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

#define MAX_NAME 50
#define MAX_NUM  50

typedef struct
{
    char name[MAX_NAME];
    char surname[MAX_NAME];
    char number[MAX_NUM];
} Student;

void insertStudent(Student *student)
{
    char number[MAX_NUM];
    int flag = 0;
    printf("Enter name: ");
    scanf("%s", student->name);
    printf("Enter surname: ");
    scanf("%s", student->surname);
    
    do {
        printf("Enter number: ");
        scanf("%s", student->number);
        flag = 0;
        
        FILE *fp = fopen("ogrenci.txt", "r");
        char name[MAX_NAME], surname[MAX_NAME], num[MAX_NUM];
        while (fscanf(fp, "%s %s %s", name, surname, num) != EOF)
        {
            if (strcmp(student->number, num) == 0)
            {
                printf("Farkli id Giriniz..\n");
                flag = 1;
                break;
            }
        }
        fclose(fp);
    } while (flag);
    
    FILE *fp = fopen("ogrenci.txt", "a");
    fprintf(fp, "%s %s %s ", student->name, student->surname, student->number);
    fclose(fp);
}


void updateStudent(char *number, Student *student)  //dosyadaki veriyi güncelleme
{
    FILE *fp = fopen("ogrenci.txt", "r");
    FILE *fp2 = fopen("ogrenci2.txt", "w");
    char name[MAX_NAME];
    char surname[MAX_NAME];
    char num[MAX_NUM];
    int flag = 0;
    while (fscanf(fp, "%s %s %s", name, surname, num) != EOF)
    {
        if (strcmp(num, number) == 0)  
        {
            printf("Enter name: ");
            scanf("%s", student->name);
            printf("Enter surname: ");
            scanf("%s", student->surname);
            fprintf(fp2, "%s %s %s ", student->name, student->surname, num);
            flag = 1;
        }
        else
        {
            fprintf(fp2, "%s %s %s ", name, surname, num);
        }
    }
    fclose(fp);
    fclose(fp2);
    remove("ogrenci.txt");
    rename("ogrenci2.txt", "ogrenci.txt");
    if (flag == 0)
    {
        printf("No student");
    }
}


void deleteStudent(char *number)  //dosyadaki veriyi silme
{
    FILE *fp = fopen("ogrenci.txt", "r");
    FILE *fp2 = fopen("ogrenci2.txt", "w");
    char name[MAX_NAME];
    char surname[MAX_NAME];
    char num[MAX_NUM];
    while (fscanf(fp, "%s %s %s", name, surname, num) != EOF)
    {
        if (strcmp(num, number) != 0)
        {
            fprintf(fp2, "%s %s %s ", name, surname, num);
        }
    }
    fclose(fp);
    fclose(fp2);
    remove("ogrenci.txt");
    rename("ogrenci2.txt", "ogrenci.txt");
}

void listStudents()  //dosyadaki verileri listeleme
{
    FILE *fp = fopen("ogrenci.txt", "r");
    char name[MAX_NAME];
    char surname[MAX_NAME];
    char number[MAX_NUM];
    while (fscanf(fp, "%s %s %s", name, surname, number) != EOF)
    {
        printf("%s %s %s \n", name, surname, number);
    }
    fclose(fp);
}

int main()
{
	
    Student * student; // bir struct oluşturuluyor.
    student = (Student *)malloc(sizeof(Student));   //Struct için sistemden bellek alınıyor
    if(!student){
    	printf("bellek hatası");
    	return 1;
	}
    char number[MAX_NUM];
    int sec;
    while (1)
    {
        printf("\n1-Insert Student 2-Update Student 3-Delete Student 4-List Students 5-Exit\n");
        scanf("%d", &sec);
        switch (sec)
        {
        case 1:
            insertStudent(&student);
            break;
        case 2:
            printf("Enter number: ");
            scanf("%s", number);
            updateStudent(number, &student);
            break;
        case 3:
            printf("Enter number: ");
            scanf("%s", number);
            deleteStudent(number);
            break;
        case 4:
            listStudents();
            break;
        case 5:
            exit(0);
            break;
        default:
            printf("Wrong choice");
        }
    }
    return 0;
}