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

struct Kayit
{
    int ogrenciNo;
    int dersKodu;
    int puan;
};
struct Kayit data;

void kayitekle()
{
    FILE *openfile;
    openfile = fopen("ogrencidata.bin","ab+");
    if(openfile == NULL)
    {
        printf("Error in Opening file\nMake sure your file is not write protected","Warning");

    }
    else
    {
        fflush(stdin);
        printf("\t\tOgrenci No: \n");
        scanf("%d",&data.ogrenciNo);
        printf("\t\tDers Kodu: \n");
        scanf("%d",&data.dersKodu);
        printf("\t\tPuan: \n");
        scanf("%d",&data.puan);
        fwrite(&data, sizeof(data), 1, openfile);
    }
    fclose(openfile);
    return;
}

void kayitbul()
{
    int ogrenciNumarasi;
    int isFound = 0;
    printf("Ogrenci Numarasini Giriniz: \n");
    fflush(stdin);
    scanf("%d",&ogrenciNumarasi);
    FILE *openfile;
    openfile = fopen("ogrencidata.bin","rb");
    while(fread(&data,sizeof(data),1,openfile) == 1)
    {
        if(ogrenciNumarasi == data.ogrenciNo)
        {
            isFound = 1;
            break;
        }
    }
    if(isFound == 1)
    {
        printf("\t\tOgrenci bulundu\n");
        printf("\t\tOgrenci no: %d \n",data.ogrenciNo);
        printf("\t\tDers Kodu: %d \n",data.dersKodu);
        printf("\t\tPuan: %d \n",data.puan);
    }
    else
    {
        printf("Ogrenci bulunamadi");
    }
    fclose(openfile);
    return;
}

void kayitlarilistele()
{
    FILE *openfile;
    int i;
    openfile = fopen("ogrencidata.bin","rb");
    printf("\nTum ogrenciler:");
    printf("\n=======================");
    i=1;
    while((fread(&data,sizeof(data),1,openfile) == 1))
    {
        printf("\nOgrenci sirasi:%d",i);
        printf("\n------------------");
        printf("\nOgrenci numarasi:%d",data.ogrenciNo);
        i++;
        printf("\n=======================");

    }
    fclose(openfile);
}

void kayitguncelle()
{
    printf("Kayit guncelleme\n");
    int ogrenciNumarasi;
    int isFound = 0;
    printf("Kayit guncellemek istediginiz ogrencinin numarasini giriniz: ");
    fflush(stdin);
    scanf("%d",&ogrenciNumarasi);
    FILE *openfile;
    openfile = fopen("ogrencidata.bin","rb+");
    while(fread(&data, sizeof(data),1,openfile) == 1)
    {
        if(ogrenciNumarasi == data.ogrenciNo)
        {
            fflush(stdin);
            printf("Ogrenci Numarasi: ");
            scanf("%d",&data.ogrenciNo);
            printf("Ders Kodu: ");
            scanf("%d",&data.dersKodu);
            printf("Puan: ");
            scanf("%d",&data.puan);
            fseek(openfile,-sizeof(data),SEEK_CUR);
            fwrite(&data,sizeof(data),1,openfile);
            printf("Ogrenci basariyla guncellendi.");
            isFound = 1;
            break;
        }
    }

    if(!isFound)
    {
        printf("Kayit bulunamadi");
    }
    fclose(openfile);
    return;

}

void kayitsil()
{
    printf("Kayit silme ekrani\n");
    int ogrenciNumarasi;
    int isFound = 0;
    printf("Silmek istediginiz ogrencinin numarasini giriniz: ");
    fflush(stdin);
    scanf("%d",&ogrenciNumarasi);
    FILE *openfile, *temporary;
    openfile = fopen("ogrencidata.bin","rb");
    temporary = fopen("temp.bin", "wb");
    while(fread(&data,sizeof(data),1,openfile) == 1)
    {
        if(ogrenciNumarasi == data.ogrenciNo)
        {
            printf("Silindi");
            isFound = 1;
        }
        else
        {
            fwrite(&data,sizeof(data),1,temporary);
        }
    }
    if(!isFound)
    {
        printf("istenilen ogrenci bulunamadi");
    }
    fclose(openfile);
    fclose(temporary);
    remove("ogrencidata.bin");
    rename("temp.bin","ogrencidata.bin");
    printf("\nThe record is sucessfully deleted");
    return;
}
void showIndex(struct Kayit *index)
    {
        printf("\t\tOgrenci No : %d\t\t\t\t\t\tDers Kodu : %d\n\n", index->ogrenciNo,index->dersKodu);
    }
void kayitlarisiralilistele(){
        FILE *openfile;
        if ((openfile = fopen("ogrencidata.bin", "rb"))!=NULL)
        {
            size_t itemSize = sizeof(data);
            struct Kayit item;
            fread(&item,1,itemSize, openfile);
            while (!feof(openfile))
            {
                showIndex(&item);
                fread(&item,1,itemSize, openfile);
            }
            fclose(openfile);
        }
}
void kayitlarisirala()
{
        FILE *openfile;
        if ((openfile = fopen("ogrencidata.bin", "rb+"))!=NULL)
        {
            size_t itemSize = sizeof(data);
            struct Kayit data1, data2;
            int flag = 1;
            // bubble sort
            while(flag)
            {
                flag = 0;
                fread(&data1, itemSize, 1, openfile);
                fread(&data2, itemSize, 1, openfile);
                while (!feof(openfile))
                {
                    if (data2.ogrenciNo < data1.ogrenciNo)
                    {
                        fseek(openfile, (itemSize * -2), SEEK_CUR);
                        fwrite(&data2, itemSize, 1, openfile);
                        fwrite(&data1, itemSize, 1, openfile);
                        flag = 1;
                    }
                    else
                    {
                        data1 = data2;
                    }
                    fread(&data2, itemSize, 1, openfile);
                }
                if (flag)
                {
                    rewind(openfile);
                }
            }
            fclose(openfile);
        }
        kayitlarisiralilistele();
}
void anaekran()
{
    int option;
    while(1)
    {
        printf("\t\tChoose 1. Add Student\n");
        printf("\t\tChoose 2. Search Student\n");
        printf("\t\tChoose 3. Update Student\n");
        printf("\t\tChoose 4. Delete Student\n");
        printf("\t\tChoose 5. Show all Students\n");
        printf("\t\tChoose 6. Show all Students with Sorting\n");
        printf("\t\tChoose 7. Exit\n");
        scanf("%d",&option);
        switch(option)
        {
        case 1:
            kayitekle();
            break;
        case 2:
            kayitbul();
            break;
        case 3:
            kayitguncelle();
            break;
        case 4:
            kayitsil();
            break;
        case 5:
            kayitlarilistele();
            break;
        case 6:
            kayitlarisirala();
            break;
        case 7:
            exit(0);
            break;
        default:
            break;
        }
    }
}

int main()
{
    anaekran();
    return 0;
}