Spellskite script uses a general clause 'ChangeSingleTarget', uses 'Defined' to specify new target

SpellAbility.canTarget now also works for SpellAbilities

res/cardsfolder/s/spellskite.txt

@@ -2,6 +2,6 @@ Name:Spellskite
 ManaCost:2
 Types:Artifact Creature Horror
 PT:0/4
-A:AB$ ChangeTargets | Cost$ PU | TargetType$ Spell,Activated,Triggered | ValidTgts$ Card | SpellSkite$ True | SpellDescription$ Change a target of target spell or ability to CARDNAME.
+A:AB$ ChangeTargets | Cost$ PU | TargetType$ Spell,Activated,Triggered | ValidTgts$ Card | Defined$ Self | ChangeSingleTarget$ True | SpellDescription$ Change a target of target spell or ability to Spellskite.
 SVar:Picture:http://www.wizards.com/global/images/magic/general/spellskite.jpg
 Oracle:{UP}: Change a target of target spell or ability to Spellskite. ({UP} can be paid with either {U} or 2 life.)

src/main/java/forge/card/ability/effects/ChangeTargetsEffect.java

@@ -6,6 +6,8 @@ import java.util.List;
 import org.apache.commons.lang3.tuple.ImmutablePair;
 import org.apache.commons.lang3.tuple.Pair;
 
+import com.google.common.collect.Iterables;
+
 import forge.Card;
 import forge.ITargetable;
 import forge.card.ability.SpellAbilityEffect;
@@ -38,13 +40,13 @@ public class ChangeTargetsEffect extends SpellAbilityEffect {
             }
 
             boolean preserveNumber = sa.hasParam("PreserveNumber"); // Redirect is not supposed to change number of targets 
-            boolean isSpellskite = sa.hasParam("SpellSkite"); // The only card known to replace targets with self is Spellskite
+            boolean changeOneTarget = sa.hasParam("ChangeSingleTarget"); // The only card known to replace targets with self is Spellskite
 
             SpellAbilityStackInstance changingTgtSI = si;
             Player chooser = sa.getActivatingPlayer();
 
-            if( isSpellskite ) {
+            if( changeOneTarget ) {
-                Card srcCard = sa.getSourceCard();
+                ITargetable newTarget = Iterables.getFirst(getDefinedCardsOrTargeted(sa), null);
                 // 1. choose a target of target spell
                 List<Pair<SpellAbilityStackInstance, ITargetable>> allTargets = new ArrayList<>();
                 while(changingTgtSI != null) {
@@ -69,8 +71,8 @@ public class ChangeTargetsEffect extends SpellAbilityEffect {
                 newTargetBlock.remove(oldTarget);
                 replaceIn.updateTarget(newTargetBlock);
                 // 3. test if replacing is correct.
-                if(replaceIn.getSpellAbility().canTarget(srcCard)) {
+                if(replaceIn.getSpellAbility().canTarget(newTarget)) {
-                    newTargetBlock.add(srcCard);
+                    newTargetBlock.add(newTarget);
                     replaceIn.updateTarget(newTargetBlock);
                 } else
                     replaceIn.updateTarget(oldTargetBlock);

src/main/java/forge/card/spellability/SpellAbility.java

@@ -1019,20 +1019,19 @@ public abstract class SpellAbility implements ISpellAbility, ITargetable {
      *            a GameEntity
      * @return a boolean.
      */
-    public final boolean canTarget(final GameEntity entity) {
+    public final boolean canTarget(final ITargetable entity) {
-        if (this.getTargetRestrictions() == null) {
+        // Restriction related to this ability
-            if (entity.canBeTargetedBy(this)) {
+        if (this.getTargetRestrictions() != null) {
-                return true;
+            if (this.getTargetRestrictions().isUniqueTargets() && this.getUniqueTargets().contains(entity))
-            }
+                return false;
-            return false;
+
-        }
+            String[] validTgt = this.getTargetRestrictions().getValidTgts();
-        if (entity.isValid(this.getTargetRestrictions().getValidTgts(), this.getActivatingPlayer(), this.getSourceCard())
+            if (entity instanceof GameEntity && !((GameEntity)entity).isValid(validTgt, this.getActivatingPlayer(), this.getSourceCard()))
-                && (!this.getTargetRestrictions().isUniqueTargets() || !this.getUniqueTargets().contains(entity))
+               return false;
-                && entity.canBeTargetedBy(this)) {
-            return true;
         }
 
-        return false;
+        // Restrictions coming from target
+        return entity.canBeTargetedBy(this);
     }
 
     // is this a wrapping ability (used by trigger abilities)
@@ -1297,13 +1296,7 @@ public abstract class SpellAbility implements ISpellAbility, ITargetable {
     public void setTemporary(boolean temporary) {
         this.temporary = temporary; // TODO: Add 0 to parameter's name.
     }
-
+    
-    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    //
-    // THE CODE BELOW IS RELATED TO TARGETING. It shall await extraction to other class from here
-    //
-    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-
     @Override
     public boolean canBeTargetedBy(SpellAbility sa) {
         return sa.canTargetSpellAbility(this);
@@ -1320,7 +1313,12 @@ public abstract class SpellAbility implements ISpellAbility, ITargetable {
     public TargetRestrictions getTargetRestrictions() {
         return targetRestricions;
     }
-
+    
+    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    //
+    // THE CODE BELOW IS RELATED TO TARGETING. It might be extracted to other class from here
+    //
+    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
     public void setTargetRestrictions(final TargetRestrictions tgt) {
         targetRestricions = tgt;