From 59c16ff1cf1efda65873dbf425bb5073a39a8691 Mon Sep 17 00:00:00 2001
From: ghoulslash <pokevoyager0@gmail.com>
Date: Sat, 10 Jul 2021 16:41:41 -0600
Subject: [PATCH] AI_IsTerrainAffected checks

---
 include/battle_ai_util.h |  1 +
 src/battle_ai_main.c     | 15 +++++++--------
 src/battle_ai_util.c     |  9 +++++++++
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/include/battle_ai_util.h b/include/battle_ai_util.h
index db33a7ff1..d4df682c6 100644
--- a/include/battle_ai_util.h
+++ b/include/battle_ai_util.h
@@ -36,6 +36,7 @@ u32 AI_GetMoveAccuracy(u8 battlerAtk, u8 battlerDef, u16 atkAbility, u16 defAbil
 bool32 DoesBattlerIgnoreAbilityChecks(u16 atkAbility, u16 move);
 bool32 AI_WeatherHasEffect(void);
 bool32 CanAttackerFaintTarget(u8 battlerAtk, u8 battlerDef, u8 index, u8 numHits);
+bool32 AI_IsTerrainAffected(u8 battlerId, u32 flags);
 bool32 AI_IsBattlerGrounded(u8 battlerId);
 bool32 HasDamagingMove(u8 battlerId);
 bool32 HasDamagingMoveOfType(u8 battlerId, u8 type);
diff --git a/src/battle_ai_main.c b/src/battle_ai_main.c
index 5dc460f6a..81d97fcab 100644
--- a/src/battle_ai_main.c
+++ b/src/battle_ai_main.c
@@ -721,22 +721,21 @@ static s16 AI_CheckBadMove(u8 battlerAtk, u8 battlerDef, u16 move, s16 score)
         #endif
         
         // terrain & effect checks
-        if (gFieldStatuses & STATUS_FIELD_MISTY_TERRAIN)
+        if (AI_IsTerrainAffected(battlerDef, STATUS_FIELD_ELECTRIC_TERRAIN))
         {
             if (moveEffect == EFFECT_SLEEP || moveEffect == EFFECT_YAWN)
                 RETURN_SCORE_MINUS(20);
         }
         
-        if (gFieldStatuses & STATUS_FIELD_ELECTRIC_TERRAIN)
+        if (AI_IsTerrainAffected(battlerDef, STATUS_FIELD_MISTY_TERRAIN))
         {
             if (IsNonVolatileStatusMoveEffect(moveEffect) || IsConfusionMoveEffect(moveEffect))
                 RETURN_SCORE_MINUS(20);
         }
         
-        if (gFieldStatuses & STATUS_FIELD_PSYCHIC_TERRAIN)
+        if (AI_IsTerrainAffected(battlerAtk, STATUS_FIELD_PSYCHIC_TERRAIN) && atkPriority > 0)
         {
-            if (atkPriority > 0)
-                RETURN_SCORE_MINUS(20);
+            RETURN_SCORE_MINUS(20);
         }
     } // end check MOVE_TARGET_USER
     
@@ -1641,11 +1640,11 @@ static s16 AI_CheckBadMove(u8 battlerAtk, u8 battlerDef, u16 move, s16 score)
         case EFFECT_TEETER_DANCE:
             if (((gBattleMons[battlerDef].status2 & STATUS2_CONFUSION)
               || (!DoesBattlerIgnoreAbilityChecks(AI_DATA->atkAbility, move) && AI_DATA->defAbility == ABILITY_OWN_TEMPO)
-              || (IsBattlerGrounded(battlerDef) && (gFieldStatuses & STATUS_FIELD_MISTY_TERRAIN))
+              || (IsBattlerGrounded(battlerDef) && AI_IsTerrainAffected(battlerDef, STATUS_FIELD_MISTY_TERRAIN))
               || (DoesSubstituteBlockMove(battlerAtk, battlerDef, move)))
              && ((gBattleMons[AI_DATA->battlerDefPartner].status2 & STATUS2_CONFUSION)
               || (!DoesBattlerIgnoreAbilityChecks(AI_DATA->atkAbility, move) && AI_DATA->defPartnerAbility == ABILITY_OWN_TEMPO)
-              || (IsBattlerGrounded(AI_DATA->battlerDefPartner) && (gFieldStatuses & STATUS_FIELD_MISTY_TERRAIN))
+              || (IsBattlerGrounded(AI_DATA->battlerDefPartner) && AI_IsTerrainAffected(AI_DATA->battlerDefPartner, STATUS_FIELD_MISTY_TERRAIN))
               || (DoesSubstituteBlockMove(battlerAtk, AI_DATA->battlerDefPartner, move))))
             {
                score -= 10;
@@ -3836,7 +3835,7 @@ static s16 AI_CheckViability(u8 battlerAtk, u8 battlerDef, u16 move, s16 score)
             score++;
         break;
     case EFFECT_SAFEGUARD:
-        if (!(gFieldStatuses & STATUS_FIELD_MISTY_TERRAIN) || !IsBattlerGrounded(battlerAtk))
+        if (!AI_IsTerrainAffected(battlerAtk, STATUS_FIELD_MISTY_TERRAIN) || !IsBattlerGrounded(battlerAtk))
             score++;
         //if (CountUsablePartyMons(battlerDef) != 0)
             //score += 8;
diff --git a/src/battle_ai_util.c b/src/battle_ai_util.c
index 5695677bb..600921d97 100644
--- a/src/battle_ai_util.c
+++ b/src/battle_ai_util.c
@@ -1110,6 +1110,15 @@ u16 AI_GetHoldEffect(u32 battlerId)
     return holdEffect;
 }
 
+bool32 AI_IsTerrainAffected(u8 battlerId, u32 flags)
+{
+    if (gStatuses3[battlerId] & STATUS3_SEMI_INVULNERABLE)
+        return FALSE;
+    else if (!(gFieldStatuses & flags))
+        return FALSE;
+    return AI_IsBattlerGrounded(battlerId);
+}
+
 // different from IsBattlerGrounded in that we don't always know battler's hold effect or ability
 bool32 AI_IsBattlerGrounded(u8 battlerId)
 {