refactor: improve stone cooldown storing and implement better cloning

src/main/java/uulm/teamname/marvelous/gamelibrary/entities/EntityID.java

@@ -32,7 +32,7 @@ public class EntityID {
      * @return The cloned {@link EntityID}
      */
     public EntityID clone() {
-        return new EntityID(this.id, this.type);
+        return new EntityID(id, type);
     }
 
     /**

src/main/java/uulm/teamname/marvelous/gamelibrary/entities/EntityManager.java

@@ -4,11 +4,22 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Iterator;
 
-/** Represents a list of {@link Entity}s. */
-public class EntityList {
+/** Represents a managed list of {@link Entity}s. */
+public class EntityManager {
     /** The internal collection of {@link Entity}s */
     private final HashSet<Entity> entities = new HashSet<>();
 
+    /**
+     * Takes over all the entities from a different {@link EntityManager}.
+     * @param other The entity list to take the data from
+     */
+    public void cloneFrom(EntityManager other) {
+        entities.clear();
+        for(Entity entity: other.entities) {
+            entities.add(entity.clone());
+        }
+    }
+
     /**
      * Clears the list of entities.
      */

src/main/java/uulm/teamname/marvelous/gamelibrary/entities/Rock.java

@@ -27,7 +27,7 @@ public class Rock extends Entity {
     }
 
     public void decreaseHp(int damage) {
-        this.hp -= damage;
+        hp -= damage;
     }
 
     @Override

src/main/java/uulm/teamname/marvelous/gamelibrary/entities/StoneCooldownManager.java

@@ -0,0 +1,52 @@
+package uulm.teamname.marvelous.gamelibrary.entities;
+
+import java.util.HashMap;
+
+/** Represents a manager for infinity stone cooldowns. */
+public class StoneCooldownManager {
+    /** The cooldown round numbers for every stone */
+    private final HashMap<StoneType, Integer> cooldowns = new HashMap<>();
+
+    /**
+     * Takes over all the cooldowns from a different {@link StoneCooldownManager}.
+     * @param other The cooldown manager to take the data from
+     */
+    public void cloneFrom(StoneCooldownManager other) {
+        cooldowns.clear();
+        cooldowns.putAll(other.cooldowns);
+    }
+
+    /**
+     * Decreases all cooldowns by one according to a round having passed.
+     */
+    public void update() {
+        cooldowns.replaceAll((s, v) -> Math.max(0, cooldowns.get(s) - 1));
+    }
+
+    /**
+     * Checks if a stone is on cooldown.
+     * @param stone The {@link StoneType} to check for
+     * @return Whether or not the stone is on cooldown
+     */
+    public boolean onCooldown(StoneType stone) {
+        return cooldowns.containsKey(stone);
+    }
+
+    /**
+     * Retrieves the current cooldown for a stone.
+     * @param stone The {@link StoneType} to check for
+     * @return The stone's cooldown in rounds
+     */
+    public int getCooldown(StoneType stone) {
+        return cooldowns.get(stone);
+    }
+
+    /**
+     * Marks a stone as on cooldown.
+     * @param stone The {@link StoneType} to check for
+     * @param duration The number of rounds the stone should be on cooldown
+     */
+    public void setCooldown(StoneType stone, int duration) {
+        cooldowns.put(stone, Math.max(0, duration));
+    }
+}