Added ability to add and remove channels.

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

@@ -12,6 +12,7 @@ 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.event.handlers.ServerMetaDataHandler;
 import nl.andrewl.concord_client.gui.MainWindow;
 import nl.andrewl.concord_client.model.ClientModel;
 import nl.andrewl.concord_core.msg.Message;
@@ -57,6 +58,7 @@ public class ConcordClient implements Runnable {
 		this.eventManager.addHandler(ChannelUsersResponse.class, new ChannelUsersResponseHandler());
 		this.eventManager.addHandler(ChatHistoryResponse.class, new ChatHistoryResponseHandler());
 		this.eventManager.addHandler(Chat.class, (msg, client) -> client.getModel().getChatHistory().addChat(msg));
+		this.eventManager.addHandler(ServerMetaData.class, new ServerMetaDataHandler());
 	}
 
 	public void sendMessage(Message message) throws IOException {

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

@@ -1,6 +1,7 @@
 package nl.andrewl.concord_client.event;
 
-import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+import nl.andrewl.concord_core.msg.types.ServerMetaData;
+import nl.andrewl.concord_core.msg.types.UserData;
 
 import java.util.List;
 import java.util.UUID;
@@ -8,5 +9,7 @@ import java.util.UUID;
 public interface ClientModelListener {
 	default void channelMoved(UUID oldChannelId, UUID newChannelId) {}
 
-	default void usersUpdated(List<ChannelUsersResponse.UserData> users) {}
+	default void usersUpdated(List<UserData> users) {}
+
+	default void serverMetaDataUpdated(ServerMetaData metaData) {}
 }

client/src/main/java/nl/andrewl/concord_client/event/handlers/ServerMetaDataHandler.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.ServerMetaData;
+
+public class ServerMetaDataHandler implements MessageHandler<ServerMetaData> {
+	@Override
+	public void handle(ServerMetaData msg, ConcordClient client) {
+		client.getModel().setServerMetaData(msg);
+	}
+}

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

@@ -4,7 +4,8 @@ import com.googlecode.lanterna.gui2.*;
 import lombok.Getter;
 import nl.andrewl.concord_client.ConcordClient;
 import nl.andrewl.concord_client.event.ClientModelListener;
-import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+import nl.andrewl.concord_core.msg.types.ServerMetaData;
+import nl.andrewl.concord_core.msg.types.UserData;
 
 import java.util.List;
 import java.util.UUID;
@@ -22,11 +23,8 @@ public class ServerPanel extends Panel implements ClientModelListener {
 	private final ChannelList channelList;
 	private final UserList userList;
 
-	private final TextGUIThread guiThread;
-
 	public ServerPanel(ConcordClient client, Window window) {
 		super(new BorderLayout());
-		this.guiThread = window.getTextGUI().getGUIThread();
 		this.channelChatBox = new ChannelChatBox(client, window);
 		this.channelList = new ChannelList(client);
 		this.channelList.setChannels();
@@ -55,9 +53,16 @@ public class ServerPanel extends Panel implements ClientModelListener {
 	}
 
 	@Override
-	public void usersUpdated(List<ChannelUsersResponse.UserData> users) {
+	public void usersUpdated(List<UserData> users) {
-		this.guiThread.invokeLater(() -> {
+		this.getTextGUI().getGUIThread().invokeLater(() -> {
 			this.userList.updateUsers(users);
 		});
 	}
+
+	@Override
+	public void serverMetaDataUpdated(ServerMetaData metaData) {
+		this.getTextGUI().getGUIThread().invokeLater(() -> {
+			this.channelList.setChannels();
+		});
+	}
 }

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

@@ -6,6 +6,7 @@ import com.googlecode.lanterna.gui2.LinearLayout;
 import com.googlecode.lanterna.gui2.Panel;
 import nl.andrewl.concord_client.ConcordClient;
 import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+import nl.andrewl.concord_core.msg.types.UserData;
 
 import java.util.List;
 
@@ -17,7 +18,7 @@ public class UserList extends Panel {
 		this.client = client;
 	}
 
-	public void updateUsers(List<ChannelUsersResponse.UserData> usersResponse) {
+	public void updateUsers(List<UserData> usersResponse) {
 		this.removeAllComponents();
 		for (var user : usersResponse) {
 			Button b = new Button(user.getName(), () -> {

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

@@ -2,8 +2,8 @@ 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 nl.andrewl.concord_core.msg.types.UserData;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -17,7 +17,7 @@ public class ClientModel {
 	private ServerMetaData serverMetaData;
 
 	private UUID currentChannelId;
-	private List<ChannelUsersResponse.UserData> knownUsers;
+	private List<UserData> knownUsers;
 	private final ChatHistory chatHistory;
 
 	private final List<ClientModelListener> modelListeners;
@@ -38,11 +38,16 @@ public class ClientModel {
 		this.modelListeners.forEach(listener -> listener.channelMoved(oldId, newChannelId));
 	}
 
-	public void setKnownUsers(List<ChannelUsersResponse.UserData> users) {
+	public void setKnownUsers(List<UserData> users) {
 		this.knownUsers = users;
 		this.modelListeners.forEach(listener -> listener.usersUpdated(this.knownUsers));
 	}
 
+	public void setServerMetaData(ServerMetaData metaData) {
+		this.serverMetaData = metaData;
+		this.modelListeners.forEach(listener -> listener.serverMetaDataUpdated(metaData));
+	}
+
 	public void addListener(ClientModelListener listener) {
 		this.modelListeners.add(listener);
 	}

core/src/main/java/nl/andrewl/concord_core/msg/Serializer.java

@@ -21,6 +21,7 @@ public class Serializer {
 		registerType(5, ChatHistoryResponse.class);
 		registerType(6, ChannelUsersRequest.class);
 		registerType(7, ChannelUsersResponse.class);
+		registerType(8, ServerMetaData.class);
 	}
 
 	private static void registerType(int id, Class<? extends Message> clazz) {

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

@@ -9,7 +9,6 @@ import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.util.List;
-import java.util.UUID;
 
 import static nl.andrewl.concord_core.msg.MessageUtils.*;
 
@@ -37,29 +36,4 @@ public class ChannelUsersResponse implements Message {
 			throw new IOException(e);
 		}
 	}
-
-	@Data
-	@NoArgsConstructor
-	@AllArgsConstructor
-	public static class UserData implements Message {
-		private UUID id;
-		private String name;
-
-		@Override
-		public int getByteCount() {
-			return UUID_BYTES + getByteSize(this.name);
-		}
-
-		@Override
-		public void write(DataOutputStream o) throws IOException {
-			writeUUID(this.id, o);
-			writeString(this.name, o);
-		}
-
-		@Override
-		public void read(DataInputStream i) throws IOException {
-			this.id = readUUID(i);
-			this.name = readString(i);
-		}
-	}
 }

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

@@ -0,0 +1,43 @@
+package nl.andrewl.concord_core.msg.types;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import nl.andrewl.concord_core.msg.Message;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.UUID;
+
+import static nl.andrewl.concord_core.msg.MessageUtils.*;
+import static nl.andrewl.concord_core.msg.MessageUtils.readString;
+
+/**
+ * Standard set of user data that is used mainly as a component of other more
+ * complex messages.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class UserData implements Message {
+	private UUID id;
+	private String name;
+
+	@Override
+	public int getByteCount() {
+		return UUID_BYTES + getByteSize(this.name);
+	}
+
+	@Override
+	public void write(DataOutputStream o) throws IOException {
+		writeUUID(this.id, o);
+		writeString(this.name, o);
+	}
+
+	@Override
+	public void read(DataInputStream i) throws IOException {
+		this.id = readUUID(i);
+		this.name = readString(i);
+	}
+}

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

@@ -4,6 +4,9 @@ import lombok.Getter;
 import nl.andrewl.concord_core.msg.Message;
 import nl.andrewl.concord_core.msg.Serializer;
 import nl.andrewl.concord_core.msg.types.ChannelUsersResponse;
+import nl.andrewl.concord_core.msg.types.UserData;
+import org.dizitart.no2.IndexOptions;
+import org.dizitart.no2.IndexType;
 import org.dizitart.no2.NitriteCollection;
 
 import java.io.ByteArrayOutputStream;
@@ -31,6 +34,29 @@ public class Channel {
 		this.name = name;
 		this.connectedClients = ConcurrentHashMap.newKeySet();
 		this.messageCollection = messageCollection;
+		this.initCollection();
+	}
+
+	private void initCollection() {
+		if (!this.messageCollection.hasIndex("timestamp")) {
+			System.out.println("Adding index on \"timestamp\" field to collection " + this.messageCollection.getName());
+			this.messageCollection.createIndex("timestamp", IndexOptions.indexOptions(IndexType.NonUnique));
+		}
+		if (!this.messageCollection.hasIndex("senderNickname")) {
+			System.out.println("Adding index on \"senderNickname\" field to collection " + this.messageCollection.getName());
+			this.messageCollection.createIndex("senderNickname", IndexOptions.indexOptions(IndexType.Fulltext));
+		}
+		if (!this.messageCollection.hasIndex("message")) {
+			System.out.println("Adding index on \"message\" field to collection " + this.messageCollection.getName());
+			this.messageCollection.createIndex("message", IndexOptions.indexOptions(IndexType.Fulltext));
+		}
+		var fields = List.of("timestamp", "senderNickname", "message");
+		for (var index : this.messageCollection.listIndices()) {
+			if (!fields.contains(index.getField())) {
+				System.out.println("Dropping unknown index " + index.getField() + " from collection " + index.getCollectionName());
+				this.messageCollection.dropIndex(index.getField());
+			}
+		}
 	}
 
 	public void addClient(ClientThread clientThread) {
@@ -66,12 +92,12 @@ public class Channel {
 		}
 	}
 
-	public List<ChannelUsersResponse.UserData> getUserData() {
+	public List<UserData> getUserData() {
-		List<ChannelUsersResponse.UserData> users = new ArrayList<>();
+		List<UserData> users = new ArrayList<>(this.connectedClients.size());
 		for (var clientThread : this.getConnectedClients()) {
-			users.add(new ChannelUsersResponse.UserData(clientThread.getClientId(), clientThread.getClientNickname()));
+			users.add(clientThread.toData());
 		}
-		users.sort(Comparator.comparing(ChannelUsersResponse.UserData::getName));
+		users.sort(Comparator.comparing(UserData::getName));
 		return users;
 	}
 

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

@@ -5,6 +5,7 @@ import lombok.Setter;
 import nl.andrewl.concord_core.msg.Message;
 import nl.andrewl.concord_core.msg.Serializer;
 import nl.andrewl.concord_core.msg.types.Identification;
+import nl.andrewl.concord_core.msg.types.UserData;
 
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
@@ -122,6 +123,10 @@ public class ClientThread extends Thread {
 		return false;
 	}
 
+	public UserData toData() {
+		return new UserData(this.clientId, this.clientNickname);
+	}
+
 	@Override
 	public String toString() {
 		return this.clientNickname + " (" + this.clientId + ")";

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

@@ -1,19 +1,24 @@
 package nl.andrewl.concord_server;
 
 import lombok.Getter;
+import nl.andrewl.concord_core.msg.Message;
+import nl.andrewl.concord_core.msg.Serializer;
 import nl.andrewl.concord_core.msg.types.Identification;
 import nl.andrewl.concord_core.msg.types.ServerMetaData;
 import nl.andrewl.concord_core.msg.types.ServerWelcome;
+import nl.andrewl.concord_core.msg.types.UserData;
+import nl.andrewl.concord_server.cli.ServerCli;
 import nl.andrewl.concord_server.config.ServerConfig;
-import org.dizitart.no2.IndexOptions;
-import org.dizitart.no2.IndexType;
 import org.dizitart.no2.Nitrite;
 
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
 import java.io.IOException;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.nio.file.Path;
 import java.util.Comparator;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
@@ -52,33 +57,14 @@ public class ConcordServer implements Runnable {
 		this.executorService = Executors.newCachedThreadPool();
 		this.eventManager = new EventManager(this);
 		this.channelManager = new ChannelManager(this);
-		for (var channelConfig : config.channels()) {
+		for (var channelConfig : config.getChannels()) {
 			this.channelManager.addChannel(new Channel(
 					this,
-					UUID.fromString(channelConfig.id()),
+					UUID.fromString(channelConfig.getId()),
-					channelConfig.name(),
+					channelConfig.getName(),
-					this.db.getCollection("channel-" + channelConfig.id())
+					this.db.getCollection("channel-" + channelConfig.getId())
 			));
 		}
-		this.updateDatabase();
-	}
-
-	private void updateDatabase() {
-		for (var channel : this.channelManager.getChannels()) {
-			var col = channel.getMessageCollection();
-			if (!col.hasIndex("timestamp")) {
-				System.out.println("Adding timestamp index to collection for channel " + channel.getName());
-				col.createIndex("timestamp", IndexOptions.indexOptions(IndexType.NonUnique));
-			}
-			if (!col.hasIndex("senderNickname")) {
-				System.out.println("Adding senderNickname index to collection for channel " + channel.getName());
-				col.createIndex("senderNickname", IndexOptions.indexOptions(IndexType.Fulltext));
-			}
-			if (!col.hasIndex("message")) {
-				System.out.println("Adding message index to collection for channel " + channel.getName());
-				col.createIndex("message", IndexOptions.indexOptions(IndexType.Fulltext));
-			}
-		}
 	}
 
 	/**
@@ -96,17 +82,9 @@ public class ConcordServer implements Runnable {
 		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.config.name(),
-				this.channelManager.getChannels().stream()
-						.map(channel -> new ServerMetaData.ChannelData(channel.getId(), channel.getName()))
-						.sorted(Comparator.comparing(ServerMetaData.ChannelData::getName))
-						.collect(Collectors.toList())
-		);
 		// Immediately add the client to the default channel and send the initial welcome message.
 		var defaultChannel = this.channelManager.getChannelByName("general").orElseThrow();
-		clientThread.sendToClient(new ServerWelcome(id, defaultChannel.getId(), metaData));
+		clientThread.sendToClient(new ServerWelcome(id, defaultChannel.getId(), this.getMetaData()));
 		// 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);
@@ -127,14 +105,52 @@ public class ConcordServer implements Runnable {
 		}
 	}
 
+	public boolean isRunning() {
+		return running;
+	}
+
+	public List<UserData> getClients() {
+		return this.clients.values().stream()
+				.sorted(Comparator.comparing(ClientThread::getClientNickname))
+				.map(ClientThread::toData)
+				.collect(Collectors.toList());
+	}
+
+	public ServerMetaData getMetaData() {
+		return new ServerMetaData(
+				this.config.getName(),
+				this.channelManager.getChannels().stream()
+						.map(channel -> new ServerMetaData.ChannelData(channel.getId(), channel.getName()))
+						.sorted(Comparator.comparing(ServerMetaData.ChannelData::getName))
+						.collect(Collectors.toList())
+		);
+	}
+
+	/**
+	 * Sends a message to every connected client.
+	 * @param message The message to send.
+	 */
+	public void broadcast(Message message) {
+		ByteArrayOutputStream baos = new ByteArrayOutputStream(message.getByteCount());
+		try {
+			Serializer.writeMessage(message, baos);
+			byte[] data = baos.toByteArray();
+			for (var client : this.clients.values()) {
+				client.sendToClient(data);
+			}
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
 	@Override
 	public void run() {
 		this.running = true;
 		ServerSocket serverSocket;
 		try {
-			serverSocket = new ServerSocket(this.config.port());
+			serverSocket = new ServerSocket(this.config.getPort());
 			StringBuilder startupMessage = new StringBuilder();
-			startupMessage.append("Opened server on port ").append(config.port()).append("\n");
+			startupMessage.append("Opened server on port ").append(config.getPort()).append("\n");
 			for (var channel : this.channelManager.getChannels()) {
 				startupMessage.append("\tChannel \"").append(channel).append('\n');
 			}
@@ -151,6 +167,7 @@ public class ConcordServer implements Runnable {
 
 	public static void main(String[] args) {
 		var server = new ConcordServer();
-		server.run();
+		new Thread(server).start();
+		new ServerCli(server).run();
 	}
 }

server/src/main/java/nl/andrewl/concord_server/cli/ServerCli.java

@@ -0,0 +1,53 @@
+package nl.andrewl.concord_server.cli;
+
+import nl.andrewl.concord_server.ConcordServer;
+import nl.andrewl.concord_server.cli.command.AddChannelCommand;
+import nl.andrewl.concord_server.cli.command.ListClientsCommand;
+import nl.andrewl.concord_server.cli.command.RemoveChannelCommand;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ServerCli implements Runnable {
+	private final ConcordServer server;
+	private final Map<String, ServerCliCommand> commands;
+
+	public ServerCli(ConcordServer server) {
+		this.server = server;
+		this.commands = new HashMap<>();
+
+		this.commands.put("list-clients", new ListClientsCommand());
+		this.commands.put("add-channel", new AddChannelCommand());
+		this.commands.put("remove-channel", new RemoveChannelCommand());
+	}
+
+	@Override
+	public void run() {
+		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+		String line;
+		try {
+			while (this.server.isRunning() && (line = reader.readLine()) != null) {
+				if (!line.isBlank()) {
+					String[] words = line.split("\\s+");
+					String command = words[0];
+					String[] args = Arrays.copyOfRange(words, 1, words.length);
+					var cliCommand = this.commands.get(command.trim().toLowerCase());
+					if (cliCommand != null) {
+						try {
+							cliCommand.handle(this.server, args);
+						} catch (Exception e) {
+							e.printStackTrace();
+						}
+					} else {
+						System.err.println("Unknown command.");
+					}
+				}
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+}

server/src/main/java/nl/andrewl/concord_server/cli/ServerCliCommand.java

@@ -0,0 +1,7 @@
+package nl.andrewl.concord_server.cli;
+
+import nl.andrewl.concord_server.ConcordServer;
+
+public interface ServerCliCommand {
+	void handle(ConcordServer server, String[] args) throws Exception;
+}

server/src/main/java/nl/andrewl/concord_server/cli/command/AddChannelCommand.java

@@ -0,0 +1,36 @@
+package nl.andrewl.concord_server.cli.command;
+
+import nl.andrewl.concord_server.Channel;
+import nl.andrewl.concord_server.ConcordServer;
+import nl.andrewl.concord_server.cli.ServerCliCommand;
+import nl.andrewl.concord_server.config.ServerConfig;
+
+import java.util.UUID;
+
+public class AddChannelCommand implements ServerCliCommand {
+	@Override
+	public void handle(ConcordServer server, String[] args) throws Exception {
+		if (args.length < 1) {
+			System.err.println("Missing required name argument.");
+		}
+		String name = args[0].trim().toLowerCase().replaceAll("\\s+", "-");
+		if (name.isBlank()) {
+			System.err.println("Cannot create channel with blank name.");
+		}
+		if (server.getChannelManager().getChannelByName(name).isPresent()) {
+			System.err.println("Channel with that name already exists.");
+		}
+		String description = null;
+		if (args.length > 1) {
+			description = args[1].trim();
+		}
+		UUID id = server.getIdProvider().newId();
+		var channelConfig = new ServerConfig.ChannelConfig(id.toString(), name, description);
+		server.getConfig().getChannels().add(channelConfig);
+		server.getConfig().save();
+
+		var col = server.getDb().getCollection("channel-" + id);
+		server.getChannelManager().addChannel(new Channel(server, id, name, col));
+		server.broadcast(server.getMetaData());
+	}
+}

server/src/main/java/nl/andrewl/concord_server/cli/command/ListClientsCommand.java

@@ -0,0 +1,20 @@
+package nl.andrewl.concord_server.cli.command;
+
+import nl.andrewl.concord_server.ConcordServer;
+import nl.andrewl.concord_server.cli.ServerCliCommand;
+
+public class ListClientsCommand implements ServerCliCommand {
+	@Override
+	public void handle(ConcordServer server, String[] args) throws Exception {
+		var users = server.getClients();
+		if (users.isEmpty()) {
+			System.out.println("There are no connected clients.");
+		} else {
+			StringBuilder sb = new StringBuilder("Online Users:\n");
+			for (var userData : users) {
+				sb.append("\t").append(userData.getName()).append(" (").append(userData.getId()).append(")\n");
+			}
+			System.out.print(sb);
+		}
+	}
+}

server/src/main/java/nl/andrewl/concord_server/cli/command/RemoveChannelCommand.java

@@ -0,0 +1,41 @@
+package nl.andrewl.concord_server.cli.command;
+
+import nl.andrewl.concord_server.Channel;
+import nl.andrewl.concord_server.ConcordServer;
+import nl.andrewl.concord_server.cli.ServerCliCommand;
+
+import java.util.Optional;
+
+public class RemoveChannelCommand implements ServerCliCommand {
+	@Override
+	public void handle(ConcordServer server, String[] args) throws Exception {
+		if (args.length != 1) {
+			System.err.println("Missing required channel name.");
+			return;
+		}
+		String name = args[0].trim().toLowerCase();
+		Optional<Channel> optionalChannel = server.getChannelManager().getChannelByName(name);
+		if (optionalChannel.isEmpty()) {
+			System.err.println("No channel with that name exists.");
+			return;
+		}
+		Channel channelToRemove = optionalChannel.get();
+		Channel alternative = null;
+		for (var c : server.getChannelManager().getChannels()) {
+			if (!c.equals(channelToRemove)) {
+				alternative = c;
+				break;
+			}
+		}
+		if (alternative == null) {
+			System.err.println("No alternative channel could be found. A server must always have at least one channel.");
+			return;
+		}
+		for (var client : channelToRemove.getConnectedClients()) {
+			server.getChannelManager().moveToChannel(client, alternative);
+		}
+		server.getChannelManager().removeChannel(channelToRemove);
+		server.getDb().getContext().dropCollection(channelToRemove.getMessageCollection().getName());
+		server.broadcast(server.getMetaData());
+	}
+}

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

@@ -1,31 +1,43 @@
 package nl.andrewl.concord_server.config;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import lombok.extern.java.Log;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
 import nl.andrewl.concord_server.IdProvider;
 
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.List;
 
-public record ServerConfig(
+@Data
-		String name,
+@NoArgsConstructor
-		int port,
+@AllArgsConstructor
+public final class ServerConfig {
+	private String name;
+	private int port;
+	private int chatHistoryMaxCount;
+	private int chatHistoryDefaultCount;
+	private int maxMessageLength;
+	private List<ChannelConfig> channels;
 
-		// Global Channel configuration
+	/**
-		int chatHistoryMaxCount,
+	 * The path at which this config is stored.
-		int chatHistoryDefaultCount,
+	 */
-		int maxMessageLength,
+	@JsonIgnore
+	private transient Path filePath;
 
-		ChannelConfig[] channels
+	@Data
-) {
+	@NoArgsConstructor
-
+	@AllArgsConstructor
-	public static record ChannelConfig (
+	public static final class ChannelConfig {
-			String id,
+		private String id;
-			String name,
+		private String name;
-			String description
+		private String description;
-	) {}
+	}
 
 	public static ServerConfig loadOrCreate(Path filePath, IdProvider idProvider) {
 		ObjectMapper mapper = new ObjectMapper();
@@ -37,9 +49,8 @@ public record ServerConfig(
 					100,
 					50,
 					8192,
-					new ServerConfig.ChannelConfig[]{
+					List.of(new ChannelConfig(idProvider.newId().toString(), "general", "Default channel for general discussion.")),
-							new ServerConfig.ChannelConfig(idProvider.newId().toString(), "general", "Default channel for general discussion.")
+					filePath
-					}
 			);
 			try (var out = Files.newOutputStream(filePath)) {
 				mapper.writerWithDefaultPrettyPrinter().writeValue(out, config);
@@ -50,6 +61,7 @@ public record ServerConfig(
 		} else {
 			try {
 				config = mapper.readValue(Files.newInputStream(filePath), ServerConfig.class);
+				config.setFilePath(filePath);
 			} catch (IOException e) {
 				throw new UncheckedIOException(e);
 			}
@@ -57,4 +69,11 @@ public record ServerConfig(
 		}
 		return config;
 	}
+
+	public void save() throws IOException {
+		ObjectMapper mapper = new ObjectMapper();
+		try (var out = Files.newOutputStream(filePath)) {
+			mapper.writerWithDefaultPrettyPrinter().writeValue(out, this);
+		}
+	}
 }

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

@@ -21,8 +21,8 @@ public class ChatHistoryRequestHandler implements MessageHandler<ChatHistoryRequ
 		if (optionalChannel.isPresent()) {
 			var channel = optionalChannel.get();
 			var params = msg.getQueryAsMap();
-			Long count = this.getOrDefault(params, "count", (long) server.getConfig().chatHistoryDefaultCount());
+			Long count = this.getOrDefault(params, "count", (long) server.getConfig().getChatHistoryDefaultCount());
-			if (count > server.getConfig().chatHistoryMaxCount()) {
+			if (count > server.getConfig().getChatHistoryMaxCount()) {
 				return;
 			}
 			Long from = this.getOrDefault(params, "from", null);