sys

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MOBILE_LENGTH 11
typedef struct {
    char name[256], mobile_number[MOBILE_LENGTH], book_name[256], author_name[256];
    int cost;
}data;

typedef enum {
    false,
    true
}bool;

int press(void);
void save_data(data client);
void flush(void);
void get_data(data *client);
bool continue_or_not(void);
void print_data(void);

int main(void) {
    data client;
    FILE *p;
    char file_name[MOBILE_LENGTH + 4];
    int numb;

    while(true) {
        numb = press();

        switch(numb) {
            case 1:
            get_data(&client);
            save_data(client);
            break;

            case 2:
            print_data();
        }

        if(continue_or_not())
            continue;
        else
            break;
    }

    return 0;
}

int press(void) {
    int temp;

    printf("press 1 for sign-up.\n");
    printf("press 2 to enter books.");

    while(true) {
        printf("\n> ");
        scanf("%d", &temp);

        if(temp == 1)
            return 1;

        else if(temp == 2)
            return 2;
    }
}

void save_data(data client) {
    FILE *temp;
    char file_name[MOBILE_LENGTH + 4];

    strcpy(file_name, client.mobile_number);
    strcat(file_name, ".txt");

    temp = fopen(file_name, "a+");

    if(temp == NULL) {
        fprintf(stderr, "error epenning the file.");
        exit(EXIT_FAILURE);
    }

    fprintf(temp, "%s%s\n%s%s%d\n", client.name, client.mobile_number, client.book_name, client.author_name, client.cost);
    fclose(temp);
    return;
}

void flush(void) {
    int flush = 0;

    while((flush = getchar()) != '\n' && flush != EOF);

    return;
}

void get_data(data *client) {
    flush();
    printf("customer name     : ");
    fgets(client->name, 256, stdin);

    printf("mobile number     : ");
    fgets(client->mobile_number, MOBILE_LENGTH, stdin);
    flush();

    printf("enter a book name : ");
    fgets(client->book_name, 256, stdin);

    printf("book author       : ");
    fgets(client->author_name, 256, stdin);

    printf("cost of the book  : ");
    scanf("%d", &client->cost);
    return;
}

bool continue_or_not(void) {
    char answer;
    while(true) {
        printf("would you like to continue ? (y/n) ");
        scanf(" %c", &answer);
        if(answer == 'y' || answer == 'Y')
            return true;

        else if(answer == 'n' || answer == 'N')
            return false;
    }
}

void print_data(void) {
    char file_name[MOBILE_LENGTH + 4];
    FILE *temp;
    data client;

    flush();
    printf("enter a mobile number : ");
    fgets(file_name, MOBILE_LENGTH, stdin);
    strcat(file_name, ".txt");

    temp = fopen(file_name, "r");
    if(temp == NULL) {
        printf("\nthis number isn't registered.\n");
        return;
    }

    fscanf(temp, "%s", client.name);
    fscanf(temp, "%s", client.mobile_number);
    fscanf(temp, "%s", client.book_name);
    fscanf(temp, "%s", client.author_name);
    fscanf(temp ,"%d", &client.cost);

    fclose(temp);

    printf("--------------------------------------\n");
    printf("name   : %s\n", client.name);
    printf("mobile : %s\n", client.mobile_number);
    printf("--------------------------------------\n");
    printf("book   : %s\n", client.book_name);
    printf("author : %s\n", client.author_name);
    printf("cost   : %d\n", client.cost);
    printf("--------------------------------------\n");
    return;
}