Take weight into account when getting the tier of modifiers

src/data/mystery-encounters/encounters/clowning-around-encounter.ts

@@ -1,7 +1,7 @@
 import { EnemyPartyConfig, generateModifierType, initBattleWithEnemyConfig, leaveEncounterWithoutBattle, loadCustomMovesForEncounter, selectPokemonForOption, setEncounterRewards, transitionMysteryEncounterIntroVisuals } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
 import { trainerConfigs, TrainerPartyCompoundTemplate, TrainerPartyTemplate, } from "#app/data/trainer-config";
 import { ModifierTier } from "#app/modifier/modifier-tier";
-import { modifierTypes, PokemonHeldItemModifierType } from "#app/modifier/modifier-type";
+import { ModifierPoolType, modifierTypes, PokemonHeldItemModifierType } from "#app/modifier/modifier-type";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
 import { PartyMemberStrength } from "#enums/party-member-strength";
 import BattleScene from "#app/battle-scene";
@@ -280,7 +280,7 @@ export const ClowningAroundEncounter: MysteryEncounter =
           let numRogue = 0;
           items.filter(m => m.isTransferable && !(m instanceof BerryModifier))
             .forEach(m => {
-              const type = m.type.withTierFromPool();
+              const type = m.type.withTierFromPool(ModifierPoolType.PLAYER, party);
               const tier = type.tier ?? ModifierTier.ULTRA;
               if (type.id === "GOLDEN_EGG" || tier === ModifierTier.ROGUE) {
                 numRogue += m.stackCount;

src/data/mystery-encounters/utils/encounter-phase-utils.ts

@@ -418,7 +418,7 @@ export function generateModifierType(scene: BattleScene, modifier: () => Modifie
   // Populates item id and tier (order matters)
   result = result
     .withIdFromFunc(modifierTypes[modifierId])
-    .withTierFromPool();
+    .withTierFromPool(ModifierPoolType.PLAYER, scene.getParty());
 
   return result instanceof ModifierTypeGenerator ? result.generateType(scene.getParty(), pregenArgs) : result;
 }

src/modifier/modifier-type.ts

@@ -19,7 +19,7 @@ import { Unlockables } from "#app/system/unlockables";
 import { getVoucherTypeIcon, getVoucherTypeName, VoucherType } from "#app/system/voucher";
 import PartyUiHandler, { PokemonMoveSelectFilter, PokemonSelectFilter } from "#app/ui/party-ui-handler";
 import { getModifierTierTextTint } from "#app/ui/text";
-import { formatMoney, getEnumKeys, getEnumValues, IntegerHolder, NumberHolder, padInt, randSeedInt, randSeedItem } from "#app/utils";
+import { formatMoney, getEnumKeys, getEnumValues, IntegerHolder, isNullOrUndefined, NumberHolder, padInt, randSeedInt, randSeedItem } from "#app/utils";
 import { Abilities } from "#enums/abilities";
 import { BattlerTagType } from "#enums/battler-tag-type";
 import { BerryType } from "#enums/berry-type";
@@ -121,18 +121,41 @@ export class ModifierType {
    * Populates item tier for ModifierType instance
    * Tier is a necessary field for items that appear in player shop (determines the Pokeball visual they use)
    * To find the tier, this function performs a reverse lookup of the item type in modifier pools
+   * It checks the weight of the item and will use the first tier for which the weight is greater than 0
+   * This is to allow items to be in multiple item pools depending on the conditions, for example for events
+   * If all tiers have a weight of 0 for the item, the first tier where the item was found is used
    * @param poolType Default 'ModifierPoolType.PLAYER'. Which pool to lookup item tier from
+   * @param party optional. Needed to check the weight of modifiers with conditional weight (see {@linkcode WeightedModifierTypeWeightFunc})
+   *  if not provided or empty, the weight check will be ignored
+   * @param rerollCount Default `0`. Used to check the weight of modifiers with conditional weight (see {@linkcode WeightedModifierTypeWeightFunc})
    */
-  withTierFromPool(poolType: ModifierPoolType = ModifierPoolType.PLAYER): ModifierType {
+  withTierFromPool(poolType: ModifierPoolType = ModifierPoolType.PLAYER, party?: PlayerPokemon[], rerollCount: number = 0): ModifierType {
+    let defaultTier: undefined | ModifierTier;
     for (const tier of Object.values(getModifierPoolForType(poolType))) {
       for (const modifier of tier) {
         if (this.id === modifier.modifierType.id) {
-          this.tier = modifier.modifierType.tier;
-          return this;
+          let weight: number;
+          if (modifier.weight instanceof Function) {
+            weight = party ? (modifier.weight as Function)(party, rerollCount) : 0;
+          } else {
+            weight = modifier.weight as number;
+          }
+          if (weight > 0) {
+            this.tier = modifier.modifierType.tier;
+            return this;
+          } else if (!isNullOrUndefined(defaultTier)) {
+            // If weight is 0, keep track of the first tier where the item was found
+            defaultTier = modifier.modifierType.tier;
+          }
         }
       }
     }
 
+    // Didn't find a pool with weight > 0, fallback to first tier where the item was found, if any
+    if (defaultTier) {
+      this.tier = defaultTier;
+    }
+
     return this;
   }
 
@@ -2117,7 +2140,7 @@ export function getPlayerModifierTypeOptions(count: integer, party: PlayerPokemo
         // Populates item id and tier
         guaranteedMod = guaranteedMod
           .withIdFromFunc(modifierTypes[modifierId])
-          .withTierFromPool();
+          .withTierFromPool(ModifierPoolType.PLAYER, party);
 
         const modType = guaranteedMod instanceof ModifierTypeGenerator ? guaranteedMod.generateType(party) : guaranteedMod;
         if (modType) {
@@ -2186,7 +2209,7 @@ export function overridePlayerModifierTypeOptions(options: ModifierTypeOption[],
     }
 
     if (modifierType) {
-      options[i].type = modifierType.withIdFromFunc(modifierFunc).withTierFromPool();
+      options[i].type = modifierType.withIdFromFunc(modifierFunc).withTierFromPool(ModifierPoolType.PLAYER, party);
     }
   }
 }