Added chat history stuff.

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

@@ -82,4 +82,13 @@ public interface Message {
 		if (read != length) throw new IOException("Not all bytes of a string of length " + length + " could be read.");
 		return new String(data, StandardCharsets.UTF_8);
 	}
+
+	default void writeEnum(Enum<?> value, DataOutputStream o) throws IOException {
+		o.writeInt(value.ordinal());
+	}
+
+	default <T extends Enum<?>> T readEnum(Class<T> e, DataInputStream i) throws IOException {
+		int ordinal = i.readInt();
+		return e.getEnumConstants()[ordinal];
+	}
 }

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

@@ -0,0 +1,71 @@
+package nl.andrewl.concord_core.msg.types;
+
+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;
+
+/**
+ * A message which clients can send to the server to request some messages from
+ * the server's history of all sent messages from a particular source. Every
+ * request must provide the id of the source that messages should be fetched
+ * from, in addition to the type of source (channel, thread, dm).
+ * <p>
+ *     The query string is a specially-formatted string that allows you to
+ *     filter results to only certain messages, using different parameters that
+ *     are separated by the <code>;</code> character.
+ * </p>
+ * <p>
+ *     All query parameters are of the form <code>param=value</code>, where
+ *     <code>param</code> is the case-sensitive name of the parameter, and
+ *     <code>value</code> is the value of the parameter.
+ * </p>
+ * <p>
+ *     The following query parameters are supported:
+ *     <ul>
+ *         <li><code>count</code> - Fetch up to N messages. Minimum of 1, and
+ *         a server-specific maximum count, usually no higher than 1000.</li>
+ *         <li><code>from</code> - ISO-8601 timestamp indicating the timestamp
+ *         after which messages should be fetched. Only messages after this
+ *         point in time are returned.</li>
+ *         <li><code>to</code> - ISO-8601 timestamp indicating the timestamp
+ *         before which messages should be fetched. Only messages before this
+ *         point in time are returned.</li>
+ *     </ul>
+ * </p>
+ * <p>
+ *     Responses to this request are sent via {@link ChatHistoryResponse}, where
+ *     the list of messages is always sorted by the timestamp.
+ * </p>
+ */
+@Data
+@NoArgsConstructor
+public class ChatHistoryRequest implements Message {
+	public enum Source {CHANNEL, THREAD, DIRECT_MESSAGE}
+
+	private long sourceId;
+	private Source sourceType;
+	private String query;
+
+	@Override
+	public int getByteCount() {
+		return Long.BYTES + Integer.BYTES + getByteSize(this.query);
+	}
+
+	@Override
+	public void write(DataOutputStream o) throws IOException {
+		o.writeLong(sourceId);
+		writeEnum(this.sourceType, o);
+		writeString(this.query, o);
+	}
+
+	@Override
+	public void read(DataInputStream i) throws IOException {
+		this.sourceId = i.readLong();
+		this.sourceType = readEnum(Source.class, i);
+		this.query = readString(i);
+	}
+}

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

@@ -0,0 +1,54 @@
+package nl.andrewl.concord_core.msg.types;
+
+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.List;
+
+/**
+ * The response that a server sends to a {@link ChatHistoryRequest}.
+ */
+@Data
+@NoArgsConstructor
+public class ChatHistoryResponse implements Message {
+	private long sourceId;
+	private ChatHistoryRequest.Source sourceType;
+	List<Chat> messages;
+
+	@Override
+	public int getByteCount() {
+		int count = Long.BYTES + Integer.BYTES + Integer.BYTES;
+		for (var message : this.messages) {
+			count += message.getByteCount();
+		}
+		return count;
+	}
+
+	@Override
+	public void write(DataOutputStream o) throws IOException {
+		o.writeLong(this.sourceId);
+		writeEnum(this.sourceType, o);
+		o.writeInt(messages.size());
+		for (var message : this.messages) {
+			message.write(o);
+		}
+	}
+
+	@Override
+	public void read(DataInputStream i) throws IOException {
+		this.sourceId = i.readInt();
+		this.sourceType = readEnum(ChatHistoryRequest.Source.class, i);
+		int messageCount = i.readInt();
+		Chat[] messages = new Chat[messageCount];
+		for (int k = 0; k < messageCount; k++) {
+			Chat c = new Chat();
+			c.read(i);
+			messages[k] = c;
+		}
+		this.messages = List.of(messages);
+	}
+}

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

@@ -5,6 +5,7 @@ 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.Chat;
+import nl.andrewl.concord_core.msg.types.ChatHistoryRequest;
 import nl.andrewl.concord_core.msg.types.Identification;
 import nl.andrewl.concord_core.msg.types.ServerWelcome;
 
@@ -65,6 +66,8 @@ public class ClientThread extends Thread {
 				var msg = Serializer.readMessage(this.in);
 				if (msg instanceof Chat chat) {
 					this.server.handleChat(chat);
+				} else if (msg instanceof ChatHistoryRequest historyRequest) {
+					this.server.handleHistoryRequest(historyRequest, this);
 				}
 			} catch (IOException e) {
 				log.info("Client disconnected: " + e.getMessage());

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

@@ -3,6 +3,9 @@ package nl.andrewl.concord_server;
 import lombok.extern.java.Log;
 import nl.andrewl.concord_core.msg.Serializer;
 import nl.andrewl.concord_core.msg.types.Chat;
+import nl.andrewl.concord_core.msg.types.ChatHistoryRequest;
+import org.dizitart.no2.Document;
+import org.dizitart.no2.Nitrite;
 
 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
@@ -19,10 +22,14 @@ public class ConcordServer implements Runnable {
 	private final Map<Long, ClientThread> clients = new ConcurrentHashMap<>(32);
 	private final int port;
 	private final Random random;
+	private final Nitrite db;
 
 	public ConcordServer(int port) {
 		this.port = port;
 		this.random = new SecureRandom();
+		this.db = Nitrite.builder()
+				.filePath("concord-server.db")
+				.openOrCreate();
 	}
 
 	public long registerClient(ClientThread clientThread) {
@@ -37,6 +44,15 @@ public class ConcordServer implements Runnable {
 	}
 
 	public void handleChat(Chat chat) {
+		var collection = db.getCollection("channel-TEST");
+		long messageId = this.random.nextLong();
+		Document doc = Document.createDocument(Long.toHexString(messageId), "message")
+				.put("senderId", Long.toHexString(chat.getSenderId()))
+				.put("senderNickname", chat.getSenderNickname())
+				.put("timestamp", chat.getTimestamp())
+				.put("message", chat.getMessage());
+		collection.insert(doc);
+		db.commit();
 		System.out.println(chat.getSenderNickname() + ": " + chat.getMessage());
 		ByteArrayOutputStream baos = new ByteArrayOutputStream(chat.getByteCount());
 		try {
@@ -51,6 +67,10 @@ public class ConcordServer implements Runnable {
 		}
 	}
 
+	public void handleHistoryRequest(ChatHistoryRequest request, ClientThread clientThread) {
+
+	}
+
 	@Override
 	public void run() {
 		ServerSocket serverSocket;