import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

class AuthService {
    private Map<String, User> userList = new HashMap<>();
    private List<User> lastLogin = new ArrayList<>();
    static AuthService obj = new AuthService();

    private AuthService() {
    }

    public static AuthService getObject() {
        return obj;
    }

    public String check(String password) {
        if (password.length() < 8) {
            return "Password Not Valid!";
        }
        char[] b = password.toCharArray();

        for (int i = 0; i < b.length; i++) {
            if (Character.isUpperCase(b[i]) == true) {
                break;
            } else if (i == b.length - 1) {
                return "Password Not Valid!";

            }
        }
        for (int j = 0; j < b.length; j++) {
            if (Character.isLowerCase(b[j]) == true) {
                break;
            } else if (j == b.length - 1) {
                return "Password Not Valid!";

            }
        }
        for (int k = 0; k < b.length; k++) {
            if (Character.isDigit(b[k]) == true) {
                break;
            } else if (k == b.length - 1) {
                return "Password Not Valid!";

            }
        }
        for (int l = 0; l < b.length; l++) {
            if (b[l] == '@' || b[l] == '#' || b[l] == '$' || b[l] == '%' || b[l] == '^' || b[l] == '&' || b[l] == '+'
                    || b[l] == '=') {
                break;
            } else if (l == b.length - 1) {
                return "Password Not Valid!";

            }
        }
        return "";

    }

    public void signup(String username, String password) {
        if (userList.size() == 0) {

            if (check(password).equals("Password Not Valid!")) {
                System.out.println("Password Not Valid!");
                return;
            } else {
                System.out.println("SignUp Successful!");
                User u = new User(username, password, 0);
                userList.put(u.getUsername(), u);
                Leaderboard.getObject().addUser(u);
                return;
            }

        } else {

            if (userList.keySet().contains(username)) {
                System.out.println("Username Exists!");
                return;
            } else {

                if (check(password).equals("Password Not Valid!")) {
                    System.out.println("Password Not Valid!");
                    return;
                } else {

                    System.out.println("SignUp Successful!");
                    User u = new User(username, password, 0);
                    Leaderboard.getObject().addUser(u);
                    userList.put(u.getUsername(), u);

                    return;
                }

            }

        }

    }

    public String login(String username, String password) {
        if (userList.size() == 0) {
            System.out.println("Invalid Username or Password!");

            return ("Invalid Username or Password!");

        } else {

            if (userList.keySet().contains(username)) {

                if ((userList.get(username).getEncryptedPassword().equals(password))) {
                    System.out.println("Login Successful!");

                    lastLogin.add(userList.get(username));

                    return ("Login Successful!");
                } else {
                    System.out.println("Invalid Username or Password!");

                    return ("Invalid Username or Password!");

                }

            }

            System.out.println("Invalid Username or Password!");

            return ("Invalid Username or Password!");

        }

    }

    public Set<String> getUsers() {
        return (userList.keySet());
    }

    public User getlastlogin() {
        return (lastLogin.get(lastLogin.size() - 1));

    }

}