student.c

#include <stdio.h>
#include <string.h>
#include "student.h"
#include "file_handler.h"

void addStudent() {
    ensure_data_file();
    Student s;

    FILE *fp = fopen(STUDENT_DATA_FILE, "ab");
    if (!fp) {
        printf("Failed to open data file for writing\n");
        return;
    }

    printf("Enter ID (number): ");
    if (scanf("%d", &s.id) != 1) {
        while (getchar() != '\n');
        printf("Invalid ID\n");
        fclose(fp);
        return;
    }

    // Check duplicate
    Student tmp;
    long pos;
    if (find_student_by_id(s.id, &tmp, &pos)) {
        printf("Student with ID %d already exists\n", s.id);
        fclose(fp);
        return;
    }

    printf("Enter Name: ");
    getchar();
    fgets(s.name, sizeof(s.name), stdin);
    s.name[strcspn(s.name, "\n")] = '\0';

    printf("Enter Room No: ");
    if (scanf("%d", &s.room) != 1) {
        while (getchar() != '\n');
        printf("Invalid room\n");
        fclose(fp);
        return;
    }

    s.mealCount = 0;
    s.bill = 0.0f;

    if (fwrite(&s, sizeof(Student), 1, fp) != 1) {
        printf("Failed to write student to file\n");
    } else {
        printf("Student added successfully\n");
    }
    fclose(fp);
}

void viewStudents() {
    ensure_data_file();
    FILE *fp = fopen(STUDENT_DATA_FILE, "rb");
    if (!fp) {
        printf("Failed to open data file for reading\n");
        return;
    }

    Student s;
    printf("\n--- All Students ---\n");
    while (fread(&s, sizeof(Student), 1, fp) == 1) {
        printf("ID: %d | Name: %s | Room: %d | Meals: %d | Bill: %.2f\n",
               s.id, s.name, s.room, s.mealCount, s.bill);
    }

    fclose(fp);
}

void updateRoom() {
    int id;
    printf("Enter Student ID to update room: ");
    if (scanf("%d", &id) != 1) {
        while (getchar() != '\n');
        printf("Invalid ID\n");
        return;
    }
    updateStudentRoomInFile(id);
}

void showStudentInfo(int id) {
    ensure_data_file();
    Student s;
    long pos;

    if (find_student_by_id(id, &s, &pos)) {
        printf("\n--- Student Profile ---\n");
        printf("ID: %d\nName: %s\nRoom: %d\nMeals: %d\nBill: %.2f\n",
               s.id, s.name, s.room, s.mealCount, s.bill);
    } else {
        printf("Student with ID %d not found\n", id);
    }
}