Implemented Zhalfirin Decoy

Mage.Sets/src/mage/cards/z/ZhalfirinDecoy.java

@@ -0,0 +1,108 @@
+package mage.cards.z;
+
+import mage.MageInt;
+import mage.abilities.Ability;
+import mage.abilities.common.ActivateIfConditionActivatedAbility;
+import mage.abilities.condition.Condition;
+import mage.abilities.costs.common.TapSourceCost;
+import mage.abilities.effects.common.TapTargetEffect;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.SubType;
+import mage.constants.WatcherScope;
+import mage.constants.Zone;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.events.ZoneChangeEvent;
+import mage.target.common.TargetCreaturePermanent;
+import mage.watchers.Watcher;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * @author TheElk801
+ */
+public final class ZhalfirinDecoy extends CardImpl {
+
+    public ZhalfirinDecoy(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{1}{W}");
+
+        this.subtype.add(SubType.HUMAN);
+        this.subtype.add(SubType.SOLDIER);
+        this.power = new MageInt(1);
+        this.toughness = new MageInt(3);
+
+        // {T}: Tap target creature. Activate this ability only if you had a creature enter the battlefield under your control this turn.
+        Ability ability = new ActivateIfConditionActivatedAbility(
+                Zone.BATTLEFIELD, new TapTargetEffect(), new TapSourceCost(), ZhalfirinDecoyCondition.instance
+        );
+        ability.addTarget(new TargetCreaturePermanent());
+        this.addAbility(ability, new ZhalfirinDecoyWatcher());
+    }
+
+    private ZhalfirinDecoy(final ZhalfirinDecoy card) {
+        super(card);
+    }
+
+    @Override
+    public ZhalfirinDecoy copy() {
+        return new ZhalfirinDecoy(this);
+    }
+}
+
+enum ZhalfirinDecoyCondition implements Condition {
+    instance;
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        ZhalfirinDecoyWatcher watcher = game.getState().getWatcher(ZhalfirinDecoyWatcher.class);
+        return watcher != null && watcher.enteredCreatureForPlayer(source.getControllerId());
+    }
+
+    @Override
+    public String toString() {
+        return "you had a creature enter the battlefield under your control this turn";
+    }
+}
+
+class ZhalfirinDecoyWatcher extends Watcher {
+
+    private final Set<UUID> players = new HashSet<>();
+
+    ZhalfirinDecoyWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    private ZhalfirinDecoyWatcher(final ZhalfirinDecoyWatcher watcher) {
+        super(watcher);
+        this.players.addAll(watcher.players);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() == GameEvent.EventType.ZONE_CHANGE) {
+            ZoneChangeEvent zEvent = (ZoneChangeEvent) event;
+            if (zEvent.getToZone() == Zone.BATTLEFIELD
+                    && zEvent.getTarget().isCreature()) {
+                players.add(zEvent.getTarget().getControllerId());
+            }
+        }
+    }
+
+    @Override
+    public void reset() {
+        players.clear();
+    }
+
+    boolean enteredCreatureForPlayer(UUID playerId) {
+        return players.contains(playerId);
+    }
+
+    @Override
+    public ZhalfirinDecoyWatcher copy() {
+        return new ZhalfirinDecoyWatcher(this);
+    }
+}

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

@@ -128,5 +128,6 @@ public final class ModernHorizons extends ExpansionSet {
         cards.add(new SetCardInfo("Waterlogged Grove", 249, Rarity.RARE, mage.cards.w.WaterloggedGrove.class));
         cards.add(new SetCardInfo("Wing Shards", 38, Rarity.UNCOMMON, mage.cards.w.WingShards.class));
         cards.add(new SetCardInfo("Wrenn and Six", 217, Rarity.MYTHIC, mage.cards.w.WrennAndSix.class));
+        cards.add(new SetCardInfo("Zhalfirin Decoy", 39, Rarity.UNCOMMON, mage.cards.z.ZhalfirinDecoy.class));
     }
 }