:\n1)Register new student\n2)Register new subject\n3)Register new period\n4)Register student's subject\n5)Remove student\n6)Remove student's subjects\n7)Remove period\n8)Remove subject\n";
        cin >> action;
        cout << "Type 1 to keep using the aplications. Type 0 otherwise";
        cin >> is_running;
   }
}