[Move] Fully Implement Secret Power (#4647)

* initial work

* move go

* biomes for damo

* more cleanup

* added effect for space

* test

* balance change 1

* i'm silly

* fixed effect cahnce

* secret power atr

* Apply suggestions from code review

Co-authored-by: NightKev <34855794+DayKev@users.noreply.github.com>

* got tests to work + added final balance biomes

* added documentation

* Apply suggestions from code review

Co-authored-by: NightKev <34855794+DayKev@users.noreply.github.com>

* Update src/data/move.ts

Co-authored-by: NightKev <34855794+DayKev@users.noreply.github.com>

---------

Co-authored-by: frutescens <info@laptop>
Co-authored-by: NightKev <34855794+DayKev@users.noreply.github.com>

src/data/move.ts

@@ -1024,7 +1024,7 @@ export class MoveEffectAttr extends MoveAttr {
 
     applyAbAttrs(MoveEffectChanceMultiplierAbAttr, user, null, false, moveChance, move, target, selfEffect, showAbility);
 
-    if (!move.hasAttr(FlinchAttr) || moveChance.value <= move.chance) {
+    if ((!move.hasAttr(FlinchAttr) || moveChance.value <= move.chance) && !move.hasAttr(SecretPowerAttr)) {
       const userSide = user.isPlayer() ? ArenaTagSide.PLAYER : ArenaTagSide.ENEMY;
       user.scene.arena.applyTagsForSide(ArenaTagType.WATER_FIRE_PLEDGE, userSide, false, moveChance);
     }
@@ -2875,6 +2875,162 @@ export class StatStageChangeAttr extends MoveEffectAttr {
   }
 }
 
+/**
+ * Attribute used to determine the Biome/Terrain-based secondary effect of Secret Power
+ */
+export class SecretPowerAttr extends MoveEffectAttr {
+  constructor() {
+    super(false);
+  }
+
+  /**
+   * Used to determine if the move should apply a secondary effect based on Secret Power's 30% chance
+   * @returns `true` if the move's secondary effect should apply
+   */
+  override canApply(user: Pokemon, target: Pokemon, move: Move, args?: any[]): boolean {
+    this.effectChanceOverride = move.chance;
+    const moveChance = this.getMoveChance(user, target, move, this.selfTarget);
+    if (moveChance < 0 || moveChance === 100 || user.randSeedInt(100) < moveChance) {
+      // effectChanceOverride used in the application of the actual secondary effect
+      this.effectChanceOverride = 100;
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  /**
+   * Used to apply the secondary effect to the target Pokemon
+   * @returns `true` if a secondary effect is successfully applied
+   */
+  override apply(user: Pokemon, target: Pokemon, move: Move, args?: any[]): boolean | Promise<boolean> {
+    if (!super.apply(user, target, move, args)) {
+      return false;
+    }
+    let secondaryEffect: MoveEffectAttr;
+    const terrain = user.scene.arena.getTerrainType();
+    if (terrain !== TerrainType.NONE) {
+      secondaryEffect = this.determineTerrainEffect(terrain);
+    } else {
+      const biome = user.scene.arena.biomeType;
+      secondaryEffect = this.determineBiomeEffect(biome);
+    }
+    return secondaryEffect.apply(user, target, move, []);
+  }
+
+  /**
+   * Determines the secondary effect based on terrain.
+   * Takes precedence over biome-based effects.
+   * ```
+   * Electric Terrain | Paralysis
+   * Misty Terrain    | SpAtk -1
+   * Grassy Terrain   | Sleep
+   * Psychic Terrain  | Speed -1
+   * ```
+   * @param terrain - {@linkcode TerrainType} The current terrain
+   * @returns the chosen secondary effect {@linkcode MoveEffectAttr}
+   */
+  private determineTerrainEffect(terrain: TerrainType): MoveEffectAttr {
+    let secondaryEffect: MoveEffectAttr;
+    switch (terrain) {
+    case TerrainType.ELECTRIC:
+    default:
+      secondaryEffect = new StatusEffectAttr(StatusEffect.PARALYSIS, false);
+      break;
+    case TerrainType.MISTY:
+      secondaryEffect = new StatStageChangeAttr([ Stat.SPATK ], -1, false);
+      break;
+    case TerrainType.GRASSY:
+      secondaryEffect = new StatusEffectAttr(StatusEffect.SLEEP, false);
+      break;
+    case TerrainType.PSYCHIC:
+      secondaryEffect = new StatStageChangeAttr([ Stat.SPD ], -1, false);
+      break;
+    }
+    return secondaryEffect;
+  }
+
+  /**
+   * Determines the secondary effect based on biome
+   * ```
+   * Town, Metropolis, Slum, Dojo, Laboratory, Power Plant + Default | Paralysis
+   * Plains, Grass, Tall Grass, Forest, Jungle, Meadow               | Sleep
+   * Swamp, Mountain, Temple, Ruins                                  | Speed -1
+   * Ice Cave, Snowy Forest                                          | Freeze
+   * Volcano                                                         | Burn
+   * Fairy Cave                                                      | SpAtk -1
+   * Desert, Construction Site, Beach, Island, Badlands              | Accuracy -1
+   * Sea, Lake, Seabed                                               | Atk -1
+   * Cave, Wasteland, Graveyard, Abyss, Space                        | Flinch
+   * End                                                             | Def -1
+   * ```
+   * @param biome - The current {@linkcode Biome} the battle is set in
+   * @returns the chosen secondary effect {@linkcode MoveEffectAttr}
+   */
+  private determineBiomeEffect(biome: Biome): MoveEffectAttr {
+    let secondaryEffect: MoveEffectAttr;
+    switch (biome) {
+    case Biome.PLAINS:
+    case Biome.GRASS:
+    case Biome.TALL_GRASS:
+    case Biome.FOREST:
+    case Biome.JUNGLE:
+    case Biome.MEADOW:
+      secondaryEffect = new StatusEffectAttr(StatusEffect.SLEEP, false);
+      break;
+    case Biome.SWAMP:
+    case Biome.MOUNTAIN:
+    case Biome.TEMPLE:
+    case Biome.RUINS:
+      secondaryEffect = new StatStageChangeAttr([ Stat.SPD ], -1, false);
+      break;
+    case Biome.ICE_CAVE:
+    case Biome.SNOWY_FOREST:
+      secondaryEffect = new StatusEffectAttr(StatusEffect.FREEZE, false);
+      break;
+    case Biome.VOLCANO:
+      secondaryEffect = new StatusEffectAttr(StatusEffect.BURN, false);
+      break;
+    case Biome.FAIRY_CAVE:
+      secondaryEffect = new StatStageChangeAttr([ Stat.SPATK ], -1, false);
+      break;
+    case Biome.DESERT:
+    case Biome.CONSTRUCTION_SITE:
+    case Biome.BEACH:
+    case Biome.ISLAND:
+    case Biome.BADLANDS:
+      secondaryEffect = new StatStageChangeAttr([ Stat.ACC ], -1, false);
+      break;
+    case Biome.SEA:
+    case Biome.LAKE:
+    case Biome.SEABED:
+      secondaryEffect = new StatStageChangeAttr([ Stat.ATK ], -1, false);
+      break;
+    case Biome.CAVE:
+    case Biome.WASTELAND:
+    case Biome.GRAVEYARD:
+    case Biome.ABYSS:
+    case Biome.SPACE:
+      secondaryEffect = new AddBattlerTagAttr(BattlerTagType.FLINCHED, false, true);
+      break;
+    case Biome.END:
+      secondaryEffect = new StatStageChangeAttr([ Stat.DEF ], -1, false);
+      break;
+    case Biome.TOWN:
+    case Biome.METROPOLIS:
+    case Biome.SLUM:
+    case Biome.DOJO:
+    case Biome.FACTORY:
+    case Biome.LABORATORY:
+    case Biome.POWER_PLANT:
+    default:
+      secondaryEffect = new StatusEffectAttr(StatusEffect.PARALYSIS, false);
+      break;
+    }
+    return secondaryEffect;
+  }
+}
+
 export class PostVictoryStatStageChangeAttr extends MoveAttr {
   private stats: BattleStat[];
   private stages: number;
@@ -7898,7 +8054,7 @@ export function initMoves() {
       .unimplemented(),
     new AttackMove(Moves.SECRET_POWER, Type.NORMAL, MoveCategory.PHYSICAL, 70, 100, 20, 30, 0, 3)
       .makesContact(false)
-      .partial(), // No effect implemented
+      .attr(SecretPowerAttr),
     new AttackMove(Moves.DIVE, Type.WATER, MoveCategory.PHYSICAL, 80, 100, 10, -1, 0, 3)
       .attr(ChargeAttr, ChargeAnim.DIVE_CHARGING, i18next.t("moveTriggers:hidUnderwater", { pokemonName: "{USER}" }), BattlerTagType.UNDERWATER, true)
       .attr(GulpMissileTagAttr)

src/test/moves/secret_power.test.ts

@@ -0,0 +1,89 @@
+import { Abilities } from "#enums/abilities";
+import { Biome } from "#enums/biome";
+import { Moves } from "#enums/moves";
+import { Stat } from "#enums/stat";
+import { allMoves, SecretPowerAttr } from "#app/data/move";
+import { Species } from "#enums/species";
+import GameManager from "#test/utils/gameManager";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { StatusEffect } from "#enums/status-effect";
+import { BattlerIndex } from "#app/battle";
+import { ArenaTagType } from "#enums/arena-tag-type";
+import { ArenaTagSide } from "#app/data/arena-tag";
+
+describe("Moves - Secret Power", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override
+      .moveset([ Moves.SECRET_POWER ])
+      .ability(Abilities.BALL_FETCH)
+      .battleType("single")
+      .disableCrits()
+      .enemySpecies(Species.MAGIKARP)
+      .enemyLevel(60)
+      .enemyAbility(Abilities.BALL_FETCH);
+  });
+
+  it("Secret Power checks for an active terrain first then looks at the biome for its secondary effect", async () => {
+    game.override
+      .startingBiome(Biome.VOLCANO)
+      .enemyMoveset([ Moves.SPLASH, Moves.MISTY_TERRAIN ]);
+    vi.spyOn(allMoves[Moves.SECRET_POWER], "chance", "get").mockReturnValue(100);
+    await game.classicMode.startBattle([ Species.FEEBAS ]);
+
+    const enemyPokemon  = game.scene.getEnemyPokemon()!;
+
+    // No Terrain + Biome.VOLCANO --> Burn
+    game.move.select(Moves.SECRET_POWER);
+    await game.forceEnemyMove(Moves.SPLASH);
+    await game.phaseInterceptor.to("TurnEndPhase");
+    expect(enemyPokemon.status?.effect).toBe(StatusEffect.BURN);
+
+    // Misty Terrain --> SpAtk -1
+    game.move.select(Moves.SECRET_POWER);
+    await game.forceEnemyMove(Moves.MISTY_TERRAIN);
+    await game.phaseInterceptor.to("TurnEndPhase");
+    expect(enemyPokemon.getStatStage(Stat.SPATK)).toBe(-1);
+  });
+
+  it("the 'rainbow' effect of fire+water pledge does not double the chance of secret power's secondary effect",
+    async () => {
+      game.override
+        .moveset([ Moves.FIRE_PLEDGE, Moves.WATER_PLEDGE, Moves.SECRET_POWER, Moves.SPLASH ])
+        .enemyMoveset([ Moves.SPLASH ])
+        .battleType("double");
+      await game.classicMode.startBattle([ Species.BLASTOISE, Species.CHARIZARD ]);
+
+      const secretPowerAttr = allMoves[Moves.SECRET_POWER].getAttrs(SecretPowerAttr)[0];
+      vi.spyOn(secretPowerAttr, "getMoveChance");
+
+      game.move.select(Moves.WATER_PLEDGE, 0, BattlerIndex.ENEMY);
+      game.move.select(Moves.FIRE_PLEDGE, 1, BattlerIndex.ENEMY_2);
+
+      await game.phaseInterceptor.to("TurnEndPhase");
+
+      expect(game.scene.arena.getTagOnSide(ArenaTagType.WATER_FIRE_PLEDGE, ArenaTagSide.PLAYER)).toBeDefined();
+
+      game.move.select(Moves.SECRET_POWER, 0, BattlerIndex.ENEMY);
+      game.move.select(Moves.SPLASH, 1);
+
+      await game.phaseInterceptor.to("BerryPhase", false);
+
+      expect(secretPowerAttr.getMoveChance).toHaveLastReturnedWith(30);
+    }
+  );
+});