WIP: Mobs can Read Books

CHANGELOG.md

@@ -6,6 +6,9 @@ All notable changes to **CreatureChat™** are documented in this file. The form
 
 ## Unreleased
 
+### Added
+- Mobs can now read books! Right-click to share the book or add it to their inventory.
+
 ### Added
 - Document SPDX header and changelog requirements in AGENTS.md for contributors
 

src/main/java/com/owlmaddie/inventory/MobInventoryMenu.java

@@ -233,6 +233,17 @@ public void removed(Player player) {
                         AdvancementHelper.potatoWar(serverPlayer);
                     }
                 }
+                if (added.size() == 1 && removed.isEmpty() && disarmedToInventory.isEmpty() && disarmedTaken.isEmpty() && !swapped && !handChanged) {
+                    Item item = added.keySet().iterator().next();
+                    if (com.owlmaddie.utils.BookHelper.isBook(item)) {
+                        ItemStack stack = findBookStack(item);
+                        String contents = com.owlmaddie.utils.BookHelper.summarizeBook(stack);
+                        String msg = "<" + player.getDisplayName().getString() +
+                                " shared a book with you> - Book contents: \"" + contents + "\"";
+                        ServerPackets.generate_chat("N/A", chatData, serverPlayer, mob, msg, true);
+                        return;
+                    }
+                }
                 StringBuilder msg = new StringBuilder("<" + player.getDisplayName().getString());
                 boolean first = true;
                 if (swapped) {
@@ -340,6 +351,16 @@ private void collectDisarmed(ItemStack initial, ItemStack finalMain, ItemStack f
         });
     }
 
+    private ItemStack findBookStack(Item item) {
+        for (int i = 0; i < mobInvSize; i++) {
+            ItemStack stack = inventory.getItem(i);
+            if (!stack.isEmpty() && stack.getItem() == item) {
+                return stack;
+            }
+        }
+        return ItemStack.EMPTY;
+    }
+
     private static String joinCounts(Map<Item, Integer> map) {
         List<String> parts = new ArrayList<>();
         for (Map.Entry<Item, Integer> entry : map.entrySet()) {

src/main/java/com/owlmaddie/mixin/MixinMobEntity.java

@@ -208,21 +208,30 @@ private void onItemGiven(Player player, InteractionHand hand, CallbackInfoReturn
             // Player has item in hand
             if (!itemStack.isEmpty()) {
                 ServerPlayer serverPlayer = (ServerPlayer) player;
-                String itemName = itemStack.getItem().getName(itemStack).getString();
-                int itemCount = itemStack.getCount();
-
-                // Decide verb
-                String action_verb = " shows ";
-                if (cir.getReturnValue().consumesAction()) {
-                    action_verb = " gives ";
-                }
-
-                // Prepare a message about the interaction
-                String giveItemMessage = "<" + serverPlayer.getDisplayName().getString() +
-                        action_verb + "you " + itemCount + " " + itemName + ">";
-
-                if (!entityData.characterSheet.isEmpty()) {
-                    ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, giveItemMessage, true);
+                if (com.owlmaddie.utils.BookHelper.isBook(itemStack.getItem())) {
+                    String contents = com.owlmaddie.utils.BookHelper.summarizeBook(itemStack);
+                    String msg = "<" + serverPlayer.getDisplayName().getString() +
+                            " shared a book with you> - Book contents: \"" + contents + "\"";
+                    if (!entityData.characterSheet.isEmpty()) {
+                        ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, msg, true);
+                    }
+                } else {
+                    String itemName = itemStack.getItem().getName(itemStack).getString();
+                    int itemCount = itemStack.getCount();
+
+                    // Decide verb
+                    String action_verb = " shows ";
+                    if (cir.getReturnValue().consumesAction()) {
+                        action_verb = " gives ";
+                    }
+
+                    // Prepare a message about the interaction
+                    String giveItemMessage = "<" + serverPlayer.getDisplayName().getString() +
+                            action_verb + "you " + itemCount + " " + itemName + ">";
+
+                    if (!entityData.characterSheet.isEmpty()) {
+                        ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, giveItemMessage, true);
+                    }
                 }
 
             } else if (itemStack.isEmpty() && playerData.friendship == 3) {

src/main/java/com/owlmaddie/utils/BookHelper.java

@@ -0,0 +1,91 @@
+// SPDX-FileCopyrightText: 2025 owlmaddie LLC
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Assets CC-BY-NC-SA-4.0; CreatureChat™ trademark © owlmaddie LLC - unauthorized use prohibited
+package com.owlmaddie.utils;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
+public class BookHelper {
+    public static boolean isBook(Item item) {
+        return item == Items.WRITTEN_BOOK || item == Items.WRITABLE_BOOK || item == Items.BOOK;
+    }
+
+    private static String extractText(String json) {
+        try {
+            JsonElement element = JsonParser.parseString(json);
+            return collectText(element);
+        } catch (Exception e) {
+            return json;
+        }
+    }
+
+    private static String collectText(JsonElement element) {
+        if (element == null) {
+            return "";
+        }
+        if (element.isJsonPrimitive()) {
+            return element.getAsString();
+        }
+        StringBuilder sb = new StringBuilder();
+        if (element.isJsonObject()) {
+            JsonObject obj = element.getAsJsonObject();
+            if (obj.has("text")) {
+                sb.append(obj.get("text").getAsString());
+            }
+            if (obj.has("extra")) {
+                JsonArray arr = obj.getAsJsonArray("extra");
+                for (JsonElement e : arr) {
+                    sb.append(collectText(e));
+                }
+            }
+        } else if (element.isJsonArray()) {
+            for (JsonElement e : element.getAsJsonArray()) {
+                sb.append(collectText(e));
+            }
+        }
+        return sb.toString();
+    }
+
+    private static String readBook(ItemStack stack) {
+        if (!stack.hasTag()) {
+            return "";
+        }
+        CompoundTag tag = stack.getTag();
+        ListTag pages = tag.getList("pages", 8);
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < pages.size(); i++) {
+            String page = pages.getString(i);
+            if (stack.is(Items.WRITTEN_BOOK)) {
+                sb.append(extractText(page));
+            } else {
+                sb.append(page);
+            }
+        }
+        return sb.toString();
+    }
+
+    public static String summarizeBook(ItemStack stack) {
+        if (!isBook(stack.getItem())) {
+            return "N/A";
+        }
+        String text = readBook(stack);
+        if (text.isEmpty()) {
+            return "N/A";
+        }
+        if (text.length() <= 2048) {
+            return text;
+        }
+        int skip = text.length() - 2048;
+        String start = text.substring(0, 1024);
+        String end = text.substring(text.length() - 1024);
+        return start + "... skipped " + skip + " chars ..." + end;
+    }
+}

src/vs/v1_20_5/main/java/com/owlmaddie/mixin/MixinMobEntity.java

@@ -210,21 +210,30 @@ private void onItemGiven(Player player, InteractionHand hand, CallbackInfoReturn
             // Player has item in hand
             if (!itemStack.isEmpty()) {
                 ServerPlayer serverPlayer = (ServerPlayer) player;
-                String itemName = itemStack.getItem().getName(itemStack).getString();
-                int itemCount = itemStack.getCount();
-
-                // Decide verb
-                String action_verb = " shows ";
-                if (cir.getReturnValue().consumesAction()) {
-                    action_verb = " gives ";
-                }
-
-                // Prepare a message about the interaction
-                String giveItemMessage = "<" + serverPlayer.getDisplayName().getString() +
-                        action_verb + "you " + itemCount + " " + itemName + ">";
-
-                if (!entityData.characterSheet.isEmpty()) {
-                    ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, giveItemMessage, true);
+                if (com.owlmaddie.utils.BookHelper.isBook(itemStack.getItem())) {
+                    String contents = com.owlmaddie.utils.BookHelper.summarizeBook(itemStack);
+                    String msg = "<" + serverPlayer.getDisplayName().getString() +
+                            " shared a book with you> - Book contents: \"" + contents + "\"";
+                    if (!entityData.characterSheet.isEmpty()) {
+                        ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, msg, true);
+                    }
+                } else {
+                    String itemName = itemStack.getItem().getName(itemStack).getString();
+                    int itemCount = itemStack.getCount();
+
+                    // Decide verb
+                    String action_verb = " shows ";
+                    if (cir.getReturnValue().consumesAction()) {
+                        action_verb = " gives ";
+                    }
+
+                    // Prepare a message about the interaction
+                    String giveItemMessage = "<" + serverPlayer.getDisplayName().getString() +
+                            action_verb + "you " + itemCount + " " + itemName + ">";
+
+                    if (!entityData.characterSheet.isEmpty()) {
+                        ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, giveItemMessage, true);
+                    }
                 }
 
             } else if (itemStack.isEmpty() && playerData.friendship == 3) {

src/vs/v1_20_5/main/java/com/owlmaddie/utils/BookHelper.java

@@ -0,0 +1,100 @@
+// SPDX-FileCopyrightText: 2025 owlmaddie LLC
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Assets CC-BY-NC-SA-4.0; CreatureChat™ trademark © owlmaddie LLC - unauthorized use prohibited
+package com.owlmaddie.utils;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.network.chat.Component;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.item.component.WrittenBookContent;
+import net.minecraft.world.item.component.WritableBookContent;
+
+public class BookHelper {
+    public static boolean isBook(Item item) {
+        return item == Items.WRITTEN_BOOK || item == Items.WRITABLE_BOOK || item == Items.BOOK;
+    }
+
+    private static String extractText(String json) {
+        try {
+            JsonElement element = JsonParser.parseString(json);
+            return collectText(element);
+        } catch (Exception e) {
+            return json;
+        }
+    }
+
+    private static String collectText(JsonElement element) {
+        if (element == null) {
+            return "";
+        }
+        if (element.isJsonPrimitive()) {
+            return element.getAsString();
+        }
+        StringBuilder sb = new StringBuilder();
+        if (element.isJsonObject()) {
+            JsonObject obj = element.getAsJsonObject();
+            if (obj.has("text")) {
+                sb.append(obj.get("text").getAsString());
+            }
+            if (obj.has("extra")) {
+                JsonArray arr = obj.getAsJsonArray("extra");
+                for (JsonElement e : arr) {
+                    sb.append(collectText(e));
+                }
+            }
+        } else if (element.isJsonArray()) {
+            for (JsonElement e : element.getAsJsonArray()) {
+                sb.append(collectText(e));
+            }
+        }
+        return sb.toString();
+    }
+
+    private static String readBook(ItemStack stack) {
+        StringBuilder sb = new StringBuilder();
+        if (stack.is(Items.WRITTEN_BOOK)) {
+            WrittenBookContent content = stack.get(DataComponents.WRITTEN_BOOK_CONTENT);
+            if (content == null) {
+                return "";
+            }
+            for (var page : content.pages()) {
+                Component c = page.raw();
+                sb.append(c.getString());
+            }
+        } else {
+            WritableBookContent content = stack.get(DataComponents.WRITABLE_BOOK_CONTENT);
+            if (content == null) {
+                return "";
+            }
+            for (var page : content.pages()) {
+                String raw = page.raw();
+                // Writable books store raw JSON strings; attempt to extract plain text
+                sb.append(extractText(raw));
+            }
+        }
+        return sb.toString();
+    }
+
+    public static String summarizeBook(ItemStack stack) {
+        if (!isBook(stack.getItem())) {
+            return "N/A";
+        }
+        String text = readBook(stack);
+        if (text.isEmpty()) {
+            return "N/A";
+        }
+        if (text.length() <= 2048) {
+            return text;
+        }
+        int skip = text.length() - 2048;
+        String start = text.substring(0, 1024);
+        String end = text.substring(text.length() - 1024);
+        return start + "... skipped " + skip + " chars ..." + end;
+    }
+}

src/vs/v1_21_0/main/java/com/owlmaddie/mixin/MixinMobEntity.java

@@ -213,21 +213,30 @@ private void onItemGiven(Player player, InteractionHand hand, CallbackInfoReturn
             // Player has item in hand
             if (!itemStack.isEmpty()) {
                 ServerPlayer serverPlayer = (ServerPlayer) player;
-                String itemName = itemStack.getItem().getName(itemStack).getString();
-                int itemCount = itemStack.getCount();
-
-                // Decide verb
-                String action_verb = " shows ";
-                if (cir.getReturnValue().consumesAction()) {
-                    action_verb = " gives ";
-                }
-
-                // Prepare a message about the interaction
-                String giveItemMessage = "<" + serverPlayer.getDisplayName().getString() +
-                        action_verb + "you " + itemCount + " " + itemName + ">";
-
-                if (!entityData.characterSheet.isEmpty()) {
-                    ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, giveItemMessage, true);
+                if (com.owlmaddie.utils.BookHelper.isBook(itemStack.getItem())) {
+                    String contents = com.owlmaddie.utils.BookHelper.summarizeBook(itemStack);
+                    String msg = "<" + serverPlayer.getDisplayName().getString() +
+                            " shared a book with you> - Book contents: \"" + contents + "\"";
+                    if (!entityData.characterSheet.isEmpty()) {
+                        ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, msg, true);
+                    }
+                } else {
+                    String itemName = itemStack.getItem().getName(itemStack).getString();
+                    int itemCount = itemStack.getCount();
+
+                    // Decide verb
+                    String action_verb = " shows ";
+                    if (cir.getReturnValue().consumesAction()) {
+                        action_verb = " gives ";
+                    }
+
+                    // Prepare a message about the interaction
+                    String giveItemMessage = "<" + serverPlayer.getDisplayName().getString() +
+                            action_verb + "you " + itemCount + " " + itemName + ">";
+
+                    if (!entityData.characterSheet.isEmpty()) {
+                        ServerPackets.generate_chat("N/A", entityData, serverPlayer, thisEntity, giveItemMessage, true);
+                    }
                 }
 
             } else if (itemStack.isEmpty() && playerData.friendship == 3) {