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




int main()
{

    FILE* data = fopen("data","rw");
    FILE* libbooks = fopen("books","r");
    int n;
    int o;
    char books [100];
    char bookname [30];
    char password [10];
    char username [10];
    char eof;
    int bob;
    char exiter;
    char password2 [10];
    char username2 [10];
    char eof2;
    char loginstatus [20];
    int userstatus = 0;
    int available;
    int copies;
    printf("WELCOME\n--------------------------\n\n");
    while (1)
    {
        printf("Please choose what to do: \n\n");
        printf("1- Login. \n 2- Scan for a book. \n 3- Request a book.\n 4- Exit.\n ");

        scanf("%d",&bob);
        switch (bob)
        {
        case 1:
            printf("Enter Username:\n");
            scanf("%s",username);
            printf("Enter Password:\n");
            scanf("%s",password);

            while (fscanf(data,"%c",&eof) != EOF)
            {
                fscanf(data,"%s %s",username2,password2);
                if( ( strcmp(password,password2) && strcmp(username,username2) ) == 0)
                {
                    printf("login accepted!\n\n");
                    userstatus = 1;
                    break;
                }


            }

            if(userstatus == 0)
                printf("Authentication failed!\n\n");

            break;

        case 2:

            printf("Enter the title of the book you want:\n");
            scanf("%s",bookname);

            while(fscanf(libbooks,"%c",&eof2) != EOF)
            {

                fscanf(libbooks,"%s %d %d",books,&available,&copies);
                if (strcmp( bookname,books) == 0)
                {

                    printf("Book found!\n");
                    if(available ==0 && copies == 0)
                    {
                        printf("The book is not available right know.\n");

                    }

                    else if (available != 0 && copies != 0)
                    {
                        printf("The book is available,there are %d copies of the book.\n",copies);
                    }
                }

            }

            break;
        case 4:
            return 0;
            break;

            case 5:
            if(userstatus == 1)
                printf("status: logged in\n\n");

            else
                printf("status: logged out\n\n");

            break;




        default:
            printf("Enter a number between the options listed above please.\n");

        }

        fclose(data);
        fclose(libbooks);

    }

    return 0;

}