From 346d64aea5aef89f2a2ea32831915bc0d339121e Mon Sep 17 00:00:00 2001
From: DmitriyMX <dimon550@gmail.com>
Date: Sat, 8 May 2021 22:31:36 +0300
Subject: [PATCH] SetExperiencePacket

---
 protocol/src/main/java/mc/protocol/State.java |  1 +
 .../packets/server/SetExperiencePacket.java   | 35 +++++++++++++++++++
 .../main/java/mc/server/PacketHandler.java    | 29 ++++++++++++++-
 3 files changed, 64 insertions(+), 1 deletion(-)
 create mode 100644 protocol/src/main/java/mc/protocol/packets/server/SetExperiencePacket.java

diff --git a/protocol/src/main/java/mc/protocol/State.java b/protocol/src/main/java/mc/protocol/State.java
index 70cfb0f..d634b08 100644
--- a/protocol/src/main/java/mc/protocol/State.java
+++ b/protocol/src/main/java/mc/protocol/State.java
@@ -60,6 +60,7 @@ public enum State {
 					JoinGamePacket.class, 0x23,
 					PlayerAbilitiesPacket.class,0x2C,
 					SPlayerPositionAndLookPacket.class, 0x2F,
+					SetExperiencePacket.class, 0x40,
 					SpawnPositionPacket.class, 0x46
 			)
 	);
diff --git a/protocol/src/main/java/mc/protocol/packets/server/SetExperiencePacket.java b/protocol/src/main/java/mc/protocol/packets/server/SetExperiencePacket.java
new file mode 100644
index 0000000..7277c8b
--- /dev/null
+++ b/protocol/src/main/java/mc/protocol/packets/server/SetExperiencePacket.java
@@ -0,0 +1,35 @@
+package mc.protocol.packets.server;
+
+import lombok.Data;
+import mc.protocol.io.NetByteBuf;
+import mc.protocol.packets.ServerSidePacket;
+
+/**
+ * Set Experience packet.
+ *
+ * <p>Структура пакета</p>
+ * <pre>
+ * | FIELD            | TYPE     | NOTES                  |
+ * |------------------|----------|------------------------|
+ * | Experience bar   | Float    | Значение от 0.0 до 1.0 |
+ * | Level            | VarInt   |                        |
+ * | Total Experience | VarInt   |                        |
+ * </pre>
+ *
+ * @see <a href="https://wiki.vg/index.php?title=Protocol&oldid=14204#Set_Experience">Set Experience</a>
+ * @see <a href="https://minecraft.fandom.com/wiki/Experience#Leveling_up">Experience: Leveling up</a>
+ */
+@Data
+public class SetExperiencePacket implements ServerSidePacket {
+
+	private float experienceBar;
+	private int level;
+	private int totalExperience;
+
+	@Override
+	public void writeSelf(NetByteBuf netByteBuf) {
+		netByteBuf.writeFloat(this.experienceBar);
+		netByteBuf.writeVarInt(this.level);
+		netByteBuf.writeVarInt(this.totalExperience);
+	}
+}
diff --git a/server/src/main/java/mc/server/PacketHandler.java b/server/src/main/java/mc/server/PacketHandler.java
index fad97df..893e8cf 100644
--- a/server/src/main/java/mc/server/PacketHandler.java
+++ b/server/src/main/java/mc/server/PacketHandler.java
@@ -2,7 +2,8 @@ package mc.server;
 
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import mc.protocol.*;
+import mc.protocol.ProtocolConstant;
+import mc.protocol.State;
 import mc.protocol.api.ConnectionContext;
 import mc.protocol.model.Location;
 import mc.protocol.model.Look;
@@ -26,6 +27,7 @@ import java.util.Base64;
 import java.util.Collections;
 import java.util.Random;
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 
 @Slf4j
 @RequiredArgsConstructor
@@ -67,6 +69,7 @@ public class PacketHandler {
 		context.sendNow(response);
 	}
 
+	@SuppressWarnings("java:S2189")
 	public void onLoginStart(ConnectionContext context, LoginStartPacket loginStartPacket) {
 		var loginSuccessPacket = new LoginSuccessPacket();
 		loginSuccessPacket.setUuid(UUID.randomUUID());
@@ -122,6 +125,30 @@ public class PacketHandler {
 		context.send(pingPacket);
 
 		context.flushSending();
+
+		// -- Эксперименты -- //
+
+		var setExperiencePacket = new SetExperiencePacket();
+		setExperiencePacket.setExperienceBar(0f);
+		setExperiencePacket.setLevel(0);
+		setExperiencePacket.setTotalExperience(100);
+
+		while (true) {
+			context.sendNow(setExperiencePacket);
+
+			setExperiencePacket.setExperienceBar(setExperiencePacket.getExperienceBar() + 0.01f);
+			setExperiencePacket.setLevel(setExperiencePacket.getLevel() + 1);
+			if (setExperiencePacket.getExperienceBar() > 1.0f) {
+				setExperiencePacket.setExperienceBar(0f);
+				setExperiencePacket.setLevel(0);
+			}
+
+			try {
+				TimeUnit.MILLISECONDS.sleep(10);
+			} catch (InterruptedException e) {
+				break;
+			}
+		}
 	}
 
 	private static String faviconToBase64(Path iconPath) {