Account.java

import java.util.HashMap;
import java.util.Arrays;
import java.io.File;
import java.lang.StringBuilder;

public class Account {

    private String first, last, email, username;
    private int id; // user id
    private String password; // hexadecimal representation of hashed bytes of String password
    private static HashMap<Integer, Account> idToAcc = new HashMap<Integer, Account>();
    private static HashMap<String, String> loginInfo = new HashMap<String, String>();
    private static HashMap<String, Integer> userToID = new HashMap<String, Integer>();

    // constructor
    public Account(String first, String last, String email, String username, String password) {
        this.first = first;
        this.last = last;
        this.email = email;
        this.username = username;
        this.password = password;
        this.id = idToAcc.size(); // assign unique id to this account
    }

    // creates new account
    public static void create(String f, String l, String e, String u, String p) {

        // check if arguments are allowed
        try {
            checkProfanity(f);
            checkProfanity(l);
            checkProfanity(u);
            checkUserValidity(u);
            checkEmailValidity(e);
            checkPasswordLength(p);
        }
        catch (IllegalArgumentException x) {
            System.out.println("Error.");
        }
        String pass = Encrypt.encrypt(p);

        Account newUser = new Account(f, l, e, u, pass);
        idToAcc.put(newUser.id, newUser);
        loginInfo.put(newUser.email, newUser.password);
        userToID.put(newUser.username, newUser.id);
    }

    // throws error if username contains profanity
    private static void checkProfanity(String m) {
        if (m.contains("Fuck") || m.contains("fuck") || m.contains("Shit") || m.contains("shit") || m.contains("Bitch") || m.contains("bitch")
        || m.contains("Cunt") || m.contains("cunt") || m.contains("Nigger") || m.contains("nigger") || m.contains("Ass") || m.contains("ass")
        || m.contains("Dick") || m.contains("dick") || m.contains("Vagina") || m.contains("vagina") || m.contains("Nigga") || m.contains("nigga"))
        throw new IllegalArgumentException("Please pick an appropriate username.");
    }

    // throws error if not a valid email
    private static void checkEmailValidity(String e) {
        // check if username and email are available
        if (!loginInfo.isEmpty()) {
            if (loginInfo.containsKey(e))
            throw new IllegalArgumentException("Email already taken!");
        }
    }

    private static void checkPasswordLength(String p) {
        if (p.length() < 7)
        throw new IllegalArgumentException("Password must be over 6 characters!");
    }

    // throws error if username contains non-valid characters
    private static void checkUserValidity(String m) {
        if (m.contains("~") || m.contains("!") || m.contains("@") || m.contains("#") || m.contains("$") || m.contains("%")
        || m.contains("^") || m.contains("&") || m.contains("*") || m.contains("(") || m.contains(")") || m.contains("-")
        || m.contains("+") || m.contains("=") || m.contains("[") || m.contains("]") || m.contains("{") || m.contains("}")
        || m.contains("?") || m.contains("/") || m.contains(";") || m.contains(":") || m.contains("<") || m.contains(">")
        || m.contains(","))
        throw new IllegalArgumentException("Please pick an appropriate username.");

        if (m.length() >= 16)
        throw new IllegalArgumentException("Username must be under 16 characters!");

        if (m.length() <= 3)
        throw new IllegalArgumentException("Username must be at least 4 characters!");

        if (userToID.get(m) != null)
        throw new IllegalArgumentException("Username is taken!");

    }

    // change email
    public static void changeEmail(int accID, String newEmail) {
        Account acc = idToAcc.get(accID);
        loginInfo.remove(acc.email);
        acc.email = newEmail;
        loginInfo.put(newEmail, acc.password);
        idToAcc.put(acc.id, acc);
    }

    // change username
    public static void changeUsername(int accID, String newUser) {
        Account acc = idToAcc.get(accID);
        userToID.remove(acc.username);
        acc.username = newUser;
        userToID.put(newUser, acc.id);
        idToAcc.put(acc.id, acc);
    }

    // change password
    public static void changePassword(int accID, String newPass) {
        Account acc = idToAcc.get(accID);
        acc.password = Encrypt.encrypt(newPass);
        loginInfo.put(acc.email, acc.password);
        idToAcc.put(acc.id, acc);
    }

    public static String showUser(int accID) {
        Account acc = idToAcc.get(accID);
        return acc.username;
    }

    public static String showFirstName(int accID) {
        Account acc = idToAcc.get(accID);
        return acc.first;
    }

    public static String showLastName(int accID) {
        Account acc = idToAcc.get(accID);
        return acc.last;
    }

    public static String showPass(int accID) {
        Account acc = idToAcc.get(accID);
        return acc.password;
    }

    public static String showEmail(int accID) {
        Account acc = idToAcc.get(accID);
        return acc.email;
    }

    public static int showID(int accID) {
        Account acc = idToAcc.get(accID);
        return acc.id;
    }

}