Crystal/tests/overworld-rom.test.ts

import { describe, expect, it } from "vitest";
import { existsSync, readFileSync } from "node:fs";
import { CrystalAssets } from "../src/game/rom/assets";
import { GameWorld } from "../src/game/world/world";
import { emptyScriptState } from "../src/game/scripts/interpreter";
import { generatePartyMon } from "../src/game/party/pokemon";
import type { Direction } from "../src/game/world/types";
import { settle, walkTo } from "./world-driver";

const romPath =
  process.env.CRYSTAL_ROM_PATH ??
  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
const BURNED_TOWER_1F = "3:13",
  BURNED_TOWER_B1F = "3:14";
const EVENT_HOLE_IN_BURNED_TOWER = 818;

/** A world on maps that normal play does not enable yet. */
function fixture(maps: string[]) {
  const assets = new CrystalAssets(new Uint8Array(readFileSync(romPath)));
  const ported = assets.isPorted.bind(assets);
  assets.isPorted = (id) => ported(id) || maps.includes(id);
  const world = new GameWorld(assets, () => new Date("2026-09-22T12:00:00"), () => 0);
  world.state = emptyScriptState();
  return { assets, world };
}

function hold(world: GameWorld, direction: Direction | undefined, ticks: number) {
  for (let tick = 0; tick < ticks; tick++) world.tick(direction);
}

describe.skipIf(!existsSync(romPath))("overworld foundation with the local ROM", () => {
  it("changeblock in Burned Tower's TILES callback closes the hole until the event is set", () => {
    const { assets, world } = fixture([BURNED_TOWER_1F, BURNED_TOWER_B1F]);
    world.state.scenes[BURNED_TOWER_1F] = 2; // SCENE_BURNEDTOWER1F_NOOP
    world.warpTo(BURNED_TOWER_1F, 10, 10);
    expect(assets.permission(assets.collision(world.map, 10, 9))).toBe(0);
    expect(assets.collision(world.map, 10, 9)).not.toBe(0x60);
    // The ROM's own block data still has the hole; only the working copy changed.
    expect(assets.collision(assets.map(BURNED_TOWER_1F), 10, 9)).toBe(0x60);
    world.state.events.add(EVENT_HOLE_IN_BURNED_TOWER);
    world.warpTo(BURNED_TOWER_1F, 10, 10);
    expect(assets.collision(world.map, 10, 9)).toBe(0x60);
  });

  it("falls through a pit with FallIntoMapScript's skyfall and earthquake", () => {
    const { world } = fixture([BURNED_TOWER_1F, BURNED_TOWER_B1F]);
    world.state.scenes[BURNED_TOWER_1F] = 2;
    world.state.scenes[BURNED_TOWER_B1F] = 1;
    world.state.events.add(EVENT_HOLE_IN_BURNED_TOWER);
    world.warpTo(BURNED_TOWER_1F, 10, 10);
    // Turn, then walk up onto the hole.
    hold(world, "up", 4);
    hold(world, "up", 8);
    expect([world.mapId, world.x, world.y]).toEqual([BURNED_TOWER_1F, 10, 9]);
    // The arrival tick falls through; the next starts the rest of the script.
    hold(world, undefined, 2);
    expect(world.notice, world.diagnostic).toBe("");
    expect([world.mapId, world.x, world.y]).toEqual([BURNED_TOWER_B1F, 10, 9]);
    expect(world.activity).toBe("scene");
    // Invisible above the screen at first, then falling into view.
    expect(world.poses().some((pose) => pose.id === 0)).toBe(false);
    let shook = false;
    for (let tick = 0; tick < 200 && world.busy; tick++) {
      world.tick();
      if (world.screenShake) shook = true;
    }
    expect(world.busy).toBe(false);
    expect(shook).toBe(true);
    expect(world.notice, world.diagnostic).toBe("");
    expect(world.poses().find((pose) => pose.id === 0)).toMatchObject({ x: 160, y: 144 });
  });

  it("rides the Goldenrod Dept. Store elevator through its menu and -1 warps", () => {
    const [store1F, store3F, elevator] = ["11:11", "11:13", "11:17"];
    const { world } = fixture([store1F, store3F, elevator]);
    world.warpTo(store1F, 2, 1);
    walkTo(world, 2, 0);
    expect([world.mapId, world.x, world.y]).toEqual([elevator, 1, 3]);
    // The arrival warp is numbered -1, so the entrance became the backup.
    expect(world.state.backupWarp).toEqual({ map: store1F, warp: 4 });
    walkTo(world, 3, 1);
    world.move("up");
    world.interact();
    const menu = world.dialogue!;
    const shown = settle(world, [3]);
    expect(shown.join("\n")).toContain("Now on: 1F");
    expect(menu.choice).toMatchObject({ kind: "menu" });
    expect((menu.choice as { items: string[] }).items).toEqual([
      "B1F", "1F", "2F", "3F", "4F", "5F", "6F",
    ]);
    expect(world.notice, world.diagnostic).toBe("");
    expect(world.state.backupWarp).toEqual({ map: store3F, warp: 3 });
    walkTo(world, 2, 3);
    world.move("down");
    settle(world);
    // Arrival at warp 3 (2, 0), then the doorway's forced step down.
    expect([world.mapId, world.x, world.y]).toEqual([store3F, 2, 1]);
    expect(world.notice, world.diagnostic).toBe("");
  });

  it("keeps the floor when the elevator menu is cancelled or the same floor is chosen", () => {
    const [store1F, elevator] = ["11:11", "11:17"];
    const { world } = fixture([store1F, elevator]);
    world.warpTo(store1F, 2, 1);
    walkTo(world, 2, 0);
    walkTo(world, 3, 1);
    world.move("up");
    for (const answer of [-1, 1]) {
      world.interact();
      settle(world, [answer]);
      expect(world.notice, world.diagnostic).toBe("");
      expect(world.state.backupWarp).toEqual({ map: store1F, warp: 4 });
    }
  });

  describe("wild encounters (CanEncounterWildMon and ChooseWildEncounter)", () => {
    const UNION_CAVE_1F = "3:37";
    const cave = () => {
      const { assets, world } = fixture([UNION_CAVE_1F]);
      world.state.party = [
        generatePartyMon(assets.pokemon, {
          species: 155, level: 20, item: 0, otId: 1, ot: "CHRIS", dvs: 0, caughtData: 0,
        }),
      ];
      return { assets, world };
    };
    /** Walk back and forth until a battle starts or the steps run out. */
    const pace = (world: GameWorld, steps: number, directions: Direction[]) => {
      for (let step = 0; step < steps && !world.battle; step++) {
        world.move(directions[step % directions.length]);
        for (let tick = 0; tick < 4 && !world.battle; tick++) world.tick();
      }
      return world.battle?.engine;
    };

    it("starts on any cave floor after the five-step cooldown", () => {
      const { world } = cave();
      world.warpTo(UNION_CAVE_1F, 9, 6);
      const battle = pace(world, 12, ["right", "left"]);
      expect(world.notice, world.diagnostic).toBe("");
      expect(battle).toBeDefined();
      expect(world.tilesWalked).toBe(5);
    });

    it("stays off with wildoff", () => {
      const { world } = cave();
      world.state.noWildEncounters = true;
      world.warpTo(UNION_CAVE_1F, 9, 6);
      expect(pace(world, 12, ["right", "left"])).toBeUndefined();
    });

    it("uses the water table's rate and slots while surfing", () => {
      const { assets, world } = cave();
      const sea = assets.waterWildMons(UNION_CAVE_1F)!;
      expect(sea).toBeDefined();
      world.state.playerState = 4; // PLAYER_SURF
      world.restore({ ...world.save(), map: UNION_CAVE_1F, x: 7, y: 4, direction: "right", objects: [] });
      const battle = pace(world, 12, ["right", "left"]);
      expect(battle).toBeDefined();
      // Random is always 0: the first slot, with no level variety.
      expect(battle!.enemy.mon).toMatchObject({
        species: sea.slots[0].species,
        level: sea.slots[0].level,
      });
    });
  });

  it("draws overworld Pokémon from their party menu icons (GetMonSprite)", () => {
    const { assets } = fixture([]);
    const unown = assets.sprite(0x80)!; // SPRITE_UNOWN
    expect(unown.walking).toBe(true);
    expect(unown.palette).toBe(0);
    expect(unown.graphics).toHaveLength(8 * 16);
    expect(assets.sprite(0x80 + 35)).toBeUndefined();
    expect(assets.sprite(103)).toBeUndefined();
  });

  it("surfing onto a whirlpool spins the player back with Script_ForcedMovement", () => {
    const { assets, world } = fixture([]);
    // Find a whirlpool with water on the side a surfer comes from.
    let found: { map: string; x: number; y: number } | undefined;
    for (let group = 1; group <= 26 && !found; group++)
      for (let number = 1; number <= 40 && !found; number++) {
        let map;
        try {
          map = assets.map(`${group}:${number}`);
        } catch {
          continue;
        }
        for (let y = 1; y < map.height - 1 && !found; y++)
          for (let x = 0; x < map.width && !found; x++)
            if (
              assets.collision(map, x, y) === 0x24 &&
              assets.permission(assets.collision(map, x, y + 1)) === 1 &&
              assets.permission(assets.collision(map, x, y + 2)) === 1 &&
              !map.objects.some((o) => o.x === x && (o.y === y + 1 || o.y === y + 2))
            )
              found = { map: map.id, x, y };
      }
    expect(found).toBeDefined();
    const { map, x, y } = found!;
    const ported = assets.isPorted.bind(assets);
    assets.isPorted = (id) => ported(id) || id === map;
    world.state.playerState = 4; // PLAYER_SURF
    world.restore({ ...world.save(), map, x, y: y + 2, direction: "up", objects: [] });
    hold(world, "up", 8);
    expect([world.x, world.y]).toEqual([x, y + 1]);
    hold(world, "up", 9);
    expect([world.x, world.y]).toEqual([x, y]);
    expect(world.activity).toBe("scene");
    const directions = new Set<string>();
    for (let tick = 0; tick < 120 && world.busy; tick++) {
      world.tick();
      directions.add(world.direction);
    }
    expect(world.notice, world.diagnostic).toBe("");
    // .MovementData_up: spin, turn_in DOWN back off the whirlpool, spin,
    // then face down.
    expect([world.x, world.y, world.direction]).toEqual([x, y + 1, "down"]);
    expect(directions.size).toBe(4);
  });
});

describe.skipIf(!existsSync(romPath))("field moves with the local ROM", () => {
  const TOTODILE = 158;
  const partyWith = (assets: CrystalAssets, moves: number[], species = TOTODILE) => {
    const mon = generatePartyMon(assets.pokemon, {
      species, level: 30, item: 0, otId: 1, ot: "CHRIS", dvs: 0, caughtData: 0,
    });
    mon.moves = [...moves, 0, 0, 0, 0].slice(0, 4) as typeof mon.moves;
    mon.pp = [10, 10, 10, 10];
    mon.nickname = "SWIMMY";
    return [mon];
  };
  /** Find a tile on some map, searching every group. */
  const find = (
    assets: CrystalAssets,
    test: (map: ReturnType<CrystalAssets["map"]>, x: number, y: number) => boolean,
  ) => {
    for (let group = 1; group <= 26; group++)
      for (let number = 1; number <= 60; number++) {
        let map;
        try {
          map = assets.map(`${group}:${number}`);
        } catch {
          continue;
        }
        for (let y = 1; y < map.height - 1; y++)
          for (let x = 1; x < map.width - 1; x++) if (test(map, x, y)) return { map: map.id, x, y };
      }
    throw new Error("No suitable tile.");
  };

  it("surfs from New Bark Town's shore through AskSurfScript and lands again", () => {
    const { assets, world } = fixture([]);
    world.state.party = partyWith(assets, [0x39]); // SURF
    world.state.flags.add(30); // ENGINE_FOGBADGE
    world.state.scenes["24:4"] = 1;
    world.restore({ ...world.save(), map: "24:4", x: 17, y: 7, direction: "right", objects: [] });
    world.interact();
    const shown = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown).toContain("SWIMMY used\nSURF!");
    expect(world.state.playerState).toBe(4);
    expect([world.x, world.y]).toEqual([18, 7]);
    // The surfer sprite (SPRITE_SURF) replaces Chris.
    expect(world.poses().find((pose) => pose.id === 0)?.sprite).toBe(0x53);
    // Water saves and reloads with the surfer on it.
    world.restore(world.save());
    expect(world.state.playerState).toBe(4);
    world.move("left");
    expect([world.x, world.y, world.state.playerState]).toEqual([17, 7, 0]);
  });

  it("does not offer Surf without the Fog Badge or a Pokémon that knows it", () => {
    const { assets, world } = fixture([]);
    world.state.party = partyWith(assets, [0x39]);
    world.state.scenes["24:4"] = 1;
    world.restore({ ...world.save(), map: "24:4", x: 17, y: 7, direction: "right", objects: [] });
    world.interact();
    expect(world.dialogue).toBeUndefined();
    world.state.flags.add(30);
    world.state.party = partyWith(assets, [0x0f]);
    world.interact();
    expect(world.dialogue).toBeUndefined();
  });

  it("cuts a tree with AskCutScript until the map loads again", () => {
    const { assets, world } = fixture([]);
    const spot = find(assets, (map, x, y) =>
      [1, 2, 3, 12, 25].includes(map.tileset) &&
      assets.collision(map, x, y) === 0x12 &&
      assets.permission(assets.collision(map, x, y + 1)) === 0 &&
      !map.objects.some((o) => o.x === x && o.y === y + 1) &&
      map.callbacks.length === 0,
    );
    const ported = assets.isPorted.bind(assets);
    assets.isPorted = (id) => ported(id) || id === spot.map;
    world.state.party = partyWith(assets, [0x0f]); // CUT
    world.state.flags.add(28); // ENGINE_HIVEBADGE
    world.warpTo(spot.map, spot.x, spot.y + 1);
    world.restore({ ...world.save(), direction: "up" });
    const before = world.map.blocks.slice();
    world.interact();
    const shown = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown).toContain("SWIMMY used\nCUT!");
    expect(world.map.blocks).not.toEqual(before);
    expect(assets.permission(assets.collision(world.map, spot.x, spot.y))).toBe(0);
    world.move("up");
    expect([world.x, world.y]).toEqual([spot.x, spot.y]);
    world.warpTo(spot.map, spot.x, spot.y + 1);
    expect(world.map.blocks).toEqual(before);
  });

  it("explains a Cut tree without the move", () => {
    const { assets, world } = fixture([]);
    const spot = find(assets, (map, x, y) =>
      assets.collision(map, x, y) === 0x12 &&
      assets.permission(assets.collision(map, x, y + 1)) === 0 &&
      !map.objects.some((o) => o.x === x && o.y === y + 1) &&
      map.callbacks.length === 0,
    );
    const ported = assets.isPorted.bind(assets);
    assets.isPorted = (id) => ported(id) || id === spot.map;
    world.state.party = partyWith(assets, [0x21]);
    world.warpTo(spot.map, spot.x, spot.y + 1);
    world.restore({ ...world.save(), direction: "up" });
    world.interact();
    const shown = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown.length).toBeGreaterThan(0);
    expect(assets.permission(assets.collision(world.map, spot.x, spot.y))).not.toBe(0);
  });

  it("uses Strength through AskStrengthScript and pushes a boulder", () => {
    const { assets, world } = fixture([]);
    // A Strength boulder object with floor below it and two floor tiles above.
    const spot = find(assets, (map, x, y) => {
      const boulder = map.objects.find(
        (o) => o.x === x && o.y === y && o.movement === 25 && o.eventFlag === 0xffff,
      );
      return Boolean(
        boulder &&
          map.callbacks.length === 0 &&
          [y + 1, y - 1, y - 2].every(
            (row) =>
              assets.permission(assets.collision(map, x, row)) === 0 &&
              !map.objects.some((o) => o !== boulder && o.x === x && o.y === row),
          ),
      );
    });
    const ported = assets.isPorted.bind(assets);
    assets.isPorted = (id) => ported(id) || id === spot.map;
    world.state.party = partyWith(assets, [0x46]); // STRENGTH
    world.state.flags.add(29); // ENGINE_PLAINBADGE
    world.warpTo(spot.map, spot.x, spot.y + 1);
    world.restore({ ...world.save(), direction: "up" });
    world.interact();
    const shown = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown).toContain("SWIMMY used\nSTRENGTH!");
    expect(world.state.flags.has(24)).toBe(true); // ENGINE_STRENGTH_ACTIVE
    for (let tick = 0; tick < 20; tick++) world.tick("up");
    const boulder = world.objects().find((o) => o.movement === 25 && o.x === spot.x);
    expect(boulder?.y).toBe(spot.y - 1);
    // Talking to it again: "Boulders may now be moved!"
    settle(world);
  });

  it("rides the Bicycle on a route and gets off indoors", () => {
    const { assets, world } = fixture([]);
    world.state.party = partyWith(assets, [0x21]);
    world.state.bag.keyItems.push(7); // BICYCLE
    world.state.scenes["24:4"] = 1;
    world.restore({ ...world.save(), map: "24:4", x: 13, y: 7, direction: "down", objects: [] });
    expect(world.useBicycle()).toBe(true);
    const shown = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown).toContain("got on the\nBICYCLE.");
    expect(world.state.playerState).toBe(1);
    expect(world.poses().find((pose) => pose.id === 0)?.sprite).toBe(2); // SPRITE_CHRIS_BIKE
    // Turn left (four ticks), then four ticks per tile on the bike.
    for (let tick = 0; tick < 4; tick++) world.tick("left");
    world.tick("left");
    expect(world.x).toBe(12);
    for (let tick = 0; tick < 4; tick++) world.tick("left");
    expect(world.x).toBe(11);
    // Entering the house (indoors) gets the player off (CheckUpdatePlayerSprite).
    settle(world);
    walkTo(world, 13, 5);
    expect(world.mapId).toBe("24:6");
    expect(world.state.playerState).toBe(0);
    expect(world.useBicycle()).toBe(false);
  });

  it("offers Whirlpool and Waterfall only with the move and badge", () => {
    const { assets, world } = fixture([]);
    world.state.party = partyWith(assets, [0x39]);
    const whirlpool = find(assets, (map, x, y) =>
      assets.collision(map, x, y) === 0x24 &&
      assets.permission(assets.collision(map, x, y + 1)) === 1 &&
      !map.objects.some((o) => o.x === x && o.y === y + 1),
    );
    const ported = assets.isPorted.bind(assets);
    assets.isPorted = (id) => ported(id) || id === whirlpool.map;
    world.state.playerState = 4;
    world.restore({ ...world.save(), map: whirlpool.map, x: whirlpool.x, y: whirlpool.y + 1, direction: "up", objects: [] });
    world.interact();
    const mighty = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(mighty.length).toBeGreaterThan(0);
    world.state.party = partyWith(assets, [0x39, 250]); // SURF, WHIRLPOOL
    world.state.flags.add(33); // ENGINE_GLACIERBADGE
    const before = world.map.blocks.slice();
    world.interact();
    const used = settle(world).join("\n");
    expect(world.notice, world.diagnostic).toBe("");
    expect(used).toContain("used\nWHIRLPOOL!");
    expect(world.map.blocks).not.toEqual(before);
  });
});

describe.skipIf(!existsSync(romPath))("Strength boulders and stone tables with the local ROM", () => {
  it("drops a boulder pushed into Ice Path B1F's hole through its stone table script", () => {
    const ICE_PATH_B1F = "3:62";
    const EVENT_BOULDER_IN_ICE_PATH_2A = 1806;
    const { assets, world } = fixture([ICE_PATH_B1F]);
    const mon = generatePartyMon(assets.pokemon, {
      species: 158, level: 30, item: 0, otId: 1, ot: "CHRIS", dvs: 0, caughtData: 0,
    });
    world.state.party = [mon];
    world.warpTo(ICE_PATH_B1F, 4, 5);
    world.state.flags.add(24); // ENGINE_STRENGTH_ACTIVE
    world.state.events.add(EVENT_BOULDER_IN_ICE_PATH_2A);
    world.restore({
      ...world.save(),
      x: 4,
      y: 5,
      direction: "down",
      objects: [{ id: 3, x: 4, y: 6, direction: "down" }],
    });
    world.state.flags.add(24);
    expect(world.objects().some((o) => o.id === 3)).toBe(true);
    world.tick("down");
    const shown: string[] = [];
    for (let tick = 0; tick < 40 && world.activity !== "scene"; tick++) world.tick();
    expect(world.activity).toBe("scene");
    shown.push(...settle(world));
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown.join("\n")).toMatch(/fell\s+through/i);
    expect(world.objects().some((o) => o.id === 3)).toBe(false);
    expect(world.state.events.has(EVENT_BOULDER_IN_ICE_PATH_2A)).toBe(false);
  });
});