envoy/src/main/java/envoy/client/ui/ChatSceneController.java

package envoy.client.ui;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.stream.Collectors;

import envoy.client.data.Chat;
import envoy.client.data.LocalDB;
import envoy.client.event.MessageCreationEvent;
import envoy.client.net.Client;
import envoy.client.net.WriteProxy;
import envoy.data.Contact;
import envoy.data.Message;
import envoy.data.MessageBuilder;
import envoy.event.EventBus;
import envoy.event.MessageStatusChangeEvent;
import envoy.event.UserStatusChangeEvent;
import envoy.util.EnvoyLog;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.fxml.FXML;
import javafx.scene.control.*;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;

/**
 * Project: <strong>envoy-client</strong><br>
 * File: <strong>ChatSceneController.java</strong><br>
 * Created: <strong>26.03.2020</strong><br>
 *
 * @author Kai S. K. Engelbart
 * @since Envoy Client v0.1-beta
 */
public final class ChatSceneController {

	@FXML
	private Label contactLabel;

	@FXML
	private ListView<Message> messageList;

	@FXML
	private ListView<Contact> userList;

	@FXML
	private Button postButton;

	@FXML
	private Button settingsButton;

	@FXML
	private TextArea messageTextArea;

	private LocalDB		localDB;
	private Client		client;
	private WriteProxy	writeProxy;

	private Chat currentChat;

	private static final EventBus	eventBus	= EventBus.getInstance();
	private static final Logger		logger		= EnvoyLog.getLogger(ChatSceneController.class);

	@FXML
	private void initialize() {

		// Initialize message and user rendering
		messageList.setCellFactory(listView -> new MessageListCell());
		userList.setCellFactory(listView -> new UserListCell());

		// Listen to received messages
		eventBus.register(MessageCreationEvent.class, e -> {
			final var	message	= e.get();
			final var	chat	= localDB.getChats().stream().filter(c -> c.getRecipient().getID() == message.getSenderID()).findAny().get();
			chat.getMessages().add(message);

			// Update UI if in current chat
			if (chat == currentChat) Platform.runLater(() -> messageList.getItems().add(message));
		});

		// Listen to message status changes
		eventBus.register(MessageStatusChangeEvent.class, e -> {
			final var message = localDB.getMessage(e.getID());
			message.setStatus(e.get());

			// Update UI if in current chat
			if (currentChat != null && message.getSenderID() == currentChat.getRecipient().getID()) Platform.runLater(() -> messageList.refresh());
		});

		// Listen to user status changes
		eventBus.register(UserStatusChangeEvent.class, e -> Platform.runLater(() -> userList.refresh()));
	}

	void initializeData(LocalDB localDB, Client client, WriteProxy writeProxy) {
		this.localDB	= localDB;
		this.client		= client;
		this.writeProxy	= writeProxy;

		// TODO: handle offline mode
		userList.setItems(FXCollections.observableList(localDB.getUser().getContacts().stream().collect(Collectors.toList())));
	}

	@FXML
	private void userListClicked() {
		final Contact user = userList.getSelectionModel().getSelectedItem();
		if (user != null && (currentChat == null || user.getID() != currentChat.getRecipient().getID())) {
			contactLabel.setText(user.getName());

			// LEON: JFC <===> JAVA FRIED CHICKEN <=/=> Java Foundation Classes

			// Load the chat or create a new one and add it to the LocalDB
			currentChat = localDB.getChats()
				.stream()
				.filter(c -> c.getRecipient().getID() == user.getID())
				.findAny()
				.orElseGet(() -> { var chat = new Chat(user); localDB.getChats().add(chat); return chat; });

			messageList.setItems(FXCollections.observableList(currentChat.getMessages()));
		}
	}

	@FXML
	private void postButtonClicked() { postMessage(); }

	@FXML
	private void settingsButtonClicked() { logger.info("Settings Button clicked."); }

	@FXML
	private void messageTextUpdated(KeyEvent e) {
		if (e.getCode() == KeyCode.ENTER) postMessage();
		else postButton.setDisable(messageTextArea.getText().isBlank());
	}

	/**
	 * Sends a new message to the server based on the text entered in the
	 * messageTextArea.
	 *
	 * @since Envoy Client v0.1-beta
	 */
	private void postMessage() {

		// Create and send message
		sendMessage(new MessageBuilder(localDB.getUser().getID(), currentChat.getRecipient().getID(), localDB.getIDGenerator())
			.setText(messageTextArea.getText().strip())
			.build());

		// Clear text field and disable post button
		messageTextArea.setText("");
		postButton.setDisable(true);
	}

	/**
	 * Sends a message to the server and appends it to the current chat. If all
	 * message IDs have been used, a new ID generator is requested.
	 *
	 * @param message the message to send
	 * @since Envoy Client v0.1-beta
	 */
	private void sendMessage(Message message) {
		try {

			// Send message
			writeProxy.writeMessage(message);

			// Add message to LocalDB and update UI
			messageList.getItems().add(message);

			// Request a new ID generator if all IDs were used
			if (!localDB.getIDGenerator().hasNext() && client.isOnline()) client.requestIdGenerator();

		} catch (IOException e) {
			logger.log(Level.SEVERE, "Error sending message", e);
		}
	}
}