Implement Pickup ability

src/battle-scene.ts

@@ -1604,9 +1604,9 @@ export default class BattleScene extends Phaser.Scene {
 
 	tryTransferHeldItemModifier(itemModifier: PokemonHeldItemModifier, target: Pokemon, transferStack: boolean, playSound: boolean, instant?: boolean, ignoreUpdate?: boolean): Promise<boolean> {
 		return new Promise(resolve => {
-			const source = itemModifier.getPokemon(target.scene);
+			const source = itemModifier.pokemonId ? itemModifier.getPokemon(target.scene) : null;
 			const cancelled = new Utils.BooleanHolder(false);
-			applyAbAttrs(BlockItemTheftAbAttr, source, cancelled).then(() => {
+			Utils.executeIf(!!source, () => applyAbAttrs(BlockItemTheftAbAttr, source, cancelled)).then(() => {
 				if (cancelled.value)
 					return resolve(false);
 				const newItemModifier = itemModifier.clone() as PokemonHeldItemModifier;
@@ -1615,7 +1615,7 @@ export default class BattleScene extends Phaser.Scene {
 					&& (m as PokemonHeldItemModifier).matchType(itemModifier) && m.pokemonId === target.id, target.isPlayer()) as PokemonHeldItemModifier;
 				let removeOld = true;
 				if (matchingModifier) {
-					const maxStackCount = matchingModifier.getMaxStackCount(source.scene);
+					const maxStackCount = matchingModifier.getMaxStackCount(target.scene);
 					if (matchingModifier.stackCount >= maxStackCount)
 						return resolve(false);
 					const countTaken = transferStack ? Math.min(itemModifier.stackCount, maxStackCount - matchingModifier.stackCount) : 1;
@@ -1626,7 +1626,7 @@ export default class BattleScene extends Phaser.Scene {
 					newItemModifier.stackCount = 1;
 					removeOld = !(--itemModifier.stackCount);
 				}
-				if (!removeOld || this.removeModifier(itemModifier, !source.isPlayer())) {
+				if (!removeOld || !source || this.removeModifier(itemModifier, !source.isPlayer())) {
 					const addModifier = () => {
 						if (!matchingModifier || this.removeModifier(matchingModifier, !target.isPlayer())) {
 							if (target.isPlayer())
@@ -1636,7 +1636,7 @@ export default class BattleScene extends Phaser.Scene {
 						} else
 							resolve(false);
 					};
-					if (source.isPlayer() !== target.isPlayer() && !ignoreUpdate)
+					if (source && source.isPlayer() !== target.isPlayer() && !ignoreUpdate)
 						this.updateModifiers(source.isPlayer(), instant).then(() => addModifier());
 					else
 						addModifier();

src/battle.ts

@@ -9,6 +9,7 @@ import { TrainerType } from "./data/enums/trainer-type";
 import { GameMode } from "./game-mode";
 import { BattleSpec } from "./enums/battle-spec";
 import { PlayerGender } from "./system/game-data";
+import { PersistentModifier, PokemonHeldItemModifier } from "./modifier/modifier";
 
 export enum BattleType {
     WILD,
@@ -49,8 +50,9 @@ export default class Battle {
     public started: boolean;
     public turn: integer;
     public turnCommands: TurnCommands;
-    public playerParticipantIds: Set<integer> = new Set<integer>();
+    public playerParticipantIds: Set<integer>;
-    public escapeAttempts: integer = 0;
+    public postBattleLoot: PokemonHeldItemModifier[];
+    public escapeAttempts: integer;
     public lastMove: Moves;
     public battleSeed: string;
     private battleSeedState: string;
@@ -68,6 +70,9 @@ export default class Battle {
         this.seenEnemyPartyMemberIds = new Set<integer>();
         this.double = double;
         this.turn = 0;
+        this.playerParticipantIds = new Set<integer>();
+        this.postBattleLoot = [];
+        this.escapeAttempts = 0;
         this.started = false;
         this.battleSeed = Utils.randomString(16, true);
         this.battleSeedState = null;
@@ -123,6 +128,14 @@ export default class Battle {
         this.playerParticipantIds.delete(playerPokemon.id);
     }
 
+    addPostBattleLoot(enemyPokemon: EnemyPokemon): void {
+        this.postBattleLoot.push(...enemyPokemon.scene.findModifiers(m => m instanceof PokemonHeldItemModifier && m.pokemonId === enemyPokemon.id, false).map(i => {
+            const ret = i as PokemonHeldItemModifier;
+            ret.pokemonId = null;
+            return ret;
+        }));
+    }
+
     getBgmOverride(scene: BattleScene): string {
         const battlers = this.enemyParty.slice(0, this.getBattlerCount());
         if (this.battleType === BattleType.TRAINER) {

src/data/ability.ts

@@ -1020,6 +1020,31 @@ export class MaxMultiHitAbAttr extends AbAttr {
   }
 }
 
+export class PostBattleAbAttr extends AbAttr {
+  constructor() {
+    super(true);
+  }
+
+  applyPostBattle(pokemon: Pokemon, args: any[]): boolean {
+    return false;
+  }
+}
+
+export class PostBattleLootAbAttr extends PostBattleAbAttr {
+  applyPostBattle(pokemon: Pokemon, args: any[]): boolean {
+    const postBattleLoot = pokemon.scene.currentBattle.postBattleLoot;
+    if (postBattleLoot.length) {
+      const randItem = Utils.randSeedItem(postBattleLoot);
+      if (pokemon.scene.tryTransferHeldItemModifier(randItem, pokemon, false, true, true)) {
+        pokemon.scene.queueMessage(getPokemonMessage(pokemon, ` picked up\n${randItem.type.name}!`));
+        return true;
+      }
+    }
+
+    return false;
+  }
+}
+
 export class ReduceStatusEffectDurationAbAttr extends AbAttr {
   private statusEffect: StatusEffect;
 
@@ -1247,6 +1272,11 @@ export function applyCheckTrappedAbAttrs(attrType: { new(...args: any[]): CheckT
   return applyAbAttrsInternal<CheckTrappedAbAttr>(attrType, pokemon, attr => attr.applyCheckTrapped(pokemon, trapped, args), true);
 }
 
+export function applyPostBattleAbAttrs(attrType: { new(...args: any[]): PostBattleAbAttr },
+  pokemon: Pokemon, ...args: any[]): Promise<void> {
+  return applyAbAttrsInternal<PostBattleAbAttr>(attrType, pokemon, attr => attr.applyPostBattle(pokemon, args));
+}
+
 function canApplyAttr(pokemon: Pokemon, attr: AbAttr): boolean {
   const condition = attr.getCondition();
   return !condition || condition(pokemon);
@@ -1676,7 +1706,8 @@ export function initAbilities() {
       .attr(ProtectStatAbAttr, BattleStat.ACC),
     new Ability(Abilities.HYPER_CUTTER, "Hyper Cutter", "The Pokémon's proud of its powerful pincers. They prevent other Pokémon from lowering its Attack stat.", 3)
       .attr(ProtectStatAbAttr, BattleStat.ATK),
-    new Ability(Abilities.PICKUP, "Pickup (N)", "The Pokémon may pick up the item an opposing Pokémon used during a battle. It may pick up items outside of battle, too.", 3),
+    new Ability(Abilities.PICKUP, "Pickup", "The Pokémon may pick up the item an opposing Pokémon held during a battle.", 3)
+      .attr(PostBattleLootAbAttr),
     new Ability(Abilities.TRUANT, "Truant", "The Pokémon can't use a move if it had used a move on the previous turn.", 3)
       .attr(PostSummonAddBattlerTagAbAttr, BattlerTagType.TRUANT, 1, false),
     new Ability(Abilities.HUSTLE, "Hustle", "Boosts the Attack stat, but lowers accuracy.", 3)

src/phases.ts

@@ -30,7 +30,7 @@ import { Weather, WeatherType, getRandomWeatherType, getWeatherDamageMessage, ge
 import { TempBattleStat } from "./data/temp-battle-stat";
 import { ArenaTagSide, ArenaTrapTag, MistTag, TrickRoomTag } from "./data/arena-tag";
 import { ArenaTagType } from "./data/enums/arena-tag-type";
-import { Abilities, CheckTrappedAbAttr, IgnoreOpponentStatChangesAbAttr, PostAttackAbAttr, PostDefendAbAttr, PostSummonAbAttr, PostTurnAbAttr, PostWeatherLapseAbAttr, PreSwitchOutAbAttr, PreWeatherDamageAbAttr, ProtectStatAbAttr, RunSuccessAbAttr, StatChangeMultiplierAbAttr, SuppressWeatherEffectAbAttr, SyncEncounterNatureAbAttr, applyAbAttrs, applyCheckTrappedAbAttrs, applyPostAttackAbAttrs, applyPostDefendAbAttrs, applyPostSummonAbAttrs, applyPostTurnAbAttrs, applyPostWeatherLapseAbAttrs, applyPreStatChangeAbAttrs, applyPreSwitchOutAbAttrs, applyPreWeatherEffectAbAttrs } from "./data/ability";
+import { Abilities, CheckTrappedAbAttr, IgnoreOpponentStatChangesAbAttr, PostAttackAbAttr, PostBattleAbAttr, PostDefendAbAttr, PostSummonAbAttr, PostTurnAbAttr, PostWeatherLapseAbAttr, PreSwitchOutAbAttr, PreWeatherDamageAbAttr, ProtectStatAbAttr, RunSuccessAbAttr, StatChangeMultiplierAbAttr, SuppressWeatherEffectAbAttr, SyncEncounterNatureAbAttr, applyAbAttrs, applyCheckTrappedAbAttrs, applyPostAttackAbAttrs, applyPostBattleAbAttrs, applyPostDefendAbAttrs, applyPostSummonAbAttrs, applyPostTurnAbAttrs, applyPostWeatherLapseAbAttrs, applyPreStatChangeAbAttrs, applyPreSwitchOutAbAttrs, applyPreWeatherEffectAbAttrs } from "./data/ability";
 import { Unlockables, getUnlockableName } from "./system/unlockables";
 import { getBiomeKey } from "./field/arena";
 import { BattleType, BattlerIndex, TurnCommand } from "./battle";
@@ -1772,6 +1772,9 @@ export class BattleEndPhase extends BattlePhase {
         pokemon.resetBattleSummonData();
     }
 
+    for (let pokemon of this.scene.getParty())
+      applyPostBattleAbAttrs(PostBattleAbAttr, pokemon);
+
     this.scene.clearEnemyHeldItemModifiers();
 
     const lapsingModifiers = this.scene.findModifiers(m => m instanceof LapsingPersistentModifier || m instanceof LapsingPokemonHeldItemModifier) as (LapsingPersistentModifier | LapsingPokemonHeldItemModifier)[];
@@ -2688,6 +2691,8 @@ export class FaintPhase extends PokemonPhase {
           pokemon.trySetStatus(StatusEffect.FAINT);
           if (pokemon.isPlayer())
             this.scene.currentBattle.removeFaintedParticipant(pokemon as PlayerPokemon);
+          else
+            this.scene.currentBattle.addPostBattleLoot(pokemon as EnemyPokemon);
           this.scene.field.remove(pokemon);
           this.end();
         }