package envoy.data;

import java.io.*;
import java.util.*;

/**
 * Represents a unique user with a unique, numeric ID, a name and a current {@link UserStatus}.<br>
 *
 * @author Kai S. K. Engelbart
 * @since Envoy Common v0.2-alpha
 */
public final class User extends Contact {

	private UserStatus status;

	/**
	 * Used to serialize contact list to a maximum depth of one.
	 */
	private transient boolean serializeContacts = true;

	private static final long serialVersionUID = 1L;

	/**
	 * This enumeration defines all possible statuses a user can have.
	 *
	 * @since Envoy Common v0.2-alpha
	 */
	public enum UserStatus {

		/**
		 * select this, if a user is online and can be interacted with
		 */
		ONLINE,

		/**
		 * select this, if a user is online but unavailable at the moment (sudden interruption)
		 */
		AWAY,

		/**
		 * select this, if a user is online but unavailable at the moment (polite way)
		 */
		BUSY,

		/**
		 * select this, if a user is offline
		 */
		OFFLINE;
	}

	/**
	 * Initializes a {@link User}. <br>
	 * The {@link UserStatus} is set to {@link UserStatus#ONLINE}. No contacts are initialized.
	 *
	 * @param id   unique ID
	 * @param name user name
	 * @since Envoy Common v0.2-alpha
	 */
	public User(long id, String name) {
		super(id, name, new HashSet<>());
		status = UserStatus.ONLINE;
	}

	/**
	 * Initializes a {@link User}. <br>
	 * The {@link UserStatus} is set to {@link UserStatus#ONLINE}.
	 *
	 * @param id       unique ID
	 * @param name     user name
	 * @param contacts the contacts of this user
	 * @since Envoy Common v0.2-alpha
	 */
	public User(long id, String name, Set<Contact> contacts) {
		super(id, name, contacts);
		status = UserStatus.ONLINE;
	}

	/**
	 * Initializes a {@link User}.
	 *
	 * @param id       unique ID
	 * @param name     user name
	 * @param status   the status of this user
	 * @param contacts the contacts of this user
	 * @since Envoy Common v0.2-alpha
	 */
	public User(long id, String name, UserStatus status, Set<Contact> contacts) {
		super(id, name, contacts);
		this.status = status;
	}

	@Override
	public String toString() {
		return String.format("User[id=%d,name=%s,status=%s", id, name, status)
			+ (contacts.isEmpty() ? "]" : "," + contacts.size() + " contact(s)]");
	}

	/**
	 * @return the current status of this user
	 * @since Envoy Common v0.2-alpha
	 */
	public UserStatus getStatus() { return status; }

	/**
	 * @param status the next status of this user
	 * @since Envoy Common v0.2-alpha
	 */
	public void setStatus(UserStatus status) { this.status = status; }

	private void readObject(ObjectInputStream inputStream) throws Exception {
		inputStream.defaultReadObject();
		var contacts = Contact.class.getDeclaredField("contacts");
		contacts.setAccessible(true);
		contacts.set(this, inputStream.readObject());
	}

	private void writeObject(ObjectOutputStream outputStream) throws Exception {
		outputStream.defaultWriteObject();
		if (serializeContacts) {
			getContacts().stream().filter(User.class::isInstance).map(User.class::cast)
				.forEach(user -> user.serializeContacts = false);
			outputStream.writeObject(getContacts());
		} else
			outputStream.writeObject(new HashSet<>());
	}

	/**
	 * @param serializeContacts whether the contacts of this {@link User} should be serialized
	 * @since Envoy Common v0.1-beta
	 */
	public void serializeContacts(boolean serializeContacts) {
		this.serializeContacts = serializeContacts;
	}
}