CENG 103 LAB - 24.12.2018

#include <stdio.h>

int findSizeOfFile(FILE *file_reader) {
    char holder, size = 0;

    int status = fscanf(file_reader, "%c", &holder);

    for (int i = 0; status != EOF; i++) {
        if (holder == '\n')
            size++;

        status = fscanf(file_reader, "%c", &holder);

        if (status == EOF)
            size++;
    }

    fclose(file_reader);

    return size;
}

void readWordFromFile(FILE *file_reader, char list_arr[][100]) {
    char holder;

    int status = 0;

    for (int i = 0; status!=EOF; i++) {

        status = fscanf(file_reader, "%c", &holder);

        for (int j = 0; holder!='\n'; j++) {
            list_arr[i][j] = holder;

            status = fscanf(file_reader, "%c", &holder);

            if (status == EOF)
                break;
        }
    }

    fclose(file_reader);
}

void displayArray(char arr[][100], int size) {
    for (int i = 0; i < size; i++) {
        printf("%s\n", arr[i]);
    }
}

void menu(char user_arr[], char pass_arr[]) {
    int error=0;
    char holder;

    printf("\n---------------------------\nWELCOME TO THE DATABASE OF PENTAGON\n");

    printf("---------------------------\nUsername: ");
    scanf("%s", user_arr);

    holder = '*';

    do {
        for (int i = 0; holder != '\0'; i++) {
            holder = user_arr[i];
            if (((holder >= 48 && holder <= 57) || (holder >= 65 && holder <= 90)) || holder == '\0')
                error = 0;
            else {
                error = 1;
                break;
            }
        }

        if (error == 1) {
            holder = '*';
            printf("\nInput can consist only of capital letters and numerals. Please enter an input accordingly: ");
            scanf("%s", user_arr);
        }
    } while (error == 1);

    printf("---------------------------\nPassword: ");
    scanf("%s", pass_arr);

    holder = '*';

    do {
        for (int i = 0; holder != '\0'; i++) {
            holder = pass_arr[i];
            if (((holder >= 48 && holder <= 57) || (holder >= 65 && holder <= 90)) || holder == '\0')
                error = 0;
            else {
                error = 1;
                break;
            }
        }

        if (error == 1) {
            holder = '*';
            printf("\nInput can consist only of capital letters and numerals. Please enter an input accordingly: ");
            scanf("%s", pass_arr);
        }
    } while (error == 1);
}

int findSize(char arr[]) {
    char holder = '*';
    int size = 0;

    for (int i = 0; arr[i] != '\0'; i++)
        size++;

    return size;
}

int isEqual(char input_arr[], char list_arr[], int input_size, int list_size) {
    if (input_size != list_size)
        return 0;

    for (int i = 0; i < input_size; i++) {
        if (input_arr[i] != list_arr[i])
            return 0;
    }

    return 1;
}

int main() {
    FILE *user_reader = fopen("Users.txt", "r");
    FILE *password_reader = fopen("Passwords.txt", "r");

    char users[100][100] = {}, passwords[100][100] = {};
    char username[100] = {}, password[100] = {};

    int orderNumber;

    readWordFromFile(user_reader, users);
    readWordFromFile(password_reader, passwords);

    user_reader = fopen("Users.txt", "r");
    int sizeOfUsers = findSizeOfFile(user_reader);

    password_reader = fopen("Passwords.txt", "r");
    int sizeOfPasswords = findSizeOfFile(user_reader);

    do {
        int i;

        menu(username, password);

        for (i = 0; i < sizeOfUsers; i++) {
            if (isEqual(username, users[i], findSize(username), findSize(users[i])) == 1) {
                orderNumber = i;
                break;
            }
            else
                orderNumber = -1;
        }

        if (orderNumber != -1) {
            if (isEqual(password, passwords[i], findSize(password), findSize(passwords[i])) == 1)
                printf("---------------------------\n\nYou're now (somehow) logged in to Pentagon, great job\n");
            else
                printf("(!)\n\nPassword is not correct\n");
        }

        else
            printf("\n(?)\nUsername not found\n");
    } while (orderNumber == -1);

    return 0;
}