[WOE] Implement Faerie Fencing (#10899)

Mage.Sets/src/mage/cards/f/FaerieFencing.java

@@ -0,0 +1,111 @@
+package mage.cards.f;
+
+import java.util.HashMap;
+import java.util.UUID;
+
+import mage.MageObject;
+import mage.MageObjectReference;
+import mage.abilities.Ability;
+import mage.abilities.effects.OneShotEffect;
+import mage.abilities.effects.common.continuous.BoostTargetEffect;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.Duration;
+import mage.constants.Outcome;
+import mage.constants.SubType;
+import mage.constants.WatcherScope;
+import mage.filter.FilterPermanent;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.stack.Spell;
+import mage.target.common.TargetCreaturePermanent;
+import mage.watchers.Watcher;
+
+/**
+ *
+ * @author Xanderhall
+ */
+public final class FaerieFencing extends CardImpl {
+
+    public FaerieFencing(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.INSTANT}, "{X}{B}");
+        
+        // Target creature gets -X/-X until end of turn. It gets an additional -3/-3 if you controlled a Faerie as you cast this spell.
+        this.getSpellAbility().addTarget(new TargetCreaturePermanent());
+        this.getSpellAbility().addEffect(new FaerieFencingEffect());
+        this.getSpellAbility().addWatcher(new ControlledFaerieAsSpellCastWatcher());
+    }
+
+    private FaerieFencing(final FaerieFencing card) {
+        super(card);
+    }
+
+    @Override
+    public FaerieFencing copy() {
+        return new FaerieFencing(this);
+    }
+}
+
+class FaerieFencingEffect extends OneShotEffect {
+
+    FaerieFencingEffect() {
+        super(Outcome.UnboostCreature);
+        this.staticText = "target creature gets -X/-X until end of turn. It gets an additional -3/-3 if you controlled a Faerie as you cast this spell.";
+    }
+
+    private FaerieFencingEffect(final FaerieFencingEffect effect) {
+        super(effect);
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        ControlledFaerieAsSpellCastWatcher watcher = game.getState().getWatcher(ControlledFaerieAsSpellCastWatcher.class);
+        MageObject mo = source.getSourceObject(game);
+        int reduction = source.getManaCostsToPay().getX();
+
+        if (watcher != null && mo != null && watcher.getCount(new MageObjectReference(mo, game)) > 0) {
+            reduction += 3;
+        }
+        game.addEffect(new BoostTargetEffect(-reduction, -reduction, Duration.EndOfTurn), source);
+        return true;
+    }
+
+    @Override
+    public FaerieFencingEffect copy() {
+        return new FaerieFencingEffect(this);
+    }
+
+}
+
+class ControlledFaerieAsSpellCastWatcher extends Watcher {
+
+    private final FilterPermanent filter = new FilterPermanent(SubType.FAERIE, "");
+
+    ControlledFaerieAsSpellCastWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    private final HashMap<MageObjectReference, Integer> permanentsWhenCast = new HashMap<>();
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() == GameEvent.EventType.SPELL_CAST) {
+            Spell spell = game.getSpell(event.getTargetId());
+            if (spell != null) {
+                MageObjectReference mor = new MageObjectReference(spell, game);
+                permanentsWhenCast.put(mor, game.getBattlefield().countAll(filter, spell.getControllerId(), game));
+            }
+        }
+    }
+
+    @Override
+    public void reset() {
+        super.reset();
+        permanentsWhenCast.clear();
+    }
+
+    public int getCount(MageObjectReference mor) {
+        return permanentsWhenCast.getOrDefault(mor, 0);
+    }
+}

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

@@ -48,6 +48,7 @@ public final class WildsOfEldraine extends ExpansionSet {
         cards.add(new SetCardInfo("Evolving Wilds", 256, Rarity.COMMON, mage.cards.e.EvolvingWilds.class));
         cards.add(new SetCardInfo("Expel the Interlopers", 13, Rarity.RARE, mage.cards.e.ExpelTheInterlopers.class));
         cards.add(new SetCardInfo("Faerie Dreamthief", 89, Rarity.UNCOMMON, mage.cards.f.FaerieDreamthief.class));
+        cards.add(new SetCardInfo("Faerie Fencing", 90, Rarity.UNCOMMON, mage.cards.f.FaerieFencing.class));
         cards.add(new SetCardInfo("Farsight Ritual", 49, Rarity.RARE, mage.cards.f.FarsightRitual.class));
         cards.add(new SetCardInfo("Faunsbane Troll", 203, Rarity.RARE, mage.cards.f.FaunsbaneTroll.class));
         cards.add(new SetCardInfo("Flick a Coin", 128, Rarity.COMMON, mage.cards.f.FlickACoin.class));

Mage.Tests/src/test/java/org/mage/test/cards/single/woe/FaerieFencingTest.java

@@ -0,0 +1,39 @@
+package org.mage.test.cards.single.woe;
+
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+
+public class FaerieFencingTest extends CardTestPlayerBase {
+    
+    private static String SPELL = "Faerie Fencing";
+    private static String FAERIE = "Faerie Miscreant";
+    private static String LION = "Silvercoat Lion";
+
+    @Test
+    public void testEffect() {
+        addCard(Zone.BATTLEFIELD, playerA, "Swamp", 2);    
+        addCard(Zone.BATTLEFIELD, playerA, FAERIE, 1);
+        addCard(Zone.HAND, playerA, SPELL, 1);
+
+        addCard(Zone.BATTLEFIELD, playerB, "Mountain", 1);
+        addCard(Zone.BATTLEFIELD, playerB, LION, 1);
+        addCard(Zone.HAND, playerB, "Lightning Bolt", 1);
+
+        // Player A casts Faerie Fencing for 1, controls a Faerie so lion should get -4/-4
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, SPELL, LION);
+        setChoice(playerA, "X=1");
+        
+        // Player B kills Faerie in response
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerB, "Lightning Bolt", FAERIE, SPELL);
+
+        setStopAt(1, PhaseStep.POSTCOMBAT_MAIN);
+        setStrictChooseMode(true);
+        execute();
+
+        // Lion should still have died
+        assertGraveyardCount(playerB, LION, 1);
+    }
+}