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

void read_file(void);
void add_student(void);
void search_student_id(void);
void delete_student_info(void);
void edit_student_info(void);
void display_info(void);
void display_all_id(void);
void save(void);

struct students {

    int student_id;
    float score ;
};

struct students info[100];


int i;

void main (){

    int choice ;

    while (1){


        printf("\t------MENU------\n\n");
        printf("1.Read the student info\n");
        printf("2.Add a student\n");
        printf("3.Search based on students ID\n");
        printf("4.Delete a students basic info by ID\n");
        printf("5.Edit a students basic info\n");
        printf("6.Display students info\n");
        printf("7.Display all existing students ID\n");
        printf("8.Save \n");

        printf("\n\nEnter your choice\n");
        scanf("%d",&choice);

        switch (choice ){

        case 1 : read_file () ;
            break;
        case 2 :  add_student(); ;
            break;
        case 3 : search_student_id() ;
            break;
        case 4 : //delete_student_info() ;
            break;
        case 5 : edit_student_info() ;
            break;
        case 6 : display_info() ;
            break;
        case 7 : display_all_id() ;
            break;
        case 8 : save() ;
            break;
        case 9 :
            //exit(0);
        default :
            printf(" \n Wrong Input\n");


        }
    }
}


void read_file( ){

    int NUM=5;
    FILE*fp;
    errno_t err= fopen_s(&fp,"studentinfo.txt","r");
    if ( err !=0 ) {
        printf("\nFile is not opened\n");
    }else{

        for( i = 0; i < NUM ; i++){
            fscanf_s(fp,"%d",&info[i].student_id);
            fscanf_s(fp,"%f\n",&info[i].score);
            printf("%d\t",info[i].student_id);
            printf("%.2f\n",info[i].score);
        }
        fclose(fp);
    }

}

void add_student( ){

    int j=i ;



            printf("\nEnter student id\n");
            scanf("%d",&info[j].student_id);
            printf("\nEnter students score\n");
            scanf("%f",&info[j].score);
            j++;
        i=j;

}

void display_all_id( ) {

    int l ;

    for(l=0;l<i;l++){

        printf("%d\t",info[l].student_id);
            printf("%.2f\n",info[l].score);
    }



}


void display_info() {

    int l,id , p ;

    printf("\n Enter ID : ");
    scanf("%d", &id);

    for ( l= 0 ; l< i ; l++ ){

        if ( id == info[l].student_id){
            p=l;
            break;
        }
    }

        printf("ID: %d score: %.2f", info[p].student_id , info[p].score);


}

void search_student_id( ) {

    int l,id , p = 0;

    printf("\n Enter ID : ");
    scanf("%d", &id);

    for ( l= 0 ; l< i ; l++ ){

        if ( id == info[l].student_id){
            p=l;
            printf("ID: %d score: %.2f", info[p].student_id , info[p].score);

            break;
        }else if ( id != info[l].student_id){
            printf("\nNot Found!!\n\n");
            break;
        }
    }


}

void save( ) {

    int e ;
    FILE*fp;
    errno_t err= fopen_s(&fp,"studentinfo.txt","w");
    if ( err !=0 ) {
        printf("\nFile is not opened\n");
    }else{

        for( e = 0; e <=i ; e++){
            fprintf(fp,"%d ",info[e].student_id);
            fprintf(fp,"%.2f\n",info[e].score);
        }
        fclose(fp);
    }
}

void edit_student_info( ) {

    int p=0, l , id;
    printf("\n Enter ID : ");
    scanf("%d", &id);

    for ( l= 0 ; l< i ; l++ ){

        if ( id == info[l].student_id){
            p=l;
            printf("\nedit id : ");
            scanf("%d" , &info[p].student_id);
            printf("\nedit score : ");
            scanf("%f" , &info[p].score);

            break;
        }else if ( id != info[l].student_id){
            printf("\nNot Found!!\n\n");
            break;
        }
    }
}