pokerogue/src/field/arena.ts

import BattleScene from "#app/battle-scene";
import { biomePokemonPools, BiomePoolTier, BiomeTierTrainerPools, biomeTrainerPools, PokemonPools } from "#app/data/balance/biomes";
import { Constructor } from "#app/utils";
import * as Utils from "#app/utils";
import PokemonSpecies, { getPokemonSpecies } from "#app/data/pokemon-species";
import { getTerrainClearMessage, getTerrainStartMessage, getWeatherClearMessage, getWeatherStartMessage, Weather, WeatherType } from "#app/data/weather";
import { CommonAnim } from "#app/data/battle-anims";
import { Type } from "#app/data/type";
import Move from "#app/data/move";
import { ArenaTag, ArenaTagSide, ArenaTrapTag, getArenaTag } from "#app/data/arena-tag";
import { BattlerIndex } from "#app/battle";
import { Terrain, TerrainType } from "#app/data/terrain";
import { applyPostTerrainChangeAbAttrs, applyPostWeatherChangeAbAttrs, PostTerrainChangeAbAttr, PostWeatherChangeAbAttr } from "#app/data/ability";
import Pokemon from "#app/field/pokemon";
import Overrides from "#app/overrides";
import { TagAddedEvent, TagRemovedEvent, TerrainChangedEvent, WeatherChangedEvent } from "#app/events/arena";
import { ArenaTagType } from "#enums/arena-tag-type";
import { Biome } from "#enums/biome";
import { Moves } from "#enums/moves";
import { Species } from "#enums/species";
import { TimeOfDay } from "#enums/time-of-day";
import { TrainerType } from "#enums/trainer-type";
import { Abilities } from "#enums/abilities";
import { SpeciesFormChangeRevertWeatherFormTrigger, SpeciesFormChangeWeatherTrigger } from "#app/data/pokemon-forms";
import { CommonAnimPhase } from "#app/phases/common-anim-phase";
import { ShowAbilityPhase } from "#app/phases/show-ability-phase";

export class Arena {
  public scene: BattleScene;
  public biomeType: Biome;
  public weather: Weather | null;
  public terrain: Terrain | null;
  public tags: ArenaTag[];
  public bgm: string;
  public ignoreAbilities: boolean;
  public ignoringEffectSource: BattlerIndex | null;

  private lastTimeOfDay: TimeOfDay;

  private pokemonPool: PokemonPools;
  private trainerPool: BiomeTierTrainerPools;

  public readonly eventTarget: EventTarget = new EventTarget();

  constructor(scene: BattleScene, biome: Biome, bgm: string) {
    this.scene = scene;
    this.biomeType = biome;
    this.tags = [];
    this.bgm = bgm;
    this.trainerPool = biomeTrainerPools[biome];
    this.updatePoolsForTimeOfDay();
  }

  init() {
    const biomeKey = getBiomeKey(this.biomeType);

    this.scene.arenaPlayer.setBiome(this.biomeType);
    this.scene.arenaPlayerTransition.setBiome(this.biomeType);
    this.scene.arenaEnemy.setBiome(this.biomeType);
    this.scene.arenaNextEnemy.setBiome(this.biomeType);
    this.scene.arenaBg.setTexture(`${biomeKey}_bg`);
    this.scene.arenaBgTransition.setTexture(`${biomeKey}_bg`);

    // Redo this on initialize because during save/load the current wave isn't always
    // set correctly during construction
    this.updatePoolsForTimeOfDay();
  }

  updatePoolsForTimeOfDay(): void {
    const timeOfDay = this.getTimeOfDay();
    if (timeOfDay !== this.lastTimeOfDay) {
      this.pokemonPool = {};
      for (const tier of Object.keys(biomePokemonPools[this.biomeType])) {
        this.pokemonPool[tier] = Object.assign([], biomePokemonPools[this.biomeType][tier][TimeOfDay.ALL]).concat(biomePokemonPools[this.biomeType][tier][timeOfDay]);
      }
      this.lastTimeOfDay = timeOfDay;
    }
  }

  randomSpecies(waveIndex: integer, level: integer, attempt?: integer, luckValue?: integer, isBoss?: boolean): PokemonSpecies {
    const overrideSpecies = this.scene.gameMode.getOverrideSpecies(waveIndex);
    if (overrideSpecies) {
      return overrideSpecies;
    }
    const isBossSpecies = !!this.scene.getEncounterBossSegments(waveIndex, level) && !!this.pokemonPool[BiomePoolTier.BOSS].length
      && (this.biomeType !== Biome.END || this.scene.gameMode.isClassic || this.scene.gameMode.isWaveFinal(waveIndex));
    const randVal = isBossSpecies ? 64 : 512;
    // luck influences encounter rarity
    let luckModifier = 0;
    if (typeof luckValue !== "undefined") {
      luckModifier = luckValue * (isBossSpecies ? 0.5 : 2);
    }
    const tierValue = Utils.randSeedInt(randVal - luckModifier);
    let tier = !isBossSpecies
      ? tierValue >= 156 ? BiomePoolTier.COMMON : tierValue >= 32 ? BiomePoolTier.UNCOMMON : tierValue >= 6 ? BiomePoolTier.RARE : tierValue >= 1 ? BiomePoolTier.SUPER_RARE : BiomePoolTier.ULTRA_RARE
      : tierValue >= 20 ? BiomePoolTier.BOSS : tierValue >= 6 ? BiomePoolTier.BOSS_RARE : tierValue >= 1 ? BiomePoolTier.BOSS_SUPER_RARE : BiomePoolTier.BOSS_ULTRA_RARE;
    console.log(BiomePoolTier[tier]);
    while (!this.pokemonPool[tier].length) {
      console.log(`Downgraded rarity tier from ${BiomePoolTier[tier]} to ${BiomePoolTier[tier - 1]}`);
      tier--;
    }
    const tierPool = this.pokemonPool[tier];
    let ret: PokemonSpecies;
    let regen = false;
    if (!tierPool.length) {
      ret = this.scene.randomSpecies(waveIndex, level);
    } else {
      const entry = tierPool[Utils.randSeedInt(tierPool.length)];
      let species: Species;
      if (typeof entry === "number") {
        species = entry as Species;
      } else {
        const levelThresholds = Object.keys(entry);
        for (let l = levelThresholds.length - 1; l >= 0; l--) {
          const levelThreshold = parseInt(levelThresholds[l]);
          if (level >= levelThreshold) {
            const speciesIds = entry[levelThreshold];
            if (speciesIds.length > 1) {
              species = speciesIds[Utils.randSeedInt(speciesIds.length)];
            } else {
              species = speciesIds[0];
            }
            break;
          }
        }
      }

      ret = getPokemonSpecies(species!);

      if (ret.subLegendary || ret.legendary || ret.mythical) {
        switch (true) {
        case (ret.baseTotal >= 720):
          regen = level < 90;
          break;
        case (ret.baseTotal >= 670):
          regen = level < 70;
          break;
        case (ret.baseTotal >= 580):
          regen = level < 50;
          break;
        default:
          regen = level < 30;
          break;
        }
      }
    }

    if (regen && (attempt || 0) < 10) {
      console.log("Incompatible level: regenerating...");
      return this.randomSpecies(waveIndex, level, (attempt || 0) + 1);
    }

    const newSpeciesId = ret.getWildSpeciesForLevel(level, true, isBoss ?? isBossSpecies, this.scene.gameMode);
    if (newSpeciesId !== ret.speciesId) {
      console.log("Replaced", Species[ret.speciesId], "with", Species[newSpeciesId]);
      ret = getPokemonSpecies(newSpeciesId);
    }
    return ret;
  }

  randomTrainerType(waveIndex: integer, isBoss: boolean = false): TrainerType {
    const isTrainerBoss = !!this.trainerPool[BiomePoolTier.BOSS].length
      && (this.scene.gameMode.isTrainerBoss(waveIndex, this.biomeType, this.scene.offsetGym) || isBoss);
    console.log(isBoss, this.trainerPool);
    const tierValue = Utils.randSeedInt(!isTrainerBoss ? 512 : 64);
    let tier = !isTrainerBoss
      ? tierValue >= 156 ? BiomePoolTier.COMMON : tierValue >= 32 ? BiomePoolTier.UNCOMMON : tierValue >= 6 ? BiomePoolTier.RARE : tierValue >= 1 ? BiomePoolTier.SUPER_RARE : BiomePoolTier.ULTRA_RARE
      : tierValue >= 20 ? BiomePoolTier.BOSS : tierValue >= 6 ? BiomePoolTier.BOSS_RARE : tierValue >= 1 ? BiomePoolTier.BOSS_SUPER_RARE : BiomePoolTier.BOSS_ULTRA_RARE;
    console.log(BiomePoolTier[tier]);
    while (tier && !this.trainerPool[tier].length) {
      console.log(`Downgraded trainer rarity tier from ${BiomePoolTier[tier]} to ${BiomePoolTier[tier - 1]}`);
      tier--;
    }
    const tierPool = this.trainerPool[tier] || [];
    return !tierPool.length ? TrainerType.BREEDER : tierPool[Utils.randSeedInt(tierPool.length)];
  }

  getSpeciesFormIndex(species: PokemonSpecies): integer {
    switch (species.speciesId) {
    case Species.BURMY:
    case Species.WORMADAM:
      switch (this.biomeType) {
      case Biome.BEACH:
        return 1;
      case Biome.SLUM:
        return 2;
      }
      break;
    case Species.ROTOM:
      switch (this.biomeType) {
      case Biome.VOLCANO:
        return 1;
      case Biome.SEA:
        return 2;
      case Biome.ICE_CAVE:
        return 3;
      case Biome.MOUNTAIN:
        return 4;
      case Biome.TALL_GRASS:
        return 5;
      }
      break;
    case Species.LYCANROC:
      const timeOfDay = this.getTimeOfDay();
      switch (timeOfDay) {
      case TimeOfDay.DAY:
      case TimeOfDay.DAWN:
        return 0;
      case TimeOfDay.DUSK:
        return 2;
      case TimeOfDay.NIGHT:
        return 1;
      }
      break;
    }

    return 0;
  }

  getTypeForBiome() {
    switch (this.biomeType) {
    case Biome.TOWN:
    case Biome.PLAINS:
    case Biome.METROPOLIS:
      return Type.NORMAL;
    case Biome.GRASS:
    case Biome.TALL_GRASS:
      return Type.GRASS;
    case Biome.FOREST:
    case Biome.JUNGLE:
      return Type.BUG;
    case Biome.SLUM:
    case Biome.SWAMP:
      return Type.POISON;
    case Biome.SEA:
    case Biome.BEACH:
    case Biome.LAKE:
    case Biome.SEABED:
      return Type.WATER;
    case Biome.MOUNTAIN:
      return Type.FLYING;
    case Biome.BADLANDS:
      return Type.GROUND;
    case Biome.CAVE:
    case Biome.DESERT:
      return Type.ROCK;
    case Biome.ICE_CAVE:
    case Biome.SNOWY_FOREST:
      return Type.ICE;
    case Biome.MEADOW:
    case Biome.FAIRY_CAVE:
    case Biome.ISLAND:
      return Type.FAIRY;
    case Biome.POWER_PLANT:
      return Type.ELECTRIC;
    case Biome.VOLCANO:
      return Type.FIRE;
    case Biome.GRAVEYARD:
    case Biome.TEMPLE:
      return Type.GHOST;
    case Biome.DOJO:
    case Biome.CONSTRUCTION_SITE:
      return Type.FIGHTING;
    case Biome.FACTORY:
    case Biome.LABORATORY:
      return Type.STEEL;
    case Biome.RUINS:
    case Biome.SPACE:
      return Type.PSYCHIC;
    case Biome.WASTELAND:
    case Biome.END:
      return Type.DRAGON;
    case Biome.ABYSS:
      return Type.DARK;
    default:
      return Type.UNKNOWN;
    }
  }

  getBgTerrainColorRatioForBiome(): number {
    switch (this.biomeType) {
    case Biome.SPACE:
      return 1;
    case Biome.END:
      return 0;
    }

    return 131 / 180;
  }

  /**
   * Sets weather to the override specified in overrides.ts
   * @param weather new {@linkcode WeatherType} to set
   * @returns true to force trySetWeather to return true
   */
  trySetWeatherOverride(weather: WeatherType): boolean {
    this.weather = new Weather(weather, 0);
    this.scene.unshiftPhase(new CommonAnimPhase(this.scene, undefined, undefined, CommonAnim.SUNNY + (weather - 1)));
    this.scene.queueMessage(getWeatherStartMessage(weather)!); // TODO: is this bang correct?
    return true;
  }

  /**
   * Attempts to set a new weather to the battle
   * @param weather {@linkcode WeatherType} new {@linkcode WeatherType} to set
   * @param hasPokemonSource boolean if the new weather is from a pokemon
   * @returns true if new weather set, false if no weather provided or attempting to set the same weather as currently in use
   */
  trySetWeather(weather: WeatherType, hasPokemonSource: boolean): boolean {
    if (Overrides.WEATHER_OVERRIDE) {
      return this.trySetWeatherOverride(Overrides.WEATHER_OVERRIDE);
    }

    if (this.weather?.weatherType === (weather || undefined)) {
      return false;
    }

    const oldWeatherType = this.weather?.weatherType || WeatherType.NONE;

    this.weather = weather ? new Weather(weather, hasPokemonSource ? 5 : 0) : null;
    this.eventTarget.dispatchEvent(new WeatherChangedEvent(oldWeatherType, this.weather?.weatherType!, this.weather?.turnsLeft!)); // TODO: is this bang correct?

    if (this.weather) {
      this.scene.unshiftPhase(new CommonAnimPhase(this.scene, undefined, undefined, CommonAnim.SUNNY + (weather - 1), true));
      this.scene.queueMessage(getWeatherStartMessage(weather)!); // TODO: is this bang correct?
    } else {
      this.scene.queueMessage(getWeatherClearMessage(oldWeatherType)!); // TODO: is this bang correct?
    }

    this.scene.getField(true).filter(p => p.isOnField()).map(pokemon => {
      pokemon.findAndRemoveTags(t => "weatherTypes" in t && !(t.weatherTypes as WeatherType[]).find(t => t === weather));
      applyPostWeatherChangeAbAttrs(PostWeatherChangeAbAttr, pokemon, weather);
    });

    return true;
  }

  /**
   * Function to trigger all weather based form changes
   */
  triggerWeatherBasedFormChanges(): void {
    this.scene.getField(true).forEach( p => {
      const isCastformWithForecast = (p.hasAbility(Abilities.FORECAST) && p.species.speciesId === Species.CASTFORM);
      const isCherrimWithFlowerGift = (p.hasAbility(Abilities.FLOWER_GIFT) && p.species.speciesId === Species.CHERRIM);

      if (isCastformWithForecast || isCherrimWithFlowerGift) {
        new ShowAbilityPhase(this.scene, p.getBattlerIndex());
        this.scene.triggerPokemonFormChange(p, SpeciesFormChangeWeatherTrigger);
      }
    });
  }

  /**
   * Function to trigger all weather based form changes back into their normal forms
   */
  triggerWeatherBasedFormChangesToNormal(): void {
    this.scene.getField(true).forEach( p => {
      const isCastformWithForecast = (p.hasAbility(Abilities.FORECAST, false, true) && p.species.speciesId === Species.CASTFORM);
      const isCherrimWithFlowerGift = (p.hasAbility(Abilities.FLOWER_GIFT, false, true) && p.species.speciesId === Species.CHERRIM);

      if (isCastformWithForecast || isCherrimWithFlowerGift) {
        new ShowAbilityPhase(this.scene, p.getBattlerIndex());
        return this.scene.triggerPokemonFormChange(p, SpeciesFormChangeRevertWeatherFormTrigger);
      }
    });
  }

  trySetTerrain(terrain: TerrainType, hasPokemonSource: boolean, ignoreAnim: boolean = false): boolean {
    if (this.terrain?.terrainType === (terrain || undefined)) {
      return false;
    }

    const oldTerrainType = this.terrain?.terrainType || TerrainType.NONE;

    this.terrain = terrain ? new Terrain(terrain, hasPokemonSource ? 5 : 0) : null;
    this.eventTarget.dispatchEvent(new TerrainChangedEvent(oldTerrainType, this.terrain?.terrainType!, this.terrain?.turnsLeft!)); // TODO: are those bangs correct?

    if (this.terrain) {
      if (!ignoreAnim) {
        this.scene.unshiftPhase(new CommonAnimPhase(this.scene, undefined, undefined, CommonAnim.MISTY_TERRAIN + (terrain - 1)));
      }
      this.scene.queueMessage(getTerrainStartMessage(terrain)!); // TODO: is this bang correct?
    } else {
      this.scene.queueMessage(getTerrainClearMessage(oldTerrainType)!); // TODO: is this bang correct?
    }

    this.scene.getField(true).filter(p => p.isOnField()).map(pokemon => {
      pokemon.findAndRemoveTags(t => "terrainTypes" in t && !(t.terrainTypes as TerrainType[]).find(t => t === terrain));
      applyPostTerrainChangeAbAttrs(PostTerrainChangeAbAttr, pokemon, terrain);
    });

    return true;
  }

  public isMoveWeatherCancelled(user: Pokemon, move: Move): boolean {
    return !!this.weather && !this.weather.isEffectSuppressed(this.scene) && this.weather.isMoveWeatherCancelled(user, move);
  }

  public isMoveTerrainCancelled(user: Pokemon, targets: BattlerIndex[], move: Move): boolean {
    return !!this.terrain && this.terrain.isMoveTerrainCancelled(user, targets, move);
  }

  public getTerrainType(): TerrainType {
    return this.terrain?.terrainType ?? TerrainType.NONE;
  }

  getAttackTypeMultiplier(attackType: Type, grounded: boolean): number {
    let weatherMultiplier = 1;
    if (this.weather && !this.weather.isEffectSuppressed(this.scene)) {
      weatherMultiplier = this.weather.getAttackTypeMultiplier(attackType);
    }

    let terrainMultiplier = 1;
    if (this.terrain && grounded) {
      terrainMultiplier = this.terrain.getAttackTypeMultiplier(attackType);
    }

    return weatherMultiplier * terrainMultiplier;
  }

  /**
   * Gets the denominator for the chance for a trainer spawn
   * @returns n where 1/n is the chance of a trainer battle
   */
  getTrainerChance(): integer {
    switch (this.biomeType) {
    case Biome.METROPOLIS:
      return 2;
    case Biome.SLUM:
    case Biome.BEACH:
    case Biome.DOJO:
    case Biome.CONSTRUCTION_SITE:
      return 4;
    case Biome.PLAINS:
    case Biome.GRASS:
    case Biome.LAKE:
    case Biome.CAVE:
      return 6;
    case Biome.TALL_GRASS:
    case Biome.FOREST:
    case Biome.SEA:
    case Biome.SWAMP:
    case Biome.MOUNTAIN:
    case Biome.BADLANDS:
    case Biome.DESERT:
    case Biome.MEADOW:
    case Biome.POWER_PLANT:
    case Biome.GRAVEYARD:
    case Biome.FACTORY:
    case Biome.SNOWY_FOREST:
      return 8;
    case Biome.ICE_CAVE:
    case Biome.VOLCANO:
    case Biome.RUINS:
    case Biome.WASTELAND:
    case Biome.JUNGLE:
    case Biome.FAIRY_CAVE:
      return 12;
    case Biome.SEABED:
    case Biome.ABYSS:
    case Biome.SPACE:
    case Biome.TEMPLE:
      return 16;
    default:
      return 0;
    }
  }

  getTimeOfDay(): TimeOfDay {
    switch (this.biomeType) {
    case Biome.ABYSS:
      return TimeOfDay.NIGHT;
    }

    const waveCycle = ((this.scene.currentBattle?.waveIndex || 0) + this.scene.waveCycleOffset) % 40;

    if (waveCycle < 15) {
      return TimeOfDay.DAY;
    }

    if (waveCycle < 20) {
      return TimeOfDay.DUSK;
    }

    if (waveCycle < 35) {
      return TimeOfDay.NIGHT;
    }

    return TimeOfDay.DAWN;
  }

  isOutside(): boolean {
    switch (this.biomeType) {
    case Biome.SEABED:
    case Biome.CAVE:
    case Biome.ICE_CAVE:
    case Biome.POWER_PLANT:
    case Biome.DOJO:
    case Biome.FACTORY:
    case Biome.ABYSS:
    case Biome.FAIRY_CAVE:
    case Biome.TEMPLE:
    case Biome.LABORATORY:
      return false;
    default:
      return true;
    }
  }

  overrideTint(): [integer, integer, integer] {
    switch (Overrides.ARENA_TINT_OVERRIDE) {
    case TimeOfDay.DUSK:
      return [ 98, 48, 73 ].map(c => Math.round((c + 128) / 2)) as [integer, integer, integer];
      break;
    case (TimeOfDay.NIGHT):
      return [ 64, 64, 64 ];
      break;
    case TimeOfDay.DAWN:
    case TimeOfDay.DAY:
    default:
      return [ 128, 128, 128 ];
      break;
    }
  }

  getDayTint(): [integer, integer, integer] {
    if (Overrides.ARENA_TINT_OVERRIDE !== null) {
      return this.overrideTint();
    }
    switch (this.biomeType) {
    case Biome.ABYSS:
      return [ 64, 64, 64 ];
    default:
      return [ 128, 128, 128 ];
    }
  }

  getDuskTint(): [integer, integer, integer] {
    if (Overrides.ARENA_TINT_OVERRIDE) {
      return this.overrideTint();
    }
    if (!this.isOutside()) {
      return [ 0, 0, 0 ];
    }

    switch (this.biomeType) {
    default:
      return [ 98, 48, 73 ].map(c => Math.round((c + 128) / 2)) as [integer, integer, integer];
    }
  }

  getNightTint(): [integer, integer, integer] {
    if (Overrides.ARENA_TINT_OVERRIDE) {
      return this.overrideTint();
    }
    switch (this.biomeType) {
    case Biome.ABYSS:
    case Biome.SPACE:
    case Biome.END:
      return this.getDayTint();
    }

    if (!this.isOutside()) {
      return [ 64, 64, 64 ];
    }

    switch (this.biomeType) {
    default:
      return [ 48, 48, 98 ];
    }
  }

  setIgnoreAbilities(ignoreAbilities: boolean, ignoringEffectSource: BattlerIndex | null = null): void {
    this.ignoreAbilities = ignoreAbilities;
    this.ignoringEffectSource = ignoreAbilities ? ignoringEffectSource : null;
  }

  /**
   * Applies each `ArenaTag` in this Arena, based on which side (self, enemy, or both) is passed in as a parameter
   * @param tagType Either an {@linkcode ArenaTagType} string, or an actual {@linkcode ArenaTag} class to filter which ones to apply
   * @param side {@linkcode ArenaTagSide} which side's arena tags to apply
   * @param simulated if `true`, this applies arena tags without changing game state
   * @param args array of parameters that the called upon tags may need
   */
  applyTagsForSide(tagType: ArenaTagType | Constructor<ArenaTag>, side: ArenaTagSide, simulated: boolean, ...args: unknown[]): void {
    let tags = typeof tagType === "string"
      ? this.tags.filter(t => t.tagType === tagType)
      : this.tags.filter(t => t instanceof tagType);
    if (side !== ArenaTagSide.BOTH) {
      tags = tags.filter(t => t.side === side);
    }
    tags.forEach(t => t.apply(this, simulated, ...args));
  }

  /**
   * Applies the specified tag to both sides (ie: both user and trainer's tag that match the Tag specified)
   * by calling {@linkcode applyTagsForSide()}
   * @param tagType Either an {@linkcode ArenaTagType} string, or an actual {@linkcode ArenaTag} class to filter which ones to apply
   * @param simulated if `true`, this applies arena tags without changing game state
   * @param args array of parameters that the called upon tags may need
   */
  applyTags(tagType: ArenaTagType | Constructor<ArenaTag>, simulated: boolean, ...args: unknown[]): void {
    this.applyTagsForSide(tagType, ArenaTagSide.BOTH, simulated, ...args);
  }

  /**
   * Adds a new tag to the arena
   * @param tagType {@linkcode ArenaTagType} the tag being added
   * @param turnCount How many turns the tag lasts
   * @param sourceMove {@linkcode Moves} the move the tag came from, or `undefined` if not from a move
   * @param sourceId The ID of the pokemon in play the tag came from (see {@linkcode BattleScene.getPokemonById})
   * @param side {@linkcode ArenaTagSide} which side(s) the tag applies to
   * @param quiet If a message should be queued on screen to announce the tag being added
   * @param targetIndex The {@linkcode BattlerIndex} of the target pokemon
   * @returns `false` if there already exists a tag of this type in the Arena
   */
  addTag(tagType: ArenaTagType, turnCount: number, sourceMove: Moves | undefined, sourceId: number, side: ArenaTagSide = ArenaTagSide.BOTH, quiet: boolean = false, targetIndex?: BattlerIndex): boolean {
    const existingTag = this.getTagOnSide(tagType, side);
    if (existingTag) {
      existingTag.onOverlap(this);

      if (existingTag instanceof ArenaTrapTag) {
        const { tagType, side, turnCount, layers, maxLayers } = existingTag as ArenaTrapTag;
        this.eventTarget.dispatchEvent(new TagAddedEvent(tagType, side, turnCount, layers, maxLayers));
      }

      return false;
    }

    // creates a new tag object
    const newTag = getArenaTag(tagType, turnCount || 0, sourceMove, sourceId, targetIndex, side);
    if (newTag) {
      this.tags.push(newTag);
      newTag.onAdd(this, quiet);

      const { layers = 0, maxLayers = 0 } = newTag instanceof ArenaTrapTag ? newTag : {};

      this.eventTarget.dispatchEvent(new TagAddedEvent(newTag.tagType, newTag.side, newTag.turnCount, layers, maxLayers));
    }

    return true;
  }

  /**
   * Attempts to get a tag from the Arena via {@linkcode getTagOnSide} that applies to both sides
   * @param tagType The {@linkcode ArenaTagType} or {@linkcode ArenaTag} to get
   * @returns either the {@linkcode ArenaTag}, or `undefined` if it isn't there
   */
  getTag(tagType: ArenaTagType | Constructor<ArenaTag>): ArenaTag | undefined {
    return this.getTagOnSide(tagType, ArenaTagSide.BOTH);
  }

  hasTag(tagType: ArenaTagType) : boolean {
    return !!this.getTag(tagType);
  }

  /**
   * Attempts to get a tag from the Arena from a specific side (the tag passed in has to either apply to both sides, or the specific side only)
   *
   * eg: `MIST` only applies to the user's side, while `MUD_SPORT` applies to both user and enemy side
   * @param tagType The {@linkcode ArenaTagType} or {@linkcode ArenaTag} to get
   * @param side The {@linkcode ArenaTagSide} to look at
   * @returns either the {@linkcode ArenaTag}, or `undefined` if it isn't there
   */
  getTagOnSide(tagType: ArenaTagType | Constructor<ArenaTag>, side: ArenaTagSide): ArenaTag | undefined {
    return typeof(tagType) === "string"
      ? this.tags.find(t => t.tagType === tagType && (side === ArenaTagSide.BOTH || t.side === ArenaTagSide.BOTH || t.side === side))
      : this.tags.find(t => t instanceof tagType && (side === ArenaTagSide.BOTH || t.side === ArenaTagSide.BOTH || t.side === side));
  }

  /**
   * Uses {@linkcode findTagsOnSide} to filter (using the parameter function) for specific tags that apply to both sides
   * @param tagPredicate a function mapping {@linkcode ArenaTag}s to `boolean`s
   * @returns array of {@linkcode ArenaTag}s from which the Arena's tags return true and apply to both sides
   */
  findTags(tagPredicate: (t: ArenaTag) => boolean): ArenaTag[] {
    return this.findTagsOnSide(tagPredicate, ArenaTagSide.BOTH);
  }

  /**
   * Returns specific tags from the arena that pass the `tagPredicate` function passed in as a parameter, and apply to the given side
   * @param tagPredicate a function mapping {@linkcode ArenaTag}s to `boolean`s
   * @param side The {@linkcode ArenaTagSide} to look at
   * @returns array of {@linkcode ArenaTag}s from which the Arena's tags return `true` and apply to the given side
   */
  findTagsOnSide(tagPredicate: (t: ArenaTag) => boolean, side: ArenaTagSide): ArenaTag[] {
    return this.tags.filter(t => tagPredicate(t) && (side === ArenaTagSide.BOTH || t.side === ArenaTagSide.BOTH || t.side === side));
  }

  lapseTags(): void {
    this.tags.filter(t => !(t.lapse(this))).forEach(t => {
      t.onRemove(this);
      this.tags.splice(this.tags.indexOf(t), 1);

      this.eventTarget.dispatchEvent(new TagRemovedEvent(t.tagType, t.side, t.turnCount));
    });
  }

  removeTag(tagType: ArenaTagType): boolean {
    const tags = this.tags;
    const tag = tags.find(t => t.tagType === tagType);
    if (tag) {
      tag.onRemove(this);
      tags.splice(tags.indexOf(tag), 1);

      this.eventTarget.dispatchEvent(new TagRemovedEvent(tag.tagType, tag.side, tag.turnCount));
    }
    return !!tag;
  }

  removeTagOnSide(tagType: ArenaTagType, side: ArenaTagSide, quiet: boolean = false): boolean {
    const tag = this.getTagOnSide(tagType, side);
    if (tag) {
      tag.onRemove(this, quiet);
      this.tags.splice(this.tags.indexOf(tag), 1);

      this.eventTarget.dispatchEvent(new TagRemovedEvent(tag.tagType, tag.side, tag.turnCount));
    }
    return !!tag;
  }


  removeAllTags(): void {
    while (this.tags.length) {
      this.tags[0].onRemove(this);
      this.eventTarget.dispatchEvent(new TagRemovedEvent(this.tags[0].tagType, this.tags[0].side, this.tags[0].turnCount));

      this.tags.splice(0, 1);
    }
  }

  /**
   * Clears weather, terrain and arena tags when entering new biome or trainer battle.
   */
  resetArenaEffects(): void {
    // Don't reset weather if a Biome's permanent weather is active
    if (this.weather?.turnsLeft !== 0) {
      this.trySetWeather(WeatherType.NONE, false);
    }
    this.trySetTerrain(TerrainType.NONE, false, true);
    this.removeAllTags();
  }

  preloadBgm(): void {
    this.scene.loadBgm(this.bgm);
  }

  getBgmLoopPoint(): number {
    switch (this.biomeType) {
    case Biome.TOWN:
      return 7.288;
    case Biome.PLAINS:
      return 17.485;
    case Biome.GRASS:
      return 1.995;
    case Biome.TALL_GRASS:
      return 9.608;
    case Biome.METROPOLIS:
      return 141.470;
    case Biome.FOREST:
      return 4.294;
    case Biome.SEA:
      return 0.024;
    case Biome.SWAMP:
      return 4.461;
    case Biome.BEACH:
      return 3.462;
    case Biome.LAKE:
      return 7.215;
    case Biome.SEABED:
      return 2.600;
    case Biome.MOUNTAIN:
      return 4.018;
    case Biome.BADLANDS:
      return 17.790;
    case Biome.CAVE:
      return 14.240;
    case Biome.DESERT:
      return 1.143;
    case Biome.ICE_CAVE:
      return 0.000;
    case Biome.MEADOW:
      return 3.891;
    case Biome.POWER_PLANT:
      return 9.447;
    case Biome.VOLCANO:
      return 17.637;
    case Biome.GRAVEYARD:
      return 3.232;
    case Biome.DOJO:
      return 6.205;
    case Biome.FACTORY:
      return 4.985;
    case Biome.RUINS:
      return 0.000;
    case Biome.WASTELAND:
      return 6.336;
    case Biome.ABYSS:
      return 5.130;
    case Biome.SPACE:
      return 20.036;
    case Biome.CONSTRUCTION_SITE:
      return 1.222;
    case Biome.JUNGLE:
      return 0.000;
    case Biome.FAIRY_CAVE:
      return 4.542;
    case Biome.TEMPLE:
      return 2.547;
    case Biome.ISLAND:
      return 2.751;
    case Biome.LABORATORY:
      return 114.862;
    case Biome.SLUM:
      return 0.000;
    case Biome.SNOWY_FOREST:
      return 3.047;
    default:
      console.warn(`missing bgm loop-point for biome "${Biome[this.biomeType]}" (=${this.biomeType})`);
      return 0;
    }
  }
}

export function getBiomeKey(biome: Biome): string {
  return Biome[biome].toLowerCase();
}

export function getBiomeHasProps(biomeType: Biome): boolean {
  switch (biomeType) {
  case Biome.METROPOLIS:
  case Biome.BEACH:
  case Biome.LAKE:
  case Biome.SEABED:
  case Biome.MOUNTAIN:
  case Biome.BADLANDS:
  case Biome.CAVE:
  case Biome.DESERT:
  case Biome.ICE_CAVE:
  case Biome.MEADOW:
  case Biome.POWER_PLANT:
  case Biome.VOLCANO:
  case Biome.GRAVEYARD:
  case Biome.FACTORY:
  case Biome.RUINS:
  case Biome.WASTELAND:
  case Biome.ABYSS:
  case Biome.CONSTRUCTION_SITE:
  case Biome.JUNGLE:
  case Biome.FAIRY_CAVE:
  case Biome.TEMPLE:
  case Biome.SNOWY_FOREST:
  case Biome.ISLAND:
  case Biome.LABORATORY:
  case Biome.END:
    return true;
  }

  return false;
}

export class ArenaBase extends Phaser.GameObjects.Container {
  public player: boolean;
  public biome: Biome;
  public propValue: integer;
  public base: Phaser.GameObjects.Sprite;
  public props: Phaser.GameObjects.Sprite[];

  constructor(scene: BattleScene, player: boolean) {
    super(scene, 0, 0);

    this.player = player;

    this.base = scene.addFieldSprite(0, 0, "plains_a", undefined, 1);
    this.base.setOrigin(0, 0);

    this.props = !player ?
      new Array(3).fill(null).map(() => {
        const ret = scene.addFieldSprite(0, 0, "plains_b", undefined, 1);
        ret.setOrigin(0, 0);
        ret.setVisible(false);
        return ret;
      }) : [];
  }

  setBiome(biome: Biome, propValue?: integer): void {
    const hasProps = getBiomeHasProps(biome);
    const biomeKey = getBiomeKey(biome);
    const baseKey = `${biomeKey}_${this.player ? "a" : "b"}`;

    if (biome !== this.biome) {
      this.base.setTexture(baseKey);

      if (this.base.texture.frameTotal > 1) {
        const baseFrameNames = this.scene.anims.generateFrameNames(baseKey, { zeroPad: 4, suffix: ".png", start: 1, end: this.base.texture.frameTotal - 1 });
        if (!(this.scene.anims.exists(baseKey))) {
          this.scene.anims.create({
            key: baseKey,
            frames: baseFrameNames,
            frameRate: 12,
            repeat: -1
          });
        }
        this.base.play(baseKey);
      } else {
        this.base.stop();
      }

      this.add(this.base);
    }

    if (!this.player) {
      (this.scene as BattleScene).executeWithSeedOffset(() => {
        this.propValue = propValue === undefined
          ? hasProps ? Utils.randSeedInt(8) : 0
          : propValue;
        this.props.forEach((prop, p) => {
          const propKey = `${biomeKey}_b${hasProps ? `_${p + 1}` : ""}`;
          prop.setTexture(propKey);

          if (hasProps && prop.texture.frameTotal > 1) {
            const propFrameNames = this.scene.anims.generateFrameNames(propKey, { zeroPad: 4, suffix: ".png", start: 1, end: prop.texture.frameTotal - 1 });
            if (!(this.scene.anims.exists(propKey))) {
              this.scene.anims.create({
                key: propKey,
                frames: propFrameNames,
                frameRate: 12,
                repeat: -1
              });
            }
            prop.play(propKey);
          } else {
            prop.stop();
          }

          prop.setVisible(hasProps && !!(this.propValue & (1 << p)));
          this.add(prop);
        });
      }, (this.scene as BattleScene).currentBattle?.waveIndex || 0, (this.scene as BattleScene).waveSeed);
    }
  }
}