From ae4e7c252ac867c499a072c59493a7484daf1ae2 Mon Sep 17 00:00:00 2001
From: Agetian <stavdev@mail.ru>
Date: Sat, 28 Jan 2017 14:11:22 +0000
Subject: [PATCH] - More precise ChangeTargetsEffect replacement deduction for
 the purpose of DividedAsYouChoose

---
 .../ability/effects/ChangeTargetsEffect.java  |  6 +--
 .../SpellAbilityStackInstance.java            | 37 ++++++++++++++-----
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/forge-game/src/main/java/forge/game/ability/effects/ChangeTargetsEffect.java b/forge-game/src/main/java/forge/game/ability/effects/ChangeTargetsEffect.java
index 8c340cc626b..f019ef12ee5 100644
--- a/forge-game/src/main/java/forge/game/ability/effects/ChangeTargetsEffect.java
+++ b/forge-game/src/main/java/forge/game/ability/effects/ChangeTargetsEffect.java
@@ -82,7 +82,7 @@ public class ChangeTargetsEffect extends SpellAbilityEffect {
                 GameObject newTarget = Iterables.getFirst(getDefinedCardsOrTargeted(sa), null);
                 if (replaceIn.getSpellAbility(true).canTarget(newTarget)) {
                     newTargetBlock.add(newTarget);
-                    replaceIn.updateTarget(newTargetBlock);
+                    replaceIn.updateTarget(newTargetBlock, oldTarget, newTarget);
                 }
                 else {
                     replaceIn.updateTarget(oldTargetBlock);
@@ -97,7 +97,7 @@ public class ChangeTargetsEffect extends SpellAbilityEffect {
                             List<GameEntity> candidates = changingTgtSA.getTargetRestrictions().getAllCandidates(changingTgtSA, true);
                             GameEntity choice = Aggregates.random(candidates);
                             changingTgtSA.getTargets().add(choice);
-                            changingTgtSI.updateTarget(changingTgtSA.getTargets());
+                            changingTgtSI.updateTarget(changingTgtSA.getTargets(), null, choice);
                         }
                     }
                     else if (sa.hasParam("DefinedMagnet")){
@@ -105,7 +105,7 @@ public class ChangeTargetsEffect extends SpellAbilityEffect {
                         if (newTarget != null && changingTgtSA.canTarget(newTarget)) {
                             changingTgtSA.resetTargets();
                             changingTgtSA.getTargets().add(newTarget);
-                            changingTgtSI.updateTarget(changingTgtSA.getTargets());
+                            changingTgtSI.updateTarget(changingTgtSA.getTargets(), null, newTarget);
                         }
                     }
                     else {
diff --git a/forge-game/src/main/java/forge/game/spellability/SpellAbilityStackInstance.java b/forge-game/src/main/java/forge/game/spellability/SpellAbilityStackInstance.java
index d85be098e0e..b26c764888e 100644
--- a/forge-game/src/main/java/forge/game/spellability/SpellAbilityStackInstance.java
+++ b/forge-game/src/main/java/forge/game/spellability/SpellAbilityStackInstance.java
@@ -32,6 +32,7 @@ import org.apache.commons.lang3.StringUtils;
 
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
+import forge.game.GameObject;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -285,6 +286,10 @@ public class SpellAbilityStackInstance implements IIdentifiable, IHasCardView {
     }
 
     public void updateTarget(TargetChoices target) {
+        updateTarget(target, null, null);
+    }
+
+    public void updateTarget(TargetChoices target, GameObject oldTarget, GameObject newTarget) {
         if (target != null) {
             tc = target;
             ability.setTargets(tc);
@@ -298,18 +303,30 @@ public class SpellAbilityStackInstance implements IIdentifiable, IHasCardView {
                 Object toRemove = null;
                 Object toAdd = null;
                 HashMap<Object,Integer> map = ability.getTargetRestrictions().getDividedMap();
-                // detect which target has changed
-                for (Object obj : map.keySet()) {
-                    if (!target.getTargets().contains(obj)) {
-                        toRemove = obj;
-                        break;
+
+                if (oldTarget != null) {
+                    toRemove = oldTarget;
+                } else {
+                    // try to deduce which target has been replaced
+                    // (this may be imprecise, updateTarget should specify old target if possible)
+                    for (Object obj : map.keySet()) {
+                        if (!target.getTargets().contains((GameObject)obj)) {
+                            toRemove = obj;
+                            break;
+                        }
                     }
                 }
-                // detect a new target
-                for (Object newTgts : target.getTargets()) {
-                    if (!map.containsKey(newTgts)) {
-                        toAdd = newTgts;
-                        break;
+
+                if (newTarget != null) {
+                    toAdd = newTarget;
+                } else {
+                    // try to deduce which target was added
+                    // (this may be imprecise, updateTarget should specify new target if possible)
+                    for (Object newTgts : target.getTargets()) {
+                        if (!map.containsKey(newTgts)) {
+                            toAdd = newTgts;
+                            break;
+                        }
                     }
                 }