[WOE] Implement Ash, Party Crasher (add Celebration Condition) (#10818)

* implement Ash, Party Crasher (add Celebration Condition)

* test Celebration with Ash

Mage/src/main/java/mage/abilities/condition/common/CelebrationCondition.java

@@ -0,0 +1,25 @@
+
+package mage.abilities.condition.common;
+
+import mage.abilities.Ability;
+import mage.abilities.condition.Condition;
+import mage.game.Game;
+import mage.watchers.common.CelebrationWatcher;
+
+/**
+ * @author Susucr
+ */
+public enum CelebrationCondition implements Condition {
+    instance;
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        CelebrationWatcher watcher = game.getState().getWatcher(CelebrationWatcher.class);
+        return watcher != null && watcher.celebrationActive(source.getControllerId());
+    }
+
+    @Override
+    public String toString() {
+        return "two or more nonland permanents entered the battlefield under your control this turn";
+    }
+}

Mage/src/main/java/mage/constants/AbilityWord.java

@@ -12,6 +12,7 @@ public enum AbilityWord {
     ALLIANCE("Alliance"),
     BATTALION("Battalion"),
     BLOODRUSH("Bloodrush"),
+    CELEBRATION("Celebration"),
     CHANNEL("Channel"),
     CHROMA("Chroma"),
     COHORT("Cohort"),

Mage/src/main/java/mage/watchers/common/CelebrationWatcher.java

@@ -0,0 +1,47 @@
+package mage.watchers.common;
+
+import mage.constants.WatcherScope;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
+import mage.util.CardUtil;
+import mage.watchers.Watcher;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * @author Susucr
+ */
+public class CelebrationWatcher extends Watcher {
+
+    // playerId -> number of nonland permanents entered the battlefield this turn under that player's control.
+    private final Map<UUID, Integer> celebrationCounts = new HashMap<>();
+
+    public CelebrationWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() != GameEvent.EventType.ENTERS_THE_BATTLEFIELD) {
+            return;
+        }
+
+        Permanent permanent = game.getPermanent(event.getTargetId());
+        if (permanent != null && !permanent.isLand(game)) {
+            celebrationCounts.compute(permanent.getControllerId(), CardUtil::setOrIncrementValue);
+        }
+    }
+
+    public boolean celebrationActive(UUID playerId) {
+        return celebrationCounts.getOrDefault(playerId, 0) >= 2;
+    }
+
+    @Override
+    public void reset() {
+        super.reset();
+        celebrationCounts.clear();
+    }
+}