From 61d07dec614db7417d50cb6e49485102e35e1fc1 Mon Sep 17 00:00:00 2001
From: Pierre Maurice Schwang <mail@pschwang.eu>
Date: Sun, 28 Aug 2022 00:11:39 +0200
Subject: [PATCH] fix: check for return types (optional) (#51)

---
 .../legacysupport/injector/NMSReflection.java       | 12 ++++++++++++
 .../legacysupport/listener/SoundListener.java       |  6 ++++--
 .../legacysupport/reflection/MethodSignature.java   | 13 +++++++++++++
 .../legacysupport/reflection/ReflectionAPI.java     |  4 ++++
 4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/main/java/de/gerrygames/viarewind/legacysupport/injector/NMSReflection.java b/src/main/java/de/gerrygames/viarewind/legacysupport/injector/NMSReflection.java
index 4c39a35..1341b6b 100644
--- a/src/main/java/de/gerrygames/viarewind/legacysupport/injector/NMSReflection.java
+++ b/src/main/java/de/gerrygames/viarewind/legacysupport/injector/NMSReflection.java
@@ -27,6 +27,18 @@ public class NMSReflection {
                 protocolVersion;
     }
 
+    public static Class<?> getBlockDataClass() {
+        try {
+            if (getProtocolVersion() >= PROTOCOL_1_17) {
+                return Class.forName("net.minecraft.world.level.block.state.IBlockData");
+            }
+            return getLegacyNMSClass("IBlockData");
+        } catch (ClassNotFoundException ex) {
+            ex.printStackTrace();
+        }
+        return null;
+    }
+
     public static Class<?> getBlockPositionClass() {
         try {
             if (getProtocolVersion() >= PROTOCOL_1_17) {
diff --git a/src/main/java/de/gerrygames/viarewind/legacysupport/listener/SoundListener.java b/src/main/java/de/gerrygames/viarewind/legacysupport/listener/SoundListener.java
index a3d77b6..c2157e1 100644
--- a/src/main/java/de/gerrygames/viarewind/legacysupport/listener/SoundListener.java
+++ b/src/main/java/de/gerrygames/viarewind/legacysupport/listener/SoundListener.java
@@ -31,6 +31,8 @@ public class SoundListener implements Listener {
 		} catch (ClassNotFoundException ignored) {}
 	}
 
+	private static final Class<?> I_BLOCK_DATA = NMSReflection.getBlockDataClass();
+
 	public SoundListener() {
 		try {
 			Class.forName("org.bukkit.event.entity.EntityPickupItemEvent");
@@ -102,8 +104,8 @@ public class SoundListener implements Listener {
 			}
 			Method getTypeMethod = ReflectionAPI.pickMethod(
 					nmsWorld.getClass(),
-					new MethodSignature("getType", blockPositionClass),
-					new MethodSignature("a_", blockPositionClass) // 1.18.2
+					new MethodSignature("getType", blockPositionClass).withReturnType(I_BLOCK_DATA),
+					new MethodSignature("a_", blockPositionClass).withReturnType(I_BLOCK_DATA) // 1.18.2
 			);
 			Object blockData = getTypeMethod.invoke(nmsWorld, blockPosition);
 			Method getBlock = ReflectionAPI.pickMethod(
diff --git a/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/MethodSignature.java b/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/MethodSignature.java
index c85e3d0..c468baa 100644
--- a/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/MethodSignature.java
+++ b/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/MethodSignature.java
@@ -1,6 +1,7 @@
 package de.gerrygames.viarewind.legacysupport.reflection;
 
 import java.util.Arrays;
+import java.util.Objects;
 import java.util.StringJoiner;
 
 public class MethodSignature {
@@ -8,6 +9,8 @@ public class MethodSignature {
     private final String name;
     private final Class<?>[] parameterTypes;
 
+    private Class<?> returnType;
+
     public MethodSignature(String name, Class<?>... parameterTypes) {
         this.name = name;
         this.parameterTypes = parameterTypes;
@@ -21,6 +24,16 @@ public class MethodSignature {
         return parameterTypes;
     }
 
+    public Class<?> returnType() {
+        return returnType;
+    }
+
+    public MethodSignature withReturnType(Class<?> returnType) {
+        Objects.requireNonNull(returnType);
+        this.returnType = returnType;
+        return this;
+    }
+
     @Override
     public String toString() {
         return new StringJoiner(", ", MethodSignature.class.getSimpleName() + "[", "]")
diff --git a/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/ReflectionAPI.java b/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/ReflectionAPI.java
index 479cae3..8b97bb1 100644
--- a/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/ReflectionAPI.java
+++ b/src/main/java/de/gerrygames/viarewind/legacysupport/reflection/ReflectionAPI.java
@@ -10,6 +10,7 @@ import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 
 public class ReflectionAPI {
 	private static Map<String, Field> fields = new HashMap<>();
@@ -41,6 +42,9 @@ public class ReflectionAPI {
             for (MethodSignature signature : signatures) {
                 try {
                     Method method = depth.getDeclaredMethod(signature.name(), signature.parameterTypes());
+					if (signature.returnType() != null && !Objects.equals(method.getReturnType(), signature.returnType())) {
+						continue;
+					}
                     if (!method.isAccessible()) {
                         method.setAccessible(true);
                     }