feat: implement GameState.snapshot and make entities cloneable

src/main/java/uulm/teamname/marvelous/gamelibrary/gamelogic/GameState.java

@@ -9,6 +9,7 @@ import uulm.teamname.marvelous.gamelibrary.Tuple;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.Iterator;
 
 /** Represents the state of a game instance. */
 class GameState {
@@ -22,13 +23,13 @@ class GameState {
     public int roundNumber = 0;
 
     /** The turn order of every character */
-    public ArrayList<EntityID> turnOrder;
+    public ArrayList<EntityID> turnOrder = new ArrayList<>();
 
     /** The total amount of turns that occurred */
     public int turnNumber = 0;
 
     /** The {@link EntityID} of the active character */
-    public EntityID activeCharacter;
+    public EntityID activeCharacter = null;
 
     /** Whether or not the game was won */
     public boolean won = false;
@@ -48,11 +49,37 @@ class GameState {
     }
 
     /**
-     * Clones the state into a new {@link GameState} object.
+     * Clones the state into a new {@link GameState} object. This is slow.
      * @return The cloned game state
      */
     public GameState snapshot() {
-        //TODO: implement GameState.snapshot
-        return this;
+        GameState clone = new GameState(this.mapSize);
+
+        for(Iterator<Entity> it = this.entities.getEntities(); it.hasNext(); ) {
+            clone.entities.addEntity(it.next().clone());
+        }
+
+        clone.roundNumber = roundNumber;
+
+        clone.turnOrder = new ArrayList<>();
+        for(EntityID id: turnOrder) {
+            clone.turnOrder.add(id.clone());
+        }
+
+        clone.turnNumber = turnNumber;
+
+        clone.activeCharacter = activeCharacter != null ? activeCharacter.clone() : null;
+
+        clone.won = won;
+
+        for(StoneType type: stoneCooldown.keySet()) {
+            clone.stoneCooldown.put(type, stoneCooldown.get(type));
+        }
+
+        for(Tuple<ParticipantType, WinCondition> condition: winConditions.keySet()) {
+            clone.winConditions.put(condition, winConditions.get(condition));
+        }
+
+        return clone;
     }
 }