From c2afac8b02a6ca793263c68dc5a93bf10386b7bc Mon Sep 17 00:00:00 2001
From: Mumble <171087428+frutescens@users.noreply.github.com>
Date: Sat, 16 Nov 2024 15:32:05 -0800
Subject: [PATCH] [Bug] Moved code preventing MBH's transfer to post modifier
 generation  (#4858)

* Moved code preventing MBH's transfer to after enemy modifiers were generated.

* Removed unnecessary !

* Removed unnecessary ?

* Created a new enum and functions for retrieving final bosses.

* Moved isBattleClassicFinalBoss to game-mode.ts and reverted battle.ts

* Preventing item transfer with tryTransferModifier instead

* Added filtering to modifier-retrieve methods.

* Revised logic in tryTransferHeldItemModifier

* Adding what works to the game even though it's not the best.

* Added comments

* Removing past changes to files.

* Added check for Classic Final Boss.

---------

Co-authored-by: frutescens <info@laptop>
---
 src/game-mode.ts              |  7 +++++++
 src/phases/encounter-phase.ts | 13 +++++++++----
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/game-mode.ts b/src/game-mode.ts
index 0f997bf651e..3f12c5b056e 100644
--- a/src/game-mode.ts
+++ b/src/game-mode.ts
@@ -230,6 +230,13 @@ export class GameMode implements GameModeConfig {
     return waveIndex % 10 === 0;
   }
 
+  /**
+   * @returns `true` if the current battle is against classic mode's final boss
+   */
+  isBattleClassicFinalBoss(waveIndex: number): boolean {
+    return (this.modeId === GameModes.CLASSIC || this.modeId === GameModes.CHALLENGE) && this.isWaveFinal(waveIndex);
+  }
+
   /**
      * Every 50 waves of an Endless mode is a boss
      * At this time it is paradox pokemon
diff --git a/src/phases/encounter-phase.ts b/src/phases/encounter-phase.ts
index e58500c934e..03126ba81bb 100644
--- a/src/phases/encounter-phase.ts
+++ b/src/phases/encounter-phase.ts
@@ -141,10 +141,6 @@ export class EncounterPhase extends BattlePhase {
         } else if (!(battle.waveIndex % 1000)) {
           enemyPokemon.formIndex = 1;
           enemyPokemon.updateScale();
-          const bossMBH = this.scene.findModifier(m => m instanceof TurnHeldItemTransferModifier && m.pokemonId === enemyPokemon.id, false) as TurnHeldItemTransferModifier;
-          this.scene.removeModifier(bossMBH!);
-          bossMBH?.setTransferrableFalse();
-          this.scene.addEnemyModifier(bossMBH!);
         }
       }
 
@@ -443,6 +439,15 @@ export class EncounterPhase extends BattlePhase {
       if (enemyPokemon.isShiny()) {
         this.scene.unshiftPhase(new ShinySparklePhase(this.scene, BattlerIndex.ENEMY + e));
       }
+      /** This sets Eternatus' held item to be untransferrable, preventing it from being stolen  */
+      if (enemyPokemon.species.speciesId === Species.ETERNATUS && (this.scene.gameMode.isBattleClassicFinalBoss(this.scene.currentBattle.waveIndex) || this.scene.gameMode.isEndlessMajorBoss(this.scene.currentBattle.waveIndex))) {
+        const enemyMBH = this.scene.findModifier(m => m instanceof TurnHeldItemTransferModifier, false) as TurnHeldItemTransferModifier;
+        if (enemyMBH) {
+          this.scene.removeModifier(enemyMBH, true);
+          enemyMBH.setTransferrableFalse();
+          this.scene.addEnemyModifier(enemyMBH);
+        }
+      }
     });
 
     if (![ BattleType.TRAINER, BattleType.MYSTERY_ENCOUNTER ].includes(this.scene.currentBattle.battleType)) {