From 46525c1bac523d59073308137b91608384d2a6c6 Mon Sep 17 00:00:00 2001
From: Zedarflight <quinn.pearce@gmail.com>
Date: Fri, 10 May 2024 18:39:49 -0700
Subject: [PATCH] implemented Tera Shell

---
 src/data/ability.ts  | 25 +++++++++++++++++++++++--
 src/field/pokemon.ts |  3 ++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/data/ability.ts b/src/data/ability.ts
index 8a244b85b..f99099f7e 100644
--- a/src/data/ability.ts
+++ b/src/data/ability.ts
@@ -300,6 +300,27 @@ export class ReceivedMoveDamageMultiplierAbAttr extends PreDefendAbAttr {
   }
 }
 
+export class ReceivedMoveEffectivenessAbAttr extends PreDefendAbAttr {
+  protected condition: PokemonDefendCondition;
+  private newType: number;
+
+  constructor(condition: PokemonDefendCondition, newType: number) {
+    super();
+
+    this.condition = condition;
+    this.newType = newType;
+  }
+
+  applyPreDefend(pokemon: Pokemon, passive: boolean, attacker: Pokemon, move: PokemonMove, cancelled: Utils.BooleanHolder, args: any[]): boolean {
+    if (this.condition(pokemon, attacker, move.getMove())) {
+      (args[0] as Utils.NumberHolder).value = this.newType; // Set new effectiveness value.
+      return true;
+    }
+
+    return false;
+  }
+}
+
 export class ReceivedTypeDamageMultiplierAbAttr extends ReceivedMoveDamageMultiplierAbAttr {
   constructor(moveType: Type, powerMultiplier: number) {
     super((user, target, move) => move.type === moveType, powerMultiplier);
@@ -3705,8 +3726,8 @@ export function initAbilities() {
     new Ability(Abilities.TERA_SHELL, 9)
       .attr(UncopiableAbilityAbAttr)
       .attr(UnswappableAbilityAbAttr)
-      .ignorable()
-      .unimplemented(),
+      .attr(ReceivedMoveEffectivenessAbAttr,(target, user, move) => target.getHpRatio() === 1 && target.getAttackTypeEffectiveness(move.type, user) > 0, 0.5)
+      .ignorable(),
     new Ability(Abilities.TERAFORM_ZERO, 9)
       .attr(UncopiableAbilityAbAttr)
       .attr(UnswappableAbilityAbAttr)
diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index 8afff1b27..028b7dd3e 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -27,7 +27,7 @@ import { TempBattleStat } from '../data/temp-battle-stat';
 import { ArenaTagSide, WeakenMoveScreenTag, WeakenMoveTypeTag } from '../data/arena-tag';
 import { ArenaTagType } from "../data/enums/arena-tag-type";
 import { Biome } from "../data/enums/biome";
-import { Ability, AbAttr, BattleStatMultiplierAbAttr, BlockCritAbAttr, BonusCritAbAttr, BypassBurnDamageReductionAbAttr, FieldPriorityMoveImmunityAbAttr, FieldVariableMovePowerAbAttr, IgnoreOpponentStatChangesAbAttr, MoveImmunityAbAttr, MoveTypeChangeAttr, NonSuperEffectiveImmunityAbAttr, PreApplyBattlerTagAbAttr, PreDefendFullHpEndureAbAttr, ReceivedMoveDamageMultiplierAbAttr, ReduceStatusEffectDurationAbAttr, StabBoostAbAttr, StatusEffectImmunityAbAttr, TypeImmunityAbAttr, VariableMovePowerAbAttr, VariableMoveTypeAbAttr, WeightMultiplierAbAttr, allAbilities, applyAbAttrs, applyBattleStatMultiplierAbAttrs, applyPostDefendAbAttrs, applyPreApplyBattlerTagAbAttrs, applyPreAttackAbAttrs, applyPreDefendAbAttrs, applyPreSetStatusAbAttrs, UnsuppressableAbilityAbAttr, SuppressFieldAbilitiesAbAttr, NoFusionAbilityAbAttr, MultCritAbAttr, IgnoreTypeImmunityAbAttr } from '../data/ability';
+import { Ability, AbAttr, BattleStatMultiplierAbAttr, BlockCritAbAttr, BonusCritAbAttr, BypassBurnDamageReductionAbAttr, FieldPriorityMoveImmunityAbAttr, FieldVariableMovePowerAbAttr, IgnoreOpponentStatChangesAbAttr, MoveImmunityAbAttr, MoveTypeChangeAttr, NonSuperEffectiveImmunityAbAttr, PreApplyBattlerTagAbAttr, PreDefendFullHpEndureAbAttr, ReceivedMoveDamageMultiplierAbAttr, ReceivedMoveEffectivenessAbAttr, ReduceStatusEffectDurationAbAttr, StabBoostAbAttr, StatusEffectImmunityAbAttr, TypeImmunityAbAttr, VariableMovePowerAbAttr, VariableMoveTypeAbAttr, WeightMultiplierAbAttr, allAbilities, applyAbAttrs, applyBattleStatMultiplierAbAttrs, applyPostDefendAbAttrs, applyPreApplyBattlerTagAbAttrs, applyPreAttackAbAttrs, applyPreDefendAbAttrs, applyPreSetStatusAbAttrs, UnsuppressableAbilityAbAttr, SuppressFieldAbilitiesAbAttr, NoFusionAbilityAbAttr, MultCritAbAttr, IgnoreTypeImmunityAbAttr } from '../data/ability';
 import { Abilities } from "#app/data/enums/abilities";
 import PokemonData from '../system/pokemon-data';
 import Battle, { BattlerIndex } from '../battle';
@@ -1318,6 +1318,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
         this.scene.getField(true).map(p => applyPreAttackAbAttrs(FieldVariableMovePowerAbAttr, this, source, battlerMove, power));
 
         applyPreDefendAbAttrs(ReceivedMoveDamageMultiplierAbAttr, this, source, battlerMove, cancelled, power);
+        applyPreDefendAbAttrs(ReceivedMoveEffectivenessAbAttr, this, source, battlerMove, cancelled, typeMultiplier);
 
         power.value *= typeChangeMovePowerMultiplier.value;