package jalview.ws2.api;

import java.util.Objects;

public final class Credentials
{
  String username = null;
  String email = null;
  String password = null;
  private static final Credentials EMPTY = new Credentials();

  private Credentials() {
  }
  
  public static final Credentials empty()
  {
    return EMPTY;
  }

  public static final Credentials usingEmail(String email) {
    Objects.requireNonNull(email);
    if (email.isEmpty())
      throw new IllegalArgumentException("empty email");
    Credentials credentials = new Credentials();
    credentials.email = email;
    return credentials;
  }
  
  public static final Credentials usingEmail(String email, String password) {
    Objects.requireNonNull(email);
    Objects.requireNonNull(password);
    if (email.isEmpty())
      throw new IllegalArgumentException("empty email");
    Credentials credentials = new Credentials();
    credentials.email = email;
    credentials.password = password;
    return credentials;
  }
  
  public static final Credentials usingUsername(String username, String password) {
    Objects.requireNonNull(username);
    Objects.requireNonNull(password);
    if (username.isEmpty())
      throw new IllegalArgumentException("empty username");
    Credentials credentials = new Credentials();
    credentials.username = username;
    credentials.password = password;
    return credentials;
  }
}