Crystal/tests/foundation-fixture.ts

import { CrystalAssets } from "../src/game/rom/assets";
import { GameWorld } from "../src/game/world/world";
import { OW } from "../src/game/world/constants";
import { generatePartyMon } from "../src/game/party/pokemon";

/** `room` places the player at the bedroom PC or poster, "center" at
 * Cherrygrove's Pokémon Center PC with two Pokémon ("candy": the first at
 * level 13, with a Rare Candy); otherwise outdoors ("pokegear": with the
 * Pokégear, its map and phone cards, and Mom's and Elm's numbers). "mom"
 * faces Mom in the living room after the Mystery Egg, with her bank open
 * and ¥2300 saved. "fly" stands outdoors with a Pidgeot that knows Fly,
 * the Storm Badge, and New Bark Town and Cherrygrove City visited.
 * "headbutt" faces Route 29's first reachable Headbutt tree from below
 * with a Pokémon that knows Headbutt; Random always returning 0 drops a
 * sleeping Hoothoot. */
export function foundationFixture(
  assets: CrystalAssets,
  room:
    | boolean
    | "poster"
    | "center"
    | "candy"
    | "pokegear"
    | "mom"
    | "fly"
    | "headbutt",
) {
  const world = new GameWorld(
    assets,
    () => new Date("2026-09-22T12:00:00"),
    () => 0,
  );
  world.state.scenes["24:4"] = 1;
  world.state.bag.keyItems.push(OW.BICYCLE);
  if (room === "center" || room === "candy") {
    world.state.party = [155, 16].map((species, i) =>
      generatePartyMon(assets.pokemon, {
        species,
        level: room === "candy" && !i ? 13 : 8 - i * 4,
        item: 0,
        otId: world.playerId,
        ot: "CHRIS",
        dvs: 0x9abc,
        caughtData: 0,
      }),
    );
    world.state.bag.items = [{ item: 18, quantity: 5 }]; // POTION
    if (room === "candy") world.state.bag.items.push({ item: 0x20, quantity: 1 });
  }
  if (room === "pokegear" || room === "mom") {
    world.state.party = [
      generatePartyMon(assets.pokemon, {
        species: 155,
        level: 8,
        item: 0,
        otId: world.playerId,
        ot: "CHRIS",
        dvs: 0x9abc,
        caughtData: 0,
      }),
    ];
    for (const flag of [OW.ENGINE_MAP_CARD, OW.ENGINE_PHONE_CARD, 4])
      world.state.flags.add(flag); // 4: ENGINE_POKEGEAR
    world.state.phone = [OW.PHONECONTACT_MOM, OW.PHONECONTACT_ELM];
    world.state.events.add(26); // EVENT_GOT_A_POKEMON_FROM_ELM
    // Walking outside clears the bedroom's temporary events.
    for (let event = 0; event < 8; event++) world.state.events.delete(event);
  }
  if (room === "fly") {
    const mon = generatePartyMon(assets.pokemon, {
      species: 18, // PIDGEOT
      level: 40,
      item: 0,
      otId: world.playerId,
      ot: "CHRIS",
      dvs: 0x9abc,
      caughtData: 0,
    });
    mon.moves = [OW.FLY, 0, 0, 0];
    mon.pp = [15, 0, 0, 0];
    world.state.party = [mon];
    world.state.flags.add(OW.ENGINE_STORMBADGE);
    for (const spawn of [14, 15]) // SPAWN_NEW_BARK, SPAWN_CHERRYGROVE
      world.state.flags.add(assets.spawnEngineFlag(spawn)!);
    for (let event = 0; event < 8; event++) world.state.events.delete(event);
  }
  if (room === "headbutt") {
    const mon = generatePartyMon(assets.pokemon, {
      species: 158, // TOTODILE
      level: 30,
      item: 0,
      otId: world.playerId,
      ot: "CHRIS",
      dvs: 0x9abc,
      caughtData: 0,
    });
    mon.moves = [OW.HEADBUTT, 33, 0, 0]; // TACKLE
    mon.pp = [15, 35, 0, 0];
    world.state.party = [mon];
    for (let event = 0; event < 8; event++) world.state.events.delete(event);
  }
  if (room === "mom") {
    // EVENT_GOT_MYSTERY_EGG_FROM_MR_POKEMON, EVENT_GAVE_MYSTERY_EGG_TO_ELM
    // and EVENT_TALKED_TO_MOM_AFTER_MYSTERY_EGG_QUEST.
    for (const event of [30, 31, 64]) world.state.events.add(event);
    world.state.flags.add(OW.ENGINE_MOM_ACTIVE);
    world.state.scenes["24:6"] = 1;
    world.state.momsMoney = 2300;
  }
  const save = world.save();
  const [map, x, y] =
    room === "headbutt"
      ? headbuttSpot(assets)
      : room === "center" || room === "candy"
        ? ["26:5", 9, 2]
        : room === "poster"
          ? ["24:7", 6, 1]
          : room === "mom"
            ? ["24:6", 7, 3]
            : room && room !== "pokegear" && room !== "fly"
              ? ["24:7", 2, 2]
              : ["24:4", 9, 6];
  world.restore({
    ...save,
    map,
    x,
    y,
    direction: room === "mom" ? "down" : "up",
    objects: [],
  });
  return world;
}

/** Below Route 29's first Headbutt tree with walkable ground under it. */
function headbuttSpot(assets: CrystalAssets): [string, number, number] {
  const map = assets.map("24:3");
  for (let y = 1; y < map.height - 1; y++)
    for (let x = 0; x < map.width; x++)
      if (
        assets.collision(map, x, y) === OW.COLL_HEADBUTT_TREE &&
        assets.permission(assets.collision(map, x, y + 1)) === 0 &&
        !map.objects.some((o) => o.x === x && o.y <= y + 1 && o.y >= y)
      )
        return ["24:3", x, y + 1];
  throw new Error("No reachable Headbutt tree.");
}