[LGN] Rework Whipgrass Entangler (#10802)

* Rework Whipgrass Entangler

Made a class for "Ability linked with an Effect", that also takes responsability of manually calling its effect's newId method.

* apply review & cleanup

Mage/src/main/java/mage/abilities/common/LinkedEffectIdStaticAbility.java

@@ -0,0 +1,82 @@
+package mage.abilities.common;
+
+import mage.abilities.effects.Effect;
+import mage.constants.Zone;
+import mage.util.CardUtil;
+
+import java.util.Objects;
+import java.util.UUID;
+
+/**
+ * Warning: please test with a lot of care when using this class for new things.
+ * <p>
+ * A static Ability linked to an Effect.
+ * The parent Ability does take responsability of setting the id for the child.
+ *
+ * @author Susucr
+ */
+public class LinkedEffectIdStaticAbility extends SimpleStaticAbility {
+
+    public interface ChildEffect extends Effect {
+        /**
+         * Set the link for the child.
+         */
+        void setParentLinkHandshake(UUID parentLinkHandshake);
+
+        /**
+         * The child Id should only change on copy when the parent wants it to.
+         */
+        void manualNewId();
+    }
+
+
+    /**
+     * The handshake UUID between this parent ability and its child.
+     */
+    private UUID linkedHandshake;
+
+    public LinkedEffectIdStaticAbility(ChildEffect effect) {
+        this(Zone.BATTLEFIELD, effect);
+    }
+
+    public LinkedEffectIdStaticAbility(Zone zone, ChildEffect effect) {
+        super(Zone.BATTLEFIELD, effect);
+        this.linkedHandshake = UUID.randomUUID();
+        initHandshake();
+        setEffectIdManually();
+    }
+
+    private LinkedEffectIdStaticAbility(final LinkedEffectIdStaticAbility effect) {
+        super(effect);
+        this.linkedHandshake = UUID.randomUUID();
+        initHandshake();
+    }
+
+    @Override
+    public LinkedEffectIdStaticAbility copy() {
+        return new LinkedEffectIdStaticAbility(this);
+    }
+
+    private void initHandshake() {
+        this.linkedHandshake = UUID.randomUUID();
+        CardUtil.castStream(this.getEffects().stream(), ChildEffect.class)
+                .filter(Objects::nonNull)
+                .forEach(e -> e.setParentLinkHandshake(linkedHandshake));
+    }
+
+    public void setEffectIdManually() {
+        CardUtil.castStream(this.getEffects().stream(), ChildEffect.class)
+                .filter(Objects::nonNull)
+                .forEach(e -> e.manualNewId());
+    }
+
+    public boolean checkLinked(UUID handshake) {
+        return linkedHandshake.equals(handshake);
+    }
+
+    @Override
+    public void newId() {
+        super.newId();
+    }
+}
+

Mage/src/main/java/mage/abilities/effects/common/combat/CantAttackBlockUnlessPaysSourceEffect.java

@@ -8,7 +8,6 @@ import mage.constants.Duration;
 import mage.constants.Outcome;
 import mage.game.Game;
 import mage.game.events.GameEvent;
-import mage.game.events.GameEvent.EventType;
 
 /**
  * @author LevelX2
@@ -26,7 +25,7 @@ public class CantAttackBlockUnlessPaysSourceEffect extends PayCostToAttackBlockE
         staticText = "{this} can't " + restrictType.toString() + " unless you pay " + (manaCosts == null ? "" : manaCosts.getText());
     }
 
-    public CantAttackBlockUnlessPaysSourceEffect(CantAttackBlockUnlessPaysSourceEffect effect) {
+    protected CantAttackBlockUnlessPaysSourceEffect(final CantAttackBlockUnlessPaysSourceEffect effect) {
         super(effect);
     }
 

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

@@ -3,13 +3,12 @@ package mage.abilities.effects.common.continuous;
 import mage.MageObjectReference;
 import mage.abilities.Ability;
 import mage.abilities.Mode;
+import mage.abilities.common.LinkedEffectIdStaticAbility;
 import mage.abilities.effects.ContinuousEffectImpl;
 import mage.cards.Card;
 import mage.constants.*;
 import mage.game.Game;
 import mage.game.permanent.Permanent;
-import mage.target.Target;
-import mage.util.CardUtil;
 
 import java.util.*;
 
@@ -18,7 +17,7 @@ import java.util.*;
  */
 public class GainAbilityTargetEffect extends ContinuousEffectImpl {
 
-    protected Ability ability;
+    protected final Ability ability;
 
     // shall a card gain the ability (otherwise a permanent)
     private final boolean useOnCard; // only one card per ability supported
@@ -43,7 +42,8 @@ public class GainAbilityTargetEffect extends ContinuousEffectImpl {
 
     public GainAbilityTargetEffect(Ability ability, Duration duration, String rule, boolean useOnCard) {
         super(duration, Layer.AbilityAddingRemovingEffects_6, SubLayer.NA, ability.getEffects().getOutcome(ability, Outcome.AddAbility));
-        this.ability = ability;
+        this.ability = copyAbility(ability); // See the method's comment, ability.copy() is not enough.
+        
         this.staticText = rule;
         this.useOnCard = useOnCard;
 
@@ -52,8 +52,7 @@ public class GainAbilityTargetEffect extends ContinuousEffectImpl {
 
     protected GainAbilityTargetEffect(final GainAbilityTargetEffect effect) {
         super(effect);
-        this.ability = effect.ability.copy();
-        this.ability.newId(); // This is needed if the effect is copied e.g. by a clone so the ability can be added multiple times to permanents
+        this.ability = copyAbility(effect.ability); // See the method's comment, ability.copy() is not enough.
         this.useOnCard = effect.useOnCard;
         this.waitingCardPermanent = effect.waitingCardPermanent;
         this.durationPhaseStep = effect.durationPhaseStep;
@@ -202,6 +201,23 @@ public class GainAbilityTargetEffect extends ContinuousEffectImpl {
         return affectedTargets > 0;
     }
 
+    /**
+     * Copying the ability and providing ability is needed in a few situations,
+     * The copy in order to have internal fields be proper to that ability in particular.
+     * Id must be different for the copy, for a few things like the GainAbilityTargetEffect gained
+     * by a clone, or in the case of an activated ability, called multiple times on the same target,
+     * and thus the ability should be gained multiple times.
+     */
+
+    private Ability copyAbility(Ability toCopyAbility) {
+        Ability ability = toCopyAbility.copy();
+        ability.newId();
+        if (ability instanceof LinkedEffectIdStaticAbility) {
+            ((LinkedEffectIdStaticAbility) ability).setEffectIdManually();
+        }
+        return ability;
+    }
+
     @Override
     public String getText(Mode mode) {
         if (staticText != null && !staticText.isEmpty()) {