Merge branch 'refactor_prevention' into 'master'

Refactor Damage Prevention - Step 1

See merge request core-developers/forge!4675

forge-ai/src/main/java/forge/ai/ComputerUtilCombat.java

@@ -2256,11 +2256,12 @@ public class ComputerUtilCombat {
      * @return a int.
      */
     public final static int getDamageToKill(final Card c) {
-        int killDamage = c.getLethalDamage() + c.getPreventNextDamageTotalShields();
+        int damageShield = c.getPreventNextDamageTotalShields();
+        int killDamage = c.getLethalDamage() + damageShield;
 
-        if ((killDamage > c.getPreventNextDamageTotalShields())
+        if ((killDamage > damageShield)
                 && c.hasSVar("DestroyWhenDamaged")) {
-            killDamage = 1 + c.getPreventNextDamageTotalShields();
+            killDamage = 1 + damageShield;
         }
 
         return killDamage;

forge-ai/src/main/java/forge/ai/simulation/GameCopier.java

@@ -88,7 +88,6 @@ public class GameCopier {
             newPlayer.setCounters(Maps.newHashMap(origPlayer.getCounters()));
             newPlayer.setLifeLostLastTurn(origPlayer.getLifeLostLastTurn());
             newPlayer.setLifeLostThisTurn(origPlayer.getLifeLostThisTurn());
-            newPlayer.setPreventNextDamage(origPlayer.getPreventNextDamage());
             newPlayer.getManaPool().add(origPlayer.getManaPool());
             newPlayer.setCommanders(origPlayer.getCommanders()); // will be fixed up below
             playerMap.put(origPlayer, newPlayer);

forge-game/src/main/java/forge/game/GameEntity.java

@@ -45,9 +45,7 @@ import forge.game.zone.ZoneType;
 public abstract class GameEntity extends GameObject implements IIdentifiable {
     protected final int id;
     private String name = "";
-    private int preventNextDamage = 0;
     protected CardCollection attachedCards = new CardCollection();
-    private Map<Card, Map<String, String>> preventionShieldsWithEffects = Maps.newTreeMap();
     protected Map<CounterType, Integer> counters = Maps.newHashMap();
 
     protected GameEntity(int id0) {
@@ -192,20 +190,6 @@ public abstract class GameEntity extends GameObject implements IIdentifiable {
         // then apply static Damage Prevention effects
         restDamage = staticDamagePrevention(restDamage, source, isCombat, false);
 
-        // then apply ShieldEffects with Special Effect
-        restDamage = preventShieldEffect(restDamage);
-
-        // then do Shield with only number
-        if (restDamage <= 0) {
-            restDamage = 0;
-        } else if (restDamage >= getPreventNextDamage()) {
-            restDamage = restDamage - getPreventNextDamage();
-            setPreventNextDamage(0);
-        } else {
-            setPreventNextDamage(getPreventNextDamage() - restDamage);
-            restDamage = 0;
-        }
-
         // if damage is greater than restDamage, damage was prevented
         if (damage > restDamage) {
             int prevent = damage - restDamage;
@@ -223,60 +207,8 @@ public abstract class GameEntity extends GameObject implements IIdentifiable {
         return restDamage;
     }
 
-    protected abstract int preventShieldEffect(final int damage);
-
-    public int getPreventNextDamage() {
-        return preventNextDamage;
-    }
-    public void setPreventNextDamage(final int n) {
-        preventNextDamage = n;
-    }
-    public void addPreventNextDamage(final int n) {
-        preventNextDamage += n;
-    }
-    public void subtractPreventNextDamage(final int n) {
-        preventNextDamage -= n;
-    }
-    public void resetPreventNextDamage() {
-        preventNextDamage = 0;
-    }
-
-    // PreventNextDamageWithEffect
-    public Map<Card, Map<String, String>> getPreventNextDamageWithEffect() {
-        return preventionShieldsWithEffects;
-    }
     public int getPreventNextDamageTotalShields() {
-        int shields = preventNextDamage;
+        return getGame().getReplacementHandler().getTotalPreventionShieldAmount(this);
-        for (final Map<String, String> value : preventionShieldsWithEffects.values()) {
-            shields += Integer.valueOf(value.get("ShieldAmount"));
-        }
-        return shields;
-    }
-    /**
-     * Adds a damage prevention shield with an effect that happens at time of prevention.
-     * @param shieldSource - The source card which generated the shield
-     * @param effectMap - A map of the effect occurring with the damage prevention
-     */
-    public void addPreventNextDamageWithEffect(final Card shieldSource, Map<String, String> effectMap) {
-        if (preventionShieldsWithEffects.containsKey(shieldSource)) {
-            int currentShields = Integer.valueOf(preventionShieldsWithEffects.get(shieldSource).get("ShieldAmount"));
-            currentShields += Integer.valueOf(effectMap.get("ShieldAmount"));
-            effectMap.put("ShieldAmount", Integer.toString(currentShields));
-            preventionShieldsWithEffects.put(shieldSource, effectMap);
-        } else {
-            preventionShieldsWithEffects.put(shieldSource, effectMap);
-        }
-    }
-    public void subtractPreventNextDamageWithEffect(final Card shieldSource, final int n) {
-        int currentShields = Integer.valueOf(preventionShieldsWithEffects.get(shieldSource).get("ShieldAmount"));
-        if (currentShields > n) {
-            preventionShieldsWithEffects.get(shieldSource).put("ShieldAmount", String.valueOf(currentShields - n));
-        } else {
-            preventionShieldsWithEffects.remove(shieldSource);
-        }
-    }
-    public void resetPreventNextDamageWithEffect() {
-        preventionShieldsWithEffects.clear();
     }
 
     public abstract boolean hasKeyword(final String keyword);

forge-game/src/main/java/forge/game/ability/effects/DamagePreventAllEffect.java

@@ -2,14 +2,13 @@ package forge.game.ability.effects;
 
 import forge.game.Game;
 import forge.game.ability.AbilityUtils;
-import forge.game.ability.SpellAbilityEffect;
 import forge.game.card.Card;
 import forge.game.card.CardCollectionView;
 import forge.game.player.Player;
 import forge.game.spellability.SpellAbility;
 import forge.game.zone.ZoneType;
 
-public class DamagePreventAllEffect extends SpellAbilityEffect {
+public class DamagePreventAllEffect extends DamagePreventEffectBase {
     @Override
     public void resolve(SpellAbility sa) {
         final Card source = sa.getHostCard();
@@ -26,14 +25,14 @@ public class DamagePreventAllEffect extends SpellAbilityEffect {
             CardCollectionView list = game.getCardsIn(ZoneType.Battlefield);
             list = AbilityUtils.filterListByType(list, sa.getParam("ValidCards"), sa);
             for (final Card c : list) {
-                c.addPreventNextDamage(numDam);
+                addPreventNextDamage(sa, c, numDam);
             }
         }
 
         if (!players.equals("")) {
             for (final Player p : game.getPlayers()) {
                 if (p.isValid(players, source.getController(), source, sa)) {
-                    p.addPreventNextDamage(numDam);
+                    addPreventNextDamage(sa, p, numDam);
                 }
             }
         }

forge-game/src/main/java/forge/game/ability/effects/DamagePreventEffect.java

@@ -1,20 +1,16 @@
 package forge.game.ability.effects;
 
-import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
-import java.util.TreeMap;
 
 import forge.game.GameObject;
 import forge.game.ability.AbilityUtils;
-import forge.game.ability.SpellAbilityEffect;
 import forge.game.card.Card;
 import forge.game.card.CardCollection;
 import forge.game.card.CardUtil;
 import forge.game.player.Player;
 import forge.game.spellability.SpellAbility;
 
-public class DamagePreventEffect extends SpellAbilityEffect {
+public class DamagePreventEffect extends DamagePreventEffectBase {
 
     @Override
     protected String getStackDescription(SpellAbility sa) {
@@ -73,69 +69,25 @@ public class DamagePreventEffect extends SpellAbilityEffect {
         final CardCollection untargetedCards = CardUtil.getRadiance(sa);
 
         final boolean targeted = (sa.usesTargeting());
-        final boolean preventionWithEffect = sa.hasParam("PreventionSubAbility");
 
         for (final GameObject o : tgts) {
             numDam = (sa.usesTargeting() && sa.isDividedAsYouChoose()) ? sa.getDividedValue(o) : numDam;
             if (o instanceof Card) {
                 final Card c = (Card) o;
                 if (c.isInPlay() && (!targeted || c.canBeTargetedBy(sa))) {
-                    if (preventionWithEffect) {
+                    addPreventNextDamage(sa, o, numDam);
-                        Map<String, String> effectMap = new TreeMap<>();
-                        effectMap.put("EffectString", sa.getSVar(sa.getParam("PreventionSubAbility")));
-                        effectMap.put("ShieldAmount", String.valueOf(numDam));
-                        if (sa.hasParam("ShieldEffectTarget")) {
-                            String effTgtString = "";
-                            List<GameObject> effTgts = new ArrayList<>();
-                            effTgts = AbilityUtils.getDefinedObjects(host, sa.getParam("ShieldEffectTarget"), sa);
-                            for (final Object effTgt : effTgts) {
-                                if (effTgt instanceof Card) {
-                                    effTgtString = String.valueOf(((Card) effTgt).getId());
-                                    effectMap.put("ShieldEffectTarget", "CardUID_" + effTgtString);
-                                } else if (effTgt instanceof Player) {
-                                    effTgtString = ((Player) effTgt).getName();
-                                    effectMap.put("ShieldEffectTarget", "PlayerNamed_" + effTgtString);
                 }
-                            }
-                        }
-                        c.addPreventNextDamageWithEffect(host, effectMap);
-                    } else {
-                        c.addPreventNextDamage(numDam);
-                    }
-                }
-
             } else if (o instanceof Player) {
                 final Player p = (Player) o;
                 if (!targeted || p.canBeTargetedBy(sa)) {
-                    if (preventionWithEffect) {
+                    addPreventNextDamage(sa, o, numDam);
-                        Map<String, String> effectMap = new TreeMap<>();
-                        effectMap.put("EffectString", sa.getSVar(sa.getParam("PreventionSubAbility")));
-                        effectMap.put("ShieldAmount", String.valueOf(numDam));
-                        if (sa.hasParam("ShieldEffectTarget")) {
-                            String effTgtString = "";
-                            List<GameObject> effTgts = new ArrayList<>();
-                            effTgts = AbilityUtils.getDefinedObjects(host, sa.getParam("ShieldEffectTarget"), sa);
-                            for (final Object effTgt : effTgts) {
-                                if (effTgt instanceof Card) {
-                                    effTgtString = String.valueOf(((Card) effTgt).getId());
-                                    effectMap.put("ShieldEffectTarget", "CardUID_" + effTgtString);
-                                } else if (effTgt instanceof Player) {
-                                    effTgtString = ((Player) effTgt).getName();
-                                    effectMap.put("ShieldEffectTarget", "PlayerNamed_" + effTgtString);
-                                }
-                            }
-                        }
-                        p.addPreventNextDamageWithEffect(host, effectMap);
-                    } else {
-                        p.addPreventNextDamage(numDam);
-                    }
                 }
             }
         }
 
         for (final Card c : untargetedCards) {
             if (c.isInPlay()) {
-                c.addPreventNextDamage(numDam);
+                addPreventNextDamage(sa, c, numDam);
             }
         }
     } // preventDamageResolve

forge-game/src/main/java/forge/game/ability/effects/DamagePreventEffectBase.java

@@ -0,0 +1,76 @@
+package forge.game.ability.effects;
+
+import java.util.List;
+
+import forge.GameCommand;
+import forge.game.Game;
+import forge.game.GameObject;
+import forge.game.ability.AbilityFactory;
+import forge.game.ability.AbilityUtils;
+import forge.game.ability.SpellAbilityEffect;
+import forge.game.card.Card;
+import forge.game.player.Player;
+import forge.game.replacement.ReplacementEffect;
+import forge.game.replacement.ReplacementHandler;
+import forge.game.spellability.AbilitySub;
+import forge.game.spellability.SpellAbility;
+import forge.game.trigger.TriggerType;
+import forge.game.zone.ZoneType;
+import forge.util.TextUtil;
+
+public abstract class DamagePreventEffectBase extends SpellAbilityEffect {
+    public static void addPreventNextDamage(SpellAbility sa, GameObject o, int numDam) {
+        final Card hostCard = sa.getHostCard();
+        final Game game = hostCard.getGame();
+        final Player player = hostCard.getController();
+        final String name = hostCard.getName() + "'s Effect";
+        final String image = hostCard.getImageKey();
+        StringBuilder sb = new StringBuilder("Event$ DamageDone | ActiveZones$ Command | ValidTarget$ ");
+        sb.append((o instanceof Card ? "Card.IsRemembered" : "Player.IsRemembered"));
+        sb.append(" | PreventionEffect$ True | Description$ Prevent the next ").append(numDam).append(" damage.");
+        String repeffstr = sb.toString();
+        String effect = "DB$ ReplaceDamage | Amount$ ShieldAmount";
+
+        final Card eff = createEffect(sa, player, name, image);
+        eff.setSVar("ShieldAmount", "Number$" + numDam);
+        eff.setSVar("PreventedDamage", "Number$0");
+        eff.addRemembered(o);
+
+        SpellAbility replaceDamage = AbilityFactory.getAbility(effect, eff);
+        if (sa.hasParam("PreventionSubAbility")) {
+            String subAbString = sa.getSVar(sa.getParam("PreventionSubAbility"));
+            if (sa.hasParam("ShieldEffectTarget")) {
+                List<GameObject> effTgts = AbilityUtils.getDefinedObjects(hostCard, sa.getParam("ShieldEffectTarget"), sa);
+                String effTgtString = "";
+                for (final GameObject effTgt : effTgts) {
+                    if (effTgt instanceof Card) {
+                        effTgtString = "CardUID_" + String.valueOf(((Card) effTgt).getId());
+                    } else if (effTgt instanceof Player) {
+                        effTgtString = "PlayerNamed_" + ((Player) effTgt).getName();
+                    }
+                }
+                subAbString = TextUtil.fastReplace(subAbString, "ShieldEffectTarget", effTgtString);
+            }
+            replaceDamage.setSubAbility((AbilitySub) AbilityFactory.getAbility(subAbString, eff));
+        }
+
+        ReplacementEffect re = ReplacementHandler.parseReplacement(repeffstr, eff, true);
+        re.setOverridingAbility(replaceDamage);
+        eff.addReplacementEffect(re);
+        if (o instanceof Card) {
+            addForgetOnMovedTrigger(eff, "Battlefield");
+        }
+        eff.updateStateForView();
+
+        game.getTriggerHandler().suppressMode(TriggerType.ChangesZone);
+        game.getAction().moveTo(ZoneType.Command, eff, sa);
+        game.getTriggerHandler().clearSuppression(TriggerType.ChangesZone);
+
+        game.getEndOfTurn().addUntil(new GameCommand() {
+            @Override
+            public void run() {
+                game.getAction().exile(eff, null);
+            }
+        });
+    }
+}

forge-game/src/main/java/forge/game/ability/effects/ReplaceDamageEffect.java

@@ -29,7 +29,7 @@ public class ReplaceDamageEffect extends SpellAbilityEffect {
 
         final ReplacementType event = sa.getReplacementEffect().getMode();
         
-        String varValue = sa.getParamOrDefault("VarName", "1");
+        String varValue = sa.getParamOrDefault("Amount", "1");
 
         @SuppressWarnings("unchecked")
         Map<AbilityKey, Object> originalParams = (Map<AbilityKey, Object>) sa.getReplacingObject(AbilityKey.OriginalParams);
@@ -51,6 +51,8 @@ public class ReplaceDamageEffect extends SpellAbilityEffect {
             } else if (!StringUtils.isNumeric(varValue)) {
                 card.setSVar(varValue, "Number$" + prevent);
             }
+            // Set PreventedDamage SVar for PreventionSubAbility
+            card.setSVar("PreventedDamage", "Number$" + n);
         }
 
         // no damage for original target anymore

forge-game/src/main/java/forge/game/card/Card.java

@@ -5231,83 +5231,6 @@ public class Card extends GameEntity implements Comparable<Card>, IHasSVars {
         return restDamage > 0 ? restDamage : 0;
     }
 
-    protected int preventShieldEffect(final int damage) {
-        if (damage <= 0) {
-            return 0;
-        }
-
-        int restDamage = damage;
-
-        boolean DEBUGShieldsWithEffects = false;
-        while (!getPreventNextDamageWithEffect().isEmpty() && restDamage != 0) {
-            Map<Card, Map<String, String>> shieldMap = getPreventNextDamageWithEffect();
-            CardCollectionView preventionEffectSources = new CardCollection(shieldMap.keySet());
-            Card shieldSource = preventionEffectSources.get(0);
-            if (preventionEffectSources.size() > 1) {
-                Map<String, Card> choiceMap = Maps.newTreeMap();
-                List<String> choices = Lists.newArrayList();
-                for (final Card key : preventionEffectSources) {
-                    String effDesc = shieldMap.get(key).get("EffectString");
-                    int descIndex = effDesc.indexOf("SpellDescription");
-                    effDesc = effDesc.substring(descIndex + 18);
-                    String shieldDescription = key.toString() + " - " + shieldMap.get(key).get("ShieldAmount")
-                            + " shields - " + effDesc;
-                    choices.add(shieldDescription);
-                    choiceMap.put(shieldDescription, key);
-                }
-                shieldSource = getController().getController().chooseProtectionShield(this, choices, choiceMap);
-            }
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Prevention shield source: " + shieldSource);
-            }
-
-            int shieldAmount = Integer.valueOf(shieldMap.get(shieldSource).get("ShieldAmount"));
-            int dmgToBePrevented = Math.min(restDamage, shieldAmount);
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Selected source initial shield amount: " + shieldAmount);
-                System.out.println("Incoming damage: " + restDamage);
-                System.out.println("Damage to be prevented: " + dmgToBePrevented);
-            }
-
-            //Set up ability
-            SpellAbility shieldSA;
-            String effectAbString = shieldMap.get(shieldSource).get("EffectString");
-            effectAbString = TextUtil.fastReplace(effectAbString, "PreventedDamage", Integer.toString(dmgToBePrevented));
-            effectAbString = TextUtil.fastReplace(effectAbString, "ShieldEffectTarget", shieldMap.get(shieldSource).get("ShieldEffectTarget"));
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Final shield ability string: " + effectAbString);
-            }
-            shieldSA = AbilityFactory.getAbility(effectAbString, shieldSource);
-            if (shieldSA.usesTargeting()) {
-                System.err.println(shieldSource + " - Targeting for prevention shield's effect should be done with initial spell");
-            }
-
-            boolean apiIsEffect = (shieldSA.getApi() == ApiType.Effect);
-            CardCollectionView cardsInCommand = null;
-            if (apiIsEffect) {
-                cardsInCommand = getGame().getCardsIn(ZoneType.Command);
-            }
-
-            getController().getController().playSpellAbilityNoStack(shieldSA, true);
-            if (apiIsEffect) {
-                CardCollection newCardsInCommand = (CardCollection)getGame().getCardsIn(ZoneType.Command);
-                newCardsInCommand.removeAll(cardsInCommand);
-                if (!newCardsInCommand.isEmpty()) {
-                    newCardsInCommand.get(0).setSVar("PreventedDamage", "Number$" + dmgToBePrevented);
-                }
-            }
-            subtractPreventNextDamageWithEffect(shieldSource, restDamage);
-            restDamage = restDamage - dmgToBePrevented;
-
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Remaining shields: "
-                    + (shieldMap.containsKey(shieldSource) ? shieldMap.get(shieldSource).get("ShieldAmount") : "all shields used"));
-                System.out.println("Remaining damage: " + restDamage);
-            }
-        }
-        return restDamage;
-    }
-
     // This is used by the AI to forecast an effect (so it must not change the game state)
     @Override
     public final int staticReplaceDamage(final int damage, final Card source, final boolean isCombat) {
@@ -6205,8 +6128,6 @@ public class Card extends GameEntity implements Comparable<Card>, IHasSVars {
     public void onCleanupPhase(final Player turn) {
         setDamage(0);
         setHasBeenDealtDeathtouchDamage(false);
-        resetPreventNextDamage();
-        resetPreventNextDamageWithEffect();
         resetReceivedDamageFromThisTurn();
         resetDealtDamageToThisTurn();
         resetDealtDamageToPlayerThisTurn();

forge-game/src/main/java/forge/game/player/Player.java

@@ -31,7 +31,6 @@ import java.util.Map.Entry;
 import java.util.NavigableMap;
 import java.util.Set;
 import java.util.SortedSet;
-import java.util.TreeMap;
 import java.util.concurrent.ConcurrentSkipListMap;
 
 import org.apache.commons.lang3.tuple.ImmutablePair;
@@ -840,83 +839,6 @@ public class Player extends GameEntity implements Comparable<Player> {
         return restDamage;
     }
 
-    protected int preventShieldEffect(final int damage) {
-        if (damage <= 0) {
-            return 0;
-        }
-
-        int restDamage = damage;
-
-        boolean DEBUGShieldsWithEffects = false;
-        while (!getPreventNextDamageWithEffect().isEmpty() && restDamage != 0) {
-            Map<Card, Map<String, String>> shieldMap = getPreventNextDamageWithEffect();
-            CardCollection preventionEffectSources = new CardCollection(shieldMap.keySet());
-            Card shieldSource = preventionEffectSources.get(0);
-            if (preventionEffectSources.size() > 1) {
-                Map<String, Card> choiceMap = new TreeMap<>();
-                List<String> choices = new ArrayList<>();
-                for (final Card key : preventionEffectSources) {
-                    String effDesc = shieldMap.get(key).get("EffectString");
-                    int descIndex = effDesc.indexOf("SpellDescription");
-                    effDesc = effDesc.substring(descIndex + 18);
-                    String shieldDescription = key.toString() + " - " + shieldMap.get(shieldSource).get("ShieldAmount")
-                            + " shields - " + effDesc;
-                    choices.add(shieldDescription);
-                    choiceMap.put(shieldDescription, key);
-                }
-                shieldSource = getController().chooseProtectionShield(this, choices, choiceMap);
-            }
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Prevention shield source: " + shieldSource);
-            }
-
-            int shieldAmount = Integer.valueOf(shieldMap.get(shieldSource).get("ShieldAmount"));
-            int dmgToBePrevented = Math.min(restDamage, shieldAmount);
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Selected source initial shield amount: " + shieldAmount);
-                System.out.println("Incoming damage: " + restDamage);
-                System.out.println("Damage to be prevented: " + dmgToBePrevented);
-            }
-
-            //Set up ability
-            SpellAbility shieldSA = null;
-            String effectAbString = shieldMap.get(shieldSource).get("EffectString");
-            effectAbString = TextUtil.fastReplace(effectAbString, "PreventedDamage", Integer.toString(dmgToBePrevented));
-            effectAbString = TextUtil.fastReplace(effectAbString, "ShieldEffectTarget", shieldMap.get(shieldSource).get("ShieldEffectTarget"));
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Final shield ability string: " + effectAbString);
-            }
-            shieldSA = AbilityFactory.getAbility(effectAbString, shieldSource);
-            if (shieldSA.usesTargeting()) {
-                System.err.println(shieldSource + " - Targeting for prevention shield's effect should be done with initial spell");
-            }
-
-            boolean apiIsEffect = (shieldSA.getApi() == ApiType.Effect);
-            CardCollectionView cardsInCommand = null;
-            if (apiIsEffect) {
-                cardsInCommand = getGame().getCardsIn(ZoneType.Command);
-            }
-
-            getController().playSpellAbilityNoStack(shieldSA, true);
-            if (apiIsEffect) {
-                CardCollection newCardsInCommand = new CardCollection(getGame().getCardsIn(ZoneType.Command));
-                newCardsInCommand.removeAll(cardsInCommand);
-                if (!newCardsInCommand.isEmpty()) {
-                    newCardsInCommand.get(0).setSVar("PreventedDamage", "Number$" + dmgToBePrevented);
-                }
-            }
-            subtractPreventNextDamageWithEffect(shieldSource, restDamage);
-            restDamage = restDamage - dmgToBePrevented;
-
-            if (DEBUGShieldsWithEffects) {
-                System.out.println("Remaining shields: "
-                        + (shieldMap.containsKey(shieldSource) ? shieldMap.get(shieldSource).get("ShieldAmount") : "all shields used"));
-                System.out.println("Remaining damage: " + restDamage);
-            }
-        }
-        return restDamage;
-    }
-
     public final void clearAssignedDamage() {
         assignedDamage.clear();
         assignedCombatDamage.clear();
@@ -2597,8 +2519,6 @@ public class Player extends GameEntity implements Comparable<Player> {
         for (final PlayerZone pz : zones.values()) {
             pz.resetCardsAddedThisTurn();
         }
-        resetPreventNextDamage();
-        resetPreventNextDamageWithEffect();
         resetNumDrawnThisTurn();
         resetNumDiscardedThisTurn();
         resetNumForetoldThisTurn();

forge-game/src/main/java/forge/game/replacement/ReplacementHandler.java

@@ -29,11 +29,13 @@ import com.google.common.collect.Sets;
 
 import forge.game.CardTraitBase;
 import forge.game.Game;
+import forge.game.GameEntity;
 import forge.game.GameLogEntryType;
 import forge.game.IHasSVars;
 import forge.game.ability.AbilityFactory;
 import forge.game.ability.AbilityKey;
 import forge.game.ability.AbilityUtils;
+import forge.game.ability.ApiType;
 import forge.game.card.Card;
 import forge.game.card.CardCollection;
 import forge.game.card.CardState;
@@ -436,4 +438,39 @@ public class ReplacementHandler {
         }
         return true;
     }
+
+    /**
+     * Helper function to get total prevention shield amount (limited to "prevent next N damage effects")
+     * @param o Affected game entity object
+     * @return total shield amount
+     */
+    public int getTotalPreventionShieldAmount(GameEntity o) {
+        final Map<AbilityKey, Object> repParams = AbilityKey.mapFromAffected(o);
+        repParams.put(AbilityKey.Prevention, true);
+        repParams.put(AbilityKey.DamageAmount, 1);
+        List<ReplacementEffect> list = getReplacementList(ReplacementType.DamageDone, repParams, ReplacementLayer.Other);
+        if (list.isEmpty()) {
+            return 0;
+        }
+        int totalAmount = 0;
+        for (ReplacementEffect re : list) {
+            if (re.getOverridingAbility() != null) {
+                SpellAbility sa = re.getOverridingAbility();
+                if (ApiType.ReplaceDamage == sa.getApi() && sa.hasParam("Amount")) {
+                    String varValue = sa.getParam("Amount");
+                    if (StringUtils.isNumeric(varValue)) {
+                        totalAmount += Integer.parseInt(varValue);
+                    } else {
+                        varValue = sa.getSVar(varValue);
+                        if (StringUtils.isNumeric(varValue)) {
+                            totalAmount += Integer.parseInt(varValue);
+                        } else if (varValue.startsWith("Number$")) {
+                            totalAmount += Integer.parseInt(varValue.substring(7));
+                        }
+                    }
+                }
+            }
+        }
+        return totalAmount;
+    }
 }

forge-gui/res/cardsfolder/h/healing_grace.txt

@@ -3,10 +3,10 @@ ManaCost:W
 Types:Instant
 A:SP$ ChooseSource | Cost$ W | Choices$ Card,Emblem | SubAbility$ DBEffect | StackDescription$ SpellDescription | SpellDescription$ Prevent the next 3 damage that would be dealt to any target this turn by a source of your choice. You gain 3 life.
 SVar:DBEffect:DB$ Effect | ValidTgts$ Creature,Player,Planeswalker | TgtPrompt$ Select any target to prevent damage to | ReplacementEffects$ GraceDamage | ForgetOnMoved$ Battlefield | RememberObjects$ Targeted | SubAbility$ DBGainLife
-SVar:GraceDamage:Event$ DamageDone | ValidTarget$ Creature.IsRemembered,Player.IsRemembered | ValidSource$ Card.ChosenCard,Emblem.ChosenCard | ReplaceWith$ GraceDmg | PreventionEffect$ True | Description$ Prevent the next 3 damage that would be dealt to any target this turn by a source of your choice. 
+SVar:GraceDamage:Event$ DamageDone | ValidTarget$ Card.IsRemembered,Player.IsRemembered | ValidSource$ Card.ChosenCard,Emblem.ChosenCard | ReplaceWith$ GraceDmg | PreventionEffect$ True | Description$ Prevent the next 3 damage that would be dealt to any target this turn by a source of your choice.
-SVar:GraceDmg:DB$ ReplaceDamage | VarName$ X
+SVar:GraceDmg:DB$ ReplaceDamage | Amount$ ShieldAmount
 SVar:DBGainLife:DB$ GainLife | LifeAmount$ 3 | SubAbility$ DBCleanup
 SVar:DBCleanup:DB$ Cleanup | ClearChosenCard$ True
-SVar:X:Number$3
+SVar:ShieldAmount:Number$3
 AI:RemoveDeck:All
 Oracle:Prevent the next 3 damage that would be dealt to any target this turn by a source of your choice. You gain 3 life.