Make heads persistent, arbitrary object serializer (#4)

* Fix typo in URL for WRENCH resource pack and DRY it

During module registration, the URL had a trailing 0.

* Add general PersistentDataType which uses GSON for arbitrary object serialization

* Add PersistentHeads module, allowing for keeping name/lore after placing and breaking them

src/main/java/me/machinemaker/vanillatweaks/VanillaTweaksModules.java

@@ -102,6 +102,9 @@ public class VanillaTweaksModules extends BaseConfig {
     @Path("utilities.real-time-clock")
     public Boolean realTimeClock = false;
 
+    @Path("utilities.persist-head-data")
+    public Boolean persistHeadData = false;
+
     @Path("villagers.villagerdeathmessage")
     public Boolean villagerDeathMsgs = false;
 

src/main/java/me/machinemaker/vanillatweaks/_managers/ModuleManager.java

@@ -15,6 +15,7 @@
 import me.machinemaker.vanillatweaks.mobheads.MobHeads;
 import me.machinemaker.vanillatweaks.multiplayersleep.MultiplayerSleep;
 import me.machinemaker.vanillatweaks.netherportalcoords.NetherPortalCoords;
+import me.machinemaker.vanillatweaks.persistentheads.PersistentHeads;
 import me.machinemaker.vanillatweaks.pillagertools.PillagerTools;
 import me.machinemaker.vanillatweaks.playergraves.PlayerGraves;
 import me.machinemaker.vanillatweaks.playerheaddrops.PlayerHeadDrops;
@@ -90,6 +91,7 @@ public List<BaseModule> allModules() {
                     new PlayerHeadDrops(plugin),
                     new TrackRawStats(plugin),
                     new Tag(plugin),
+                    new PersistentHeads(plugin),
 
                     new VillagerDeathMessages(plugin),
                     new PillagerTools(plugin),

src/main/java/me/machinemaker/vanillatweaks/persistentheads/PersistentHeads.java

@@ -0,0 +1,88 @@
+package me.machinemaker.vanillatweaks.persistentheads;
+
+import io.papermc.lib.PaperLib;
+import io.papermc.lib.features.blockstatesnapshot.BlockStateSnapshotResult;
+import me.machinemaker.vanillatweaks.BaseModule;
+import me.machinemaker.vanillatweaks.VanillaTweaks;
+import me.machinemaker.vanillatweaks.utils.datatypes.JsonDataType;
+import org.bukkit.Material;
+import org.bukkit.NamespacedKey;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockState;
+import org.bukkit.block.TileState;
+import org.bukkit.entity.Item;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.BlockBreakEvent;
+import org.bukkit.event.block.BlockDropItemEvent;
+import org.bukkit.event.block.BlockPlaceEvent;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.bukkit.persistence.PersistentDataContainer;
+import org.bukkit.persistence.PersistentDataType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class PersistentHeads extends BaseModule implements Listener {
+
+    private final NamespacedKey NAME_KEY = new NamespacedKey(plugin, "head_name");
+    private final NamespacedKey LORE_KEY = new NamespacedKey(plugin, "head_lore");
+    private final PersistentDataType<String,String[]> LORE_PDT = new JsonDataType<>(String[].class);
+
+    public PersistentHeads(VanillaTweaks plugin) {
+        super(plugin, config -> config.persistHeadData);
+    }
+
+    @EventHandler
+    public void onBlockPlaceEvent(BlockPlaceEvent event) {
+        @NotNull ItemStack headItem = event.getItemInHand();
+        if (headItem.getType() != Material.PLAYER_HEAD) return;
+        ItemMeta meta = headItem.getItemMeta();
+        if (meta == null) return;
+        @NotNull String name = meta.getDisplayName();
+        @Nullable List<String> lore = meta.getLore();
+        @NotNull Block block = event.getBlockPlaced();
+        // NOTE: Not using snapshots is broken: https://github.com/PaperMC/Paper/issues/3913
+        BlockStateSnapshotResult blockStateSnapshotResult = PaperLib.getBlockState(block, true);
+        TileState skullState = (TileState) blockStateSnapshotResult.getState();
+        @NotNull PersistentDataContainer skullPDC = skullState.getPersistentDataContainer();
+        skullPDC.set(NAME_KEY, PersistentDataType.STRING, name);
+        if (lore != null) skullPDC.set(LORE_KEY, LORE_PDT, lore.toArray(new String[0]));
+        if (blockStateSnapshotResult.isSnapshot()) skullState.update();
+    }
+
+    @EventHandler
+    public void onBlockDropItemEvent(BlockDropItemEvent event) {
+        @NotNull BlockState blockState = event.getBlockState();
+        if (blockState.getType() != Material.PLAYER_HEAD) return;
+        TileState skullState = (TileState) blockState;
+        @NotNull PersistentDataContainer skullPDC = skullState.getPersistentDataContainer();
+        @Nullable String name = skullPDC.get(NAME_KEY, PersistentDataType.STRING);
+        @Nullable String[] lore = skullPDC.get(LORE_KEY, LORE_PDT);
+        if (name == null) return;
+        for (Item item: event.getItems()) { // Ideally should only be one...
+            @NotNull ItemStack itemstack = item.getItemStack();
+            if (itemstack.getType() == Material.PLAYER_HEAD) {
+                @Nullable ItemMeta meta = itemstack.getItemMeta();
+                if (meta == null) continue; // This shouldn't happen
+                meta.setDisplayName(name);
+                if (lore != null) meta.setLore(Arrays.asList(lore));
+                itemstack.setItemMeta(meta);
+            }
+        }
+
+    }
+
+    @Override
+    public void register() {
+        registerEvents(this);
+    }
+
+    @Override
+    public void unregister() {
+        unregisterEvents(this);
+    }
+}

src/main/java/me/machinemaker/vanillatweaks/utils/datatypes/JsonDataType.java

@@ -0,0 +1,42 @@
+package me.machinemaker.vanillatweaks.utils.datatypes;
+
+import com.google.gson.Gson;
+import org.bukkit.persistence.PersistentDataAdapterContext;
+import org.bukkit.persistence.PersistentDataType;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Lets you store arbitrary data in PDC.
+ * @param <T>
+ */
+public class JsonDataType<T> implements PersistentDataType<String, T> {
+
+    private static final Gson gson = new Gson();
+    private final Class<T> typeClass;
+
+    public JsonDataType(Class<T> typeClass) {
+        this.typeClass = typeClass;
+    }
+
+    @Override
+    public @NotNull Class<String> getPrimitiveType() {
+        return String.class;
+    }
+
+    @Override
+    public @NotNull Class<T> getComplexType() {
+        return typeClass;
+    }
+
+    @NotNull
+    @Override
+    public String toPrimitive(@NotNull T complex, @NotNull PersistentDataAdapterContext persistentDataAdapterContext) {
+        return gson.toJson(complex);
+    }
+
+    @NotNull
+    @Override
+    public T fromPrimitive(@NotNull String primitive, @NotNull PersistentDataAdapterContext context) {
+        return gson.fromJson(primitive, getComplexType());
+    }
+}

src/main/java/me/machinemaker/vanillatweaks/wrenches/Wrench.java

@@ -28,6 +28,7 @@
 
 public class Wrench extends BaseModule implements Listener {
 
+    private final String resourcePackUrl = "https://potrebic.box.com/shared/static/uw4fvii2o8qsjuz6xuant1safwjdnrez.zip";
     private final byte[] hash = new BigInteger("1ACF79C491B3CB9EEE50816AD0CC1FC45AABA147", 16).toByteArray();
     private final NamespacedKey RECIPE_KEY = new NamespacedKey(this.plugin, "redstone_wrench");
     private final List<BlockFace> faces = Lists.newArrayList(BlockFace.EAST, BlockFace.SOUTH, BlockFace.WEST, BlockFace.NORTH, BlockFace.UP, BlockFace.DOWN);
@@ -75,14 +76,14 @@ public void onPlayerInteract(PlayerInteractEvent event) {
 
     @EventHandler
     public void onPlayerJoin(PlayerJoinEvent event) {
-        event.getPlayer().setResourcePack("https://potrebic.box.com/shared/static/uw4fvii2o8qsjuz6xuant1safwjdnrez.zip", hash);
+        event.getPlayer().setResourcePack(resourcePackUrl, hash);
     }
 
     @Override
     public void register() {
         Bukkit.addRecipe(recipe);
         this.registerEvents(this);
-        Bukkit.getOnlinePlayers().forEach(player -> player.setResourcePack("https://potrebic.box.com/shared/static/uw4fvii2o8qsjuz6xuant1safwjdnrez.zip0", hash));
+        Bukkit.getOnlinePlayers().forEach(player -> player.setResourcePack(resourcePackUrl, hash));
     }
 
     @Override