From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 1 May 2016 21:19:14 -0400
Subject: [PATCH] LootTable API and replenishable lootables

Provides an API to control the loot table for an object.
Also provides a feature that any Lootable Inventory (Chests in Structures)
can automatically replenish after a given time.

This feature is good for long term worlds so that newer players
do not suffer with "Every chest has been looted"

== AT ==
public org.bukkit.craftbukkit.block.CraftBlockEntityState getTileEntity()Lnet/minecraft/world/level/block/entity/BlockEntity;
public org.bukkit.craftbukkit.block.CraftLootable setLootTable(Lorg/bukkit/loot/LootTable;J)V
public org.bukkit.craftbukkit.entity.CraftMinecartContainer setLootTable(Lorg/bukkit/loot/LootTable;J)V

diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootable.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootable.java
new file mode 100644
index 0000000000000000000000000000000000000000..a53d51be1da25b87f2bc0a29a196d8f9996dbd2b
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootable.java
@@ -0,0 +1,21 @@
+package com.destroystokyo.paper.loottable;
+
+import org.bukkit.loot.LootTable;
+import org.bukkit.loot.Lootable;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+public interface PaperLootable extends Lootable {
+
+    @Override
+    default void setLootTable(final @Nullable LootTable table) {
+        this.setLootTable(table, this.getSeed());
+    }
+
+    @Override
+    default void setSeed(final long seed) {
+        this.setLootTable(this.getLootTable(), seed);
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootableBlock.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableBlock.java
new file mode 100644
index 0000000000000000000000000000000000000000..9e9ea13234703d3e4a39eed2b007e8be69dfbd12
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableBlock.java
@@ -0,0 +1,27 @@
+package com.destroystokyo.paper.loottable;
+
+import net.minecraft.world.RandomizableContainer;
+import org.bukkit.craftbukkit.CraftLootTable;
+import org.bukkit.loot.LootTable;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface PaperLootableBlock extends PaperLootable {
+
+    RandomizableContainer getRandomizableContainer();
+
+    /* Lootable */
+    @Override
+    default @Nullable LootTable getLootTable() {
+        return CraftLootTable.minecraftToBukkit(this.getRandomizableContainer().getLootTable());
+    }
+
+    @Override
+    default void setLootTable(final @Nullable LootTable table, final long seed) {
+        this.getRandomizableContainer().setLootTable(CraftLootTable.bukkitToMinecraft(table), seed);
+    }
+
+    @Override
+    default long getSeed() {
+        return this.getRandomizableContainer().getLootTableSeed();
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootableBlockInventory.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableBlockInventory.java
new file mode 100644
index 0000000000000000000000000000000000000000..0699c60920333ea1fec04e3c94d952244d2abeae
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableBlockInventory.java
@@ -0,0 +1,26 @@
+package com.destroystokyo.paper.loottable;
+
+import java.util.Objects;
+import net.minecraft.core.BlockPos;
+import org.bukkit.block.Block;
+import org.bukkit.craftbukkit.block.CraftBlock;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+public interface PaperLootableBlockInventory extends LootableBlockInventory, PaperLootableInventory, PaperLootableBlock {
+
+    /* PaperLootableInventory */
+    @Override
+    default PaperLootableInventoryData lootableDataForAPI() {
+        return Objects.requireNonNull(this.getRandomizableContainer().lootableData(), "Can only manage loot tables on tile entities with lootableData");
+    }
+
+    /* LootableBlockInventory */
+    @Override
+    default Block getBlock() {
+        final BlockPos position = this.getRandomizableContainer().getBlockPos();
+        return CraftBlock.at(this.getNMSWorld(), position);
+    }
+
+}
diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootableEntity.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableEntity.java
new file mode 100644
index 0000000000000000000000000000000000000000..de528b8bafd75b6f14b1384157f3a8a27e06b4a2
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableEntity.java
@@ -0,0 +1,29 @@
+package com.destroystokyo.paper.loottable;
+
+import net.minecraft.world.entity.vehicle.ContainerEntity;
+import org.bukkit.craftbukkit.CraftLootTable;
+import org.bukkit.loot.LootTable;
+import org.bukkit.loot.Lootable;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface PaperLootableEntity extends Lootable {
+
+    ContainerEntity getHandle();
+
+    /* Lootable */
+    @Override
+    default @Nullable LootTable getLootTable() {
+        return CraftLootTable.minecraftToBukkit(this.getHandle().getLootTable());
+    }
+
+    @Override
+    default void setLootTable(final @Nullable LootTable table, final long seed) {
+        this.getHandle().setLootTable(CraftLootTable.bukkitToMinecraft(table));
+        this.getHandle().setLootTableSeed(seed);
+    }
+
+    @Override
+    default long getSeed() {
+        return this.getHandle().getLootTableSeed();
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootableEntityInventory.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableEntityInventory.java
new file mode 100644
index 0000000000000000000000000000000000000000..5c57acc95f638a8bcb351ae44e9434a056835470
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableEntityInventory.java
@@ -0,0 +1,26 @@
+package com.destroystokyo.paper.loottable;
+
+import net.minecraft.world.level.Level;
+import org.bukkit.entity.Entity;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+public interface PaperLootableEntityInventory extends LootableEntityInventory, PaperLootableInventory, PaperLootableEntity {
+
+    /* PaperLootableInventory */
+    @Override
+    default Level getNMSWorld() {
+        return this.getHandle().level();
+    }
+
+    @Override
+    default PaperLootableInventoryData lootableDataForAPI() {
+        return this.getHandle().lootableData();
+    }
+
+    /* LootableEntityInventory */
+    default Entity getEntity() {
+        return ((net.minecraft.world.entity.Entity) this.getHandle()).getBukkitEntity();
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootableInventory.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableInventory.java
new file mode 100644
index 0000000000000000000000000000000000000000..9e7c22ef49f1699df298f7121d50d27b4cb0923f
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableInventory.java
@@ -0,0 +1,79 @@
+package com.destroystokyo.paper.loottable;
+
+import java.util.UUID;
+import net.minecraft.world.level.Level;
+import org.bukkit.World;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+public interface PaperLootableInventory extends PaperLootable, LootableInventory {
+
+    /* impl */
+    PaperLootableInventoryData lootableDataForAPI();
+
+    Level getNMSWorld();
+
+    default World getBukkitWorld() {
+        return this.getNMSWorld().getWorld();
+    }
+
+    /* LootableInventory */
+    @Override
+    default boolean isRefillEnabled() {
+        return this.getNMSWorld().paperConfig().lootables.autoReplenish;
+    }
+
+    @Override
+    default boolean hasBeenFilled() {
+        return this.getLastFilled() != -1;
+    }
+
+    @Override
+    default boolean hasPlayerLooted(final UUID player) {
+        return this.lootableDataForAPI().hasPlayerLooted(player);
+    }
+
+    @Override
+    default boolean canPlayerLoot(final UUID player) {
+        return this.lootableDataForAPI().canPlayerLoot(player, this.getNMSWorld().paperConfig());
+    }
+
+    @Override
+    default Long getLastLooted(final UUID player) {
+        return this.lootableDataForAPI().getLastLooted(player);
+    }
+
+    @Override
+    default boolean setHasPlayerLooted(final UUID player, final boolean looted) {
+        final boolean hasLooted = this.hasPlayerLooted(player);
+        if (hasLooted != looted) {
+            this.lootableDataForAPI().setPlayerLootedState(player, looted);
+        }
+        return hasLooted;
+    }
+
+    @Override
+    default boolean hasPendingRefill() {
+        final long nextRefill = this.lootableDataForAPI().getNextRefill();
+        return nextRefill != -1 && nextRefill > this.lootableDataForAPI().getLastFill();
+    }
+
+    @Override
+    default long getLastFilled() {
+        return this.lootableDataForAPI().getLastFill();
+    }
+
+    @Override
+    default long getNextRefill() {
+        return this.lootableDataForAPI().getNextRefill();
+    }
+
+    @Override
+    default long setNextRefill(long refillAt) {
+        if (refillAt < -1) {
+            refillAt = -1;
+        }
+        return this.lootableDataForAPI().setNextRefill(refillAt);
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/loottable/PaperLootableInventoryData.java b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableInventoryData.java
new file mode 100644
index 0000000000000000000000000000000000000000..fea92d280c6817cee1f18379d5ed51a3a22ee344
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/loottable/PaperLootableInventoryData.java
@@ -0,0 +1,249 @@
+package com.destroystokyo.paper.loottable;
+
+import io.papermc.paper.configuration.WorldConfiguration;
+import io.papermc.paper.configuration.type.DurationOrDisabled;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Random;
+import java.util.UUID;
+import java.util.concurrent.TimeUnit;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.nbt.Tag;
+import net.minecraft.world.RandomizableContainer;
+import net.minecraft.world.entity.vehicle.ContainerEntity;
+import org.bukkit.entity.Player;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+public class PaperLootableInventoryData {
+
+    private static final Random RANDOM = new Random();
+
+    private long lastFill = -1;
+    private long nextRefill = -1;
+    private int numRefills = 0;
+    private @Nullable Map<UUID, Long> lootedPlayers;
+
+    long getLastFill() {
+        return this.lastFill;
+    }
+
+    long getNextRefill() {
+        return this.nextRefill;
+    }
+
+    long setNextRefill(final long nextRefill) {
+        final long prev = this.nextRefill;
+        this.nextRefill = nextRefill;
+        return prev;
+    }
+
+    public <T> boolean shouldReplenish(final T lootTableHolder, final LootTableInterface<T> holderInterface, final net.minecraft.world.entity.player.@Nullable Player player) {
+
+        // No Loot Table associated
+        if (!holderInterface.hasLootTable(lootTableHolder)) {
+            return false;
+        }
+
+        // ALWAYS process the first fill or if the feature is disabled
+        if (this.lastFill == -1 || !holderInterface.paperConfig(lootTableHolder).lootables.autoReplenish) {
+            return true;
+        }
+
+        // Only process refills when a player is set
+        if (player == null) {
+            return false;
+        }
+
+        // Chest is not scheduled for refill
+        if (this.nextRefill == -1) {
+            return false;
+        }
+
+        final WorldConfiguration paperConfig = holderInterface.paperConfig(lootTableHolder);
+
+        // Check if max refills has been hit
+        if (paperConfig.lootables.maxRefills != -1 && this.numRefills >= paperConfig.lootables.maxRefills) {
+            return false;
+        }
+
+        // Refill has not been reached
+        if (this.nextRefill > System.currentTimeMillis()) {
+            return false;
+        }
+
+
+        final Player bukkitPlayer = (Player) player.getBukkitEntity();
+        final LootableInventoryReplenishEvent event = new LootableInventoryReplenishEvent(bukkitPlayer, holderInterface.getInventoryForEvent(lootTableHolder));
+        event.setCancelled(!this.canPlayerLoot(player.getUUID(), paperConfig));
+        return event.callEvent();
+    }
+
+    public interface LootTableInterface<T> {
+
+        WorldConfiguration paperConfig(T holder);
+
+        void setSeed(T holder, long seed);
+
+        boolean hasLootTable(T holder);
+
+        LootableInventory getInventoryForEvent(T holder);
+    }
+
+    public static final LootTableInterface<RandomizableContainer> CONTAINER = new LootTableInterface<>() {
+        @Override
+        public WorldConfiguration paperConfig(final RandomizableContainer holder) {
+            return Objects.requireNonNull(holder.getLevel(), "Can only manager loot replenishment on block entities in a world").paperConfig();
+        }
+
+        @Override
+        public void setSeed(final RandomizableContainer holder, final long seed) {
+            holder.setLootTableSeed(seed);
+        }
+
+        @Override
+        public boolean hasLootTable(final RandomizableContainer holder) {
+            return holder.getLootTable() != null;
+        }
+
+        @Override
+        public LootableInventory getInventoryForEvent(final RandomizableContainer holder) {
+            return holder.getLootableInventory();
+        }
+    };
+
+    public static final LootTableInterface<ContainerEntity> ENTITY = new LootTableInterface<>() {
+        @Override
+        public WorldConfiguration paperConfig(final ContainerEntity holder) {
+            return holder.level().paperConfig();
+        }
+
+        @Override
+        public void setSeed(final ContainerEntity holder, final long seed) {
+            holder.setLootTableSeed(seed);
+        }
+
+        @Override
+        public boolean hasLootTable(final ContainerEntity holder) {
+            return holder.getLootTable() != null;
+        }
+
+        @Override
+        public LootableInventory getInventoryForEvent(final ContainerEntity holder) {
+            return holder.getLootableInventory();
+        }
+    };
+
+    public <T> boolean shouldClearLootTable(final T lootTableHolder, final LootTableInterface<T> holderInterface, final net.minecraft.world.entity.player.@Nullable Player player) {
+        this.lastFill = System.currentTimeMillis();
+        final WorldConfiguration paperConfig = holderInterface.paperConfig(lootTableHolder);
+        if (paperConfig.lootables.autoReplenish) {
+            final long min = paperConfig.lootables.refreshMin.seconds();
+            final long max = paperConfig.lootables.refreshMax.seconds();
+            this.nextRefill = this.lastFill + (min + RANDOM.nextLong(max - min + 1)) * 1000L;
+            this.numRefills++;
+            if (paperConfig.lootables.resetSeedOnFill) {
+                holderInterface.setSeed(lootTableHolder, 0);
+            }
+            if (player != null) { // This means that numRefills can be incremented without a player being in the lootedPlayers list - Seems to be EntityMinecartChest specific
+                this.setPlayerLootedState(player.getUUID(), true);
+            }
+            return false;
+        }
+        return true;
+    }
+
+    private static final String ROOT = "Paper.LootableData";
+    private static final String LAST_FILL = "lastFill";
+    private static final String NEXT_REFILL = "nextRefill";
+    private static final String NUM_REFILLS = "numRefills";
+    private static final String LOOTED_PLAYERS = "lootedPlayers";
+
+    public void loadNbt(final CompoundTag base) {
+        if (!base.contains(ROOT, Tag.TAG_COMPOUND)) {
+            return;
+        }
+        final CompoundTag comp = base.getCompound(ROOT);
+        if (comp.contains(LAST_FILL)) {
+            this.lastFill = comp.getLong(LAST_FILL);
+        }
+        if (comp.contains(NEXT_REFILL)) {
+            this.nextRefill = comp.getLong(NEXT_REFILL);
+        }
+
+        if (comp.contains(NUM_REFILLS)) {
+            this.numRefills = comp.getInt(NUM_REFILLS);
+        }
+        if (comp.contains(LOOTED_PLAYERS, Tag.TAG_LIST)) {
+            final ListTag list = comp.getList(LOOTED_PLAYERS, Tag.TAG_COMPOUND);
+            final int size = list.size();
+            if (size > 0) {
+                this.lootedPlayers = new HashMap<>(list.size());
+            }
+            for (int i = 0; i < size; i++) {
+                final CompoundTag cmp = list.getCompound(i);
+                this.lootedPlayers.put(cmp.getUUID("UUID"), cmp.getLong("Time"));
+            }
+        }
+    }
+
+    public void saveNbt(final CompoundTag base) {
+        final CompoundTag comp = new CompoundTag();
+        if (this.nextRefill != -1) {
+            comp.putLong(NEXT_REFILL, this.nextRefill);
+        }
+        if (this.lastFill != -1) {
+            comp.putLong(LAST_FILL, this.lastFill);
+        }
+        if (this.numRefills != 0) {
+            comp.putInt(NUM_REFILLS, this.numRefills);
+        }
+        if (this.lootedPlayers != null && !this.lootedPlayers.isEmpty()) {
+            final ListTag list = new ListTag();
+            for (final Map.Entry<UUID, Long> entry : this.lootedPlayers.entrySet()) {
+                final CompoundTag cmp = new CompoundTag();
+                cmp.putUUID("UUID", entry.getKey());
+                cmp.putLong("Time", entry.getValue());
+                list.add(cmp);
+            }
+            comp.put(LOOTED_PLAYERS, list);
+        }
+
+        if (!comp.isEmpty()) {
+            base.put(ROOT, comp);
+        }
+    }
+
+    void setPlayerLootedState(final UUID player, final boolean looted) {
+        if (looted && this.lootedPlayers == null) {
+            this.lootedPlayers = new HashMap<>();
+        }
+        if (looted) {
+            this.lootedPlayers.put(player, System.currentTimeMillis());
+        } else if (this.lootedPlayers != null) {
+            this.lootedPlayers.remove(player);
+        }
+    }
+
+    boolean canPlayerLoot(final UUID player, final WorldConfiguration worldConfiguration) {
+        final @Nullable Long lastLooted = this.getLastLooted(player);
+        if (!worldConfiguration.lootables.restrictPlayerReloot || lastLooted == null) return true;
+
+        final DurationOrDisabled restrictPlayerRelootTime = worldConfiguration.lootables.restrictPlayerRelootTime;
+        if (restrictPlayerRelootTime.value().isEmpty()) return false;
+
+        return TimeUnit.SECONDS.toMillis(restrictPlayerRelootTime.value().get().seconds()) + lastLooted < System.currentTimeMillis();
+    }
+
+    boolean hasPlayerLooted(final UUID player) {
+        return this.lootedPlayers != null && this.lootedPlayers.containsKey(player);
+    }
+
+    @Nullable Long getLastLooted(final UUID player) {
+        return this.lootedPlayers != null ? this.lootedPlayers.get(player) : null;
+    }
+}
diff --git a/src/main/java/net/minecraft/world/RandomizableContainer.java b/src/main/java/net/minecraft/world/RandomizableContainer.java
index 9715f1b63aeea39bde9258275f51e3e8508ca6e4..597cd5dbb4bb415a9b4d874c1c5dd621be1d6fc8 100644
--- a/src/main/java/net/minecraft/world/RandomizableContainer.java
+++ b/src/main/java/net/minecraft/world/RandomizableContainer.java
@@ -28,7 +28,7 @@ public interface RandomizableContainer extends Container {
 
     void setLootTable(@Nullable ResourceKey<LootTable> lootTable);
 
-    default void setLootTable(ResourceKey<LootTable> lootTableId, long lootTableSeed) {
+    default void setLootTable(@Nullable ResourceKey<LootTable> lootTableId, long lootTableSeed) { // Paper - add nullable
         this.setLootTable(lootTableId);
         this.setLootTableSeed(lootTableSeed);
     }
@@ -51,13 +51,14 @@ public interface RandomizableContainer extends Container {
     default boolean tryLoadLootTable(CompoundTag nbt) {
         if (nbt.contains("LootTable", 8)) {
             this.setLootTable(ResourceKey.create(Registries.LOOT_TABLE, ResourceLocation.parse(nbt.getString("LootTable"))));
+            if (this.lootableData() != null && this.getLootTable() != null) this.lootableData().loadNbt(nbt); // Paper - LootTable API
             if (nbt.contains("LootTableSeed", 4)) {
                 this.setLootTableSeed(nbt.getLong("LootTableSeed"));
             } else {
                 this.setLootTableSeed(0L);
             }
 
-            return true;
+            return this.lootableData() == null; // Paper - only track the loot table if there is chance for replenish
         } else {
             return false;
         }
@@ -69,12 +70,13 @@ public interface RandomizableContainer extends Container {
             return false;
         } else {
             nbt.putString("LootTable", resourceKey.location().toString());
+            if (this.lootableData() != null) this.lootableData().saveNbt(nbt); // Paper - LootTable API
             long l = this.getLootTableSeed();
             if (l != 0L) {
                 nbt.putLong("LootTableSeed", l);
             }
 
-            return true;
+            return this.lootableData() == null; // Paper - only track the loot table if there is chance for replenish
         }
     }
 
@@ -82,13 +84,17 @@ public interface RandomizableContainer extends Container {
         Level level = this.getLevel();
         BlockPos blockPos = this.getBlockPos();
         ResourceKey<LootTable> resourceKey = this.getLootTable();
-        if (resourceKey != null && level != null && level.getServer() != null) {
+        if (resourceKey != null && level != null && level.getServer() != null && (this.lootableData() == null || this.lootableData().shouldReplenish(this, com.destroystokyo.paper.loottable.PaperLootableInventoryData.CONTAINER, player))) { // Paper - LootTable API
             LootTable lootTable = level.getServer().reloadableRegistries().getLootTable(resourceKey);
             if (player instanceof ServerPlayer) {
                 CriteriaTriggers.GENERATE_LOOT.trigger((ServerPlayer)player, resourceKey);
             }
 
-            this.setLootTable(null);
+            // Paper start - LootTable API
+            if (this.lootableData() == null || this.lootableData().shouldClearLootTable(this, com.destroystokyo.paper.loottable.PaperLootableInventoryData.CONTAINER, player)) {
+                this.setLootTable(null);
+            }
+            // Paper end - LootTable API
             LootParams.Builder builder = new LootParams.Builder((ServerLevel)level).withParameter(LootContextParams.ORIGIN, Vec3.atCenterOf(blockPos));
             if (player != null) {
                 builder.withLuck(player.getLuck()).withParameter(LootContextParams.THIS_ENTITY, player);
@@ -97,4 +103,16 @@ public interface RandomizableContainer extends Container {
             lootTable.fill(this, builder.create(LootContextParamSets.CHEST), this.getLootTableSeed());
         }
     }
+
+    // Paper start - LootTable API
+    @Nullable @org.jetbrains.annotations.Contract(pure = true)
+    default com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData() {
+        return null; // some containers don't really have a "replenish" ability like decorated pots
+    }
+
+    default com.destroystokyo.paper.loottable.PaperLootableInventory getLootableInventory() {
+        final org.bukkit.block.Block block = org.bukkit.craftbukkit.block.CraftBlock.at(java.util.Objects.requireNonNull(this.getLevel(), "Cannot manage loot tables on block entities not in world"), this.getBlockPos());
+        return (com.destroystokyo.paper.loottable.PaperLootableInventory) block.getState(false);
+    }
+    // Paper end - LootTable API
 }
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java
index 67840327e934b631a85cf2d64911f5cfab4402b1..9549eee0d92f322bd5232abd7e695213660c2e22 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/AbstractMinecartContainer.java
@@ -35,6 +35,14 @@ public abstract class AbstractMinecartContainer extends AbstractMinecart impleme
     public ResourceKey<LootTable> lootTable;
     public long lootTableSeed;
 
+    // Paper start - LootTable API
+    final com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData = new com.destroystokyo.paper.loottable.PaperLootableInventoryData();
+
+    @Override
+    public com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData() {
+        return this.lootableData;
+    }
+    // Paper end - LootTable API
     // CraftBukkit start
     public List<HumanEntity> transaction = new java.util.ArrayList<HumanEntity>();
     private int maxStack = MAX_STACK;
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/ChestBoat.java b/src/main/java/net/minecraft/world/entity/vehicle/ChestBoat.java
index 42f8e2d961f83c3e9ce384158b9dfc4014eb0a5f..4cdf3b54187ebcb1f5ddfa6114386127a2846f01 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/ChestBoat.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/ChestBoat.java
@@ -217,7 +217,7 @@ public class ChestBoat extends Boat implements HasCustomInventoryScreen, Contain
     @Nullable
     @Override
     public AbstractContainerMenu createMenu(int syncId, Inventory playerInventory, Player player) {
-        if (this.lootTable != null && player.isSpectator()) {
+        if (this.lootTable != null && player.isSpectator()) { // Paper - LootTable API (TODO spectators can open chests that aren't ready to be re-generated but this doesn't support that)
             return null;
         } else {
             this.unpackLootTable(playerInventory.player);
@@ -265,6 +265,14 @@ public class ChestBoat extends Boat implements HasCustomInventoryScreen, Contain
         this.level().gameEvent((Holder) GameEvent.CONTAINER_CLOSE, this.position(), GameEvent.Context.of((Entity) player));
     }
 
+    // Paper start - LootTable API
+    final com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData = new com.destroystokyo.paper.loottable.PaperLootableInventoryData();
+
+    @Override
+    public com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData() {
+        return this.lootableData;
+    }
+    // Paper end - LootTable API
     // CraftBukkit start
     public List<HumanEntity> transaction = new java.util.ArrayList<HumanEntity>();
     private int maxStack = MAX_STACK;
diff --git a/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java b/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
index 3ee99193de5deb6a38d6ded561fe8f2fbf711327..ccc7367ab2740bea0f2b907223a0920b11665092 100644
--- a/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
+++ b/src/main/java/net/minecraft/world/entity/vehicle/ContainerEntity.java
@@ -62,22 +62,26 @@ public interface ContainerEntity extends Container, MenuProvider {
     default void addChestVehicleSaveData(CompoundTag nbt, HolderLookup.Provider registriesLookup) {
         if (this.getLootTable() != null) {
             nbt.putString("LootTable", this.getLootTable().location().toString());
+            this.lootableData().saveNbt(nbt); // Paper
             if (this.getLootTableSeed() != 0L) {
                 nbt.putLong("LootTableSeed", this.getLootTableSeed());
             }
-        } else {
-            ContainerHelper.saveAllItems(nbt, this.getItemStacks(), registriesLookup);
         }
+        ContainerHelper.saveAllItems(nbt, this.getItemStacks(), registriesLookup); // Paper - always save the items, table may still remain
     }
 
     default void readChestVehicleSaveData(CompoundTag nbt, HolderLookup.Provider registriesLookup) {
         this.clearItemStacks();
         if (nbt.contains("LootTable", 8)) {
             this.setLootTable(ResourceKey.create(Registries.LOOT_TABLE, ResourceLocation.parse(nbt.getString("LootTable"))));
+            // Paper start - LootTable API
+            if (this.getLootTable() != null) {
+                this.lootableData().loadNbt(nbt);
+            }
+            // Paper end - LootTable API
             this.setLootTableSeed(nbt.getLong("LootTableSeed"));
-        } else {
-            ContainerHelper.loadAllItems(nbt, this.getItemStacks(), registriesLookup);
         }
+        ContainerHelper.loadAllItems(nbt, this.getItemStacks(), registriesLookup); // Paper - always save the items, table may still remain
     }
 
     default void chestVehicleDestroyed(DamageSource source, Level world, Entity vehicle) {
@@ -99,13 +103,17 @@ public interface ContainerEntity extends Container, MenuProvider {
 
     default void unpackChestVehicleLootTable(@Nullable Player player) {
         MinecraftServer minecraftServer = this.level().getServer();
-        if (this.getLootTable() != null && minecraftServer != null) {
+        if (minecraftServer != null && this.lootableData().shouldReplenish(this, com.destroystokyo.paper.loottable.PaperLootableInventoryData.ENTITY, player)) { // Paper - LootTable API
             LootTable lootTable = minecraftServer.reloadableRegistries().getLootTable(this.getLootTable());
             if (player != null) {
                 CriteriaTriggers.GENERATE_LOOT.trigger((ServerPlayer)player, this.getLootTable());
             }
 
-            this.setLootTable(null);
+            // Paper start - LootTable API
+            if (this.lootableData().shouldClearLootTable(this, com.destroystokyo.paper.loottable.PaperLootableInventoryData.ENTITY, player)) {
+                this.setLootTable(null);
+            }
+            // Paper end - LootTable API
             LootParams.Builder builder = new LootParams.Builder((ServerLevel)this.level()).withParameter(LootContextParams.ORIGIN, this.position());
             if (player != null) {
                 builder.withLuck(player.getLuck()).withParameter(LootContextParams.THIS_ENTITY, player);
@@ -175,4 +183,14 @@ public interface ContainerEntity extends Container, MenuProvider {
     default boolean isChestVehicleStillValid(Player player) {
         return !this.isRemoved() && player.canInteractWithEntity(this.getBoundingBox(), 4.0);
     }
+
+    // Paper start - LootTable API
+    default com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData() {
+        throw new UnsupportedOperationException("Implement this method");
+    }
+
+    default com.destroystokyo.paper.loottable.PaperLootableInventory getLootableInventory() {
+        return ((com.destroystokyo.paper.loottable.PaperLootableInventory) ((net.minecraft.world.entity.Entity) this).getBukkitEntity());
+    }
+    // Paper end - LootTable API
 }
diff --git a/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java
index c2493c15d8fe4587d6ee2db100cc13303b66b39b..13c9a68b604d4c7c6e09e72b3cea7ab2214b06ab 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/RandomizableContainerBlockEntity.java
@@ -115,4 +115,13 @@ public abstract class RandomizableContainerBlockEntity extends BaseContainerBloc
         nbt.remove("LootTable");
         nbt.remove("LootTableSeed");
     }
+
+    // Paper start - LootTable API
+    final com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData = new com.destroystokyo.paper.loottable.PaperLootableInventoryData(); // Paper
+
+    @Override
+    public com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData() {
+        return this.lootableData;
+    }
+    // Paper end - LootTable API
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBrushableBlock.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBrushableBlock.java
index 949e074a32b6593bd8b7405499e686a074e283e5..1f084b73f2ec67dd2022feafc5ab5dac02c338f6 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBrushableBlock.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBrushableBlock.java
@@ -58,7 +58,8 @@ public class CraftBrushableBlock extends CraftBlockEntityState<BrushableBlockEnt
         this.setLootTable(this.getLootTable(), seed);
     }
 
-    private void setLootTable(LootTable table, long seed) {
+    @Override // Paper - this is now an override
+    public void setLootTable(LootTable table, long seed) { // Paper - make public since it overrides a public method
         this.getSnapshot().setLootTable(CraftLootTable.bukkitToMinecraft(table), seed);
     }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftLootable.java b/src/main/java/org/bukkit/craftbukkit/block/CraftLootable.java
index 74315a46f6101775321b1cf4944c124c69aed182..f23fbb8ed39a754b36d2eb162358877ef6dacb17 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftLootable.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftLootable.java
@@ -8,7 +8,7 @@ import org.bukkit.craftbukkit.CraftLootTable;
 import org.bukkit.loot.LootTable;
 import org.bukkit.loot.Lootable;
 
-public abstract class CraftLootable<T extends RandomizableContainerBlockEntity> extends CraftContainer<T> implements Nameable, Lootable {
+public abstract class CraftLootable<T extends RandomizableContainerBlockEntity> extends CraftContainer<T> implements Nameable, Lootable, com.destroystokyo.paper.loottable.PaperLootableBlockInventory { // Paper
 
     public CraftLootable(World world, T tileEntity) {
         super(world, tileEntity);
@@ -27,29 +27,17 @@ public abstract class CraftLootable<T extends RandomizableContainerBlockEntity>
         }
     }
 
+    // Paper start - move to PaperLootableBlockInventory
     @Override
-    public LootTable getLootTable() {
-        return CraftLootTable.minecraftToBukkit(this.getSnapshot().lootTable);
+    public net.minecraft.world.level.Level getNMSWorld() {
+        return ((org.bukkit.craftbukkit.CraftWorld) this.getWorld()).getHandle();
     }
 
     @Override
-    public void setLootTable(LootTable table) {
-        this.setLootTable(table, this.getSeed());
-    }
-
-    @Override
-    public long getSeed() {
-        return this.getSnapshot().lootTableSeed;
-    }
-
-    @Override
-    public void setSeed(long seed) {
-        this.setLootTable(this.getLootTable(), seed);
-    }
-
-    public void setLootTable(LootTable table, long seed) {
-        this.getSnapshot().setLootTable(CraftLootTable.bukkitToMinecraft(table), seed);
+    public net.minecraft.world.RandomizableContainer getRandomizableContainer() {
+        return this.getSnapshot();
     }
+    // Paper end - move to PaperLootableBlockInventory
 
     @Override
     public abstract CraftLootable<T> copy();
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftChestBoat.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftChestBoat.java
index cfde210ea9d4b62fe514d3ab0dbab2f43eda0c7a..e4f899a6a1d055b3ea17d1114ed0228fbba53352 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftChestBoat.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftChestBoat.java
@@ -7,8 +7,7 @@ import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.loot.LootTable;
 
-public class CraftChestBoat extends CraftBoat implements org.bukkit.entity.ChestBoat {
-
+public class CraftChestBoat extends CraftBoat implements org.bukkit.entity.ChestBoat, com.destroystokyo.paper.loottable.PaperLootableEntityInventory { // Paper
     private final Inventory inventory;
 
     public CraftChestBoat(CraftServer server, ChestBoat entity) {
@@ -31,28 +30,5 @@ public class CraftChestBoat extends CraftBoat implements org.bukkit.entity.Chest
         return this.inventory;
     }
 
-    @Override
-    public void setLootTable(LootTable table) {
-        this.setLootTable(table, this.getSeed());
-    }
-
-    @Override
-    public LootTable getLootTable() {
-        return CraftLootTable.minecraftToBukkit(this.getHandle().getLootTable());
-    }
-
-    @Override
-    public void setSeed(long seed) {
-        this.setLootTable(this.getLootTable(), seed);
-    }
-
-    @Override
-    public long getSeed() {
-        return this.getHandle().getLootTableSeed();
-    }
-
-    private void setLootTable(LootTable table, long seed) {
-        this.getHandle().setLootTable(CraftLootTable.bukkitToMinecraft(table));
-        this.getHandle().setLootTableSeed(seed);
-    }
+    // Paper - moved loot table logic to PaperLootableEntityInventory
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartChest.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartChest.java
index fd42f0b20132d08039ca7735d31a61806a6b07dc..b1a708de6790bbe336202b13ab862ced78de084f 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartChest.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartChest.java
@@ -7,7 +7,7 @@ import org.bukkit.entity.minecart.StorageMinecart;
 import org.bukkit.inventory.Inventory;
 
 @SuppressWarnings("deprecation")
-public class CraftMinecartChest extends CraftMinecartContainer implements StorageMinecart {
+public class CraftMinecartChest extends CraftMinecartContainer implements StorageMinecart, com.destroystokyo.paper.loottable.PaperLootableEntityInventory { // Paper
     private final CraftInventory inventory;
 
     public CraftMinecartChest(CraftServer server, MinecartChest entity) {
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartContainer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartContainer.java
index 4388cd0303b45faf21631e7644baebb63baaba10..451f3a6f0b47493da3af3f5d6baced6a8c97f350 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartContainer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartContainer.java
@@ -7,7 +7,7 @@ import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.loot.LootTable;
 import org.bukkit.loot.Lootable;
 
-public abstract class CraftMinecartContainer extends CraftMinecart implements Lootable {
+public abstract class CraftMinecartContainer extends CraftMinecart implements com.destroystokyo.paper.loottable.PaperLootableEntityInventory { // Paper
 
     public CraftMinecartContainer(CraftServer server, AbstractMinecart entity) {
         super(server, entity);
@@ -18,27 +18,5 @@ public abstract class CraftMinecartContainer extends CraftMinecart implements Lo
         return (AbstractMinecartContainer) this.entity;
     }
 
-    @Override
-    public void setLootTable(LootTable table) {
-        this.setLootTable(table, this.getSeed());
-    }
-
-    @Override
-    public LootTable getLootTable() {
-        return CraftLootTable.minecraftToBukkit(this.getHandle().lootTable);
-    }
-
-    @Override
-    public void setSeed(long seed) {
-        this.setLootTable(this.getLootTable(), seed);
-    }
-
-    @Override
-    public long getSeed() {
-        return this.getHandle().lootTableSeed;
-    }
-
-    public void setLootTable(LootTable table, long seed) {
-        this.getHandle().setLootTable(CraftLootTable.bukkitToMinecraft(table), seed);
-    }
+    // Paper - moved loot table logic to PaperLootableEntityInventory
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartHopper.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartHopper.java
index 39427b4f284e9402663be2b160ccb5f03f8b91da..17f5684cba9d3ed22d9925d1951520cc4751dfe2 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartHopper.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartHopper.java
@@ -6,7 +6,7 @@ import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.minecart.HopperMinecart;
 import org.bukkit.inventory.Inventory;
 
-public final class CraftMinecartHopper extends CraftMinecartContainer implements HopperMinecart {
+public final class CraftMinecartHopper extends CraftMinecartContainer implements HopperMinecart, com.destroystokyo.paper.loottable.PaperLootableEntityInventory { // Paper
     private final CraftInventory inventory;
 
     public CraftMinecartHopper(CraftServer server, MinecartHopper entity) {
