Merge branch 'healinggrace' into 'master'

ReplaceDamage: new Effect for reducing Damage inside ReplacementEffect

Closes #268

See merge request core-developers/forge!427

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

@@ -126,6 +126,7 @@ public enum SpellApiToAi {
             .put(ApiType.Repeat, RepeatAi.class)
             .put(ApiType.RepeatEach, RepeatEachAi.class)
             .put(ApiType.ReplaceEffect, AlwaysPlayAi.class)
+            .put(ApiType.ReplaceDamage, AlwaysPlayAi.class)
             .put(ApiType.ReplaceSplitDamage, AlwaysPlayAi.class)
             .put(ApiType.RestartGame, RestartGameAi.class)
             .put(ApiType.Reveal, RevealAi.class)

forge-game/src/main/java/forge/game/ability/ApiType.java

@@ -124,6 +124,7 @@ public enum ApiType {
     Repeat (RepeatEffect.class),
     RepeatEach (RepeatEachEffect.class),
     ReplaceEffect (ReplaceEffect.class),
+    ReplaceDamage (ReplaceDamageEffect.class),
     ReplaceSplitDamage (ReplaceSplitDamageEffect.class),
     RestartGame (RestartGameEffect.class),
     Reveal (RevealEffect.class),

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

@@ -0,0 +1,79 @@
+package forge.game.ability.effects;
+
+import java.util.Map;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.collect.Maps;
+
+import forge.game.Game;
+import forge.game.ability.AbilityUtils;
+import forge.game.ability.SpellAbilityEffect;
+import forge.game.card.Card;
+import forge.game.replacement.ReplacementResult;
+import forge.game.spellability.SpellAbility;
+
+public class ReplaceDamageEffect extends SpellAbilityEffect {
+
+    @Override
+    public void resolve(SpellAbility sa) {
+        final Card card = sa.getHostCard();
+        final Game game = card.getGame();
+
+        // outside of Replacement Effect, unwanted result
+        if (!sa.getRootAbility().isReplacementAbility()) {
+            return;
+        }
+        
+        String varValue = sa.getParamOrDefault("VarName", "1");
+
+        @SuppressWarnings("unchecked")
+        Map<String, Object> originalParams = (Map<String, Object>) sa.getReplacingObject("OriginalParams");
+        Map<String, Object> params = Maps.newHashMap(originalParams);
+        
+        Integer dmg = (Integer) sa.getReplacingObject("DamageAmount");
+                
+        int prevent = AbilityUtils.calculateAmount(card, varValue, sa);
+        
+        // Currently it does reduce damage by amount, need second mode for Setting Damage
+        
+        if (prevent > 0) {
+            int n = Math.min(dmg, prevent);
+            dmg -= n;
+            prevent -= n;
+
+            if (card.getType().hasStringType("Effect") && prevent <= 0) {
+               game.getAction().exile(card, null);
+            } else if (!StringUtils.isNumeric(varValue)) {
+                card.setSVar(varValue, "Number$" + prevent);
+            }
+        }
+
+        // no damage for original target anymore
+        if (dmg <= 0) {
+            originalParams.put("ReplacementResult", ReplacementResult.Replaced);
+            return;
+        }
+        params.put("DamageAmount", dmg);
+
+
+        //try to call replacementHandler with new Params
+        ReplacementResult result = game.getReplacementHandler().run(params); 
+        switch (result) {
+        case NotReplaced:
+        case Updated: {
+            for (Map.Entry<String, Object> e : params.entrySet()) {
+                originalParams.put(e.getKey(), e.getValue());
+            }
+            // effect was updated
+            originalParams.put("ReplacementResult", ReplacementResult.Updated);
+            break;
+        }
+        default:
+            // effect was replaced with something else
+            originalParams.put("ReplacementResult", result);
+            break;
+        }
+    }
+
+}

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

@@ -0,0 +1,12 @@
+Name:Healing Grace
+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 | TgtPrompt$ Select target to prevent damage to | ReplacementEffects$ GraceDamage | SVars$ GraceDmg,X | References$ GraceDamage,GraceDmg,X | 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:GraceDmg:DB$ ReplaceDamage | VarName$ X | References$ X
+SVar:DBGainLife:DB$ GainLife | LifeAmount$ 3 | SubAbility$ DBCleanup
+SVar:DBCleanup:DB$ Cleanup | ClearChosenCard$ True
+SVar:X:Number$3
+SVar:RemAIDeck:True
+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.