Implemented Alena, Kessig Trapper

Mage.Sets/src/mage/cards/a/AlenaKessigTrapper.java

@@ -0,0 +1,122 @@
+package mage.cards.a;
+
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+
+import mage.MageInt;
+import mage.MageObject;
+import mage.MageObjectReference;
+import mage.Mana;
+import mage.abilities.Ability;
+import mage.abilities.costs.common.TapSourceCost;
+import mage.abilities.dynamicvalue.DynamicValue;
+import mage.abilities.effects.Effect;
+import mage.abilities.keyword.PartnerAbility;
+import mage.abilities.mana.DynamicManaAbility;
+import mage.constants.*;
+import mage.abilities.keyword.FirstStrikeAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.events.ZoneChangeEvent;
+import mage.watchers.Watcher;
+
+/**
+ * @author TheElk801
+ */
+public final class AlenaKessigTrapper extends CardImpl {
+
+    public AlenaKessigTrapper(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{4}{R}");
+
+        this.addSuperType(SuperType.LEGENDARY);
+        this.subtype.add(SubType.HUMAN);
+        this.subtype.add(SubType.SCOUT);
+        this.power = new MageInt(4);
+        this.toughness = new MageInt(3);
+
+        // First strike
+        this.addAbility(FirstStrikeAbility.getInstance());
+
+        // {T}: Add an amount of {R} equal to the greatest power among creatures you control that entered the battlefield this turn.
+        this.addAbility(new DynamicManaAbility(
+                Mana.RedMana(1), AlenaKessigTrapperValue.instance, new TapSourceCost(), "Add an amount of {R} " +
+                "equal to the greatest power among creatures you control that entered the battlefield this turn."
+        ), new AlenaKessigTrapperWatcher());
+
+        // Partner
+        this.addAbility(PartnerAbility.getInstance());
+    }
+
+    private AlenaKessigTrapper(final AlenaKessigTrapper card) {
+        super(card);
+    }
+
+    @Override
+    public AlenaKessigTrapper copy() {
+        return new AlenaKessigTrapper(this);
+    }
+}
+
+enum AlenaKessigTrapperValue implements DynamicValue {
+    instance;
+
+    @Override
+    public int calculate(Game game, Ability sourceAbility, Effect effect) {
+        AlenaKessigTrapperWatcher watcher = game.getState().getWatcher(AlenaKessigTrapperWatcher.class);
+        if (watcher == null) {
+            return 0;
+        }
+        return watcher.getPower(sourceAbility.getControllerId(), game);
+    }
+
+    @Override
+    public AlenaKessigTrapperValue copy() {
+        return instance;
+    }
+
+    @Override
+    public String getMessage() {
+        return "";
+    }
+}
+
+class AlenaKessigTrapperWatcher extends Watcher {
+
+    private final Set<MageObjectReference> enteredThisTurn = new HashSet<>();
+
+    public AlenaKessigTrapperWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() == GameEvent.EventType.ZONE_CHANGE
+                && ((ZoneChangeEvent) event).getToZone() == Zone.BATTLEFIELD) {
+            enteredThisTurn.add(new MageObjectReference(event.getTargetId(), game));
+        }
+    }
+
+    @Override
+    public void reset() {
+        enteredThisTurn.clear();
+        super.reset();
+    }
+
+    int getPower(UUID playerId, Game game) {
+        return enteredThisTurn
+                .stream()
+                .filter(Objects::nonNull)
+                .map(mor -> mor.getPermanent(game))
+                .filter(Objects::nonNull)
+                .filter(MageObject::isCreature)
+                .filter(permanent -> permanent.isControlledBy(playerId))
+                .map(MageObject::getPower)
+                .mapToInt(MageInt::getValue)
+                .max()
+                .orElse(0);
+    }
+}

Mage.Sets/src/mage/sets/CommanderLegends.java

@@ -27,6 +27,7 @@ public final class CommanderLegends extends ExpansionSet {
         this.ratioBoosterMythic = 8;
         this.maxCardNumberInBooster = 361;
 
+        cards.add(new SetCardInfo("Alena, Kessig Trapper", 160, Rarity.UNCOMMON, mage.cards.a.AlenaKessigTrapper.class));
         cards.add(new SetCardInfo("Command Tower", 350, Rarity.COMMON, mage.cards.c.CommandTower.class));
         cards.add(new SetCardInfo("Commander's Sphere", 306, Rarity.COMMON, mage.cards.c.CommandersSphere.class));
         cards.add(new SetCardInfo("Keeper of the Accord", 27, Rarity.RARE, mage.cards.k.KeeperOfTheAccord.class));