From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: kickash32 <kickash32@gmail.com>
Date: Mon, 3 Jun 2019 02:02:39 -0400
Subject: [PATCH] Implement alternative item-despawn-rate

Co-authored-by: Noah van der Aa <ndvdaa@gmail.com>

diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index ed976e0582dee32ccf3aad49efb0dd773f5f9d80..f41e292e78b2c6874ee9f0cb4336263581339ca6 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -560,5 +560,74 @@ public class PaperWorldConfig {
             Bukkit.getLogger().warning("You have enabled permission-based Anti-Xray checking - depending on your permission plugin, this may cause performance issues");
         }
     }
-}
 
+    public boolean altItemDespawnRateEnabled;
+    public java.util.Map<net.minecraft.resources.ResourceLocation, Integer> altItemDespawnRateMap = new HashMap<>();
+    private void altItemDespawnRate() {
+        String path = "alt-item-despawn-rate";
+        // Migrate from bukkit material to Mojang item ids
+        if (PaperConfig.version < 26) {
+            String world = worldName;
+            try {
+                org.bukkit.configuration.ConfigurationSection mapSection = config.getConfigurationSection("world-settings." + world + "." + path + ".items");
+                if (mapSection == null) {
+                    world = "default";
+                    mapSection = config.getConfigurationSection("world-settings." + world + "." + path + ".items");
+                }
+                if (mapSection != null) {
+                    for (String key : mapSection.getKeys(false)) {
+                        int val = mapSection.getInt(key);
+                        try {
+                            // Ignore options that are already valid mojang wise, otherwise we might try to migrate the same config twice and fail.
+                            boolean isMojangMaterial = net.minecraft.core.Registry.ITEM.getOptional(new net.minecraft.resources.ResourceLocation(key.toLowerCase())).isPresent();
+                            mapSection.set(key, null);
+                            String newKey = isMojangMaterial ? key.toLowerCase() : org.bukkit.Material.valueOf(key).getKey().getKey().toLowerCase();
+                            mapSection.set(newKey, val);
+                        } catch (Exception e) {
+                            logError("Could not add item " + key + " to altItemDespawnRateMap: " + e.getMessage());
+                        }
+                    }
+                    config.set("world-settings." + world + "." + path + ".items", mapSection);
+                }
+            } catch (Exception e) {
+                logError("alt-item-despawn-rate was malformatted");
+                return;
+            }
+        }
+
+        altItemDespawnRateEnabled = getBoolean(path + ".enabled", false);
+
+        if (config.getConfigurationSection("world-settings.default." + path + ".items") == null) {
+            // Initialize default
+            config.addDefault("world-settings.default." + path + ".items.cobblestone", 300);
+        }
+
+        if (!altItemDespawnRateEnabled) {
+            return;
+        }
+
+        org.bukkit.configuration.ConfigurationSection mapSection = config.getConfigurationSection("world-settings." + worldName + "." + path + ".items");
+        if (mapSection == null) {
+            mapSection = config.getConfigurationSection("world-settings.default." + path + ".items");
+        }
+        if (mapSection != null) {
+            for (String key : mapSection.getKeys(false)) {
+                try {
+                    int val = mapSection.getInt(key);
+                    net.minecraft.resources.ResourceLocation keyLocation = new net.minecraft.resources.ResourceLocation(key);
+                    if (net.minecraft.core.Registry.ITEM.getOptional(keyLocation).isPresent()) {
+                        altItemDespawnRateMap.put(keyLocation, val);
+                    } else {
+                        logError("Could not add item " + key + " to altItemDespawnRateMap: not a valid item");
+                    }
+                } catch (Exception e) {
+                    logError("Could not add item " + key + " to altItemDespawnRateMap: " + e.getMessage());
+                }
+            }
+        }
+
+        for (net.minecraft.resources.ResourceLocation key : altItemDespawnRateMap.keySet()) {
+            log("Alternative item despawn rate of " + key.getPath() + ": " + altItemDespawnRateMap.get(key));
+        }
+    }
+}
diff --git a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
index 87c92e73d23a1ebb0646ba0293e1c0d51bb0e059..3938bb6aa82bd02359dede6f6b17b7ba6685579b 100644
--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
@@ -54,6 +54,7 @@ public class ItemEntity extends Entity {
     public final float bobOffs;
     private int lastTick = MinecraftServer.currentTick - 1; // CraftBukkit
     public boolean canMobPickup = true; // Paper
+    private int despawnRate = -1; // Paper
 
     public ItemEntity(EntityType<? extends ItemEntity> type, Level world) {
         super(type, world);
@@ -174,7 +175,7 @@ public class ItemEntity extends Entity {
                 }
             }
 
-            if (!this.level.isClientSide && this.age >= level.spigotConfig.itemDespawnRate) { // Spigot
+            if (!this.level.isClientSide && this.age >= this.despawnRate) { // Spigot // Paper
                 // CraftBukkit start - fire ItemDespawnEvent
                 if (org.bukkit.craftbukkit.event.CraftEventFactory.callItemDespawnEvent(this).isCancelled()) {
                     this.age = 0;
@@ -198,7 +199,7 @@ public class ItemEntity extends Entity {
         this.lastTick = MinecraftServer.currentTick;
         // CraftBukkit end
 
-        if (!this.level.isClientSide && this.age >= level.spigotConfig.itemDespawnRate) { // Spigot
+        if (!this.level.isClientSide && this.age >= this.despawnRate) { // Spigot // Paper
             // CraftBukkit start - fire ItemDespawnEvent
             if (org.bukkit.craftbukkit.event.CraftEventFactory.callItemDespawnEvent(this).isCancelled()) {
                 this.age = 0;
@@ -253,7 +254,7 @@ public class ItemEntity extends Entity {
     private boolean isMergable() {
         ItemStack itemstack = this.getItem();
 
-        return this.isAlive() && this.pickupDelay != 32767 && this.age != -32768 && this.age < 6000 && itemstack.getCount() < itemstack.getMaxStackSize();
+        return this.isAlive() && this.pickupDelay != 32767 && this.age != -32768 && this.age < this.despawnRate && itemstack.getCount() < itemstack.getMaxStackSize(); // Paper - respect despawn rate in pickup check.
     }
 
     private void tryToMerge(ItemEntity other) {
@@ -497,6 +498,8 @@ public class ItemEntity extends Entity {
         com.google.common.base.Preconditions.checkArgument(!stack.isEmpty(), "Cannot drop air"); // CraftBukkit
         this.getEntityData().set(ItemEntity.DATA_ITEM, stack);
         this.getEntityData().markDirty(ItemEntity.DATA_ITEM); // CraftBukkit - SPIGOT-4591, must mark dirty
+        net.minecraft.resources.ResourceLocation location = net.minecraft.core.Registry.ITEM.getKey(stack.getItem()); // Paper
+        this.despawnRate = level.paperConfig.altItemDespawnRateMap.getOrDefault(location, level.spigotConfig.itemDespawnRate); // Paper
     }
 
     @Override
@@ -560,7 +563,7 @@ public class ItemEntity extends Entity {
 
     public void makeFakeItem() {
         this.setNeverPickUp();
-        this.age = level.spigotConfig.itemDespawnRate - 1; // Spigot
+        this.age = this.despawnRate - 1; // Spigot
     }
 
     public float getSpin(float tickDelta) {