import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Random;
import java.util.Scanner;
import java.util.Set;
import java.util.concurrent.ThreadLocalRandom;

public class BankingSystem {
    static Scanner scanner = new Scanner(System.in);
    public static void main(String[] args) {
        selectChoice();
        String[] strArray = new String[3];
        routeChoice(strArray);
        choiceAfterLoggedIn();

    }

    public static void selectChoice() {
        System.out.println("1. Create an account");
        System.out.println("2. Log into an account");
        System.out.println("0. Exit");
    }


    public static void routeChoice(String [] choices) {

        for (int i = 0; i < choices.length; i++ ){
            choices[i] = scanner.nextLine();
            switch (i) {
            case 1 : createAccount();
            break;

            case 2 : ValidateCardNumberAndPin();
            break;

            case 3 : choiceAfterLoggedIn();

            System.out.println("You have successfully logged out");
            }
        }
    }

    public static void createAccount(){
        System.out.print("Your card number has been created");
        System.out.println("Your card number :" + generateRandomNumber());
        System.out.println("Your card PIN: " + generatePin());
    }


    //ThreadLocalRandom.current().nextLong(min, max);
    //min <= randomLongNumber < max
    public static String generateRandomNumber() {

        //int BIN = new Random(400000).nextInt();
        int BIN = ThreadLocalRandom.current().nextInt(40000, 50000);
        String random = Integer.toString(BIN);
        Random randomobj = new Random();
        //long seed = 1000000000;
        //randomobj.setSeed(seed);
        //new Random().nextInt((10-5+1))+5; // [5,10], upper bound included
        Long random10digits = ThreadLocalRandom.current().nextLong(10000000000L,90000000000L);
        String random1 = Long.toString(random10digits);

        return random + random1;
    }

    //generate a pin in a range from 0000 to 9999
    public static String generatePin() {
        Random rnd = new Random();
        int Pin = rnd.nextInt(9999);
        String pin = Integer.toString(Pin);
        return pin;
    }

    public static void LogIntoAccount() {
        ValidateCardNumberAndPin();
    }

    //  you can use HashMap to store the acc number and pin. then you can use getOrDefault to get the pin from the acc number (if u have done it in this way HashMap<acc, pin> )
    //  and if that value is not present you can return a default value.

    //  Hashmap makes it easy also a good practice for it, example cardNumber = 400k (400 000) + 10x random digit 0-9
    //  cards.get(inputCardNumber).equals(inputPIN) ... looking for pairs matching with the input where cards is my Hashmap
    //  public static void ValidateCardNumberAndPin() {
    //      System.out.println("Enter your card number: ");
    //      String userCardNo = scanner.nextLine();
    //      System.out.println("Enter your PIN: ");
    //      String userPIN = scanner.nextLine();
    //      if (userCardNo == generateRandomNumber() && userPIN == generatePin()) {
    //          System.out.println("You have successfully logged in!");
    //          choiceAfterLoggedIn();
    //      } else {
    //          System.out.println("Wrong card number of PIN!");
    //          LogIntoAccount();
    //      }
    //  }

    //using hashmap

    public static HashMap<String, String> StoreUserCardAndPin() {
        int BIN = ThreadLocalRandom.current().nextInt(40000, 50000);
        String random = Integer.toString(BIN);
        Random randomobj = new Random();
        Long random10digits = ThreadLocalRandom.current().nextLong(10000000000L,90000000000L);
        String random1 = Long.toString(random10digits);
        String CardNo = random + random1;
        Random rnd = new Random();
        int Pin = rnd.nextInt(9999);
        String pin = Integer.toString(Pin);
        HashMap<String, String> maptoAccPin = new HashMap<>();
        maptoAccPin.put(CardNo, pin);

        return maptoAccPin;
    }

    public static void ValidateCardNumberAndPin() {
        System.out.println("Enter your card number: ");
        String userCardNo = scanner.nextLine();
        System.out.println("Enter your PIN: ");
        String userPIN = scanner.nextLine();
        System.out.println("the keys to this customer account is  :"  + StoreUserCardAndPin());
        if (StoreUserCardAndPin().entrySet().equals(userCardNo) && StoreUserCardAndPin().entrySet().contains(userPIN)) {
        System.out.println("You have successfully logged in!");
            choiceAfterLoggedIn();
        }else {

            System.out.println("Wrong card number of PIN!");
            LogIntoAccount();
        }
    }



    public static void choiceAfterLoggedIn() {
        String[] selection = new String[3];
        System.out.println("1. Balance");
        System.out.println("2. Log out");
        System.out.println("3. Exit");
        for (int i = 0; i < selection.length; i++) {

            selection[i] = scanner.nextLine();
            if ( selection[i].equals(1)) {
                System.out.println("Balance: " + "0");
            }
            if (selection[i].equals(2)) {
                System.out.println("You have successfully logged out");
            } else {
                System.out.println("Bye!");
            }
        }
    }


}