Move everything to core

core/src/main/java/com/seibel/distanthorizons/core/level/DhClientServerLevel.java

@@ -39,7 +39,7 @@ public class DhClientServerLevel extends DhLevel implements IDhClientLevel, IDhS
 		{
 			LOGGER.warn("unable to create data folder.");
 		}
-		serverside = new ServerLevelModule(this, serverLevelWrapper, saveStructure);
+		serverside = new ServerLevelModule(this, serverLevelWrapper, saveStructure, false);
 		clientside = new ClientLevelModule(this);
 		LOGGER.info("Started "+DhClientServerLevel.class.getSimpleName()+" for "+ serverLevelWrapper +" with saves at "+saveStructure);
 	}

core/src/main/java/com/seibel/distanthorizons/core/level/DhServerLevel.java

@@ -25,7 +25,7 @@ public class DhServerLevel extends DhLevel implements IDhServerLevel
 		{
 			LOGGER.warn("unable to create data folder.");
 		}
-		serverside = new ServerLevelModule(this, serverLevelWrapper, saveStructure);
+		serverside = new ServerLevelModule(this, serverLevelWrapper, saveStructure, true);
 		LOGGER.info("Started DHLevel for {} with saves at {}", serverLevelWrapper, saveStructure);
 	}
 	

core/src/main/java/com/seibel/distanthorizons/core/level/ServerLevelModule.java

@@ -64,7 +64,7 @@ public class ServerLevelModule {
     public final AppliedConfigState<Boolean> worldGeneratorEnabledConfig;
     private final AtomicReference<WorldGenState> worldGenStateRef = new AtomicReference<>();
 
-    public ServerLevelModule(IDhServerLevel parent, IServerLevelWrapper levelWrapper, AbstractSaveStructure saveStructure)
+    public ServerLevelModule(IDhServerLevel parent, IServerLevelWrapper levelWrapper, AbstractSaveStructure saveStructure, boolean startLodServer)
     {
         this.parent = parent;
         this.levelWrapper = levelWrapper;

core/src/main/java/com/seibel/distanthorizons/core/network/LodClient.java

@@ -0,0 +1,24 @@
+package com.seibel.distanthorizons.core.network;
+
+import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
+//import net.minecraft.client.Minecraft;
+
+public class LodClient {
+//    public static final LodClient INSTANCE = new LodClient();
+//
+//    private final Minecraft client;
+//    private final NetworkHandler networkHandler;
+//
+//    private LodClient() {
+//        client = Minecraft.getInstance();
+//        this.networkHandler = new NetworkHandler();
+//    }
+
+    public void connect() {
+
+    }
+
+    public void disconnect() {
+
+    }
+}

core/src/main/java/com/seibel/distanthorizons/core/network/LodServer.java

@@ -0,0 +1,64 @@
+package com.seibel.distanthorizons.core.network;
+
+import com.seibel.distanthorizons.core.network.messageHandling.MessageDecoder;
+import com.seibel.distanthorizons.core.network.messageHandling.MessageHandler;
+import com.seibel.distanthorizons.core.network.messageHandling.MessageHandlerSide;
+import com.seibel.distanthorizons.core.network.messageHandling.MessageRegistry;
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
+import io.netty.handler.logging.LogLevel;
+import io.netty.handler.logging.LoggingHandler;
+
+public class LodServer {
+    // TODO move to config of some sort
+    static final int PORT = 25049;
+
+    public LodServer(/* initial settings */) {
+
+    }
+
+    public void start() throws InterruptedException {
+        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
+        EventLoopGroup workerGroup = new NioEventLoopGroup();
+        try {
+            ServerBootstrap b = new ServerBootstrap();
+            b.group(bossGroup, workerGroup)
+             .channel(NioServerSocketChannel.class)
+             .handler(new LoggingHandler(LogLevel.INFO))
+             .childHandler(getInitializer());
+
+            b.bind(PORT).sync().channel().closeFuture().sync();
+        } finally {
+            bossGroup.shutdownGracefully();
+            workerGroup.shutdownGracefully();
+        }
+    }
+
+    public void stop() {
+
+    }
+
+    private ChannelInitializer<SocketChannel> getInitializer() {
+        return new ChannelInitializer<SocketChannel>() {
+            @Override
+            public void initChannel(SocketChannel ch) {
+                ChannelPipeline pipeline = ch.pipeline();
+
+                MessageRegistry messageRegistry = new MessageRegistry();
+
+                // Encoding
+                pipeline.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 2, 0, 2));
+                pipeline.addLast(new MessageDecoder(messageRegistry));
+                // TODO packet encoder
+
+                pipeline.addLast(new MessageHandler(MessageHandlerSide.SERVER));
+            }
+        };
+    }
+}

core/src/main/java/com/seibel/distanthorizons/core/network/messageHandling/MessageDecoder.java

@@ -0,0 +1,23 @@
+package com.seibel.distanthorizons.core.network.messageHandling;
+
+import com.seibel.distanthorizons.core.network.messages.Message;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ByteToMessageDecoder;
+
+import java.util.List;
+
+public class MessageDecoder extends ByteToMessageDecoder {
+    private MessageRegistry messageRegistry;
+
+    public MessageDecoder(MessageRegistry messageRegistry) {
+        this.messageRegistry = messageRegistry;
+    }
+
+    @Override
+    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
+        Message message = messageRegistry.createMessage(in.readShort());
+        message.decode(in);
+        out.add(message);
+    }
+}

core/src/main/java/com/seibel/distanthorizons/core/network/messageHandling/MessageHandler.java

@@ -0,0 +1,27 @@
+package com.seibel.distanthorizons.core.network.messageHandling;
+
+import com.seibel.distanthorizons.core.network.messages.Message;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.SimpleChannelInboundHandler;
+
+public class MessageHandler extends SimpleChannelInboundHandler<Message> {
+    private final MessageHandlerSide side;
+
+    public MessageHandler(MessageHandlerSide side) {
+        this.side = side;
+    }
+
+    @Override
+    public void channelRead0(ChannelHandlerContext ctx, Message msg) {
+        switch (side) {
+            case CLIENT:
+                msg.handle_Client(ctx);
+                break;
+            case SERVER:
+                msg.handle_Server(ctx);
+                break;
+            default:
+                throw new IllegalStateException("Invalid handler side");
+        }
+    }
+}

core/src/main/java/com/seibel/distanthorizons/core/network/messageHandling/MessageHandlerSide.java

@@ -0,0 +1,6 @@
+package com.seibel.distanthorizons.core.network.messageHandling;
+
+public enum MessageHandlerSide {
+    CLIENT,
+    SERVER
+}

core/src/main/java/com/seibel/distanthorizons/core/network/messageHandling/MessageRegistry.java

@@ -0,0 +1,35 @@
+package com.seibel.distanthorizons.core.network.messageHandling;
+
+import com.seibel.distanthorizons.core.network.messages.HelloMessage;
+import com.seibel.distanthorizons.core.network.messages.Message;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+public class MessageRegistry {
+    private final Map<Integer, Supplier<Message>> idToConstructor = new HashMap<Integer, Supplier<Message>>() {{
+        // Note: Make sure IDs are unique
+        // Also note: Removing IDs will break backwards compatibility
+        put(1, HelloMessage::new);
+    }};
+
+    private final Map<Class<?>, Integer> classToId = idToConstructor.entrySet().stream()
+            .collect(Collectors.toMap(
+                    e -> e.getValue().getClass(),
+                    Map.Entry::getKey
+            ));
+
+    public Message createMessage(int id) throws IllegalArgumentException {
+        try {
+            return idToConstructor.get(id).get();
+        } catch (NullPointerException e) {
+            throw new IllegalArgumentException("Invalid message ID");
+        }
+    }
+
+    public int getMessageId(Message message) {
+        return classToId.get(message.getClass());
+    }
+}

core/src/main/java/com/seibel/distanthorizons/core/network/messages/HelloMessage.java

@@ -0,0 +1,26 @@
+package com.seibel.distanthorizons.core.network.messages;
+
+import com.seibel.distanthorizons.coreapi.ModInfo;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+
+// This message is critical to maintain backwards compatibility
+// as it's used to receive version BEFORE everything else.
+public class HelloMessage extends Message {
+    public int version = ModInfo.PROTOCOL_VERSION;
+
+    @Override
+    public void encode(ByteBuf out) {
+        out.writeInt(version);
+    }
+
+    @Override
+    public void decode(ByteBuf in) {
+        version = in.readInt();
+    }
+
+    @Override
+    public void handle_Server(ChannelHandlerContext ctx) {
+        // TODO Adjust message handling to client's version
+    }
+}

core/src/main/java/com/seibel/distanthorizons/core/network/messages/Message.java

@@ -0,0 +1,19 @@
+package com.seibel.distanthorizons.core.network.messages;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+
+public abstract class Message {
+    public Message() { }
+
+    public abstract void encode(ByteBuf out);
+    public abstract void decode(ByteBuf in);
+
+    public void handle_Server(ChannelHandlerContext ctx) {
+        throw new UnsupportedOperationException();
+    }
+    public void handle_Client(ChannelHandlerContext ctx) {
+        throw new UnsupportedOperationException();
+    }
+}
+