From ed2094a749be38f1e0a43fd29d45aa7e75747f66 Mon Sep 17 00:00:00 2001
From: DmitriyMX <dimon550@gmail.com>
Date: Sun, 25 Mar 2018 20:29:18 +0300
Subject: [PATCH] Handshake packet

---
 src/main/java/mc/core/netty/BasePacket.java   |  2 +
 .../java/mc/core/netty/HandshakePacket.java   | 29 ++++++++++++
 .../java/mc/core/netty/PacketDecoder.java     | 29 ++++--------
 .../java/mc/core/netty/PacketHandler.java     |  6 +--
 src/main/java/mc/core/netty/Utilits.java      | 45 +++++++++++++++++++
 5 files changed, 87 insertions(+), 24 deletions(-)
 create mode 100644 src/main/java/mc/core/netty/HandshakePacket.java
 create mode 100644 src/main/java/mc/core/netty/Utilits.java

diff --git a/src/main/java/mc/core/netty/BasePacket.java b/src/main/java/mc/core/netty/BasePacket.java
index 0c258c6..4942c29 100644
--- a/src/main/java/mc/core/netty/BasePacket.java
+++ b/src/main/java/mc/core/netty/BasePacket.java
@@ -6,9 +6,11 @@ package mc.core.netty;
 
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
+import lombok.ToString;
 
 @RequiredArgsConstructor
 @Getter
+@ToString
 class BasePacket {
     private final int length;
     private final int id;
diff --git a/src/main/java/mc/core/netty/HandshakePacket.java b/src/main/java/mc/core/netty/HandshakePacket.java
new file mode 100644
index 0000000..97d875f
--- /dev/null
+++ b/src/main/java/mc/core/netty/HandshakePacket.java
@@ -0,0 +1,29 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-25
+ */
+package mc.core.netty;
+
+import io.netty.buffer.ByteBuf;
+import lombok.Getter;
+import lombok.ToString;
+
+import static mc.core.netty.Utilits.*;
+
+@Getter
+@ToString
+public class HandshakePacket extends BasePacket {
+    private final int protocolVersion;
+    private final String serverAddress;
+    private final int serverPort;
+    private final int nextState;
+
+    public HandshakePacket(int length, int id, ByteBuf byteBuf) throws Exception {
+        super(length, id);
+
+        protocolVersion = readVarInt(byteBuf);
+        serverAddress = readString(byteBuf);
+        serverPort = readUnsignedShort(byteBuf);
+        nextState = readVarInt(byteBuf);
+    }
+}
diff --git a/src/main/java/mc/core/netty/PacketDecoder.java b/src/main/java/mc/core/netty/PacketDecoder.java
index 5a09dd8..cfb9b12 100644
--- a/src/main/java/mc/core/netty/PacketDecoder.java
+++ b/src/main/java/mc/core/netty/PacketDecoder.java
@@ -10,32 +10,19 @@ import io.netty.handler.codec.ReplayingDecoder;
 
 import java.util.List;
 
+import static mc.core.netty.Utilits.readVarInt;
+
 public class PacketDecoder extends ReplayingDecoder<BasePacket> {
-    private int readVarInt(ByteBuf byteBuf) throws Exception {
-        int result = 0;
-        byte read;
-        int numRead = 0;
-
-        do {
-            read = byteBuf.readByte();
-            int value = (read & 0b01111111);
-            result |= (value << (7 * numRead));
-
-            numRead++;
-            if (numRead > 5) {
-                throw new Exception("VarInt is too big");
-            }
-        } while ((read & 0b10000000) != 0);
-
-        return result;
-    }
-
     @Override
     protected void decode(ChannelHandlerContext context, ByteBuf byteBuf, List<Object> list) throws Exception {
         int length = readVarInt(byteBuf);
         int id = readVarInt(byteBuf);
 
-        list.add(new BasePacket(length, id));
-        byteBuf.skipBytes(length);
+        if (id == 0) {
+            list.add(new HandshakePacket(length, id, byteBuf));
+        } else {
+            list.add(new BasePacket(length, id));
+            byteBuf.skipBytes(length);
+        }
     }
 }
diff --git a/src/main/java/mc/core/netty/PacketHandler.java b/src/main/java/mc/core/netty/PacketHandler.java
index 3f40d5a..16d4982 100644
--- a/src/main/java/mc/core/netty/PacketHandler.java
+++ b/src/main/java/mc/core/netty/PacketHandler.java
@@ -12,8 +12,8 @@ import lombok.extern.slf4j.Slf4j;
 public class PacketHandler extends SimpleChannelInboundHandler<BasePacket> {
     @Override
     protected void channelRead0(ChannelHandlerContext context, BasePacket packet) throws Exception {
-        log.info("Lenght: {} | Id: {}",
-                packet.getLength(),
-                packet.getId());
+        log.info("Packet: {} | Data: {}",
+                packet.getClass().getSimpleName(),
+                packet.toString());
     }
 }
diff --git a/src/main/java/mc/core/netty/Utilits.java b/src/main/java/mc/core/netty/Utilits.java
new file mode 100644
index 0000000..2bbccfa
--- /dev/null
+++ b/src/main/java/mc/core/netty/Utilits.java
@@ -0,0 +1,45 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-25
+ */
+package mc.core.netty;
+
+import io.netty.buffer.ByteBuf;
+
+import java.nio.charset.StandardCharsets;
+
+public class Utilits {
+    public static int readVarInt(ByteBuf byteBuf) throws Exception {
+        int result = 0;
+        byte read;
+        int numRead = 0;
+
+        do {
+            read = byteBuf.readByte();
+            int value = (read & 0b01111111);
+            result |= (value << (7 * numRead));
+
+            numRead++;
+            if (numRead > 5) {
+                throw new Exception("VarInt is too big");
+            }
+        } while ((read & 0b10000000) != 0);
+
+        return result;
+    }
+
+    public static String readString(ByteBuf byteBuf) throws Exception {
+        int length = readVarInt(byteBuf);
+        byte[] buffer = new byte[length];
+        int i = 0;
+        do {
+            buffer[i++] = byteBuf.readByte();
+        } while (i < length);
+
+        return new String(buffer, StandardCharsets.UTF_8);
+    }
+
+    public static int readUnsignedShort(ByteBuf byteBuf) {
+        return byteBuf.readUnsignedShort();
+    }
+}