From d4ee65f9373e84b0fa4016ec6f40e8f8eb6e93e5 Mon Sep 17 00:00:00 2001
From: Agetian <stavdev@mail.ru>
Date: Wed, 5 Dec 2018 16:44:20 +0300
Subject: [PATCH] - Fixed the AI trying to gang-block and kill an attacker
 which can't be killed because combat damage to it would be prevented. - Added
 a couple AI hints to Ajani's Welcome.

---
 .../src/main/java/forge/ai/AiBlockController.java     | 11 +++++++++++
 .../src/main/java/forge/ai/ComputerUtilCombat.java    |  2 +-
 forge-gui/res/cardsfolder/a/ajanis_welcome.txt        |  2 ++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/forge-ai/src/main/java/forge/ai/AiBlockController.java b/forge-ai/src/main/java/forge/ai/AiBlockController.java
index d674d866cec..e948d3cebfc 100644
--- a/forge-ai/src/main/java/forge/ai/AiBlockController.java
+++ b/forge-ai/src/main/java/forge/ai/AiBlockController.java
@@ -22,6 +22,7 @@ import com.google.common.base.Predicates;
 import forge.card.CardStateName;
 import forge.game.CardTraitBase;
 import forge.game.GameEntity;
+import forge.game.GlobalRuleChange;
 import forge.game.card.*;
 import forge.game.combat.Combat;
 import forge.game.combat.CombatUtil;
@@ -771,6 +772,16 @@ public class AiBlockController {
             blockers = getPossibleBlockers(combat, attacker, blockersLeft, false);
             blockers.removeAll(combat.getBlockers(attacker));
 
+            // Don't add any blockers that won't kill the attacker because the damage would be prevented by a static effect
+            if (!ai.getGame().getStaticEffects().getGlobalRuleChange(GlobalRuleChange.noPrevention)) {
+                blockers = CardLists.filter(blockers, new Predicate<Card>() {
+                    @Override
+                    public boolean apply(Card blocker) {
+                        return !ComputerUtilCombat.isCombatDamagePrevented(blocker, attacker, blocker.getNetCombatDamage());
+                    }
+                });
+            }
+
             // Try to use safe blockers first
             if (blockers.size() > 0) {
                 safeBlockers = getSafeBlockers(combat, attacker, blockers);
diff --git a/forge-ai/src/main/java/forge/ai/ComputerUtilCombat.java b/forge-ai/src/main/java/forge/ai/ComputerUtilCombat.java
index 897be168b58..a6f3475e5f9 100644
--- a/forge-ai/src/main/java/forge/ai/ComputerUtilCombat.java
+++ b/forge-ai/src/main/java/forge/ai/ComputerUtilCombat.java
@@ -2560,7 +2560,7 @@ public class ComputerUtilCombat {
         return original;
     }
 
-    private static boolean isCombatDamagePrevented(final Card attacker, final GameEntity target, final int damage) {
+    public static boolean isCombatDamagePrevented(final Card attacker, final GameEntity target, final int damage) {
         final Game game = attacker.getGame();
 
         // first try to replace the damage
diff --git a/forge-gui/res/cardsfolder/a/ajanis_welcome.txt b/forge-gui/res/cardsfolder/a/ajanis_welcome.txt
index 21dd08c4849..a8527351f95 100644
--- a/forge-gui/res/cardsfolder/a/ajanis_welcome.txt
+++ b/forge-gui/res/cardsfolder/a/ajanis_welcome.txt
@@ -3,4 +3,6 @@ ManaCost:W
 Types:Enchantment
 T:Mode$ ChangesZone | TriggerZones$ Battlefield | ValidCard$ Creature.YouCtrl | Origin$ Any | Destination$ Battlefield | Execute$ TrigGainLife | TriggerDescription$ Whenever a creature enters the battlefield under your control, you gain 1 life.
 SVar:TrigGainLife:DB$ GainLife | Defined$ You | LifeAmount$ 1
+SVar:PlayMain1:TRUE
+SVar:AIPriorityModifier:9
 Oracle:Whenever a creature enters the battlefield under your control, you gain 1 life.
\ No newline at end of file