From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <40902469+Samsuik@users.noreply.github.com>
Date: Thu, 5 Oct 2023 14:34:30 +0100
Subject: [PATCH] Merge Cannon Entities


diff --git a/src/main/java/me/samsuik/sakura/entity/merge/MergeLevel.java b/src/main/java/me/samsuik/sakura/entity/merge/MergeLevel.java
new file mode 100644
index 0000000000000000000000000000000000000000..506ea3cb8c3b965661a65f9a91903999c1eba309
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/entity/merge/MergeLevel.java
@@ -0,0 +1,64 @@
+package me.samsuik.sakura.entity.merge;
+
+import java.util.Locale;
+
+public enum MergeLevel {
+    /**
+     * Disabled.
+     */
+    NONE(-1),
+    /**
+     * "STRICT" merges entities with the same properties, position, momentum and OOE.
+     * This is considered safe to use, and will not break cannon mechanics.
+     */
+    STRICT(1),
+    /**
+     * "LENIENT" merges entities aggressively by tracking the entities that have
+     * previously merged. This is a hybrid of "SPAWN" and "STRICT" merging, with the
+     * visuals of "STRICT" merging and better merging potential of "SPAWN" merging.
+     */
+    LENIENT(2),
+    /**
+     * "SPAWN" merges entities one gametick after they have spawned. Merging is
+     * only possible after it has been established that the entity is safe to
+     * merge by collecting information on the entities that merge together over time.
+     */
+    SPAWN(3);
+
+    private final int level;
+
+    MergeLevel(int level) {
+        this.level = level;
+    }
+
+    public boolean atLeast(MergeLevel level) {
+        return getLevel() >= level.getLevel();
+    }
+
+    public int getLevel() {
+        return level;
+    }
+
+    public static MergeLevel from(int of) {
+        for (MergeLevel t : values()) {
+            if (t.getLevel() == of) {
+                return t;
+            }
+        }
+
+        return NONE;
+    }
+
+    public static MergeLevel from(String string) {
+        try {
+            return from(Integer.parseInt(string));
+        } catch (NumberFormatException ignored) {}
+
+        try {
+            var name = string.toUpperCase(Locale.ROOT);
+            return valueOf(name);
+        } catch (IllegalArgumentException ignored) {}
+
+        return NONE;
+    }
+}
diff --git a/src/main/java/me/samsuik/sakura/entity/merge/Mergeable.java b/src/main/java/me/samsuik/sakura/entity/merge/Mergeable.java
new file mode 100644
index 0000000000000000000000000000000000000000..c241a3a359cad1d7c2cdb690649e0cacc491508b
--- /dev/null
+++ b/src/main/java/me/samsuik/sakura/entity/merge/Mergeable.java
@@ -0,0 +1,13 @@
+package me.samsuik.sakura.entity.merge;
+
+import org.jetbrains.annotations.NotNull;
+
+public interface Mergeable {
+    @NotNull MergeLevel getMergeLevel();
+
+    void setMergeLevel(@NotNull MergeLevel level);
+
+    int getStacked();
+
+    void setStacked(int stacked);
+}
diff --git a/src/main/java/org/bukkit/entity/FallingBlock.java b/src/main/java/org/bukkit/entity/FallingBlock.java
index 7904c716a3b0869ebf2f9b416536c59121a539a8..2479453b96a75fda2c307261f84c91034e73000d 100644
--- a/src/main/java/org/bukkit/entity/FallingBlock.java
+++ b/src/main/java/org/bukkit/entity/FallingBlock.java
@@ -7,7 +7,7 @@ import org.jetbrains.annotations.NotNull;
 /**
  * Represents a falling block
  */
-public interface FallingBlock extends Entity {
+public interface FallingBlock extends Entity, me.samsuik.sakura.entity.merge.Mergeable { // Sakura
 
     /**
      * Get the Material of the falling block
diff --git a/src/main/java/org/bukkit/entity/TNTPrimed.java b/src/main/java/org/bukkit/entity/TNTPrimed.java
index 87e717c9ea61b0cbf536bc62fa829ddcfae5ad8c..ba84b3cbbd3358b16b21a18baa9c1812733fc144 100644
--- a/src/main/java/org/bukkit/entity/TNTPrimed.java
+++ b/src/main/java/org/bukkit/entity/TNTPrimed.java
@@ -6,7 +6,7 @@ import org.jetbrains.annotations.Nullable;
 /**
  * Represents a Primed TNT.
  */
-public interface TNTPrimed extends Explosive {
+public interface TNTPrimed extends Explosive, me.samsuik.sakura.entity.merge.Mergeable { // Sakura
 
     /**
      * Set the number of ticks until the TNT blows up after being primed.