package envoy.data;

import java.io.Serializable;
import java.time.Instant;

/**
 * Contains a {@link User}'s login / registration information as well as the
 * client version.
 * <p>
 * If the authentication is performed with a token, the token is stored instead
 * of the password.
 *
 * @author Kai S. K. Engelbart
 * @since Envoy Common v0.2-alpha
 */
public final class LoginCredentials implements Serializable {

	private final String	identifier, password, clientVersion;
	private final boolean	registration, token, requestToken;
	private final Instant	lastSync;

	private static final long serialVersionUID = 4;

	private LoginCredentials(String identifier, String password, boolean registration, boolean token, boolean requestToken, String clientVersion,
			Instant lastSync) {
		this.identifier		= identifier;
		this.password		= password;
		this.registration	= registration;
		this.token			= token;
		this.requestToken	= requestToken;
		this.clientVersion	= clientVersion;
		this.lastSync		= lastSync;
	}

	/**
	 * Creates login credentials for a regular login.
	 *
	 * @param identifier    the identifier of the user
	 * @param password      the password of the user
	 * @param requestToken  requests the server to generate an authentication token
	 * @param clientVersion the version of the client sending these credentials
	 * @param lastSync      the timestamp of the last synchronization
	 * @return the created login credentials
	 * @since Envoy Common v0.2-beta
	 */
	public static LoginCredentials login(String identifier, String password, boolean requestToken, String clientVersion, Instant lastSync) {
		return new LoginCredentials(identifier, password, false, false, requestToken, clientVersion, lastSync);
	}

	/**
	 * Creates login credentials for a login with an authentication token.
	 *
	 * @param identifier    the identifier of the user
	 * @param token         the authentication token of the user
	 * @param clientVersion the version of the client sending these credentials
	 * @param lastSync      the timestamp of the last synchronization
	 * @return the created login credentials
	 * @since Envoy Common v0.2-beta
	 */
	public static LoginCredentials loginWithToken(String identifier, String token, String clientVersion, Instant lastSync) {
		return new LoginCredentials(identifier, token, false, true, false, clientVersion, lastSync);
	}

	/**
	 * Creates login credentials for a registration.
	 *
	 * @param identifier    the identifier of the user
	 * @param password      the password of the user
	 * @param requestToken  requests the server to generate an authentication token
	 * @param clientVersion the version of the client sending these credentials
	 * @param lastSync      the timestamp of the last synchronization
	 * @return the created login credentials
	 * @since Envoy Common v0.2-beta
	 */
	public static LoginCredentials registration(String identifier, String password, boolean requestToken, String clientVersion, Instant lastSync) {
		return new LoginCredentials(identifier, password, true, false, requestToken, clientVersion, lastSync);
	}

	@Override
	public String toString() {
		return String.format("LoginCredentials[identifier=%s,registration=%b,token=%b,requestToken=%b,clientVersion=%s,lastSync=%s]",
				identifier,
				registration,
				token,
				requestToken,
				clientVersion,
				lastSync);
	}

	/**
	 * @return the identifier of the user performing the login
	 * @since Envoy Common v0.2-alpha
	 */
	public String getIdentifier() { return identifier; }

	/**
	 * @return the password of the user performing the login
	 * @since Envoy Common v0.1-beta
	 */
	public String getPassword() { return password; }

	/**
	 * @return {@code true} if these credentials are used for user registration
	 *         instead of user login
	 * @since Envoy Common v0.2-alpha
	 */
	public boolean isRegistration() { return registration; }

	/**
	 * @return {@code true} if these credentials use an authentication token instead
	 *         of a password
	 * @since Envoy Common v0.2-beta
	 */
	public boolean usesToken() { return token; }

	/**
	 * @return {@code true} if the server should generate a new authentication token
	 * @since Envoy Common v0.2-beta
	 */
	public boolean requestToken() { return requestToken; }

	/**
	 * @return the version of the client sending these credentials
	 * @since Envoy Common v0.1-beta
	 */
	public String getClientVersion() { return clientVersion; }

	/**
	 * @return the timestamp of the last synchronization
	 * @since Envoy Common v0.2-beta
	 */
	public Instant getLastSync() { return lastSync; }
}