Improved client event handling, and server consistency and chat history requests.

client/pom.xml

@@ -21,7 +21,7 @@
         <dependency>
             <groupId>com.googlecode.lanterna</groupId>
             <artifactId>lanterna</artifactId>
-            <version>3.1.1</version>
+            <version>3.2.0-alpha1</version>
         </dependency>
     </dependencies>
 </project>

client/src/main/java/nl/andrewl/concord_client/ClientMessageListener.java

@@ -1,9 +0,0 @@
-package nl.andrewl.concord_client;
-
-import nl.andrewl.concord_core.msg.Message;
-
-import java.io.IOException;
-
-public interface ClientMessageListener {
-	void messageReceived(ConcordClient client, Message message) throws IOException;
-}

client/src/main/java/nl/andrewl/concord_client/ConcordClient.java

@@ -8,8 +8,12 @@ import com.googlecode.lanterna.screen.TerminalScreen;
 import com.googlecode.lanterna.terminal.DefaultTerminalFactory;
 import com.googlecode.lanterna.terminal.Terminal;
 import lombok.Getter;
-import lombok.Setter;
+import nl.andrewl.concord_client.event.EventManager;
+import nl.andrewl.concord_client.event.handlers.ChannelMovedHandler;
+import nl.andrewl.concord_client.event.handlers.ChannelUsersResponseHandler;
+import nl.andrewl.concord_client.event.handlers.ChatHistoryResponseHandler;
 import nl.andrewl.concord_client.gui.MainWindow;
+import nl.andrewl.concord_client.model.ClientModel;
 import nl.andrewl.concord_core.msg.Message;
 import nl.andrewl.concord_core.msg.Serializer;
 import nl.andrewl.concord_core.msg.types.*;
@@ -18,52 +22,41 @@ import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.net.Socket;
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
-import java.util.UUID;
 
 public class ConcordClient implements Runnable {
 	private final Socket socket;
 	private final DataInputStream in;
 	private final DataOutputStream out;
-	private final UUID id;
+
-	private final String nickname;
 	@Getter
-	@Setter
+	private final ClientModel model;
-	private UUID currentChannelId;
+
-	@Getter
+	private final EventManager eventManager;
-	private ServerMetaData serverMetaData;
+
-	private final Set<ClientMessageListener> messageListeners;
 	private volatile boolean running;
 
 	public ConcordClient(String host, int port, String nickname) throws IOException {
+		this.eventManager = new EventManager(this);
 		this.socket = new Socket(host, port);
 		this.in = new DataInputStream(this.socket.getInputStream());
 		this.out = new DataOutputStream(this.socket.getOutputStream());
-		this.nickname = nickname;
 		Serializer.writeMessage(new Identification(nickname), this.out);
 		Message reply = Serializer.readMessage(this.in);
 		if (reply instanceof ServerWelcome welcome) {
-			this.id = welcome.getClientId();
+			this.model = new ClientModel(welcome.getClientId(), nickname, welcome.getCurrentChannelId(), welcome.getMetaData());
-			this.currentChannelId = welcome.getCurrentChannelId();
-			this.serverMetaData = welcome.getMetaData();
-
 			// Start fetching initial data for the channel we were initially put into.
-			this.sendMessage(new ChannelUsersRequest(this.currentChannelId));
+			this.sendMessage(new ChannelUsersRequest(this.model.getCurrentChannelId()));
-			this.sendMessage(new ChatHistoryRequest(this.currentChannelId, ChatHistoryRequest.Source.CHANNEL, ""));
+			this.sendMessage(new ChatHistoryRequest(this.model.getCurrentChannelId(), ""));
 		} else {
 			throw new IOException("Unexpected response from the server after sending identification message.");
 		}
-		this.messageListeners = new HashSet<>();
-	}
 
-	public void addListener(ClientMessageListener listener) {
+		// Add event listeners.
-		this.messageListeners.add(listener);
+		this.eventManager.addHandler(MoveToChannel.class, new ChannelMovedHandler());
-	}
+		this.eventManager.addHandler(ChannelUsersResponse.class, new ChannelUsersResponseHandler());
-
+		this.eventManager.addHandler(ChatHistoryResponse.class, new ChatHistoryResponseHandler());
-	public void removeListener(ClientMessageListener listener) {
+		this.eventManager.addHandler(Chat.class, (msg, client) -> client.getModel().getChatHistory().addChat(msg));
-		this.messageListeners.remove(listener);
 	}
 
 	public void sendMessage(Message message) throws IOException {
@@ -71,7 +64,7 @@ public class ConcordClient implements Runnable {
 	}
 
 	public void sendChat(String message) throws IOException {
-		Serializer.writeMessage(new Chat(this.id, this.nickname, System.currentTimeMillis(), message), this.out);
+		Serializer.writeMessage(new Chat(this.model.getId(), this.model.getNickname(), System.currentTimeMillis(), message), this.out);
 	}
 
 	public void shutdown() {
@@ -91,9 +84,7 @@ public class ConcordClient implements Runnable {
 		while (this.running) {
 			try {
 				Message msg = Serializer.readMessage(this.in);
-				for (var listener : this.messageListeners) {
+				this.eventManager.handle(msg);
-					listener.messageReceived(this, msg);
-				}
 			} catch (IOException e) {
 				e.printStackTrace();
 				this.running = false;

client/src/main/java/nl/andrewl/concord_client/event/ChatHistoryListener.java

@@ -0,0 +1,12 @@
+package nl.andrewl.concord_client.event;
+
+import nl.andrewl.concord_client.model.ChatHistory;
+import nl.andrewl.concord_core.msg.types.Chat;
+
+public interface ChatHistoryListener {
+	default void chatAdded(Chat chat) {}
+
+	default void chatRemoved(Chat chat) {}
+
+	default void chatUpdated(ChatHistory history) {}
+}

client/src/main/java/nl/andrewl/concord_client/event/ClientModelListener.java

@@ -0,0 +1,12 @@
+package nl.andrewl.concord_client.event;
+
+import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+
+import java.util.List;
+import java.util.UUID;
+
+public interface ClientModelListener {
+	default void channelMoved(UUID oldChannelId, UUID newChannelId) {}
+
+	default void usersUpdated(List<ChannelUsersResponse.UserData> users) {}
+}

client/src/main/java/nl/andrewl/concord_client/event/EventManager.java

@@ -0,0 +1,38 @@
+package nl.andrewl.concord_client.event;
+
+import nl.andrewl.concord_client.ConcordClient;
+import nl.andrewl.concord_core.msg.Message;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+public class EventManager {
+	private final Map<Class<? extends Message>, List<MessageHandler<?>>> messageHandlers;
+	private final ConcordClient client;
+
+	public EventManager(ConcordClient client) {
+		this.client = client;
+		this.messageHandlers = new ConcurrentHashMap<>();
+	}
+
+	public <T extends Message> void addHandler(Class<T> messageClass, MessageHandler<T> handler) {
+		var handlers = this.messageHandlers.computeIfAbsent(messageClass, k -> new CopyOnWriteArrayList<>());
+		handlers.add(handler);
+	}
+
+	@SuppressWarnings("unchecked")
+	public <T extends Message> void handle(T message) {
+		var handlers = this.messageHandlers.get(message.getClass());
+		if (handlers != null) {
+			for (var handler : handlers) {
+				try {
+					((MessageHandler<T>) handler).handle(message, this.client);
+				} catch (Exception e) {
+					e.printStackTrace();
+				}
+			}
+		}
+	}
+}

client/src/main/java/nl/andrewl/concord_client/event/MessageHandler.java

@@ -0,0 +1,8 @@
+package nl.andrewl.concord_client.event;
+
+import nl.andrewl.concord_client.ConcordClient;
+import nl.andrewl.concord_core.msg.Message;
+
+public interface MessageHandler<T extends Message> {
+	void handle(T msg, ConcordClient client) throws Exception;
+}

client/src/main/java/nl/andrewl/concord_client/event/handlers/ChannelMovedHandler.java

@@ -0,0 +1,16 @@
+package nl.andrewl.concord_client.event.handlers;
+
+import nl.andrewl.concord_client.ConcordClient;
+import nl.andrewl.concord_client.event.MessageHandler;
+import nl.andrewl.concord_core.msg.types.ChannelUsersRequest;
+import nl.andrewl.concord_core.msg.types.ChatHistoryRequest;
+import nl.andrewl.concord_core.msg.types.MoveToChannel;
+
+public class ChannelMovedHandler implements MessageHandler<MoveToChannel> {
+	@Override
+	public void handle(MoveToChannel msg, ConcordClient client) throws Exception {
+		client.getModel().setCurrentChannelId(msg.getChannelId());
+		client.sendMessage(new ChatHistoryRequest(msg.getChannelId(), ""));
+		client.sendMessage(new ChannelUsersRequest(msg.getChannelId()));
+	}
+}

client/src/main/java/nl/andrewl/concord_client/event/handlers/ChannelUsersResponseHandler.java

@@ -0,0 +1,12 @@
+package nl.andrewl.concord_client.event.handlers;
+
+import nl.andrewl.concord_client.ConcordClient;
+import nl.andrewl.concord_client.event.MessageHandler;
+import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+
+public class ChannelUsersResponseHandler implements MessageHandler<ChannelUsersResponse> {
+	@Override
+	public void handle(ChannelUsersResponse msg, ConcordClient client) throws Exception {
+		client.getModel().setKnownUsers(msg.getUsers());
+	}
+}

client/src/main/java/nl/andrewl/concord_client/event/handlers/ChatHistoryResponseHandler.java

@@ -0,0 +1,12 @@
+package nl.andrewl.concord_client.event.handlers;
+
+import nl.andrewl.concord_client.ConcordClient;
+import nl.andrewl.concord_client.event.MessageHandler;
+import nl.andrewl.concord_core.msg.types.ChatHistoryResponse;
+
+public class ChatHistoryResponseHandler implements MessageHandler<ChatHistoryResponse> {
+	@Override
+	public void handle(ChatHistoryResponse msg, ConcordClient client) throws Exception {
+		client.getModel().getChatHistory().setChats(msg.getMessages());
+	}
+}

client/src/main/java/nl/andrewl/concord_client/gui/ChannelChatBox.java

@@ -26,6 +26,7 @@ public class ChannelChatBox extends Panel {
 		super(new BorderLayout());
 		this.client = client;
 		this.chatList = new ChatList();
+		this.client.getModel().getChatHistory().addListener(this.chatList);
 		this.inputTextBox = new TextBox("", TextBox.Style.MULTI_LINE);
 		this.inputTextBox.setCaretWarp(true);
 		this.inputTextBox.setPreferredSize(new TerminalSize(0, 3));
@@ -37,7 +38,6 @@ public class ChannelChatBox extends Panel {
 					String text = inputTextBox.getText();
 					if (text != null && !text.isBlank()) {
 						try {
-							System.out.println("Sending: " + text.trim());
 							client.sendChat(text.trim());
 							inputTextBox.setText("");
 						} catch (IOException e) {
@@ -53,8 +53,8 @@ public class ChannelChatBox extends Panel {
 	}
 
 	public void refreshBorder() {
-		String name = client.getServerMetaData().getChannels().stream()
+		String name = client.getModel().getServerMetaData().getChannels().stream()
-				.filter(channelData -> channelData.getId().equals(client.getCurrentChannelId()))
+				.filter(channelData -> channelData.getId().equals(client.getModel().getCurrentChannelId()))
 				.findAny().orElseThrow().getName();
 		if (this.chatBorder != null) this.removeComponent(this.chatBorder);
 		this.chatBorder = Borders.doubleLine("#" + name);

client/src/main/java/nl/andrewl/concord_client/gui/ChannelList.java

@@ -6,6 +6,10 @@ import nl.andrewl.concord_core.msg.types.MoveToChannel;
 
 import java.io.IOException;
 
+/**
+ * Panel that contains a list of channels. A user can interact with a channel to
+ * move to that channel. The current channel is indicated via a "*".
+ */
 public class ChannelList extends Panel {
 	private final ConcordClient client;
 	public ChannelList(ConcordClient client) {
@@ -15,13 +19,13 @@ public class ChannelList extends Panel {
 
 	public void setChannels() {
 		this.removeAllComponents();
-		for (var channel : this.client.getServerMetaData().getChannels()) {
+		for (var channel : this.client.getModel().getServerMetaData().getChannels()) {
 			String name = channel.getName();
-			if (client.getCurrentChannelId().equals(channel.getId())) {
+			if (client.getModel().getCurrentChannelId().equals(channel.getId())) {
 				name = "*" + name;
 			}
 			Button b = new Button(name, () -> {
-				if (!client.getCurrentChannelId().equals(channel.getId())) {
+				if (!client.getModel().getCurrentChannelId().equals(channel.getId())) {
 					try {
 						client.sendMessage(new MoveToChannel(channel.getId()));
 					} catch (IOException e) {

client/src/main/java/nl/andrewl/concord_client/gui/ChatList.java

@@ -1,9 +1,15 @@
 package nl.andrewl.concord_client.gui;
 
 import com.googlecode.lanterna.gui2.AbstractListBox;
+import nl.andrewl.concord_client.event.ChatHistoryListener;
+import nl.andrewl.concord_client.model.ChatHistory;
 import nl.andrewl.concord_core.msg.types.Chat;
 
-public class ChatList extends AbstractListBox<Chat, ChatList> {
+/**
+ * This chat list shows a section of chat messages that have been sent in a
+ * single channel (server channel, thread, or direct message).
+ */
+public class ChatList extends AbstractListBox<Chat, ChatList> implements ChatHistoryListener {
 	/**
 	 * Adds one more item to the list box, at the end.
 	 *
@@ -28,4 +34,31 @@ public class ChatList extends AbstractListBox<Chat, ChatList> {
 	protected ListItemRenderer<Chat, ChatList> createDefaultListItemRenderer() {
 		return new ChatRenderer();
 	}
+
+	@Override
+	public void chatAdded(Chat chat) {
+		this.getTextGUI().getGUIThread().invokeLater(() -> {
+			this.addItem(chat);
+		});
+	}
+
+	@Override
+	public void chatRemoved(Chat chat) {
+		for (int i = 0; i < this.getItemCount(); i++) {
+			if (this.getItemAt(i).equals(chat)) {
+				this.removeItem(i);
+				return;
+			}
+		}
+	}
+
+	@Override
+	public void chatUpdated(ChatHistory history) {
+		this.getTextGUI().getGUIThread().invokeLater(() -> {
+			this.clearItems();
+			for (var chat : history.getChats()) {
+				this.addItem(chat);
+			}
+		});
+	}
 }

client/src/main/java/nl/andrewl/concord_client/gui/MainWindow.java

@@ -52,7 +52,7 @@ public class MainWindow extends BasicWindow {
 		try {
 			var client = new ConcordClient(host, port, nickname);
 			var chatPanel = new ServerPanel(client, this);
-			client.addListener(chatPanel);
+			client.getModel().addListener(chatPanel);
 			new Thread(client).start();
 			this.setComponent(chatPanel);
 		} catch (IOException e) {

client/src/main/java/nl/andrewl/concord_client/gui/ServerPanel.java

@@ -2,12 +2,12 @@ package nl.andrewl.concord_client.gui;
 
 import com.googlecode.lanterna.gui2.*;
 import lombok.Getter;
-import nl.andrewl.concord_client.ClientMessageListener;
 import nl.andrewl.concord_client.ConcordClient;
-import nl.andrewl.concord_core.msg.Message;
+import nl.andrewl.concord_client.event.ClientModelListener;
-import nl.andrewl.concord_core.msg.types.*;
+import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
 
-import java.io.IOException;
+import java.util.List;
+import java.util.UUID;
 
 /**
  * The main panel in which a user interacts with the application during normal
@@ -16,19 +16,17 @@ import java.io.IOException;
  * meta information in the sidebars which provides the user with a list of all
  * threads and users in the server.
  */
-public class ServerPanel extends Panel implements ClientMessageListener {
+public class ServerPanel extends Panel implements ClientModelListener {
 	@Getter
 	private final ChannelChatBox channelChatBox;
 	private final ChannelList channelList;
 	private final UserList userList;
 
-	private final ConcordClient client;
 	private final TextGUIThread guiThread;
 
 	public ServerPanel(ConcordClient client, Window window) {
 		super(new BorderLayout());
 		this.guiThread = window.getTextGUI().getGUIThread();
-		this.client = client;
 		this.channelChatBox = new ChannelChatBox(client, window);
 		this.channelList = new ChannelList(client);
 		this.channelList.setChannels();
@@ -47,36 +45,19 @@ public class ServerPanel extends Panel implements ClientMessageListener {
 	}
 
 	@Override
-	public void messageReceived(ConcordClient client, Message message) {
+	public void channelMoved(UUID oldChannelId, UUID newChannelId) {
-		if (message instanceof Chat chat) {
+		this.getTextGUI().getGUIThread().invokeLater(() -> {
-			this.channelChatBox.getChatList().addItem(chat);
-		} else if (message instanceof MoveToChannel moveToChannel) {
-			client.setCurrentChannelId(moveToChannel.getChannelId());
-			try {
-				client.sendMessage(new ChatHistoryRequest(moveToChannel.getChannelId(), ChatHistoryRequest.Source.CHANNEL, ""));
-				client.sendMessage(new ChannelUsersRequest(moveToChannel.getChannelId()));
-			} catch (IOException e) {
-				e.printStackTrace();
-			}
-			this.guiThread.invokeLater(() -> {
 			this.channelList.setChannels();
 			this.channelChatBox.getChatList().clearItems();
 			this.channelChatBox.refreshBorder();
 			this.channelChatBox.getInputTextBox().takeFocus();
 		});
-		} else if (message instanceof ChannelUsersResponse channelUsersResponse) {
-			this.guiThread.invokeLater(() -> {
-				this.userList.updateUsers(channelUsersResponse);
-			});
-		} else if (message instanceof ChatHistoryResponse chatHistoryResponse) {
-			System.out.println("Got chat history response: " + chatHistoryResponse.getSourceId());
-			System.out.println(chatHistoryResponse.getMessages());
-			this.guiThread.invokeLater(() -> {
-				this.channelChatBox.getChatList().clearItems();
-				for (var chat : chatHistoryResponse.getMessages()) {
-					this.channelChatBox.getChatList().addItem(chat);
 	}
+
+	@Override
+	public void usersUpdated(List<ChannelUsersResponse.UserData> users) {
+		this.guiThread.invokeLater(() -> {
+			this.userList.updateUsers(users);
 		});
 	}
 }
-}

client/src/main/java/nl/andrewl/concord_client/gui/UserList.java

@@ -7,6 +7,8 @@ import com.googlecode.lanterna.gui2.Panel;
 import nl.andrewl.concord_client.ConcordClient;
 import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
 
+import java.util.List;
+
 public class UserList extends Panel {
 	private final ConcordClient client;
 
@@ -15,9 +17,9 @@ public class UserList extends Panel {
 		this.client = client;
 	}
 
-	public void updateUsers(ChannelUsersResponse usersResponse) {
+	public void updateUsers(List<ChannelUsersResponse.UserData> usersResponse) {
 		this.removeAllComponents();
-		for (var user : usersResponse.getUsers()) {
+		for (var user : usersResponse) {
 			Button b = new Button(user.getName(), () -> {
 				System.out.println("Opening DM channel with user " + user.getName() + ", id: " + user.getId());
 			});

client/src/main/java/nl/andrewl/concord_client/model/ChatHistory.java

@@ -0,0 +1,44 @@
+package nl.andrewl.concord_client.model;
+
+import lombok.Getter;
+import nl.andrewl.concord_client.event.ChatHistoryListener;
+import nl.andrewl.concord_core.msg.types.Chat;
+
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Stores information about a snippet of chat history that the client is
+ * currently viewing. This might be some older section of chats, or it could be
+ * the currently-in-use channel chats.
+ */
+public class ChatHistory {
+	@Getter
+	private List<Chat> chats;
+
+	private final List<ChatHistoryListener> chatHistoryListeners;
+
+	public ChatHistory() {
+		this.chats = new CopyOnWriteArrayList<>();
+		this.chatHistoryListeners = new CopyOnWriteArrayList<>();
+	}
+
+	public void setChats(List<Chat> chats) {
+		this.chats.clear();
+		this.chats.addAll(chats);
+		this.chatHistoryListeners.forEach(listener -> listener.chatUpdated(this));
+	}
+
+	public void addChat(Chat chat) {
+		this.chats.add(chat);
+		this.chatHistoryListeners.forEach(listener -> listener.chatAdded(chat));
+	}
+
+	public void addListener(ChatHistoryListener listener) {
+		this.chatHistoryListeners.add(listener);
+	}
+
+	public void removeListener(ChatHistoryListener listener) {
+		this.chatHistoryListeners.remove(listener);
+	}
+}

client/src/main/java/nl/andrewl/concord_client/model/ClientModel.java

@@ -0,0 +1,53 @@
+package nl.andrewl.concord_client.model;
+
+import lombok.Getter;
+import nl.andrewl.concord_client.event.ClientModelListener;
+import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+import nl.andrewl.concord_core.msg.types.ServerMetaData;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+@Getter
+public class ClientModel {
+	private UUID id;
+	private String nickname;
+	private ServerMetaData serverMetaData;
+
+	private UUID currentChannelId;
+	private List<ChannelUsersResponse.UserData> knownUsers;
+	private final ChatHistory chatHistory;
+
+	private final List<ClientModelListener> modelListeners;
+
+	public ClientModel(UUID id, String nickname, UUID currentChannelId, ServerMetaData serverMetaData) {
+		this.modelListeners = new CopyOnWriteArrayList<>();
+		this.id = id;
+		this.nickname = nickname;
+		this.currentChannelId = currentChannelId;
+		this.serverMetaData = serverMetaData;
+		this.knownUsers = new ArrayList<>();
+		this.chatHistory = new ChatHistory();
+	}
+
+	public void setCurrentChannelId(UUID newChannelId) {
+		UUID oldId = this.currentChannelId;
+		this.currentChannelId = newChannelId;
+		this.modelListeners.forEach(listener -> listener.channelMoved(oldId, newChannelId));
+	}
+
+	public void setKnownUsers(List<ChannelUsersResponse.UserData> users) {
+		this.knownUsers = users;
+		this.modelListeners.forEach(listener -> listener.usersUpdated(this.knownUsers));
+	}
+
+	public void addListener(ClientModelListener listener) {
+		this.modelListeners.add(listener);
+	}
+
+	public void removeListener(ClientModelListener listener) {
+		this.modelListeners.remove(listener);
+	}
+}

core/src/main/java/nl/andrewl/concord_core/msg/types/Chat.java

@@ -58,4 +58,16 @@ public class Chat implements Message {
 	public String toString() {
 		return String.format("%s: %s", this.senderNickname, this.message);
 	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (o.getClass().equals(this.getClass())) {
+			Chat other = (Chat) o;
+			return this.getSenderId().equals(other.getSenderId()) &&
+					this.getTimestamp() == other.getTimestamp() &&
+					this.getSenderNickname().equals(other.getSenderNickname()) &&
+					this.message.length() == other.message.length();
+		}
+		return false;
+	}
 }

core/src/main/java/nl/andrewl/concord_core/msg/types/ChatHistoryRequest.java

@@ -8,7 +8,10 @@ import nl.andrewl.concord_core.msg.Message;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 import static nl.andrewl.concord_core.msg.MessageUtils.*;
 
@@ -49,12 +52,36 @@ import static nl.andrewl.concord_core.msg.MessageUtils.*;
 @NoArgsConstructor
 @AllArgsConstructor
 public class ChatHistoryRequest implements Message {
-	public enum Source {CHANNEL, THREAD, DIRECT_MESSAGE}
+	private UUID channelId;
-
-	private UUID sourceId;
-	private Source sourceType;
 	private String query;
 
+	public ChatHistoryRequest(UUID channelId, Map<String, String> params) {
+		this.channelId = channelId;
+		this.query = params.entrySet().stream()
+				.map(entry -> {
+					if (entry.getKey().contains(";") || entry.getKey().contains("=")) {
+						throw new IllegalArgumentException("Parameter key \"" + entry.getKey() + "\" contains invalid characters.");
+					}
+					if (entry.getValue().contains(";") || entry.getValue().contains("=")) {
+						throw new IllegalArgumentException("Parameter value \"" + entry.getValue() + "\" contains invalid characters.");
+					}
+					return entry.getKey() + "=" + entry.getValue();
+				})
+				.collect(Collectors.joining(";"));
+	}
+
+	public Map<String, String> getQueryAsMap() {
+		String[] pairs = this.query.split(";");
+		if (pairs.length == 0) return Map.of();
+		Map<String, String> params = new HashMap<>(pairs.length);
+		for (var pair : pairs) {
+			String[] keyAndValue = pair.split("=");
+			if (keyAndValue.length != 2) continue;
+			params.put(keyAndValue[0], keyAndValue[1]);
+		}
+		return params;
+	}
+
 	@Override
 	public int getByteCount() {
 		return UUID_BYTES + Integer.BYTES + getByteSize(this.query);
@@ -62,15 +89,13 @@ public class ChatHistoryRequest implements Message {
 
 	@Override
 	public void write(DataOutputStream o) throws IOException {
-		writeUUID(this.sourceId, o);
+		writeUUID(this.channelId, o);
-		writeEnum(this.sourceType, o);
 		writeString(this.query, o);
 	}
 
 	@Override
 	public void read(DataInputStream i) throws IOException {
-		this.sourceId = readUUID(i);
+		this.channelId = readUUID(i);
-		this.sourceType = readEnum(Source.class, i);
 		this.query = readString(i);
 	}
 }

core/src/main/java/nl/andrewl/concord_core/msg/types/ChatHistoryResponse.java

@@ -20,13 +20,12 @@ import java.util.UUID;
 @NoArgsConstructor
 @AllArgsConstructor
 public class ChatHistoryResponse implements Message {
-	private UUID sourceId;
+	private UUID channelId;
-	private ChatHistoryRequest.Source sourceType;
 	List<Chat> messages;
 
 	@Override
 	public int getByteCount() {
-		int count = Long.BYTES + Integer.BYTES + Integer.BYTES;
+		int count = Long.BYTES + Integer.BYTES;
 		for (var message : this.messages) {
 			count += message.getByteCount();
 		}
@@ -35,8 +34,7 @@ public class ChatHistoryResponse implements Message {
 
 	@Override
 	public void write(DataOutputStream o) throws IOException {
-		MessageUtils.writeUUID(this.sourceId, o);
+		MessageUtils.writeUUID(this.channelId, o);
-		MessageUtils.writeEnum(this.sourceType, o);
 		o.writeInt(messages.size());
 		for (var message : this.messages) {
 			message.write(o);
@@ -45,8 +43,7 @@ public class ChatHistoryResponse implements Message {
 
 	@Override
 	public void read(DataInputStream i) throws IOException {
-		this.sourceId = MessageUtils.readUUID(i);
+		this.channelId = MessageUtils.readUUID(i);
-		this.sourceType = MessageUtils.readEnum(ChatHistoryRequest.Source.class, i);
 		int messageCount = i.readInt();
 		Chat[] messages = new Chat[messageCount];
 		for (int k = 0; k < messageCount; k++) {

server/src/main/java/nl/andrewl/concord_server/Channel.java

@@ -89,6 +89,6 @@ public class Channel {
 
 	@Override
 	public String toString() {
-		return this.name;
+		return this.name + " (" + this.id + ")";
 	}
 }

server/src/main/java/nl/andrewl/concord_server/ChannelManager.java

@@ -49,6 +49,6 @@ public class ChannelManager {
 		channel.addClient(client);
 		client.setCurrentChannel(channel);
 		client.sendToClient(new MoveToChannel(channel.getId()));
-		System.out.println("Moved client " + client.getClientNickname() + " to channel " + channel.getName());
+		System.out.println("Moved client " + client + " to channel " + channel);
 	}
 }

server/src/main/java/nl/andrewl/concord_server/ClientThread.java

@@ -2,7 +2,6 @@ package nl.andrewl.concord_server;
 
 import lombok.Getter;
 import lombok.Setter;
-import lombok.extern.java.Log;
 import nl.andrewl.concord_core.msg.Message;
 import nl.andrewl.concord_core.msg.Serializer;
 import nl.andrewl.concord_core.msg.types.Identification;
@@ -17,7 +16,6 @@ import java.util.UUID;
  * This thread is responsible for handling the connection to a single client of
  * a server. The client thread acts as the server's representation of a client.
  */
-@Log
 public class ClientThread extends Thread {
 	private final Socket socket;
 	private final DataInputStream in;
@@ -75,7 +73,7 @@ public class ClientThread extends Thread {
 	public void run() {
 		this.running = true;
 		if (!identifyClient()) {
-			log.warning("Could not identify the client; aborting connection.");
+			System.err.println("Could not identify the client; aborting connection.");
 			this.running = false;
 		}
 
@@ -84,7 +82,6 @@ public class ClientThread extends Thread {
 				var msg = Serializer.readMessage(this.in);
 				this.server.getEventManager().handle(msg, this);
 			} catch (IOException e) {
-				log.info("Client disconnected: " + e.getMessage());
 				this.running = false;
 			}
 		}
@@ -124,4 +121,9 @@ public class ClientThread extends Thread {
 		}
 		return false;
 	}
+
+	@Override
+	public String toString() {
+		return this.clientNickname + " (" + this.clientId + ")";
+	}
 }

server/src/main/java/nl/andrewl/concord_server/ConcordServer.java

@@ -22,16 +22,19 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.stream.Collectors;
 
-@Log
+/**
+ * The main server implementation, which handles accepting new clients.
+ */
 public class ConcordServer implements Runnable {
 	private final Map<UUID, ClientThread> clients;
-	private final int port;
+	private volatile boolean running;
-	private final String name;
+
+	@Getter
+	private final ServerConfig config;
 	@Getter
 	private final IdProvider idProvider;
 	@Getter
 	private final Nitrite db;
-	private volatile boolean running;
 	@Getter
 	private final ExecutorService executorService;
 	@Getter
@@ -41,9 +44,7 @@ public class ConcordServer implements Runnable {
 
 	public ConcordServer() {
 		this.idProvider = new UUIDProvider();
-		ServerConfig config = ServerConfig.loadOrCreate(Path.of("server-config.json"), idProvider);
+		this.config = ServerConfig.loadOrCreate(Path.of("server-config.json"), idProvider);
-		this.port = config.port();
-		this.name = config.name();
 		this.db = Nitrite.builder()
 				.filePath("concord-server.db")
 				.openOrCreate();
@@ -67,15 +68,15 @@ public class ConcordServer implements Runnable {
 		for (var channel : this.channelManager.getChannels()) {
 			var col = channel.getMessageCollection();
 			if (!col.hasIndex("timestamp")) {
-				log.info("Adding timestamp index to collection for channel " + channel.getName());
+				System.out.println("Adding timestamp index to collection for channel " + channel.getName());
 				col.createIndex("timestamp", IndexOptions.indexOptions(IndexType.NonUnique));
 			}
 			if (!col.hasIndex("senderNickname")) {
-				log.info("Adding senderNickname index to collection for channel " + channel.getName());
+				System.out.println("Adding senderNickname index to collection for channel " + channel.getName());
 				col.createIndex("senderNickname", IndexOptions.indexOptions(IndexType.Fulltext));
 			}
 			if (!col.hasIndex("message")) {
-				log.info("Adding message index to collection for channel " + channel.getName());
+				System.out.println("Adding message index to collection for channel " + channel.getName());
 				col.createIndex("message", IndexOptions.indexOptions(IndexType.Fulltext));
 			}
 		}
@@ -92,13 +93,13 @@ public class ConcordServer implements Runnable {
 	 */
 	public void registerClient(Identification identification, ClientThread clientThread) {
 		var id = this.idProvider.newId();
-		log.info("Registering new client " + identification.getNickname() + " with id " + id);
+		System.out.printf("Client \"%s\" joined with id %s.\n", identification.getNickname(), id);
 		this.clients.put(id, clientThread);
 		clientThread.setClientId(id);
 		clientThread.setClientNickname(identification.getNickname());
 		// Send a welcome reply containing all the initial server info the client needs.
 		ServerMetaData metaData = new ServerMetaData(
-				this.name,
+				this.config.name(),
 				this.channelManager.getChannels().stream()
 						.map(channel -> new ServerMetaData.ChannelData(channel.getId(), channel.getName()))
 						.sorted(Comparator.comparing(ServerMetaData.ChannelData::getName))
@@ -110,6 +111,7 @@ public class ConcordServer implements Runnable {
 		// It is important that we send the welcome message first. The client expects this as the initial response to their identification message.
 		defaultChannel.addClient(clientThread);
 		clientThread.setCurrentChannel(defaultChannel);
+		System.out.println("Moved client " + clientThread + " to " + defaultChannel);
 	}
 
 	/**
@@ -122,6 +124,7 @@ public class ConcordServer implements Runnable {
 		if (client != null) {
 			client.getCurrentChannel().removeClient(client);
 			client.shutdown();
+			System.out.println("Client " + client + " has disconnected.");
 		}
 	}
 
@@ -130,11 +133,15 @@ public class ConcordServer implements Runnable {
 		this.running = true;
 		ServerSocket serverSocket;
 		try {
-			serverSocket = new ServerSocket(this.port);
+			serverSocket = new ServerSocket(this.config.port());
-			log.info("Opened server on port " + this.port);
+			StringBuilder startupMessage = new StringBuilder();
+			startupMessage.append("Opened server on port ").append(config.port()).append("\n");
+			for (var channel : this.channelManager.getChannels()) {
+				startupMessage.append("\tChannel \"").append(channel).append('\n');
+			}
+			System.out.println(startupMessage);
 			while (this.running) {
 				Socket socket = serverSocket.accept();
-				log.info("Accepted new socket connection from " + socket.getInetAddress().getHostAddress());
 				ClientThread clientThread = new ClientThread(socket, this);
 				clientThread.start();
 			}

server/src/main/java/nl/andrewl/concord_server/config/ServerConfig.java

@@ -9,10 +9,15 @@ import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
-@Log
 public record ServerConfig(
 		String name,
 		int port,
+
+		// Global Channel configuration
+		int chatHistoryMaxCount,
+		int chatHistoryDefaultCount,
+		int maxMessageLength,
+
 		ChannelConfig[] channels
 ) {
 
@@ -29,6 +34,9 @@ public record ServerConfig(
 			config = new ServerConfig(
 					"My Concord Server",
 					8123,
+					100,
+					50,
+					8192,
 					new ServerConfig.ChannelConfig[]{
 							new ServerConfig.ChannelConfig(idProvider.newId().toString(), "general", "Default channel for general discussion.")
 					}
@@ -38,14 +46,14 @@ public record ServerConfig(
 			} catch (IOException e) {
 				throw new UncheckedIOException(e);
 			}
-			log.info(filePath + " does not exist. Creating it with initial values. Edit and restart to apply changes.");
+			System.err.println(filePath + " does not exist. Creating it with initial values. Edit and restart to apply changes.");
 		} else {
 			try {
 				config = mapper.readValue(Files.newInputStream(filePath), ServerConfig.class);
 			} catch (IOException e) {
 				throw new UncheckedIOException(e);
 			}
-			log.info("Loaded configuration from " + filePath);
+			System.out.println("Loaded configuration from " + filePath);
 		}
 		return config;
 	}

server/src/main/java/nl/andrewl/concord_server/event/ChatHistoryRequestHandler.java

@@ -3,30 +3,62 @@ package nl.andrewl.concord_server.event;
 import nl.andrewl.concord_core.msg.types.Chat;
 import nl.andrewl.concord_core.msg.types.ChatHistoryRequest;
 import nl.andrewl.concord_core.msg.types.ChatHistoryResponse;
+import nl.andrewl.concord_server.Channel;
 import nl.andrewl.concord_server.ClientThread;
 import nl.andrewl.concord_server.ConcordServer;
-import org.dizitart.no2.Document;
+import org.dizitart.no2.*;
-import org.dizitart.no2.FindOptions;
+import org.dizitart.no2.filters.Filters;
-import org.dizitart.no2.SortOrder;
 
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Comparator;
-import java.util.List;
-import java.util.UUID;
 
+/**
+ * Handles client requests for sections of chat history for a particular channel.
+ */
 public class ChatHistoryRequestHandler implements MessageHandler<ChatHistoryRequest> {
 	@Override
 	public void handle(ChatHistoryRequest msg, ClientThread client, ConcordServer server) {
-		var optionalChannel = server.getChannelManager().getChannelById(msg.getSourceId());
+		var optionalChannel = server.getChannelManager().getChannelById(msg.getChannelId());
 		if (optionalChannel.isPresent()) {
 			var channel = optionalChannel.get();
-			System.out.println("Looking for chats in channel-" + channel.getId());
+			var params = msg.getQueryAsMap();
-			var col = server.getDb().getCollection("channel-" + channel.getId());
+			Long count = this.getOrDefault(params, "count", (long) server.getConfig().chatHistoryDefaultCount());
-			var cursor = col.find(
+			if (count > server.getConfig().chatHistoryMaxCount()) {
-					FindOptions.sort("timestamp", SortOrder.Descending)
+				return;
-						.thenLimit(0, 10)
+			}
-			);
+			Long from = this.getOrDefault(params, "from", null);
-			List<Chat> chats = new ArrayList<>(10);
+			Long to = this.getOrDefault(params, "to", null);
+			client.sendToClient(this.getResponse(channel, count, from, to));
+		}
+	}
+
+	private Long getOrDefault(Map<String, String> params, String key, Long defaultValue) {
+		String value = params.get(key);
+		if (value == null) return defaultValue;
+		try {
+			return Long.parseLong(value);
+		} catch (NumberFormatException e) {
+			return defaultValue;
+		}
+	}
+
+	private ChatHistoryResponse getResponse(Channel channel, long count, Long from, Long to) {
+		var col = channel.getServer().getDb().getCollection("channel-" + channel.getId());
+		Cursor cursor;
+		FindOptions options = FindOptions.sort("timestamp", SortOrder.Descending).thenLimit(0, (int) count);
+		List<Filter> filters = new ArrayList<>(2);
+		if (from != null) {
+			filters.add(Filters.gt("timestamp", from));
+		}
+		if (to != null) {
+			filters.add(Filters.lt("timestamp", to));
+		}
+		if (filters.isEmpty()) {
+			cursor = col.find(options);
+		} else {
+			cursor = col.find(Filters.and(filters.toArray(new Filter[0])), options);
+		}
+
+		List<Chat> chats = new ArrayList<>((int) count);
 		for (Document doc : cursor) {
 			chats.add(new Chat(
 					doc.get("senderId", UUID.class),
@@ -37,7 +69,6 @@ public class ChatHistoryRequestHandler implements MessageHandler<ChatHistoryRequ
 		}
 		col.close();
 		chats.sort(Comparator.comparingLong(Chat::getTimestamp));
-			client.sendToClient(new ChatHistoryResponse(msg.getSourceId(), msg.getSourceType(), chats));
+		return new ChatHistoryResponse(channel.getId(), chats);
-		}
 	}
 }

server/src/main/resources/nl/andrewl/concord_server/logback.xml

@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<configuration>
-    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
-        <encoder>
-            <pattern>%d{dd.MM.yyyy HH:mm:ss} %boldCyan(%-34.-34thread) %red(%10.10X{jda.shard}) %boldGreen(%-15.-15logger{0}) %highlight(%-6level) %msg%n</pattern>
-        </encoder>
-    </appender>
-
-    <root level="info">
-        <appender-ref ref="STDOUT" />
-    </root>
-</configuration>