[MIR] Implement Haunting Apparition (#11545)

note: further improvement needed in future, see PR comments

Mage.Sets/src/mage/cards/h/HauntingApparition.java

@@ -0,0 +1,89 @@
+package mage.cards.h;
+
+import mage.MageInt;
+import mage.ObjectColor;
+import mage.abilities.Ability;
+import mage.abilities.common.AsEntersBattlefieldAbility;
+import mage.abilities.common.SimpleStaticAbility;
+import mage.abilities.dynamicvalue.DynamicValue;
+import mage.abilities.effects.Effect;
+import mage.abilities.effects.common.ChooseOpponentEffect;
+import mage.abilities.effects.common.continuous.SetBasePowerSourceEffect;
+import mage.abilities.keyword.FlyingAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.Outcome;
+import mage.constants.SubType;
+import mage.constants.Zone;
+import mage.filter.common.FilterCreatureCard;
+import mage.filter.predicate.mageobject.ColorPredicate;
+import mage.game.Game;
+import mage.players.Player;
+
+import java.util.UUID;
+
+/**
+ * @author Cguy7777
+ */
+public final class HauntingApparition extends CardImpl {
+
+    public HauntingApparition(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{1}{U}{B}");
+
+        this.subtype.add(SubType.SPIRIT);
+        this.power = new MageInt(1);
+        this.toughness = new MageInt(2);
+
+        // Flying
+        this.addAbility(FlyingAbility.getInstance());
+
+        // As Haunting Apparition enters the battlefield, choose an opponent.
+        this.addAbility(new AsEntersBattlefieldAbility(new ChooseOpponentEffect(Outcome.Detriment)));
+
+        // Haunting Apparition's power is equal to 1 plus the number of green creature cards in the chosen player's graveyard.
+        Effect effect = new SetBasePowerSourceEffect(OnePlusGreenCreatureCardsInChosenOpponentsGraveyardCount.instance);
+        effect.setText("{this}'s power is equal to 1 plus the number of green creature cards in the chosen player's graveyard");
+        this.addAbility(new SimpleStaticAbility(Zone.ALL, effect));
+    }
+
+    private HauntingApparition(final HauntingApparition card) {
+        super(card);
+    }
+
+    @Override
+    public HauntingApparition copy() {
+        return new HauntingApparition(this);
+    }
+}
+
+enum OnePlusGreenCreatureCardsInChosenOpponentsGraveyardCount implements DynamicValue {
+    instance;
+    private static final FilterCreatureCard filter = new FilterCreatureCard();
+
+    static {
+        filter.add(new ColorPredicate(ObjectColor.GREEN));
+    }
+
+    @Override
+    public int calculate(Game game, Ability sourceAbility, Effect effect) {
+        if (sourceAbility != null) {
+            UUID playerId = (UUID) game.getState().getValue(sourceAbility.getSourceId() + ChooseOpponentEffect.VALUE_KEY);
+            Player chosenOpponent = game.getPlayer(playerId);
+            if (chosenOpponent != null) {
+                return 1 + chosenOpponent.getGraveyard().count(filter, game);
+            }
+        }
+        return 1;
+    }
+
+    @Override
+    public OnePlusGreenCreatureCardsInChosenOpponentsGraveyardCount copy() {
+        return instance;
+    }
+
+    @Override
+    public String getMessage() {
+        return "1 plus the number of green creature cards in the chosen player's graveyard";
+    }
+}

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

@@ -161,6 +161,7 @@ public final class Mirage extends ExpansionSet {
         cards.add(new SetCardInfo("Harbinger of Night", 128, Rarity.RARE, mage.cards.h.HarbingerOfNight.class));
         cards.add(new SetCardInfo("Harbor Guardian", 266, Rarity.UNCOMMON, mage.cards.h.HarborGuardian.class));
         cards.add(new SetCardInfo("Harmattan Efreet", 69, Rarity.UNCOMMON, mage.cards.h.HarmattanEfreet.class));
+        cards.add(new SetCardInfo("Haunting Apparition", 267, Rarity.UNCOMMON, mage.cards.h.HauntingApparition.class));
         cards.add(new SetCardInfo("Hazerider Drake", 268, Rarity.UNCOMMON, mage.cards.h.HazeriderDrake.class));
         cards.add(new SetCardInfo("Healing Salve", 20, Rarity.COMMON, mage.cards.h.HealingSalve.class));
         cards.add(new SetCardInfo("Hivis of the Scale", 182, Rarity.RARE, mage.cards.h.HivisOfTheScale.class));