SPIGOT-4347: Add API to allow storing arbitrary values on ItemStacks

By: Bjarne Koll <LynxPlay101@gmail.com>

paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftNBTTagConfigSerializer.java

@@ -0,0 +1,80 @@
+package org.bukkit.craftbukkit.util;
+
+import com.mojang.brigadier.StringReader;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+import net.minecraft.server.MojangsonParser;
+import net.minecraft.server.NBTBase;
+import net.minecraft.server.NBTList;
+import net.minecraft.server.NBTTagCompound;
+import net.minecraft.server.NBTTagList;
+import net.minecraft.server.NBTTagString;
+
+public class CraftNBTTagConfigSerializer {
+
+    private static final Pattern ARRAY = Pattern.compile("^\\[.*]");
+    private static final MojangsonParser MOJANGSON_PARSER = new MojangsonParser(new StringReader(""));
+
+    public static Object serialize(NBTBase base) {
+        if (base instanceof NBTTagCompound) {
+            Map<String, Object> innerMap = new HashMap<>();
+            for (String key : ((NBTTagCompound) base).getKeys()) {
+                innerMap.put(key, serialize(((NBTTagCompound) base).get(key)));
+            }
+
+            return innerMap;
+        } else if (base instanceof NBTTagList) {
+            List<Object> baseList = new ArrayList<>();
+            for (int i = 0; i < ((NBTList) base).size(); i++) {
+                baseList.add(serialize(((NBTList) base).get(i)));
+            }
+
+            return baseList;
+        } else if (base instanceof NBTTagString) {
+            return base.b_(); //PAIL Rename getString
+        }
+
+        return base.toString();
+    }
+
+    public static NBTBase deserialize(Object object) {
+        if (object instanceof Map) {
+            NBTTagCompound compound = new NBTTagCompound();
+            for (Map.Entry<String, Object> entry : ((Map<String, Object>) object).entrySet()) {
+                compound.set(entry.getKey(), deserialize(entry.getValue()));
+            }
+
+            return compound;
+        } else if (object instanceof List) {
+            List<Object> list = (List<Object>) object;
+            if (list.isEmpty()) {
+                return new NBTTagList(); // Default
+            }
+
+            NBTTagList tagList = new NBTTagList();
+            for (Object tag : list) {
+                tagList.add(deserialize(tag));
+            }
+
+            return tagList;
+        } else if (object instanceof String) {
+            String string = (String) object;
+
+            if (ARRAY.matcher(string).matches()) {
+                try {
+                    return new MojangsonParser(new StringReader(string)).h(); // PAIL Rename parseTagList
+                } catch (CommandSyntaxException e) {
+                    throw new RuntimeException("Could not deserialize found list ", e);
+                }
+            } else {
+                return MOJANGSON_PARSER.b(string); // PAIL Rename parse tagBase
+            }
+        }
+
+        throw new RuntimeException("Could not deserialize NBTBase");
+    }
+}