From 1a9cda05798294b5bfc4589420e53eae75998fab Mon Sep 17 00:00:00 2001
From: EnZaXD <florian.michael07@gmail.com>
Date: Thu, 10 Oct 2024 22:42:21 +0200
Subject: [PATCH] Handle WRITTEN_BOOK_CONTENT component in rewriters as well
 (#4175)

Closes https://github.com/ViaVersion/ViaVersion/issues/4144
---
 .../rewriter/ComponentRewriter.java           | 38 ++++++++++++++++++-
 .../rewriter/StructuredItemRewriter.java      | 12 ++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/common/src/main/java/com/viaversion/viaversion/rewriter/ComponentRewriter.java b/common/src/main/java/com/viaversion/viaversion/rewriter/ComponentRewriter.java
index 5aa31652b..59dd5a010 100644
--- a/common/src/main/java/com/viaversion/viaversion/rewriter/ComponentRewriter.java
+++ b/common/src/main/java/com/viaversion/viaversion/rewriter/ComponentRewriter.java
@@ -39,8 +39,8 @@ import com.viaversion.viaversion.protocols.base.ClientboundLoginPackets;
 import com.viaversion.viaversion.util.ComponentUtil;
 import com.viaversion.viaversion.util.SerializerVersion;
 import com.viaversion.viaversion.util.TagUtil;
-import org.checkerframework.checker.nullness.qual.Nullable;
 import java.util.BitSet;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Handles json and tag components, containing methods to override certain parts of the handling.
@@ -360,6 +360,8 @@ public class ComponentRewriter<C extends ClientboundPacketType> implements com.v
             handleShowItem(connection, contentsTag, componentsTag);
             if (componentsTag != null) {
                 handleContainerContents(connection, componentsTag);
+                handleWrittenBookContents(connection, componentsTag);
+
                 handleItemArrayContents(connection, componentsTag, "bundle_contents");
                 handleItemArrayContents(connection, componentsTag, "charged_projectiles");
             }
@@ -386,6 +388,40 @@ public class ComponentRewriter<C extends ClientboundPacketType> implements com.v
         }
     }
 
+    protected void handleWrittenBookContents(final UserConnection connection, final CompoundTag tag) {
+        final CompoundTag book = TagUtil.getNamespacedCompoundTag(tag, "minecraft:written_book_content");
+        if (book == null) {
+            return;
+        }
+
+        final ListTag<CompoundTag> pagesTag = book.getListTag("pages", CompoundTag.class);
+        if (pagesTag == null) {
+            return;
+        }
+
+        for (final CompoundTag compoundTag : pagesTag) {
+            final StringTag raw = compoundTag.getStringTag("raw");
+            processJsonString(connection, raw);
+
+            final StringTag filtered = compoundTag.getStringTag("filtered");
+            processJsonString(connection, filtered);
+        }
+    }
+
+    private void processJsonString(final UserConnection connection, final StringTag tag) {
+        if (tag == null) {
+            return;
+        }
+
+        final var input = inputSerializerVersion();
+        final var output = outputSerializerVersion();
+
+        final Tag asTag = input.toTag(input.toComponent(tag.getValue()));
+        processTag(connection, asTag);
+
+        tag.setValue(output.toString(output.toComponent(asTag)));
+    }
+
     protected void handleItemArrayContents(final UserConnection connection, final CompoundTag tag, final String key) {
         final ListTag<CompoundTag> container = TagUtil.getNamespacedCompoundTagList(tag, key);
         if (container == null) {
diff --git a/common/src/main/java/com/viaversion/viaversion/rewriter/StructuredItemRewriter.java b/common/src/main/java/com/viaversion/viaversion/rewriter/StructuredItemRewriter.java
index fe3b72e63..8294702ba 100644
--- a/common/src/main/java/com/viaversion/viaversion/rewriter/StructuredItemRewriter.java
+++ b/common/src/main/java/com/viaversion/viaversion/rewriter/StructuredItemRewriter.java
@@ -28,6 +28,8 @@ import com.viaversion.viaversion.api.minecraft.data.StructuredData;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataContainer;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
 import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.minecraft.item.data.FilterableComponent;
+import com.viaversion.viaversion.api.minecraft.item.data.WrittenBook;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.ServerboundPacketType;
@@ -138,6 +140,16 @@ public class StructuredItemRewriter<C extends ClientboundPacketType, S extends S
                     protocol.getComponentRewriter().processTag(connection, tag);
                 }
             }
+
+            final WrittenBook book = container.get(StructuredDataKey.WRITTEN_BOOK_CONTENT);
+            if (book != null) {
+                for (final FilterableComponent page : book.pages()) {
+                    protocol.getComponentRewriter().processTag(connection, page.raw());
+                    if (page.isFiltered()) {
+                        protocol.getComponentRewriter().processTag(connection, page.filtered());
+                    }
+                }
+            }
         }
 
         // Look for item types