#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define CHMAX 50
typedef struct materie
{
    char nume_materie[CHMAX];
    int credite;
    float nota;
    struct materie *next;
}materie;

typedef struct student
{
    char nume_student[CHMAX];
    materie *sl;
    struct student *next;
}student;

student *root = NULL;

materie *creareMaterie(char *mat, int credit, float nota)
{
    materie *m = (materie *)malloc(sizeof(materie));
    strcpy(m->nume_materie, mat);
    m->credite = credit;
    m->nota = nota;
    m->next = NULL;

    return m;

}

student *creareStudent(char *nume)
{
    student *s = (student *)malloc(sizeof(student));
    strcpy(s->nume_student, nume);
    s->sl = NULL;
    s->next = NULL;

    return s;
}

student *existaStudent(char *nume)
{
    student *s = root;
    student *temp = NULL;

    while (s != NULL) {
        if (strcmp(s->nume_student, nume) == 0) {
            temp = s;
            return temp;
        }
        s = s->next;
    }

    return temp;

}

materie *adaugaMaterie(materie *lista, materie *x)
{
    materie *q1, *q2;
    for (q1 = q2 = lista; q1 != NULL && q1->nota > x->nota; q2 = q1, q1 = q1->next);

    if (q1 == q2) {
        x->next = lista;
        lista = x;
    }
    else {
        q2->next = x;
        x->next = q1;
    }
    return lista;
}

student *adaugaStudent(student *lista, student *x, materie *mat)
{
    student *q1, *q2;
    for (q1 = q2 = lista; q1 != NULL &&strcmp(q1->nume_student,x->nume_student)<0 ; q2 = q1, q1 = q1->next);

    if (q1 == q2) {
        x->next = lista;
        lista = x;
    }
    else {
        q2->next = x;
        x->next = q1;
    }
    x->sl = mat;
    return lista;
}

student *inserareStudent(student *stud, materie *mat)
{
    student *exSTUD;
    if (root == NULL)
    {
        stud->sl = mat;
        root = stud;
        return stud;
    }
    else
    {
        exSTUD = existaStudent(stud->nume_student);
        if (exSTUD != NULL)
        {
            if (exSTUD->sl == NULL)
            {
                exSTUD->sl = mat;
            }
            else {
                exSTUD->sl = adaugaMaterie(exSTUD->sl, mat);
            }
            return root;
        }
        else {
            return adaugaStudent(root, stud, mat);
        }
    }
}

void citire()
{
    char nume[CHMAX], mat[CHMAX];
    int credit;
    float note;
    student *nodSTUD;
    materie *nodMAT;
    FILE *f = fopen("examen.txt", "rt");

    if (!f) {
        fprintf(stderr, "Eroare la deschiderea fisierului\n");
        exit(EXIT_FAILURE);
    }

    while (!feof(f)) {
        fscanf(f, "%s %s %d %f", nume, mat, &credit, &note);

        nodMAT = creareMaterie(mat, credit, note);
        nodSTUD = creareStudent(nume);
        root = inserareStudent(nodSTUD, nodMAT);
    }
    fclose(f);
}

void afisare()
{
    student *student;
    materie *materii;
    int contor = 1;

    for (student = root; student != NULL; student = student->next) {
        printf("%d. %s\n", contor++, student->nume_student);
        for (materii = student->sl; materii != NULL; materii = materii->next) {
            printf("\t%s %d %f\n", materii->nume_materie, materii->credite, materii->nota);
        }
        printf("________________________________________\n\n");
    }
}

void afisareMaterie(char *nume)
{
    int flag = 0;
    student *stud;
    materie *mat;

    for (stud = root; stud != NULL; stud = stud->next) {
        for (mat = stud->sl; mat != NULL; mat = mat->next)
        {
            if (strcmp(mat->nume_materie, nume) == 0)
            {
                printf("%s %d %f\n",stud->nume_student, mat->credite, mat->nota);
                flag = 1;
            }
        }
    }
    if (!flag) {
        printf("Nu exista materia cu numele introdus\n ");
    }
}

void salvareRestantieri() {
    materie *mat;
    student *stud;

    FILE *g;

    for (stud = root; stud != NULL; stud = stud->next) {
        for (mat = stud->sl; mat != NULL; mat = mat->next) {
            if (mat->nota < 5)
            {
                printf("%s %s %d %f\n", stud->nume_student, mat->nume_materie, mat->credite, mat->nota);
            }
        }
    }
    g = fopen("retante.txt", "wt");

    if (g)
    {
        for (stud = root; stud != NULL; stud = stud->next) {
            for (mat = stud->sl; mat != NULL; mat = mat->next) {
                if (mat->nota < 5)
                {
                    fprintf(g,"%s %s %d %f\n", stud->nume_student, mat->nume_materie, mat->credite, mat->nota);
                }
            }
        }

    }
    fclose(g);
}
int main()
{
    int opt;
    char materie[CHMAX];
    do {
        //printf("\n__________________________________\n\n");
        printf("\n1. Citire din fisier\n");
        printf("2. Afisare date\n");
        printf("3. Afisare date despre o materie\n");
        printf("4. Salvare in fisier 'restante' a studentilor restantieri\n");
        printf("0. Iesire\n");

        printf("\nIntroduceti optiunea: ");
        scanf("%d", &opt);
        printf("\n");

        switch (opt)
        {
        case 1:
            citire();
            break;
        case 2:
            afisare();
            break;
        case 3:
            printf("Introduceti numele materiei: ");
            scanf("%s", materie);
            afisareMaterie(materie);
            break;
        case 4:
            salvareRestantieri();
            break;
        case 0: exit(0);
            break;

        default: printf("Optiune gresita\n");
            break;

        }
    } while (opt != 0);
    return 0;
}