#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>
#include <cs50.h>

/*
1. Create function that creates random key.
2. memset(arr, 0, sizeof(arr));
*/

char random_key[6];
char plain_text[50];
int keychartoint(char letter);
char *encryption(char text[], char *key, char mode);
char *generate_key();
char correct_account_password[50];
bool check_username(string username, FILE *account_file);
bool check_password(string password, FILE *account_file);
int main(void)
{
    FILE *key = fopen("key.txt", "a");
    fclose(key);
    key = fopen("key.txt", "r");
    fgets(random_key, 6, key);
    if(strcmp(random_key, "") == 0)
    {
        strcpy(random_key, generate_key());
    }
    fclose(key);
    key = fopen("key.txt", "w");
    fputs(random_key, key);
    fclose(key);
    printf("Welcome to LocalPasswordManager! Do you have an account? Enter y for yes and n for no: ");
    string has_account = get_string();
    while(!(strcmp(has_account, "y") == 0 || strcmp(has_account, "n") == 0))
    {
        printf("Please enter either y for yes and n for no: ");
        has_account = get_string();
    }
    if(strcmp(has_account, "y") == 0)
    {
        FILE *accounts = fopen("accounts.txt", "r");
        printf("Please enter your username: ");
        string account_username = get_string();
        account_username = encryption(account_username, random_key, 'e');
        bool correct_username = false;
        while(!correct_username)//while the username is not correct
        {
            if (check_username(account_username, accounts))
            {
                correct_username = true;
                printf("Welcome\n");
            }
            else
            {
                printf("Please enter a valid username: ");
                account_username = get_string();
                account_username = encryption(account_username, random_key, 'e');
                fseek(accounts, 0, SEEK_SET);
            }
        }
        account_username = encryption(account_username, random_key, 'd');
        printf("%s, please enter your password: ", account_username);
        string account_password = get_string();
        account_password = encryption(account_password, random_key, 'e');
        char account_password_string[50];//						          <----------------------------// whY is this here
        strcpy(account_password_string, account_password);
        bool correct_password = false;
        while(!correct_password)
        {
            if(check_password(account_password_string, accounts))
            {
                correct_password = true;
            }
            else
            {
                printf("length of correct password: %lu\n", strlen(correct_account_password));
                printf("Please enter the correct password: ");
                printf("%s, %s, %s\n", correct_account_password, account_password_string, account_password);
                account_password = get_string();
                account_password = encryption(account_password, random_key, 'e');
                while(strcmp(account_password, correct_account_password) != 0)
                {
                    printf("Please enter the correct password: ");
                    account_password = get_string();
                    account_password = encryption(account_password, random_key, 'e');
                }
                correct_password = true;
            }
        }
        account_password = encryption(account_password, random_key, 'd');
        printf("Welcome!\n");
        fclose(accounts);
        //open account of username.txt
        //enter accounts
        //enter name of account
        //enter username for account
        //enter password
    }
    else
    {
        FILE *accounts = fopen("accounts.txt", "a");
        printf("Please create a new username: ");
		// add this to create the suer file with user's name
				char account_username[50];
				FILE *fp;
				scanf("%s",account_username);
				fp=fopen(account_name,"w");
				fclose(fp);
        //string account_username = get_string();
        account_username = encryption(account_username, random_key, 'e');
        fputs(account_username, accounts);
        fputs("\t", accounts);
        account_username = encryption(account_username, random_key, 'd');
        printf("Please create a password: ");
        string account_password = get_string();
        char account_username_string[50];
        strcpy(account_username_string, account_username);
        account_password = encryption(account_password, random_key, 'e');
        fputs(account_password, accounts);
        fputs("\n", accounts);
        account_password = encryption(account_password, random_key, 'd');
        fclose(accounts);
        printf("Welcome, %s!\n", account_username_string);
    }
    //while(key != quit)
    //{
        //display options for resetting the password, accessing a specific website‘s username
        //and password, adding a website, deleting a website, or changing website information.

        //if the user chooses to add a website, add the website information to the end of the file.


        //if the user chooses to delete website information, then replace the information with
        //spaces in the file and remove the website from the list.

        //if the user chooses to access a website‘s information, then
        //find the information on the file and display it,

        //if the user chooses to reset the one-time password, then decrypt the information
        //and encrypt it using the new one-time password.

        //If the user chooses to change website information, then ask the user if they want to
        //change the name, the username, or the password, and then change the text in
        //the file appropriately

        //here, ask the user what he or she would like to so
    //}

}
int keychartoint(char letter)
{
    int alpha_num = toupper(letter) - 65;
    return alpha_num;
}
char *encryption(char text[], char *key, char mode)
{
    //MODES: e-encrypt, d-decrypt
    //char plain_text_array[50];
    //char *plain_text = "                    ";
    //char plain_text[50];
    strcpy(plain_text, text);
    if(mode == 'e'){
    }
    int key_char = 0;
    for (int text_char = 0; text_char < strlen(text); text_char++)
    {
        if (isalpha(text[text_char]))
        {
            int char_num = text[text_char];
            /*Different algorithms are used for upper and lower case
            characters because of their differences in the ASCII index.*/
            if (isupper(text[text_char]))
            {
                char_num -= 65;
                if(mode == 'e')
                {
                    char_num = (char_num + keychartoint(key[key_char])) % 26;
                }
                else if(mode == 'd')
                {
                    char_num = (char_num - keychartoint(key[key_char]) + 26) % 26;
                }
                char_num += 65;
            }
            else
            {
                char_num -= 97;
                if(mode == 'e')
                {
                    char_num = (char_num + keychartoint(key[key_char])) % 26;
                }
                else if(mode == 'd')
                {
                    char_num = (char_num - keychartoint(key[key_char]) + 26) % 26;
                }
                char_num += 97;
            }
            plain_text[text_char] = char_num;
            key_char++;
            /*This if statement returns back to the first character
            if all of the characters in the keyword have been used.*/
            if (key_char >= strlen(key))
            {
                key_char = 0;
            }
        }
    }
    return plain_text;
}

char *generate_key()
{
    static char string_key[6];
    srand(time(NULL));
    int rand_num = (rand() % 26) + 65;
    for(int i = 0; i < 5; i++)
    {
        string_key[i] = rand_num;
        rand_num = (rand() % 26) + 65;
    }
    return string_key;
}

bool check_username(string username, FILE *account_file)
{
    char buffer[50];
    char current_character = fgetc(account_file);
    int i = 0;
    while(current_character != EOF)//while the file has not ended
    {
        while(current_character != '\t')
        {
            buffer[i] = current_character;
            current_character = fgetc(account_file);
            i++;
        }
        if(strcmp(buffer, username) == 0)
        {
            return true;
        }
        else
        {
            while(current_character != '\n' && current_character != EOF)
            {
                current_character = fgetc(account_file);
            }
        }
        memset(buffer, 0, sizeof(buffer));
        i = 0;
        current_character = fgetc(account_file);
    }
    return false;
}

bool check_password(string password, FILE *account_file)
{
    char buffer[50];
    char current_character = fgetc(account_file);
    int i = 0;
    while(current_character != '\n')
    {
        if(current_character == '\n')
        {
            break;
        }
        buffer[i] = current_character;
        current_character = fgetc(account_file);
        i++;
    }

    int j = 0;
    while(buffer[j] != '\0')
    {
        j++;
    }
    if(fgetc(account_file) != EOF)
    {
        buffer[j - 1] = 0;
    }
    if(strcmp(buffer, password) == 0)
    {
        return true;
    }
    else
    {
        strcpy(correct_account_password, buffer);
        return false;
    }
}