pokerogue/src/data/arena-tag.ts

/**
 * ArenaTags are are meant for effects that are tied to the arena (as opposed to a specific pokemon).
 * Examples include (but are not limited to)
 * - Cross-turn effects that persist even if the user/target switches out, such as Happy Hour
 * - Effects that are applied to a specific side of the field, such as Crafty Shield, Reflect, and Spikes
 * - Field-Effects, like Gravity and Trick Room
 *
 * Any arena tag that persists across turns *must* extend from `SerializableArenaTag` in the class definition signature.
 *
 * Serializable ArenaTags have strict rules for their fields.
 * These rules ensure that only the data necessary to reconstruct the tag is serialized, and that the
 * session loader is able to deserialize saved tags correctly.
 *
 * If the data is static (i.e. it is always the same for all instances of the class, such as the
 * type that is weakened by Mud Sport/Water Sport), then it must not be defined as a field, and must
 * instead be defined as a getter.
 * A static property is also acceptable, though static properties are less ergonomic with inheritance.
 *
 * If the data is mutable (i.e. it can change over the course of the tag's lifetime), then it *must*
 * be defined as a field, and it must be set in the `loadTag` method.
 * Such fields cannot be marked as `private`/`protected`; if they were, Typescript would omit them from
 * types that are based off of the class, namely, `ArenaTagTypeData`. It is preferrable to trade the
 * type-safety of private/protected fields for the type safety when deserializing arena tags from save data.
 *
 * For data that is mutable only within a turn (e.g. SuppressAbilitiesTag's beingRemoved field),
 * where it does not make sense to be serialized, the field should use ES2020's
 * [private field syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Private_elements#private_fields).
 * If the field should be accessible outside of the class, then a public getter should be used.
 *
 *  If any new serializable fields *are* added, then the class *must* override the
 * `loadTag` method to set the new fields. Its signature *must* match the example below,
 * ```
 * class ExampleTag extends SerializableArenaTag {
 *   // Example, if we add 2 new fields that should be serialized:
 *   public a: string;
 *   public b: number;
 *   // Then we must also define a loadTag method with one of the following signatures
 *   public override loadTag(source: BaseArenaTag & Pick<ExampleTag, "tagType" | "a" | "b"): void;
 *   public override loadTag<const T extends this>(source: BaseArenaTag & Pick<T, "tagType" | "a" | "b">): void;
 * }
 * ```
 * Notes
 * - If the class has any subclasses, then the second form of `loadTag` *must* be used.
 * @module
 */

import { applyAbAttrs, applyOnGainAbAttrs, applyOnLoseAbAttrs } from "#abilities/apply-ab-attrs";
import type { BattlerTag } from "#app/data/battler-tags";
import { globalScene } from "#app/global-scene";
import { getPokemonNameWithAffix } from "#app/messages";
import { CommonBattleAnim } from "#data/battle-anims";
import { allMoves } from "#data/data-lists";
import { AbilityId } from "#enums/ability-id";
import { ArenaTagSide } from "#enums/arena-tag-side";
import { ArenaTagType } from "#enums/arena-tag-type";
import type { BattlerIndex } from "#enums/battler-index";
import { BattlerTagType } from "#enums/battler-tag-type";
import { HitResult } from "#enums/hit-result";
import { CommonAnim } from "#enums/move-anims-common";
import { MoveCategory } from "#enums/move-category";
import { MoveId } from "#enums/move-id";
import { MoveTarget } from "#enums/move-target";
import { PokemonType } from "#enums/pokemon-type";
import { Stat } from "#enums/stat";
import { StatusEffect } from "#enums/status-effect";
import type { Arena } from "#field/arena";
import type { Pokemon } from "#field/pokemon";
import { isSpreadMove } from "#moves/move-utils";
import type {
  ArenaScreenTagType,
  ArenaTagData,
  EntryHazardTagType,
  RoomArenaTagType,
  SerializableArenaTagType,
} from "#types/arena-tags";
import type { Mutable } from "#types/type-helpers";
import { BooleanHolder, type NumberHolder, toDmgValue } from "#utils/common";
import { inSpeedOrder } from "#utils/speed-order-generator";
import i18next from "i18next";

/** Interface containing the serializable fields of ArenaTagData. */
interface BaseArenaTag {
  /**
   * The tag's remaining duration. Setting to any number `<=0` will make the tag's duration effectively infinite.
   */
  turnCount: number;
  /**
   * The tag's max duration.
   */
  maxDuration: number;
  /**
   * The {@linkcode MoveId} that created this tag, or `undefined` if not set by a move.
   */
  sourceMove?: MoveId;
  /**
   * The {@linkcode Pokemon.id | PID} of the {@linkcode Pokemon} having created the tag, or `undefined` if not set by a Pokemon.
   */
  // TODO: Implement handling for `ArenaTag`s created by non-pokemon sources (most tags will throw errors without a source)
  // Note: Intentionally not using `?`, as the property should always exist, but just be undefined if not present.
  sourceId: number | undefined;
  /**
   * The {@linkcode ArenaTagSide | side of the field} that this arena tag affects.
   * @defaultValue `ArenaTagSide.BOTH`
   */
  side: ArenaTagSide;
}

/**
 * An {@linkcode ArenaTag} represents a semi-persistent effect affecting a given _side_ of the field.
 * Unlike {@linkcode BattlerTag}s (which are tied to individual {@linkcode Pokemon}), `ArenaTag`s function independently of
 * the Pokemon currently on-field, only cleared on arena reset or through their respective {@linkcode ArenaTag.lapse | lapse} methods.
 */
export abstract class ArenaTag implements BaseArenaTag {
  /** The type of the arena tag */
  public abstract readonly tagType: ArenaTagType;
  // Intentionally left undocumented to inherit comments from interface
  public turnCount: number;
  public maxDuration: number;
  public sourceMove?: MoveId;
  public sourceId: number | undefined;
  public side: ArenaTagSide;

  /**
   * Return the i18n locales key that will be shown when this tag is added. \
   * Within the text, `{{pokemonNameWithAffix}}` and `{{moveName}}` will be populated with
   * the name of the Pokemon that added the tag and the name of the move that created the tag, respectively.
   * @remarks
   * If this evaluates to an empty string, no message will be displayed.
   */
  protected abstract get onAddMessageKey(): string;

  /**
   * Return the i18n locales key that will be shown when this tag is removed. \
   * Within the text, `{{pokemonNameWithAffix}}` and `{{moveName}}` will be populated with
   * the name of the Pokemon that added the tag and the name of the move that created the tag, respectively.
   * @remarks
   * If this evaluates to an empty string, no message will be displayed.
   */
  protected abstract get onRemoveMessageKey(): string;

  /**
   * @returns A suffix corresponding to this tag's current side.
   * @sealed
   */
  // TODO: Make this an i18n context
  protected get i18nSideKey(): string {
    return this.side === ArenaTagSide.PLAYER ? "Player" : this.side === ArenaTagSide.ENEMY ? "Enemy" : "";
  }

  constructor(turnCount: number, sourceMove?: MoveId, sourceId?: number, side: ArenaTagSide = ArenaTagSide.BOTH) {
    this.turnCount = turnCount;
    this.maxDuration = turnCount;
    this.sourceMove = sourceMove;
    this.sourceId = sourceId;
    this.side = side;
  }

  /**
   * Apply this tag's effects during a turn.
   * @param _args - Arguments used by subclasses.
   */
  // TODO: Remove all boolean return values from subclasses
  // TODO: Move all classes with `apply` triggers into a unique sub-class to prevent
  // applying effects of tags that lack effect application
  public apply(..._args: unknown[]): void {}

  /**
   * Trigger effects when this tag is added to the Arena.
   * By default, will queue a message with the contents of {@linkcode getOnAddMessage}.
   * @param quiet - Whether to suppress any messages created during tag addition; default `false`
   */
  public onAdd(quiet = false): void {
    if (quiet || !this.onAddMessageKey) {
      return;
    }

    globalScene.phaseManager.queueMessage(
      i18next.t(this.onAddMessageKey, {
        pokemonNameWithAffix: getPokemonNameWithAffix(this.getSourcePokemon()),
        moveName: this.getMoveName(),
      }),
    );
  }

  /**
   * Trigger effects when this tag is removed from the Arena.
   * By default, will queue a message with the contents of {@linkcode getOnRemoveMessage}.
   * @param quiet - Whether to suppress any messages created during tag addition; default `false`
   */
  public onRemove(quiet = false): void {
    if (quiet || !this.onRemoveMessageKey) {
      return;
    }

    globalScene.phaseManager.queueMessage(
      i18next.t(this.onRemoveMessageKey, {
        pokemonNameWithAffix: getPokemonNameWithAffix(this.getSourcePokemon()),
        moveName: this.getMoveName(),
      }),
    );
  }

  /**
   * Apply effects when this Tag overlaps by creating a new instance while one is already present.
   * @param _source - The `Pokemon` having added the tag
   */
  public onOverlap(_source?: Pokemon): void {}

  /**
   * Reduce this {@linkcode ArenaTag}'s duration and apply any end-of-turn effects
   * Will ignore durations of all tags with durations `<=0`.
   * @returns `true` if this tag should be kept; `false` if it should be removed.
   */
  lapse(): boolean {
    // TODO: Rather than treating negative duration tags as being indefinite,
    // make all duration based classes inherit from their own sub-class
    return this.turnCount < 1 || --this.turnCount > 0;
  }

  protected getMoveName(): string | null {
    return this.sourceMove ? allMoves[this.sourceMove].name : null;
  }

  /**
   * When given a arena tag or json representing one, load the data for it.
   * This is meant to be inherited from by any arena tag with custom attributes
   * @param source - The arena tag being loaded
   */
  loadTag<const T extends this>(source: BaseArenaTag & Pick<T, "tagType">): void {
    this.turnCount = source.turnCount;
    this.maxDuration = source.maxDuration;
    this.sourceMove = source.sourceMove;
    this.sourceId = source.sourceId;
    this.side = source.side;
  }

  /**
   * Helper function that retrieves the source Pokemon.
   * @returns - The source {@linkcode Pokemon} for this tag.
   * Returns `undefined` if `this.sourceId` is `undefined`
   */
  protected getSourcePokemon(): Pokemon | undefined {
    return globalScene.getPokemonById(this.sourceId);
  }

  /**
   * Helper function that retrieves the Pokemon affected.
   * @returns An array containing all {@linkcode Pokemon} affected by this Tag, not in speed order.
   */
  protected getAffectedPokemon(): Pokemon[] {
    switch (this.side) {
      case ArenaTagSide.PLAYER:
        return globalScene.getPlayerField();
      case ArenaTagSide.ENEMY:
        return globalScene.getEnemyField();
      case ArenaTagSide.BOTH:
        return globalScene.getField(true);
    }
  }

  /**
   * Return whether this Tag can affect the given Pokemon, based on this tag's {@linkcode side}.
   * @param pokemon - The {@linkcode Pokemon} to check
   * @returns Whether this tag can affect `pokemon`.
   */
  protected canAffect(pokemon: Pokemon) {
    return this.getAffectedPokemon().includes(pokemon);
  }
}

/**
 * Abstract class for arena tags that can persist across turns.
 */
export abstract class SerializableArenaTag extends ArenaTag {
  abstract readonly tagType: SerializableArenaTagType;
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Mist_(move) Mist}.
 * Prevents Pokémon on the opposing side from lowering the stats of the Pokémon in the Mist.
 */
export class MistTag extends SerializableArenaTag {
  readonly tagType = ArenaTagType.MIST;
  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.MIST, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:mistOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:mistOnRemove" + this.i18nSideKey;
  }

  /**
   * Cancels the lowering of stats
   * @param simulated `true` if the effect should be applied quietly
   * @param attacker the {@linkcode Pokemon} using a move into this effect.
   * @param cancelled a {@linkcode BooleanHolder} whose value is set to `true`
   * to flag the stat reduction as cancelled
   * @returns `true` if a stat reduction was cancelled; `false` otherwise
   */
  override apply(simulated: boolean, attacker: Pokemon | null, cancelled: BooleanHolder): boolean {
    // `StatStageChangePhase` currently doesn't have a reference to the source of stat drops,
    // so this code currently has no effect on gameplay.
    if (attacker) {
      const bypassed = new BooleanHolder(false);
      // TODO: Allow this to be simulated
      applyAbAttrs("InfiltratorAbAttr", { pokemon: attacker, simulated: false, bypassed });
      if (bypassed.value) {
        return false;
      }
    }

    cancelled.value = true;

    if (!simulated) {
      globalScene.phaseManager.queueMessage(
        i18next.t("arenaTag:mistApply", {
          pokemonNameWithAffix: getPokemonNameWithAffix(this.getSourcePokemon()),
        }),
      );
    }

    return true;
  }
}

/**
 * Reduces the damage of specific move categories in the arena.
 */
export abstract class WeakenMoveScreenTag extends SerializableArenaTag {
  public abstract readonly tagType: ArenaScreenTagType;
  // Getter to avoid unnecessary serialization and prevent modification
  protected abstract get weakenedCategories(): MoveCategory[];

  /**
   * Applies the weakening effect to the move.
   * @param attacker the attacking {@linkcode Pokemon}
   * @param moveCategory the attacking move's {@linkcode MoveCategory}.
   * @param damageMultiplier A {@linkcode NumberHolder} containing the damage multiplier
   * @returns `true` if the attacking move was weakened; `false` otherwise.
   */
  override apply(attacker: Pokemon, moveCategory: MoveCategory, damageMultiplier: NumberHolder): boolean {
    if (!this.weakenedCategories.includes(moveCategory)) {
      return false;
    }
    const bypassed = new BooleanHolder(false);
    applyAbAttrs("InfiltratorAbAttr", { pokemon: attacker, bypassed });
    if (bypassed.value) {
      return false;
    }
    // Screens are less effective in Double Battles
    damageMultiplier.value = globalScene.currentBattle.double ? 2 / 3 : 1 / 2;
    return true;
  }
}

/**
 * Reduces the damage of physical moves.
 * Used by {@linkcode MoveId.REFLECT}
 */
class ReflectTag extends WeakenMoveScreenTag {
  public readonly tagType = ArenaTagType.REFLECT;
  protected override get weakenedCategories(): [MoveCategory.PHYSICAL] {
    return [MoveCategory.PHYSICAL];
  }

  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.REFLECT, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:reflectOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:reflectOnRemove" + this.i18nSideKey;
  }
}

/**
 * Reduces the damage of special moves.
 * Used by {@linkcode MoveId.LIGHT_SCREEN}
 */
class LightScreenTag extends WeakenMoveScreenTag {
  public readonly tagType = ArenaTagType.LIGHT_SCREEN;
  protected override get weakenedCategories(): [MoveCategory.SPECIAL] {
    return [MoveCategory.SPECIAL];
  }
  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.LIGHT_SCREEN, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:lightScreenOnAdd" + this.i18nSideKey;
  }
  protected override get onRemoveMessageKey(): string {
    return "arenaTag:lightScreenOnRemove" + this.i18nSideKey;
  }
}

/**
 * Reduces the damage of physical and special moves.
 * Used by {@linkcode MoveId.AURORA_VEIL}
 */
class AuroraVeilTag extends WeakenMoveScreenTag {
  public readonly tagType = ArenaTagType.AURORA_VEIL;
  protected override get weakenedCategories(): [MoveCategory.PHYSICAL, MoveCategory.SPECIAL] {
    return [MoveCategory.PHYSICAL, MoveCategory.SPECIAL];
  }

  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.AURORA_VEIL, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:auroraVeilOnAdd" + this.i18nSideKey;
  }
  protected override get onRemoveMessageKey(): string {
    return "arenaTag:auroraVeilOnRemove" + this.i18nSideKey;
  }
}

type ProtectConditionFunc = (moveId: MoveId) => boolean;

/**
 * Class to implement conditional team protection
 * applies protection based on the attributes of incoming moves
 */
export abstract class ConditionalProtectTag extends ArenaTag {
  /**
   * Whether this protection effect should apply to _all_ moves, including ones that ignore other forms of protection.
   * @defaultValue `false`
   */
  protected ignoresBypass: boolean;

  constructor(sourceMove: MoveId, sourceId: number | undefined, side: ArenaTagSide, ignoresBypass = false) {
    super(1, sourceMove, sourceId, side);

    this.ignoresBypass = ignoresBypass;
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:conditionalProtectOnAdd" + this.i18nSideKey;
  }
  protected override get onRemoveMessageKey(): string {
    return "";
  }

  /**
   * The condition function to determine which moves are negated.
   */
  protected abstract get condition(): ProtectConditionFunc;

  /**
   * Return the message key that will be used when protecting an allied target.
   * Within the text, the following variables will be populated:
   *  - `{{pokemonNameWithAffix}}`: The name of the Pokemon protected by the attack
   *  - `{{moveName}}`: The name of the move that created the tag
   *  - `{{attackName}}`: The name of the move that _triggered_ the protection effect.
   * @defaultValue `arenaTag:conditionalProtectApply`
   */
  protected get onProtectMessageKey(): string {
    return "arenaTag:conditionalProtectApply";
  }

  /**
   * Checks incoming moves against the condition function
   * and protects the target if conditions are met
   * @param simulated - `true` if the tag is applied quietly; `false` otherwise.
   * @param isProtected - A {@linkcode BooleanHolder} used to flag if the move is protected against
   * @param _attacker - The attacking {@linkcode Pokemon}
   * @param defender - The defending {@linkcode Pokemon}
   * @param moveId - The {@linkcode MoveId} of the move being used
   * @param ignoresProtectBypass - A {@linkcode BooleanHolder} used to flag if a protection effect superceded effects that ignore protection
   * @returns `true` if this tag protected against the attack; `false` otherwise
   */
  override apply(
    // TODO: `_attacker` is unused by all classes
    // TODO: Simulated is only ever passed as `false` here...
    simulated: boolean,
    isProtected: BooleanHolder,
    _attacker: Pokemon,
    defender: Pokemon,
    moveId: MoveId,
    ignoresProtectBypass: BooleanHolder,
  ): boolean {
    if (!this.canAffect(defender)) {
      return false;
    }

    if (!this.condition(moveId)) {
      return false;
    }

    if (isProtected.value) {
      return false;
    }

    isProtected.value = true;
    if (!simulated) {
      // TODO: This is a floating animation promise
      new CommonBattleAnim(CommonAnim.PROTECT, defender).play();
      globalScene.phaseManager.queueMessage(
        i18next.t(this.onProtectMessageKey, {
          pokemonNameWithAffix: getPokemonNameWithAffix(defender),
          moveName: this.getMoveName(),
          attackName: allMoves[moveId].name,
        }),
      );
    }

    ignoresProtectBypass.value ||= this.ignoresBypass;
    return true;
  }
}

/**
 * Condition function for {@link https://bulbapedia.bulbagarden.net/wiki/Quick_Guard_(move) Quick Guard's}
 * protection effect.
 * @param moveId {@linkcode MoveId} The move to check against this condition
 * @returns `true` if the incoming move's priority is greater than 0.
 *   This includes moves with modified priorities from abilities (e.g. Prankster)
 */
const QuickGuardConditionFunc: ProtectConditionFunc = moveId => {
  const move = allMoves[moveId];
  const effectPhase = globalScene.phaseManager.getCurrentPhase();

  if (effectPhase.is("MoveEffectPhase")) {
    const attacker = effectPhase.getUserPokemon();
    if (attacker) {
      return move.getPriority(attacker) > 0;
    }
  }
  return move.priority > 0;
};

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Quick_Guard_(move) Quick Guard}
 * Condition: The incoming move has increased priority.
 */
class QuickGuardTag extends ConditionalProtectTag {
  public readonly tagType = ArenaTagType.QUICK_GUARD;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.QUICK_GUARD, sourceId, side);
  }

  override get condition(): ProtectConditionFunc {
    return QuickGuardConditionFunc;
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Wide_Guard_(move) Wide Guard}
 * Condition: The incoming move can target multiple Pokemon. The move's source
 * can be an ally or enemy.
 */
class WideGuardTag extends ConditionalProtectTag {
  public readonly tagType = ArenaTagType.WIDE_GUARD;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.WIDE_GUARD, sourceId, side);
  }

  override get condition(): ProtectConditionFunc {
    return moveId => isSpreadMove(allMoves[moveId]);
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Mat_Block_(move) Mat Block}
 * Condition: The incoming move is a Physical or Special attack move.
 */
class MatBlockTag extends ConditionalProtectTag {
  public readonly tagType = ArenaTagType.MAT_BLOCK;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.MAT_BLOCK, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:matBlockOnAdd";
  }

  protected override get onProtectMessageKey(): string {
    return "arenaTag:matBlockApply";
  }

  protected override get condition(): ProtectConditionFunc {
    return moveId => allMoves[moveId].category !== MoveCategory.STATUS;
  }
}

/**
 * Condition function for {@link https://bulbapedia.bulbagarden.net/wiki/Crafty_Shield_(move) Crafty Shield's}
 * protection effect.
 * @param moveId {@linkcode MoveId} The move to check against this condition
 * @returns `true` if the incoming move is a Status move, is not a hazard, and does not target all
 * Pokemon or sides of the field.
 */
const CraftyShieldConditionFunc: ProtectConditionFunc = moveId => {
  const move = allMoves[moveId];
  return (
    move.category === MoveCategory.STATUS
    && move.moveTarget !== MoveTarget.ENEMY_SIDE
    && move.moveTarget !== MoveTarget.BOTH_SIDES
    && move.moveTarget !== MoveTarget.ALL
  );
};

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Crafty_Shield_(move) Crafty Shield}
 * Condition: The incoming move is a Status move, is not a hazard, and does
 * not target all Pokemon or sides of the field.
 */
class CraftyShieldTag extends ConditionalProtectTag {
  public readonly tagType = ArenaTagType.CRAFTY_SHIELD;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.CRAFTY_SHIELD, sourceId, side, true);
  }

  protected override get condition(): ProtectConditionFunc {
    return CraftyShieldConditionFunc;
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Lucky_Chant_(move) Lucky Chant}.
 * Prevents critical hits against the tag's side.
 */
export class NoCritTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.NO_CRIT;

  protected override get onAddMessageKey(): string {
    return "arenaTag:noCritOnAdd" + this.i18nSideKey;
  }
  protected override get onRemoveMessageKey(): string {
    return "arenaTag:noCritOnRemove" + this.i18nSideKey;
  }

  public override apply(blockCrit: BooleanHolder): void {
    blockCrit.value = true;
  }
}

/**
 * Abstract class to implement weakened moves of a specific type.
 */
export abstract class WeakenMoveTypeTag extends SerializableArenaTag {
  abstract readonly tagType: ArenaTagType.MUD_SPORT | ArenaTagType.WATER_SPORT;
  abstract get weakenedType(): PokemonType;

  /**
   * Reduces an attack's power by 0.33x if it matches this tag's weakened type.
   * @param type the attack's {@linkcode PokemonType}
   * @param power a {@linkcode NumberHolder} containing the attack's power
   * @returns `true` if the attack's power was reduced; `false` otherwise.
   */
  override apply(type: PokemonType, power: NumberHolder): boolean {
    if (type === this.weakenedType) {
      power.value *= 0.33;
      return true;
    }
    return false;
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Mud_Sport_(move) Mud Sport}.
 * Weakens Electric type moves for a set amount of turns, usually 5.
 */
class MudSportTag extends WeakenMoveTypeTag {
  public readonly tagType = ArenaTagType.MUD_SPORT;
  override get weakenedType(): PokemonType.ELECTRIC {
    return PokemonType.ELECTRIC;
  }
  constructor(turnCount: number, sourceId?: number) {
    super(turnCount, MoveId.MUD_SPORT, sourceId);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:mudSportOnAdd";
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:mudSportOnRemove";
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Water_Sport_(move) Water Sport}.
 * Weakens Fire type moves for a set amount of turns, usually 5.
 */
class WaterSportTag extends WeakenMoveTypeTag {
  public readonly tagType = ArenaTagType.WATER_SPORT;
  override get weakenedType(): PokemonType.FIRE {
    return PokemonType.FIRE;
  }
  constructor(turnCount: number, sourceId?: number) {
    super(turnCount, MoveId.WATER_SPORT, sourceId);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:waterSportOnAdd";
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:waterSportOnRemove";
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Ion_Deluge_(move) | Ion Deluge}
 * and the secondary effect of {@link https://bulbapedia.bulbagarden.net/wiki/Plasma_Fists_(move) | Plasma Fists}.
 * Converts Normal-type moves to Electric type for the rest of the turn.
 */
export class IonDelugeTag extends ArenaTag {
  public readonly tagType = ArenaTagType.ION_DELUGE;
  constructor(sourceMove?: MoveId) {
    super(1, sourceMove);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:plasmaFistsOnAdd";
  }

  protected override get onRemoveMessageKey(): string {
    return "";
  }

  /**
   * Converts Normal-type moves to Electric type
   * @param moveType a {@linkcode NumberHolder} containing a move's {@linkcode PokemonType}
   * @returns `true` if the given move type changed; `false` otherwise.
   */
  override apply(moveType: NumberHolder): boolean {
    if (moveType.value === PokemonType.NORMAL) {
      moveType.value = PokemonType.ELECTRIC;
      return true;
    }
    return false;
  }
}

/**
 * Abstract class to implement [entry hazards](https://bulbapedia.bulbagarden.net/wiki/List_of_moves_that_cause_entry_hazards).
 * These persistent tags remain on-field across turns and apply effects to any {@linkcode Pokemon} switching in. \
 * Uniquely, adding a tag multiple times may stack multiple "layers" of the effect, increasing its severity.
 */
export abstract class EntryHazardTag extends SerializableArenaTag {
  public declare abstract readonly tagType: EntryHazardTagType;
  /**
   * The current number of layers this tag has. \
   * Starts at `1` and increases each time the trap is laid.
   * @privateRemarks
   * Should not be modified by anything other than this class or its subclasses, \
   * and should (ideally) not be accessed by anything but them and the arena flyout.
   */
  public readonly layers: number = 1;
  /** The maximum number of layers this tag can have. */
  public abstract get maxLayers(): number;
  /** Whether this tag should only affect grounded targets; default `true` */
  protected get groundedOnly(): boolean {
    return true;
  }

  constructor(sourceMove: MoveId, sourceId: number | undefined, side: ArenaTagSide) {
    super(0, sourceMove, sourceId, side);
  }

  /**
   * Check if the maximum number of layers for this tag has been reached.
   * @returns Whether this tag can have another layer added to it.
   */
  public canAdd(): boolean {
    return this.layers < this.maxLayers;
  }

  /**
   * Add a new layer to this tag upon overlap, triggering the tag's normal {@linkcode onAdd} effects upon doing so.
   */
  override onOverlap(): void {
    if (!this.canAdd()) {
      return;
    }
    (this as Mutable<this>).layers++;

    this.onAdd();
  }

  /**
   * Activate the hazard effect onto a Pokemon when it enters the field.
   * @param simulated - Whether to suppress activation effects during execution
   * @param pokemon - The {@linkcode Pokemon} triggering this hazard
   * @returns `true` if this hazard affects the given Pokemon; `false` otherwise.
   */
  // TODO: Consider removing the return value; nothing uses it
  override apply(simulated: boolean, pokemon: Pokemon): boolean {
    if (!this.canAffect(pokemon)) {
      return false;
    }

    if (this.groundedOnly && !pokemon.isGrounded()) {
      return false;
    }

    return this.activateTrap(simulated, pokemon);
  }

  /**
   * Activate this trap's effects when a Pokemon switches into it.
   * @param simulated - Whether the activation is simulated
   * @param pokemon - The {@linkcode Pokemon} switching in
   * @returns Whether the trap activation succeeded
   */
  // TODO: Consider removing the return value; nothing uses it
  protected abstract activateTrap(simulated: boolean, pokemon: Pokemon): boolean;

  getMatchupScoreMultiplier(pokemon: Pokemon): number {
    return pokemon.isGrounded()
      ? 1
      : Phaser.Math.Linear(0, 1 / Math.pow(2, this.layers), Math.min(pokemon.getHpRatio(), 0.5) * 2);
  }

  public loadTag<T extends this>(source: BaseArenaTag & Pick<T, "tagType" | "layers">): void {
    super.loadTag(source);
    (this as Mutable<this>).layers = source.layers;
  }
}

/**
 * Abstract class to implement damaging entry hazards.
 * Currently used for {@linkcode SpikesTag} and {@linkcode StealthRockTag}.
 */
abstract class DamagingTrapTag extends EntryHazardTag {
  /**
   * Damage a target that switches into this Tag while active.
   * @param simulated - Whether the activation is simulated
   * @param pokemon - The {@linkcode Pokemon} switching in
   * @returns Whether the trap activation succeeded
   * @sealed
   */
  override activateTrap(simulated: boolean, pokemon: Pokemon): boolean {
    // Check for magic guard immunity
    const cancelled = new BooleanHolder(false);
    applyAbAttrs("BlockNonDirectDamageAbAttr", { pokemon, cancelled });
    if (cancelled.value) {
      return false;
    }

    if (simulated) {
      return true;
    }

    // Damage the target and trigger a message
    const damageHpRatio = this.getDamageHpRatio(pokemon);
    const damage = toDmgValue(pokemon.getMaxHp() * damageHpRatio);

    globalScene.phaseManager.queueMessage(
      i18next.t(this.triggerMessageKey, {
        pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
      }),
    );
    pokemon.damageAndUpdate(damage, { result: HitResult.INDIRECT });
    pokemon.turnData.damageTaken += damage;
    return true;
  }

  /**
   * Return the i18n key of the text to be displayed when this tag deals damage. \
   * Within the text, `{{pokemonNameWithAffix}}` will be populated with the victim's name.
   * @returns The locales key for the trigger message to be displayed on-screen.
   */
  protected abstract get triggerMessageKey(): string;

  /**
   * Return the amount of damage this tag should deal to the given Pokemon, relative to its maximum HP.
   * @param _pokemon - The {@linkcode Pokemon} switching in
   * @returns The percentage of max HP to deal upon activation.
   */
  protected abstract getDamageHpRatio(_pokemon: Pokemon): number;
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Spikes_(move) Spikes}.
 * Applies up to 3 layers of Spikes, dealing 1/8th, 1/6th, or 1/4th of the the Pokémon's HP
 * in damage for 1, 2, or 3 layers of Spikes respectively if they are summoned into this trap.
 */
class SpikesTag extends DamagingTrapTag {
  public readonly tagType = ArenaTagType.SPIKES;
  override get maxLayers() {
    return 3 as const;
  }

  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.SPIKES, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:spikesOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:spikesOnRemove" + this.i18nSideKey;
  }

  protected override get triggerMessageKey(): string {
    return "arenaTag:spikesActivateTrap";
  }

  protected override getDamageHpRatio(_pokemon: Pokemon): number {
    // 1/8 for 1 layer, 1/6 for 2, 1/4 for 3
    return 1 / (10 - 2 * this.layers);
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Stealth_Rock_(move) | Stealth Rock}.
 * Applies up to 1 layer of Stealth Rocks, dealing percentage-based damage to any Pokémon
 * who is summoned into the trap based on the Rock type's type effectiveness.
 */
class StealthRockTag extends DamagingTrapTag {
  public readonly tagType = ArenaTagType.STEALTH_ROCK;
  public override get maxLayers() {
    return 1 as const;
  }
  protected override get groundedOnly() {
    return false;
  }

  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.STEALTH_ROCK, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:stealthRockOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:stealthRockOnRemove" + this.i18nSideKey;
  }

  protected override get triggerMessageKey(): string {
    return "arenaTag:stealthRockActivateTrap";
  }

  protected override getDamageHpRatio(pokemon: Pokemon): number {
    const effectiveness = pokemon.getAttackTypeEffectiveness(PokemonType.ROCK, undefined, true);
    return 0.125 * effectiveness;
  }

  getMatchupScoreMultiplier(pokemon: Pokemon): number {
    const damageHpRatio = this.getDamageHpRatio(pokemon);
    return Phaser.Math.Linear(super.getMatchupScoreMultiplier(pokemon), 1, 1 - Math.pow(damageHpRatio, damageHpRatio));
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Toxic_Spikes_(move) | Toxic Spikes}.
 * Applies up to 2 layers of Toxic Spikes, poisoning or badly poisoning any Pokémon switched in
 * based on the current layer count. \
 * Poison-type Pokémon will remove it entirely upon switch-in.
 */
class ToxicSpikesTag extends EntryHazardTag {
  public readonly tagType = ArenaTagType.TOXIC_SPIKES;
  override get maxLayers() {
    return 2 as const;
  }

  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.TOXIC_SPIKES, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:toxicSpikesOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:toxicSpikesOnRemove" + this.i18nSideKey;
  }

  override activateTrap(simulated: boolean, pokemon: Pokemon): boolean {
    if (simulated) {
      return true;
    }

    if (pokemon.isOfType(PokemonType.POISON)) {
      // Neutralize the tag and remove it from the field.
      globalScene.arena.removeTagOnSide(this.tagType, this.side);
      return true;
    }

    // Attempt to poison the target, suppressing any status effect messages
    const effect = this.layers === 1 ? StatusEffect.POISON : StatusEffect.TOXIC;
    return pokemon.trySetStatus(effect, undefined, 0, this.getMoveName(), false, true);
  }

  getMatchupScoreMultiplier(pokemon: Pokemon): number {
    if (pokemon.isGrounded() || !pokemon.canSetStatus(StatusEffect.POISON, true)) {
      return 1;
    }
    if (pokemon.isOfType(PokemonType.POISON)) {
      return 1.25;
    }
    return super.getMatchupScoreMultiplier(pokemon);
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Sticky_Web_(move) | Sticky Web}.
 * Applies a single-layer trap that lowers the Speed of all grounded Pokémon switching in.
 */
class StickyWebTag extends EntryHazardTag {
  public readonly tagType = ArenaTagType.STICKY_WEB;
  public override get maxLayers() {
    return 1 as const;
  }

  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.STICKY_WEB, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:stickyWebOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:stickyWebOnRemove" + this.i18nSideKey;
  }

  override activateTrap(simulated: boolean, pokemon: Pokemon): boolean {
    const cancelled = new BooleanHolder(false);
    // TODO: Does this need to pass `simulated` as a parameter?
    applyAbAttrs("ProtectStatAbAttr", {
      pokemon,
      cancelled,
      stat: Stat.SPD,
      stages: -1,
    });

    if (cancelled.value) {
      return false;
    }

    if (simulated) {
      return true;
    }

    globalScene.phaseManager.queueMessage(
      i18next.t("arenaTag:stickyWebActivateTrap", {
        pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
      }),
    );

    globalScene.phaseManager.unshiftNew(
      "StatStageChangePhase",
      pokemon.getBattlerIndex(),
      false,
      [Stat.SPD],
      -1,
      true,
      false,
      true,
      null,
      false,
      true,
    );
    return true;
  }
}

/**
 * This arena tag facilitates the application of the move Imprison
 * Imprison remains in effect as long as the source Pokemon is active and present on the field.
 * Imprison will apply to any opposing Pokemon that switch onto the field as well.
 */
// TODO: refactor Imprison to no longer use an `ArenaTag` (cf https://github.com/Despair-Games/poketernity/pull/709)
class ImprisonTag extends EntryHazardTag {
  public readonly tagType = ArenaTagType.IMPRISON;
  public override get maxLayers() {
    return 1 as const;
  }

  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(MoveId.IMPRISON, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "battlerTags:imprisonOnAdd";
  }
  protected override get onRemoveMessageKey(): string {
    return "";
  }

  /**
   * Apply the effects of Imprison to all opposing on-field Pokemon.
   */
  override onAdd(quiet = false): void {
    super.onAdd(quiet);

    const party = this.getAffectedPokemon();
    party.forEach(p => {
      if (p.isAllowedInBattle()) {
        p.addTag(BattlerTagType.IMPRISON, 1, MoveId.IMPRISON, this.sourceId);
      }
    });
  }

  /**
   * Checks if the source Pokemon is still active on the field
   * @returns `true` if the source of the tag is still active on the field
   */
  override lapse(): boolean {
    const source = this.getSourcePokemon();
    return !!source?.isActive(true);
  }

  /**
   * This applies the effects of Imprison to any opposing Pokemon that switch into the field while the source Pokemon is still active
   * @param pokemon - The Pokemon Imprison is applied to
   * @returns `true`
   */
  override activateTrap(_simulated: boolean, pokemon: Pokemon): boolean {
    const source = this.getSourcePokemon();
    if (source?.isActive(true) && pokemon.isAllowedInBattle()) {
      pokemon.addTag(BattlerTagType.IMPRISON, 1, MoveId.IMPRISON, this.sourceId);
    }
    return true;
  }

  /**
   * When the arena tag is removed, it also attempts to remove any related Battler Tags if they haven't already been removed from the affected Pokemon
   */
  override onRemove(quiet = false): void {
    super.onRemove(quiet);
    const party = this.getAffectedPokemon();
    party.forEach(p => {
      p.removeTag(BattlerTagType.IMPRISON);
    });
  }
}

/**
 * Abstract base class for all Room {@linkcode ArenaTag}s, characterized by their immediate removal
 * upon overlap.
 */
abstract class RoomArenaTag extends SerializableArenaTag {
  declare abstract tagType: RoomArenaTagType;

  /**
   * Immediately remove this Tag upon overlapping.
   * @sealed
   */
  override onOverlap(): void {
    globalScene.arena.removeTagOnSide(this.tagType, this.side);
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Trick_Room_(move) Trick Room}.
 * Reverses the Speed stats for all Pokémon on the field as long as this arena tag is up,
 * also reversing the turn order for all Pokémon on the field as well.
 */
export class TrickRoomTag extends RoomArenaTag {
  public readonly tagType = ArenaTagType.TRICK_ROOM;
  constructor(turnCount: number, sourceId?: number) {
    super(turnCount, MoveId.TRICK_ROOM, sourceId);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:trickRoomOnAdd";
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:trickRoomOnRemove";
  }

  /**
   * Reverses Speed-based turn order for all Pokemon on the field
   * @param speedReversed a {@linkcode BooleanHolder} used to flag if Speed-based
   * turn order should be reversed.
   */
  override apply(speedReversed: BooleanHolder): void {
    speedReversed.value = !speedReversed.value;
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Gravity_(move) Gravity}.
 * Grounds all Pokémon on the field, including Flying-types and those with
 * {@linkcode AbilityId.LEVITATE} for the duration of the arena tag, usually 5 turns.
 */
export class GravityTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.GRAVITY;
  constructor(turnCount: number, sourceId?: number) {
    super(turnCount, MoveId.GRAVITY, sourceId);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:gravityOnAdd";
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:gravityOnRemove";
  }

  onAdd(quiet = false): void {
    super.onAdd(quiet);
    for (const pokemon of inSpeedOrder(ArenaTagSide.BOTH)) {
      if (pokemon !== null) {
        pokemon.removeTag(BattlerTagType.FLOATING);
        pokemon.removeTag(BattlerTagType.TELEKINESIS);
        if (pokemon.getTag(BattlerTagType.FLYING)) {
          pokemon.addTag(BattlerTagType.INTERRUPTED);
        }
      }
    }
  }
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Tailwind_(move) Tailwind}.
 * Doubles the Speed of the Pokémon who created this arena tag, as well as all allied Pokémon.
 * Applies this arena tag for 4 turns (including the turn the move was used).
 */
class TailwindTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.TAILWIND;
  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.TAILWIND, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:tailwindOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:tailwindOnRemove" + this.i18nSideKey;
  }

  onAdd(quiet = false): void {
    super.onAdd(quiet);
    const source = this.getSourcePokemon();

    if (source == null) {
      return;
    }

    for (const pokemon of source.getAlliesGenerator()) {
      // Apply the CHARGED tag to party members with the WIND_POWER ability
      // TODO: This should not be handled here
      if (pokemon.hasAbility(AbilityId.WIND_POWER) && !pokemon.getTag(BattlerTagType.CHARGED)) {
        pokemon.addTag(BattlerTagType.CHARGED);
        globalScene.phaseManager.queueMessage(
          i18next.t("abilityTriggers:windPowerCharged", {
            pokemonName: getPokemonNameWithAffix(pokemon),
            moveName: this.getMoveName(),
          }),
        );
      }

      // Raise attack by one stage if party member has WIND_RIDER ability
      // TODO: Ability displays should be handled by the ability
      if (pokemon.hasAbility(AbilityId.WIND_RIDER)) {
        globalScene.phaseManager.queueAbilityDisplay(pokemon, false, true);
        globalScene.phaseManager.unshiftNew(
          "StatStageChangePhase",
          pokemon.getBattlerIndex(),
          true,
          [Stat.ATK],
          1,
          true,
        );
        globalScene.phaseManager.queueAbilityDisplay(pokemon, false, false);
      }
    }
  }

  // TODO: Have the `apply` method double speed
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Happy_Hour_(move) Happy Hour}.
 * Doubles the prize money from trainers and money moves like {@linkcode MoveId.PAY_DAY} and {@linkcode MoveId.MAKE_IT_RAIN}.
 */
class HappyHourTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.HAPPY_HOUR;
  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.HAPPY_HOUR, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:happyHourOnAdd";
  }

  // Mainline technically doesn't have a "happy hour removal message", but we keep it in as nice QoL
  protected override get onRemoveMessageKey(): string {
    return "arenaTag:happyHourOnRemove";
  }
}

class SafeguardTag extends ArenaTag {
  public readonly tagType = ArenaTagType.SAFEGUARD;
  constructor(turnCount: number, sourceId: number | undefined, side: ArenaTagSide) {
    super(turnCount, MoveId.SAFEGUARD, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:safeguardOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:safeguardOnRemove" + this.i18nSideKey;
  }
}

// TODO: delete `NoneTag`
class NoneTag extends ArenaTag {
  public readonly tagType = ArenaTagType.NONE;
  constructor() {
    super(0);
  }

  protected override get onAddMessageKey(): string {
    return "";
  }

  protected override get onRemoveMessageKey(): string {
    return "";
  }
}

/**
 * Arena Tag implementing the "sea of fire" effect from the combination
 * of {@link https://bulbapedia.bulbagarden.net/wiki/Fire_Pledge_(move) | Fire Pledge}
 * and {@link https://bulbapedia.bulbagarden.net/wiki/Grass_Pledge_(move) | Grass Pledge}.
 * Damages all non-Fire-type Pokemon on the given side of the field at the end
 * of each turn for 4 turns.
 */
class FireGrassPledgeTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.FIRE_GRASS_PLEDGE;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(4, MoveId.FIRE_PLEDGE, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:fireGrassPledgeOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:fireGrassPledgeOnRemove" + this.i18nSideKey;
  }

  override lapse(): boolean {
    for (const pokemon of inSpeedOrder(this.side)) {
      if (pokemon.isOfType(PokemonType.FIRE) || pokemon.switchOutStatus) {
        continue;
      }

      // "{pokemonNameWithAffix} was hurt by the sea of fire!"
      globalScene.phaseManager.queueMessage(
        i18next.t("arenaTag:fireGrassPledgeLapse", {
          pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
        }),
      );
      // TODO: Replace this with a proper animation
      globalScene.phaseManager.unshiftNew(
        "CommonAnimPhase",
        pokemon.getBattlerIndex(),
        pokemon.getBattlerIndex(),
        CommonAnim.MAGMA_STORM,
      );
      pokemon.damageAndUpdate(toDmgValue(pokemon.getMaxHp() / 8), { result: HitResult.INDIRECT });
    }

    return super.lapse();
  }
}

/**
 * Arena Tag implementing the "rainbow" effect from the combination
 * of {@link https://bulbapedia.bulbagarden.net/wiki/Water_Pledge_(move) | Water Pledge}
 * and {@link https://bulbapedia.bulbagarden.net/wiki/Fire_Pledge_(move) | Fire Pledge}.
 * Doubles the secondary effect chance of moves from Pokemon on the
 * given side of the field for 4 turns.
 */
class WaterFirePledgeTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.WATER_FIRE_PLEDGE;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(4, MoveId.WATER_PLEDGE, sourceId, side);
  }
  protected override get onAddMessageKey(): string {
    return "arenaTag:waterFirePledgeOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:waterFirePledgeOnRemove" + this.i18nSideKey;
  }

  /**
   * Doubles the chance for the given move's secondary effect(s) to trigger
   * @param moveChance a {@linkcode NumberHolder} containing
   * the move's current effect chance
   */
  override apply(moveChance: NumberHolder): void {
    moveChance.value *= 2;
  }
}

/**
 * Arena Tag implementing the "swamp" effect from the combination
 * of {@link https://bulbapedia.bulbagarden.net/wiki/Grass_Pledge_(move) | Grass Pledge}
 * and {@link https://bulbapedia.bulbagarden.net/wiki/Water_Pledge_(move) | Water Pledge}.
 * Quarters the Speed of Pokemon on the given side of the field for 4 turns.
 */
class GrassWaterPledgeTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.GRASS_WATER_PLEDGE;
  constructor(sourceId: number | undefined, side: ArenaTagSide) {
    super(4, MoveId.GRASS_PLEDGE, sourceId, side);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:grassWaterPledgeOnAdd" + this.i18nSideKey;
  }

  protected override get onRemoveMessageKey(): string {
    return "arenaTag:grassWaterPledgeOnRemove" + this.i18nSideKey;
  }

  // TODO: Move speed drops into this class's `apply` method instead of an explicit check for it
}

/**
 * Arena Tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Fairy_Lock_(move) Fairy Lock}.
 * Fairy Lock prevents all Pokémon (except Ghost types) on the field from switching out or
 * fleeing during their next turn.
 * If a Pokémon that's on the field when Fairy Lock is used goes on to faint later in the same turn,
 * the Pokémon that replaces it will still be unable to switch out in the following turn.
 */
export class FairyLockTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.FAIRY_LOCK;
  constructor(turnCount: number, sourceId?: number) {
    super(turnCount, MoveId.FAIRY_LOCK, sourceId);
  }

  protected override get onAddMessageKey(): string {
    return "arenaTag:fairyLockOnAdd" + this.i18nSideKey;
  }
  protected override get onRemoveMessageKey(): string {
    return "";
  }
}

/**
 * Arena tag class for {@link https://bulbapedia.bulbagarden.net/wiki/Neutralizing_Gas_(Ability) Neutralizing Gas}
 *
 * Keeps track of the number of pokemon on the field with Neutralizing Gas - If it drops to zero, the effect is ended and abilities are reactivated
 *
 * Additionally ends onLose abilities when it is activated
 * @sealed
 */
export class SuppressAbilitiesTag extends SerializableArenaTag {
  // Source count is allowed to be inwardly mutable, but outwardly immutable
  public readonly sourceCount = 1;
  public readonly tagType = ArenaTagType.NEUTRALIZING_GAS;
  // Private field prevents field from appearing during serialization
  /** Whether the tag is in the process of being removed */
  #beingRemoved = false;
  /** Whether the tag is in the process of being removed */
  public get beingRemoved(): boolean {
    return this.#beingRemoved;
  }

  constructor(sourceId?: number) {
    super(0, undefined, sourceId);
  }

  // Disable on add message since we have to handle it ourself
  protected override get onAddMessageKey(): string {
    return "";
  }
  protected override get onRemoveMessageKey(): string {
    return "arenaTag:neutralizingGasOnRemove";
  }

  private playActivationMessage(pokemon: Pokemon | undefined): void {
    if (pokemon) {
      globalScene.phaseManager.queueMessage(
        i18next.t("arenaTag:neutralizingGasOnAdd", {
          pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
        }),
      );
    }
  }

  public override loadTag(source: BaseArenaTag & Pick<SuppressAbilitiesTag, "tagType" | "sourceCount">): void {
    super.loadTag(source);
    (this as Mutable<this>).sourceCount = source.sourceCount;
  }

  public override onAdd(): void {
    const pokemon = this.getSourcePokemon();
    if (pokemon) {
      this.playActivationMessage(pokemon);

      for (const fieldPokemon of inSpeedOrder(ArenaTagSide.BOTH)) {
        if (fieldPokemon.id !== pokemon.id) {
          // TODO: investigate whether we can just remove the foreach and call `applyAbAttrs` directly, providing
          // the appropriate attributes (preLEaveField and IllusionBreak)
          [true, false].forEach(passive => {
            applyOnLoseAbAttrs({ pokemon: fieldPokemon, passive });
          });
        }
      }
    }
  }

  public override onOverlap(source?: Pokemon): void {
    if (source == null) {
      return;
    }
    (this as Mutable<this>).sourceCount++;
    this.playActivationMessage(source);
  }

  public onSourceLeave(arena: Arena): void {
    (this as Mutable<this>).sourceCount--;
    if (this.sourceCount <= 0) {
      arena.removeTag(ArenaTagType.NEUTRALIZING_GAS);
    } else if (this.sourceCount === 1) {
      // With 1 source left, that pokemon's other abilities should reactivate
      // This may be confusing for players but would be the most accurate gameplay-wise
      // Could have a custom message that plays when a specific pokemon's NG ends? This entire thing exists due to passives after all
      const setter = globalScene
        .getField(true)
        .filter(p => p.hasAbilityWithAttr("PreLeaveFieldRemoveSuppressAbilitiesSourceAbAttr", false))[0];
      // Setter may not exist if both NG Pokemon faint simultaneously
      if (setter == null) {
        return;
      }

      applyOnGainAbAttrs({
        pokemon: setter,
        passive: setter.getAbility().hasAttr("PreLeaveFieldRemoveSuppressAbilitiesSourceAbAttr"),
      });
    }
  }

  public override onRemove(quiet = false) {
    this.#beingRemoved = true;
    super.onRemove(quiet);

    for (const pokemon of inSpeedOrder(ArenaTagSide.BOTH)) {
      // There is only one pokemon with this attr on the field on removal, so its abilities are already active
      if (!pokemon.hasAbilityWithAttr("PreLeaveFieldRemoveSuppressAbilitiesSourceAbAttr", false)) {
        [true, false].forEach(passive => {
          applyOnGainAbAttrs({ pokemon, passive });
        });
      }
    }
  }

  public shouldApplyToSelf(): boolean {
    return this.sourceCount > 1;
  }
}

/**
 * Interface containing data related to a queued healing effect from
 * {@link https://bulbapedia.bulbagarden.net/wiki/Healing_Wish_(move) | Healing Wish}
 * or {@link https://bulbapedia.bulbagarden.net/wiki/Lunar_Dance_(move) | Lunar Dance}.
 */
interface PendingHealEffect {
  /** The {@linkcode Pokemon.id | PID} of the {@linkcode Pokemon} that created the effect. */
  readonly sourceId: number;
  /** The {@linkcode MoveId} of the move that created the effect. */
  readonly moveId: MoveId;
  /** If `true`, also restores the target's PP when the effect activates. */
  readonly restorePP: boolean;
  /** The message to display when the effect activates */
  readonly healMessage: string;
}

/**
 * Arena tag to contain stored healing effects, namely from
 * {@link https://bulbapedia.bulbagarden.net/wiki/Healing_Wish_(move) | Healing Wish}
 * and {@link https://bulbapedia.bulbagarden.net/wiki/Lunar_Dance_(move) | Lunar Dance}.
 * When a damaged Pokemon first enters the effect's {@linkcode BattlerIndex | field position},
 * their HP is fully restored, and they are cured of any non-volatile status condition.
 * If the effect is from Lunar Dance, their PP is also restored.
 */
export class PendingHealTag extends SerializableArenaTag {
  public readonly tagType = ArenaTagType.PENDING_HEAL;
  /** All pending healing effects, organized by {@linkcode BattlerIndex} */
  public readonly pendingHeals: Partial<Record<BattlerIndex, PendingHealEffect[]>> = {};
  protected override get onAddMessageKey() {
    return "";
  }
  protected override get onRemoveMessageKey() {
    return "";
  }

  constructor() {
    super(0);
  }

  /**
   * Adds a pending healing effect to the field. Effects under the same move *and*
   * target index as an existing effect are ignored.
   * @param targetIndex - The {@linkcode BattlerIndex} under which the effect applies
   * @param healEffect - The {@linkcode PendingHealEffect | data} for the pending heal effect
   */
  public queueHeal(targetIndex: BattlerIndex, healEffect: PendingHealEffect): void {
    const existingHealEffects = this.pendingHeals[targetIndex];
    if (existingHealEffects) {
      if (!existingHealEffects.some(he => he.moveId === healEffect.moveId)) {
        existingHealEffects.push(healEffect);
      }
    } else {
      this.pendingHeals[targetIndex] = [healEffect];
    }
  }

  /** This arena tag is removed at the end of the turn if no pending healing effects are on the field */
  override lapse(): boolean {
    for (const key in this.pendingHeals) {
      if (this.pendingHeals[key].length > 0) {
        return true;
      }
    }
    return false;
  }

  /**
   * Apply a pending healing effect on the given target index
   *
   * @remarks
   * If an effect is found for the index, the Pokemon at that index is healed to
   * full HP, is cured of any non-volatile status, and has its PP fully restored
   * (if the effect is from Lunar Dance).
   *
   * @param simulated - If `true`, suppresses changes to game state
   * @param pokemon - The `pokemon` receiving the healing effect
   * @returns Whether the target Pokemon was healed by this effect
   */
  // TODO: This should also be called when a Pokemon moves into a new position via Ally Switch
  override apply(simulated: boolean, pokemon: Pokemon): boolean {
    const targetIndex = pokemon.getBattlerIndex();
    const targetEffects = this.pendingHeals[targetIndex];

    if (targetEffects == null || targetEffects.length === 0) {
      return false;
    }

    const healEffect = targetEffects.find(effect => this.canApply(effect, pokemon));

    if (healEffect == null) {
      return false;
    }

    if (simulated) {
      return true;
    }

    const { sourceId, moveId, restorePP, healMessage } = healEffect;
    const sourcePokemon = globalScene.getPokemonById(sourceId);
    if (!sourcePokemon) {
      console.warn(`Source of pending ${allMoves[moveId].name} effect is undefined!`);
      targetEffects.splice(targetEffects.indexOf(healEffect), 1);
      // Re-evaluate after the invalid heal effect is removed
      return this.apply(simulated, pokemon);
    }

    globalScene.phaseManager.unshiftNew(
      "PokemonHealPhase",
      targetIndex,
      pokemon.getMaxHp(),
      healMessage,
      true,
      false,
      false,
      true,
      false,
      restorePP,
    );

    targetEffects.splice(targetEffects.indexOf(healEffect), 1);

    return healEffect != null;
  }

  /**
   * Determines if the given {@linkcode PendingHealEffect} can immediately heal
   * the given target {@linkcode Pokemon}.
   * @param healEffect - The {@linkcode PendingHealEffect} to evaluate
   * @param pokemon - The {@linkcode Pokemon} to evaluate against
   * @returns `true` if the Pokemon can be healed by the effect
   */
  private canApply(healEffect: PendingHealEffect, pokemon: Pokemon): boolean {
    return (
      !pokemon.isFullHp()
      || pokemon.status != null
      || (healEffect.restorePP && pokemon.getMoveset().some(mv => mv.ppUsed > 0))
    );
  }

  override loadTag(source: BaseArenaTag & Pick<PendingHealTag, "tagType" | "pendingHeals">): void {
    super.loadTag(source);
    (this as Mutable<this>).pendingHeals = source.pendingHeals;
  }
}

// TODO: swap `sourceMove` and `sourceId` and make `sourceMove` an optional parameter
export function getArenaTag(
  tagType: ArenaTagType,
  turnCount: number,
  sourceMove: MoveId | undefined,
  sourceId: number | undefined,
  side: ArenaTagSide = ArenaTagSide.BOTH,
): ArenaTag | null {
  switch (tagType) {
    case ArenaTagType.MIST:
      return new MistTag(turnCount, sourceId, side);
    case ArenaTagType.QUICK_GUARD:
      return new QuickGuardTag(sourceId, side);
    case ArenaTagType.WIDE_GUARD:
      return new WideGuardTag(sourceId, side);
    case ArenaTagType.MAT_BLOCK:
      return new MatBlockTag(sourceId, side);
    case ArenaTagType.CRAFTY_SHIELD:
      return new CraftyShieldTag(sourceId, side);
    case ArenaTagType.NO_CRIT:
      return new NoCritTag(turnCount, sourceMove, sourceId, side);
    case ArenaTagType.MUD_SPORT:
      return new MudSportTag(turnCount, sourceId);
    case ArenaTagType.WATER_SPORT:
      return new WaterSportTag(turnCount, sourceId);
    case ArenaTagType.ION_DELUGE:
      return new IonDelugeTag(sourceMove);
    case ArenaTagType.SPIKES:
      return new SpikesTag(sourceId, side);
    case ArenaTagType.TOXIC_SPIKES:
      return new ToxicSpikesTag(sourceId, side);
    case ArenaTagType.STEALTH_ROCK:
      return new StealthRockTag(sourceId, side);
    case ArenaTagType.STICKY_WEB:
      return new StickyWebTag(sourceId, side);
    case ArenaTagType.TRICK_ROOM:
      return new TrickRoomTag(turnCount, sourceId);
    case ArenaTagType.GRAVITY:
      return new GravityTag(turnCount, sourceId);
    case ArenaTagType.REFLECT:
      return new ReflectTag(turnCount, sourceId, side);
    case ArenaTagType.LIGHT_SCREEN:
      return new LightScreenTag(turnCount, sourceId, side);
    case ArenaTagType.AURORA_VEIL:
      return new AuroraVeilTag(turnCount, sourceId, side);
    case ArenaTagType.TAILWIND:
      return new TailwindTag(turnCount, sourceId, side);
    case ArenaTagType.HAPPY_HOUR:
      return new HappyHourTag(turnCount, sourceId, side);
    case ArenaTagType.SAFEGUARD:
      return new SafeguardTag(turnCount, sourceId, side);
    case ArenaTagType.IMPRISON:
      return new ImprisonTag(sourceId, side);
    case ArenaTagType.FIRE_GRASS_PLEDGE:
      return new FireGrassPledgeTag(sourceId, side);
    case ArenaTagType.WATER_FIRE_PLEDGE:
      return new WaterFirePledgeTag(sourceId, side);
    case ArenaTagType.GRASS_WATER_PLEDGE:
      return new GrassWaterPledgeTag(sourceId, side);
    case ArenaTagType.FAIRY_LOCK:
      return new FairyLockTag(turnCount, sourceId);
    case ArenaTagType.NEUTRALIZING_GAS:
      return new SuppressAbilitiesTag(sourceId);
    case ArenaTagType.PENDING_HEAL:
      return new PendingHealTag();
    default:
      return null;
  }
}

/**
 * When given a battler tag or json representing one, creates an actual ArenaTag object with the same data.
 * @param source - An arena tag
 * @returns The valid arena tag
 */
export function loadArenaTag(source: ArenaTag | ArenaTagData | { tagType: ArenaTagType.NONE }): ArenaTag {
  if (source.tagType === ArenaTagType.NONE) {
    return new NoneTag();
  }
  const tag =
    getArenaTag(source.tagType, source.turnCount, source.sourceMove, source.sourceId, source.side) ?? new NoneTag();
  tag.loadTag(source);
  return tag;
}

export type ArenaTagTypeMap = {
  [ArenaTagType.MUD_SPORT]: MudSportTag;
  [ArenaTagType.WATER_SPORT]: WaterSportTag;
  [ArenaTagType.ION_DELUGE]: IonDelugeTag;
  [ArenaTagType.SPIKES]: SpikesTag;
  [ArenaTagType.MIST]: MistTag;
  [ArenaTagType.QUICK_GUARD]: QuickGuardTag;
  [ArenaTagType.WIDE_GUARD]: WideGuardTag;
  [ArenaTagType.MAT_BLOCK]: MatBlockTag;
  [ArenaTagType.CRAFTY_SHIELD]: CraftyShieldTag;
  [ArenaTagType.NO_CRIT]: NoCritTag;
  [ArenaTagType.TOXIC_SPIKES]: ToxicSpikesTag;
  [ArenaTagType.STEALTH_ROCK]: StealthRockTag;
  [ArenaTagType.STICKY_WEB]: StickyWebTag;
  [ArenaTagType.TRICK_ROOM]: TrickRoomTag;
  [ArenaTagType.GRAVITY]: GravityTag;
  [ArenaTagType.REFLECT]: ReflectTag;
  [ArenaTagType.LIGHT_SCREEN]: LightScreenTag;
  [ArenaTagType.AURORA_VEIL]: AuroraVeilTag;
  [ArenaTagType.TAILWIND]: TailwindTag;
  [ArenaTagType.HAPPY_HOUR]: HappyHourTag;
  [ArenaTagType.SAFEGUARD]: SafeguardTag;
  [ArenaTagType.IMPRISON]: ImprisonTag;
  [ArenaTagType.FIRE_GRASS_PLEDGE]: FireGrassPledgeTag;
  [ArenaTagType.WATER_FIRE_PLEDGE]: WaterFirePledgeTag;
  [ArenaTagType.GRASS_WATER_PLEDGE]: GrassWaterPledgeTag;
  [ArenaTagType.FAIRY_LOCK]: FairyLockTag;
  [ArenaTagType.NEUTRALIZING_GAS]: SuppressAbilitiesTag;
  [ArenaTagType.PENDING_HEAL]: PendingHealTag;
  [ArenaTagType.NONE]: NoneTag;
};