Manifest abilities - improved combo support for MDF, split and other cards (related to #10803, part of #11873)

Mage/src/main/java/mage/abilities/effects/common/continuous/BecomesFaceDownCreatureEffect.java

@@ -15,6 +15,7 @@ import mage.abilities.effects.common.InfoEffect;
 import mage.abilities.keyword.WardAbility;
 import mage.cards.Card;
 import mage.cards.CardImpl;
+import mage.cards.ModalDoubleFacedCard;
 import mage.cards.repository.TokenInfo;
 import mage.cards.repository.TokenRepository;
 import mage.constants.*;
@@ -31,6 +32,9 @@ import java.util.UUID;
 
 /**
  * Support different face down types: morph/manifest and disguise/cloak
+ * <p>
+ * WARNING, if you use it custom effect then must create it for left side card,
+ * not main (see findDefaultCardSideForFaceDown)
  *
  * <p>
  * This effect lets the card be a 2/2 face-down creature, with no text, no name,
@@ -334,4 +338,21 @@ public class BecomesFaceDownCreatureEffect extends ContinuousEffectImpl {
         }
     }
 
+    /**
+     * There are cards with multiple sides like MDFC, but face down must use only main/left side all the time.
+     * So try to find that side.
+     */
+    public static Card findDefaultCardSideForFaceDown(Game game, Card card) {
+        // rules example:
+        // If a double-faced card is manifested, it will be put onto the battlefield face down. While face down,
+        // it can't transform. If the front face of the card is a creature card, you can turn it face up by paying
+        // its mana cost. If you do, its front face will be up.
+
+        if (card instanceof ModalDoubleFacedCard) {
+            // only MDFC uses independent card sides on 2024
+            return ((ModalDoubleFacedCard) card).getLeftHalfCard();
+        } else {
+            return card;
+        }
+    }
 }

Mage/src/main/java/mage/abilities/effects/keyword/ManifestEffect.java

@@ -58,10 +58,6 @@ import java.util.Set;
  * 701.34g TODO: need support it
  * If a manifested permanent that’s represented by an instant or sorcery card would turn face up, its controller
  * reveals it and leaves it face down. Abilities that trigger whenever a permanent is turned face up won’t trigger.
- * <p>
- * 701.34g
- * If a manifested permanent that’s represented by an instant or sorcery card would turn face up, its controller
- * reveals it and leaves it face down. Abilities that trigger whenever a permanent is turned face up won’t trigger.
  *
  * @author LevelX2, JayDi85
  */
@@ -123,16 +119,19 @@ public class ManifestEffect extends OneShotEffect {
         // prepare face down effect for battlefield permanents
         // TODO: need research - why it add effect before move?!
         for (Card card : cardsToManifest) {
+            Card battlefieldCard = BecomesFaceDownCreatureEffect.findDefaultCardSideForFaceDown(game, card);
+
             // search mana cost for a face up ability (look at face side of the double side card)
             ManaCosts manaCosts = null;
-            if (card.isCreature(game)) {
-                manaCosts = card.getSpellAbility() != null ? card.getSpellAbility().getManaCosts() : null;
+            if (battlefieldCard.isCreature(game)) {
+                manaCosts = battlefieldCard.getSpellAbility() != null ? battlefieldCard.getSpellAbility().getManaCosts() : null;
                 if (manaCosts == null) {
                     manaCosts = new ManaCostsImpl<>("{0}");
                 }
             }
+
             // zcc + 1 for use case with Rally the Ancestors (see related test)
-            MageObjectReference objectReference = new MageObjectReference(card.getId(), card.getZoneChangeCounter(game) + 1, game);
+            MageObjectReference objectReference = new MageObjectReference(battlefieldCard.getId(), battlefieldCard.getZoneChangeCounter(game) + 1, game);
             game.addEffect(new BecomesFaceDownCreatureEffect(manaCosts, objectReference, Duration.Custom, FaceDownType.MANIFESTED), newSource);
         }
 
@@ -140,13 +139,16 @@ public class ManifestEffect extends OneShotEffect {
         // TODO: possible buggy for multiple cards, see rule 701.34e - it require manifest one by one (card to check: Omarthis, Ghostfire Initiate)
         manifestPlayer.moveCards(cardsToManifest, Zone.BATTLEFIELD, source, game, false, true, false, null);
         for (Card card : cardsToManifest) {
-            Permanent permanent = game.getPermanent(card.getId());
+            Card battlefieldCard = BecomesFaceDownCreatureEffect.findDefaultCardSideForFaceDown(game, card);
+
+            Permanent permanent = game.getPermanent(battlefieldCard.getId());
             if (permanent != null) {
-                // TODO: why it set manifested here (face down effect doesn't work?!)
+                // TODO: permanent already has manifested status, so code can be deleted later
                 // TODO: add test with battlefield trigger/watcher (must not see normal card, must not see face down status without manifest)
                 permanent.setManifested(true);
             } else {
                 // TODO: looks buggy, card can't be moved to battlefield, but face down effect already active
+                //  or it can be face down on another move to battalefield
             }
         }
 

Mage/src/main/java/mage/game/permanent/PermanentCard.java

@@ -56,6 +56,12 @@ public class PermanentCard extends PermanentImpl {
                 goodForBattlefield = false;
             }
         }
+
+        // face down cards allows in any forms (only face up restricted for non-permanents)
+        if (card.isFaceDown(game)) {
+            goodForBattlefield = true;
+        }
+
         if (!goodForBattlefield) {
             throw new IllegalArgumentException("Wrong code usage: can't create permanent card from split or mdf: " + card.getName());
         }