[CMM] Implement Descendants' Fury (#10700)

* [CMM] Implement Descendants' Fury

* various cleanup

* reset watcher on cleanup, in case of 'end the turn' during combat damage step

Mage/src/main/java/mage/target/common/TargetControlledPermanent.java

@@ -29,7 +29,7 @@ public class TargetControlledPermanent extends TargetPermanent {
         super(minNumTargets, maxNumTargets, filter, notTarget);
     }
 
-    public TargetControlledPermanent(final TargetControlledPermanent target) {
+    protected TargetControlledPermanent(final TargetControlledPermanent target) {
         super(target);
     }
 

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

@@ -0,0 +1,61 @@
+package mage.watchers.common;
+
+import mage.MageObjectReference;
+import mage.constants.WatcherScope;
+import mage.game.Game;
+import mage.game.events.DamagedPlayerEvent;
+import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
+import mage.watchers.Watcher;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+/**
+ * @author notgreat
+ */
+public class DamagedPlayerThisCombatWatcher extends Watcher {
+    // Watch over creatures that dealt combat damage to a player the last damage phase of current combat.
+    // Gets cleared post combat damage step.
+
+    // Player ID -> List of permanents they controlled that dealt damage
+    private final Map<UUID, List<MageObjectReference>> permanents = new HashMap<>();
+    // MOR -> Player they dealt damage to
+    private final Map<MageObjectReference, UUID> damageTarget = new HashMap<>();
+
+    public DamagedPlayerThisCombatWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() == GameEvent.EventType.COMBAT_DAMAGE_STEP_POST
+                || event.getType() == GameEvent.EventType.CLEANUP_STEP_POST) {
+            permanents.clear();
+            damageTarget.clear();
+            return;
+        }
+        if (event.getType() != GameEvent.EventType.DAMAGED_PLAYER
+                || !((DamagedPlayerEvent) event).isCombatDamage()) {
+            return;
+        }
+        Permanent creature = game.getPermanent(event.getSourceId());
+        if (creature == null) {
+            return;
+        }
+        MageObjectReference mor = new MageObjectReference(creature, game);
+        damageTarget.put(mor, event.getPlayerId());
+
+        List<MageObjectReference> list = permanents.computeIfAbsent(creature.getControllerId(), (key) -> new ArrayList<>());
+        list.add(mor);
+    }
+
+    // Return the set of permanents that the controller controlled which dealt combat damage to the player,
+    // during the very last combat step. (so no first striker on normal combat damage)
+    // Returns empty set if there were none
+    public Set<MageObjectReference> getPermanents(UUID controllerID, UUID damagedPlayerID) {
+        return permanents.getOrDefault(controllerID, Collections.emptyList()).stream()
+                         .filter((mor) -> damagedPlayerID.equals(damageTarget.get(mor)))
+                         .collect(Collectors.toSet());
+    }
+}