From 36ccf3bcab2c36eb6867a96995be8b014baa1150 Mon Sep 17 00:00:00 2001
From: Articdive <13535885+Articdive@users.noreply.github.com>
Date: Fri, 7 Aug 2020 13:21:59 +0200
Subject: [PATCH] Create EatBlockGoal

---
 .../themode/demo/entity/ChickenCreature.java  | 17 ++++
 .../server/entity/ai/goal/EatBlockGoal.java   | 86 +++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 src/main/java/net/minestom/server/entity/ai/goal/EatBlockGoal.java

diff --git a/src/main/java/fr/themode/demo/entity/ChickenCreature.java b/src/main/java/fr/themode/demo/entity/ChickenCreature.java
index 69da988cb..a1b354089 100644
--- a/src/main/java/fr/themode/demo/entity/ChickenCreature.java
+++ b/src/main/java/fr/themode/demo/entity/ChickenCreature.java
@@ -1,11 +1,15 @@
 package fr.themode.demo.entity;
 
 import net.minestom.server.attribute.Attribute;
+import net.minestom.server.entity.ai.goal.EatBlockGoal;
 import net.minestom.server.entity.ai.goal.RandomStrollGoal;
 import net.minestom.server.entity.ai.target.PlayerTarget;
 import net.minestom.server.entity.type.EntityChicken;
+import net.minestom.server.instance.block.Block;
 import net.minestom.server.utils.Position;
 
+import java.util.HashMap;
+
 public class ChickenCreature extends EntityChicken {
 
     public ChickenCreature(Position defaultPosition) {
@@ -13,6 +17,19 @@ public class ChickenCreature extends EntityChicken {
 
         //goalSelectors.add(new DoNothingGoal(this, 500, 0.1f));
         goalSelectors.add(new RandomStrollGoal(this, 2));
+        goalSelectors.add(new EatBlockGoal(this,
+                new HashMap<>() {
+                    {
+                        put(Block.GRASS.getBlockId(), Block.AIR.getBlockId());
+                    }
+                },
+                new HashMap<>() {
+                    {
+                        put(Block.GRASS_BLOCK.getBlockId(), Block.DIRT.getBlockId());
+                    }
+                },
+                100))
+        ;
         //goalSelectors.add(new FollowTargetGoal(this));
 
 
diff --git a/src/main/java/net/minestom/server/entity/ai/goal/EatBlockGoal.java b/src/main/java/net/minestom/server/entity/ai/goal/EatBlockGoal.java
new file mode 100644
index 000000000..162b4c6eb
--- /dev/null
+++ b/src/main/java/net/minestom/server/entity/ai/goal/EatBlockGoal.java
@@ -0,0 +1,86 @@
+package net.minestom.server.entity.ai.goal;
+
+import net.minestom.server.entity.EntityCreature;
+import net.minestom.server.entity.ai.GoalSelector;
+import net.minestom.server.instance.Instance;
+import net.minestom.server.utils.BlockPosition;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+import java.util.Random;
+
+public class EatBlockGoal extends GoalSelector {
+    private static final Random RANDOM = new Random();
+    private final Map<Short, Short> eatBelowMap;
+    private final Map<Short, Short> eatInMap;
+    private int chancePerTick;
+    private int eatAnimationTick;
+
+    /**
+     * @param entityCreature Creature that should eat a block.
+     * @param eatInMap Map containing the block IDs that the entity can eat (when inside the block) and the block ID of the replacement block.
+     * @param eatBelowMap    Map containing block IDs that the entity can eat (when above the block) and the block ID of the replacement block.
+     * @param chancePerTick The chance that the entity eats. Settings this to N would mean there is a 1 in N chance.
+     */
+    public EatBlockGoal(
+            @NotNull EntityCreature entityCreature,
+            @NotNull Map<Short, Short> eatInMap,
+            @NotNull Map<Short, Short> eatBelowMap,
+            int chancePerTick) {
+        super(entityCreature);
+        this.eatInMap = eatInMap;
+        this.eatBelowMap = eatBelowMap;
+        this.chancePerTick = chancePerTick;
+    }
+
+    @Override
+    public boolean shouldStart() {
+        // TODO: is Baby
+        if (RANDOM.nextInt(chancePerTick) != 0) {
+            return false;
+        }
+        Instance instance = entityCreature.getInstance();
+        final short blockIdIn = instance.getBlockId(entityCreature.getPosition().toBlockPosition().clone().subtract(0, 1,0));
+        final short blockIdBelow = instance.getBlockId(entityCreature.getPosition().toBlockPosition().clone().subtract(0,2,0));
+
+        return eatInMap.containsKey(blockIdIn) || eatBelowMap.containsKey(blockIdBelow);
+    }
+
+    @Override
+    public void start() {
+        this.eatAnimationTick = 40;
+        // TODO: EatBlockEvent call here.
+        // Stop moving
+        entityCreature.setPathTo(null);
+    }
+
+    @Override
+    public void tick() {
+        this.eatAnimationTick = Math.max(0, this.eatAnimationTick - 1);
+        if (this.eatAnimationTick != 4) {
+            return;
+        }
+        Instance instance = entityCreature.getInstance();
+        final BlockPosition currentPosition = entityCreature.getPosition().toBlockPosition().clone().subtract(0, 1, 0);
+        final BlockPosition belowPosition = currentPosition.clone().subtract(0, 1, 0);
+
+        final short blockIdIn = instance.getBlockId(currentPosition);
+        final short blockIdBelow = instance.getBlockId(belowPosition);
+        if (eatInMap.containsKey(blockIdIn)) {
+            instance.setBlock(currentPosition, eatInMap.get(blockIdIn));
+        } else if (eatBelowMap.containsKey(blockIdBelow)) {
+            instance.setBlock(belowPosition, eatBelowMap.get(blockIdBelow));
+        }
+        // TODO: Call Entity Eat Animation
+    }
+
+    @Override
+    public boolean shouldEnd() {
+        return eatAnimationTick <= 0;
+    }
+
+    @Override
+    public void end() {
+        this.eatAnimationTick = 0;
+    }
+}