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

typedef struct {
    int code;
    char name[20]; // הספר שם
    char author[20]; // הספר מחבר
    int amount;
}book;

FILE* bDB;
void main();


book books[500];


int print_main()
{
    printf("------------- M E N U ---------\na-- - Add a new Book\ni-- - increase items quantity\nd-- - decrease items quantity\nm-- - find maximum books\nx-- - To delete book \np----Print Books all \ns----Save to File\nl----Load from File\nq----Quit To\n");
    return getchar();
}

int check_empty()
{
    int i = 0;
    while (books[i].code != 0)i++;
    return i;
}

void new_book()
{
    system("cls");
    int bID = check_empty();
    printf("\nBook name:");
    while (getchar() != '\n');
        gets_s(books[bID].name, 20);
    printf("\nBook Code: ");
        scanf_s("%d", &books[bID].code);
    printf("\nAuthor: ");
    while (getchar() != '\n');
        gets_s(books[bID].author, 20);
    printf("Amount:");
        scanf_s("%d", &books[bID].amount);
    main();
}

void book_increase()
{
    int bID;
    int bCode = 0;
    int incAmount;
    printf("\nBook code?\n");
    scanf_s("%d", &bCode);
    for (bID = 0; bID < 500; bID++)
        if (books[bID].code == bCode)
        {
            printf("\nBook found\n");
            printf("increase by how much?\n");
            scanf_s("%d", &incAmount);
            books[bID].amount += incAmount;
            printf("%s increased by %d", books[bID].name, incAmount);
            main();
        }

    printf("Failed to find specificed book");
    main();

}

void book_decrease()
{
    int bID;
    int bCode = 0;
    int decAmount;
    printf("\nBook code?\n");
    scanf_s("%d", &bCode);
    for (bID = 0; bID < 500; bID++)
        if (books[bID].code == bCode)
        {
            printf("\nBook found\n");
            printf("decrease by how much?\n");
            scanf_s("%d", &decAmount);
            books[bID].amount -= decAmount;
            printf("%s decreased by %d", books[bID].name, decAmount);
            main();
        }

    printf("Failed to find specificed book");
    main();

}

void maximum_books()
{
    int bID = 0;
    for (int i = 0; i < 500; i++)
        if (books[bID].amount < books[i].amount) i = bID;

    printf("Maximum Books are: %d\n Book Name: %s\n", books[bID].amount, books[bID].name);
    main();
}

int delete_book()
{
    int bID;
    int bCode = 0;
    printf("\nBook code?\n");
    scanf_s("%d", &bCode);
    for (bID = 0; bID < 500; bID++)
        if (books[bID].code == bCode)
        {
            printf("\nBook deleted\n");
            books[bID].code = NULL;
            books[bID].amount = NULL;
            main();
        }

    printf("Failed to find specificed book");
    main();
}

void print_books()
{
    for (int i = 0; i < 500; i++)
    {
        if (books[i].code != 0)
        {
            printf("Book code: %d\n Book Name: %s\n Book author: %s\n Book amount: %d\n",
                books[i].code, books[i].name, books[i].author, books[i].amount);
        }
    }
    printf("Press any key to continue");
    int key = 0;
    while (key == 0)
    {
        scanf_s("%d", &key);
    }
    main();
}

void save_to_file()
{
    remove(bDB);
    bDB = fopen("books.ini", "w+");
    if (bDB == NULL)exit(EOF);
    for (int bID = 0; bID < 500; bID++)
    {
        fprintf(bDB, "%d %-20.20s %-20.20s %d\n", books[bID].code, books[bID].name, books[bID].author, books[bID].amount);

    }
    fclose(bDB);
    main();
}

void load_from_file()
{
    bDB = fopen("books.ini", "r");
    int test;
    if (bDB == NULL)exit(EOF);
    for (int bID = 0; bID < 500; bID++)
    {
        fscanf_s(bDB, "%d ", &books[bID].code);
        fgets(books[bID].name, 20, bDB);
        fgets(books[bID].author, 20, bDB);
        fscanf_s(bDB, "%d ", &books[bID].amount);
    }
    fclose(bDB);
    main();
}

void main()
{
    while (1)
    {
        system("cls");
        switch (print_main())
        {
        case 'a':
            new_book();
            break;
        case 'i':
            book_increase();
            break;
        case 'd':
            book_decrease();
            break;
        case 'm':
            maximum_books();
            break;
        case 'x':
            delete_book();
            break;
        case 'p':
            print_books();
            break;
        case 's':
            save_to_file();
            break;

        case 'l':
            load_from_file();
            break;
        case 'q':
            exit(1);
            break;
        }
    }
}