From 411a236ce767c6c6bfbe3a12c79674426022a364 Mon Sep 17 00:00:00 2001
From: Pawkkie <61265402+Pawkkie@users.noreply.github.com>
Date: Wed, 19 Mar 2025 04:32:59 -0400
Subject: [PATCH] Fix AI using Scald / fire moves against frozen / frostbitten
 targets (#6442)

---
 include/battle_script_commands.h |  1 +
 src/battle_ai_main.c             | 15 +++++++++++++++
 src/battle_script_commands.c     |  3 +--
 test/battle/ai/ai.c              | 31 +++++++++++++++++++++++++++++--
 4 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/include/battle_script_commands.h b/include/battle_script_commands.h
index 1b72239d00..ead678e993 100644
--- a/include/battle_script_commands.h
+++ b/include/battle_script_commands.h
@@ -58,6 +58,7 @@ u8 GetFirstFaintedPartyIndex(u8 battlerId);
 bool32 IsMoveAffectedByParentalBond(u32 move, u32 battler);
 void SaveBattlerTarget(u32 battler);
 void SaveBattlerAttacker(u32 battler);
+bool32 CanBurnHitThaw(u16 move);
 
 extern void (* const gBattleScriptingCommandsTable[])(void);
 extern const struct StatFractions gAccuracyStageRatios[];
diff --git a/src/battle_ai_main.c b/src/battle_ai_main.c
index c7bf1b1bb7..1b0fe8b45a 100644
--- a/src/battle_ai_main.c
+++ b/src/battle_ai_main.c
@@ -854,6 +854,21 @@ static s32 AI_CheckBadMove(u32 battlerAtk, u32 battlerDef, u32 move, s32 score)
     if (gBattleStruct->battlerState[battlerDef].commandingDondozo)
         RETURN_SCORE_MINUS(20);
 
+    // Don't use anything but super effective thawing moves if target is frozen if any other attack available
+    if (((GetMoveType(move) == TYPE_FIRE && GetMovePower(move) != 0) || CanBurnHitThaw(move)) && effectiveness < UQ_4_12(2.0) && (gBattleMons[battlerDef].status1 & (STATUS1_FROSTBITE | STATUS1_FREEZE)))
+    {
+        u32 aiMove;
+        for (i = 0; i < MAX_MON_MOVES; i++)
+        {
+            aiMove = gBattleMons[battlerAtk].moves[i];
+            if (GetMoveType(aiMove) != TYPE_FIRE && !CanBurnHitThaw(aiMove) && GetMovePower(gBattleMons[battlerAtk].moves[i] != 0))
+            {
+                ADJUST_SCORE(-1);
+                break;
+            }
+        }
+    }
+
     if (effectiveness == UQ_4_12(0.0))
     {
         RETURN_SCORE_MINUS(20);
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index ac8b633b84..a1623c8b4b 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -340,7 +340,6 @@ void ApplyExperienceMultipliers(s32 *expAmount, u8 expGetterMonId, u8 faintedBat
 static void RemoveAllWeather(void);
 static void RemoveAllTerrains(void);
 static bool8 CanAbilityPreventStatLoss(u16 abilityDef);
-static bool8 CanBurnHitThaw(u16 move);
 static u32 GetNextTarget(u32 moveTarget, bool32 excludeCurrent);
 static void TryUpdateEvolutionTracker(u32 evolutionMethod, u32 upAmount, u16 usedMove);
 static void AccuracyCheck(bool32 recalcDragonDarts, const u8 *nextInstr, const u8 *failInstr, u16 move);
@@ -16794,7 +16793,7 @@ static bool8 CanAbilityPreventStatLoss(u16 abilityDef)
     return FALSE;
 }
 
-static bool8 CanBurnHitThaw(u16 move)
+bool32 CanBurnHitThaw(u16 move)
 {
     u8 i;
 
diff --git a/test/battle/ai/ai.c b/test/battle/ai/ai.c
index 3a72508c17..cc9582a4bd 100644
--- a/test/battle/ai/ai.c
+++ b/test/battle/ai/ai.c
@@ -846,6 +846,34 @@ AI_SINGLE_BATTLE_TEST("AI won't use Sucker Punch if it expects a move of the sam
     }
 }
 
+AI_SINGLE_BATTLE_TEST("AI won't use thawing moves if target is frozen unless it is super effective or it has no other options")
+{
+    u32 aiFlags = 0; u32 status = 0; u32 aiMove = 0;
+    PARAMETRIZE { status = STATUS1_FREEZE;      aiMove = MOVE_SCALD;    aiFlags = 0; }
+    PARAMETRIZE { status = STATUS1_FREEZE;      aiMove = MOVE_SCALD;    aiFlags = AI_FLAG_CHECK_BAD_MOVE; }
+    PARAMETRIZE { status = STATUS1_FROSTBITE;   aiMove = MOVE_SCALD;    aiFlags = 0; }
+    PARAMETRIZE { status = STATUS1_FROSTBITE;   aiMove = MOVE_SCALD;    aiFlags = AI_FLAG_CHECK_BAD_MOVE; }
+    PARAMETRIZE { status = STATUS1_FREEZE;      aiMove = MOVE_EMBER;    aiFlags = 0; }
+    PARAMETRIZE { status = STATUS1_FREEZE;      aiMove = MOVE_EMBER;    aiFlags = AI_FLAG_CHECK_BAD_MOVE; }
+    PARAMETRIZE { status = STATUS1_FROSTBITE;   aiMove = MOVE_EMBER;    aiFlags = 0; }
+    PARAMETRIZE { status = STATUS1_FROSTBITE;   aiMove = MOVE_EMBER;    aiFlags = AI_FLAG_CHECK_BAD_MOVE; }
+
+    GIVEN {
+        ASSUME(GetMoveType(MOVE_EMBER) == TYPE_FIRE);
+        ASSUME(GetMoveCategory(MOVE_TACKLE) == DAMAGE_CATEGORY_PHYSICAL);
+        ASSUME(GetMoveCategory(MOVE_WATER_GUN) == DAMAGE_CATEGORY_SPECIAL);
+        ASSUME(gMovesInfo[MOVE_SCALD].thawsUser == TRUE);
+        AI_FLAGS(aiFlags | AI_FLAG_CHECK_VIABILITY | AI_FLAG_TRY_TO_FAINT);
+        PLAYER(SPECIES_WOBBUFFET) { Moves(MOVE_TACKLE); Status1(status); }
+        OPPONENT(SPECIES_VULPIX) { Moves(MOVE_TACKLE, aiMove); }
+    } WHEN {
+        if (aiFlags == AI_FLAG_CHECK_BAD_MOVE)
+            TURN { MOVE(player, MOVE_TACKLE); EXPECT_MOVE(opponent, MOVE_TACKLE); }
+        else
+            TURN { MOVE(player, MOVE_TACKLE); EXPECT_MOVE(opponent, aiMove); }
+    }
+}
+
 AI_SINGLE_BATTLE_TEST("AI score for Mean Look will be decreased if target can escape")
 {
     GIVEN {
@@ -855,5 +883,4 @@ AI_SINGLE_BATTLE_TEST("AI score for Mean Look will be decreased if target can es
     } WHEN {
         TURN { SCORE_EQ_VAL(opponent, MOVE_MEAN_LOOK, 90); }
     }
-}
-
+}
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