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 } from "./world-driver";

const romPath =
  process.env.CRYSTAL_ROM_PATH ??
  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
const NEW_BARK_TOWN = "24:4",
  PLAYERS_HOUSE_1F = "24:6",
  ROUTE_29 = "24:3",
  CHERRYGROVE_CITY = "26:3",
  ROUTE_31 = "26:2",
  DARK_CAVE_VIOLET_ENTRANCE = "3:78";
const SPAWN_NEW_BARK = 14,
  SPAWN_CHERRYGROVE = 15,
  SPAWN_MT_SILVER = 26;
const ENGINE_STORMBADGE = 32,
  EVENT_TALKED_TO_MOM_AFTER_MYSTERY_EGG_QUEST = 64;
const FLY = 0x13,
  DIG = 0x5b,
  TELEPORT = 0x64;
const PIDGEOT = 18,
  ESCAPE_ROPE = 0x13;

describe.skipIf(!existsSync(romPath))("Fly, Dig, Teleport and the Escape Rope", () => {
  /** A world with one Pokémon that knows `moves`, on `map`. */
  function fixture(
    moves: number[],
    map: string,
    x: number,
    y: number,
    direction: Direction = "down",
    ported: string[] = [],
  ) {
    const assets = new CrystalAssets(new Uint8Array(readFileSync(romPath)));
    const isPorted = assets.isPorted.bind(assets);
    assets.isPorted = (id) => isPorted(id) || ported.includes(id);
    const world = new GameWorld(
      assets,
      () => new Date("2026-09-22T12:00:00"),
      () => 0,
    );
    world.state = emptyScriptState();
    const mon = generatePartyMon(assets.pokemon, {
      species: PIDGEOT,
      level: 40,
      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 = "BIRDY";
    world.state.party = [mon];
    world.state.scenes[NEW_BARK_TOWN] = 1;
    // Route 31's NEWMAP callback would otherwise queue Mom's worried call.
    world.state.events.add(EVENT_TALKED_TO_MOM_AFTER_MYSTERY_EGG_QUEST);
    world.restore({ ...world.save(), map, x, y, direction, objects: [] });
    return { assets, world };
  }
  const visit = (world: GameWorld, ...spawns: number[]) => {
    for (const spawn of spawns)
      world.state.flags.add(world.assets.spawnEngineFlag(spawn)!);
  };
  /** Acknowledge pages up to the next choice; returns the pages seen. */
  function until(world: GameWorld) {
    const pages: string[] = [];
    for (let tick = 0; tick < 500; tick++) {
      const dialogue = world.dialogue;
      if (!dialogue) {
        if (!world.busy) return pages;
        world.tick();
        continue;
      }
      const page = dialogue.pages[dialogue.index];
      if (page && pages.at(-1) !== page) pages.push(page);
      const last = dialogue.index === dialogue.pages.length - 1;
      if (last && dialogue.choice) return pages;
      if (last && dialogue.holdTicks !== undefined) world.tick();
      else world.advanceDialogue();
    }
    throw new Error("No choice appeared.");
  }
  function pick(world: GameWorld, label: string) {
    const choice = world.dialogue?.choice;
    if (choice?.kind !== "menu") throw new Error(`No menu for ${label}`);
    const index = choice.items.findIndex((item) => item.startsWith(label));
    expect(index, `${label} in ${choice.items}`).toBeGreaterThanOrEqual(0);
    world.choose(index);
    return until(world);
  }
  /** Start → POKéMON → BIRDY → `move`. */
  function useMove(world: GameWorld, move: string) {
    expect(world.openStartMenu()).toBe(true);
    until(world);
    pick(world, "POKéMON");
    pick(world, "BIRDY");
    return pick(world, move);
  }
  /** B out of every menu, then let any queued script finish. */
  function close(world: GameWorld) {
    for (let i = 0; i < 10 && world.dialogue?.choice; i++)
      world.advanceDialogue();
    return settle(world);
  }
  const flyMap = (world: GameWorld) => {
    const choice = world.dialogue?.choice;
    return choice?.kind === "flymap" ? choice.view : undefined;
  };

  it("needs the Storm Badge and an outdoor map to open the Fly map", () => {
    const { world } = fixture([FLY], PLAYERS_HOUSE_1F, 7, 4);
    // A failure prints its message and returns to the party menu.
    expect(useMove(world, "FLY")).toEqual([
      "Sorry! A new BADGE\nis required.",
      "Choose a POKéMON.",
    ]);
    close(world);
    world.state.flags.add(ENGINE_STORMBADGE);
    expect(useMove(world, "FLY")[0]).toBe("Can't use that\nhere.");
    close(world);
    expect(world.mapId).toBe(PLAYERS_HOUSE_1F);
    expect(world.notice, world.diagnostic).toBe("");
  });

  it("cycles through visited flypoints on the Fly map, and B returns to the party", () => {
    const { world } = fixture([FLY], ROUTE_29, 50, 10);
    world.state.flags.add(ENGINE_STORMBADGE);
    visit(world, SPAWN_NEW_BARK, SPAWN_CHERRYGROVE);
    useMove(world, "FLY");
    // New Bark Town is the default, with the player's icon on Route 29.
    expect(flyMap(world)).toMatchObject({
      kanto: false,
      where: "Where?",
      name: "NEW BARK TOWN",
      cursor: 1,
      player: world.map.landmark,
      species: PIDGEOT,
    });
    // Up goes to the next visited flypoint, down back; both wrap around.
    world.moveCursor("up");
    expect(flyMap(world)?.name).toBe("CHERRYGROVE CITY");
    world.moveCursor("up");
    expect(flyMap(world)?.name).toBe("NEW BARK TOWN");
    world.moveCursor("down");
    expect(flyMap(world)?.name).toBe("CHERRYGROVE CITY");
    // Other buttons do nothing.
    world.choose("start");
    expect(flyMap(world)?.name).toBe("CHERRYGROVE CITY");
    world.advanceDialogue(); // B
    expect(world.dialogue?.choice?.kind).toBe("menu");
    close(world);
    expect([world.mapId, world.x, world.y]).toEqual([ROUTE_29, 50, 10]);
    expect(world.notice, world.diagnostic).toBe("");
  });

  it("flies to a flypoint with the party icon's animations", () => {
    const { world } = fixture([FLY], ROUTE_29, 50, 10, "left");
    world.state.flags.add(ENGINE_STORMBADGE);
    visit(world, SPAWN_NEW_BARK, SPAWN_CHERRYGROVE);
    useMove(world, "FLY");
    world.moveCursor("up");
    world.choose("a");
    // The menu closes and FlyScript starts: the icon replaces every object.
    expect(world.dialogue).toBeUndefined();
    expect(world.flyingIcon).toMatchObject({ species: PIDGEOT, x: 0, y: 0 });
    expect(world.poses()).toEqual([]);
    const heights: number[] = [];
    while (world.busy && world.mapId === ROUTE_29) {
      heights.push(world.flyingIcon?.y ?? 0);
      world.tick();
    }
    // SpriteAnimFunc_FlyFrom: 64 frames in place, then two pixels a frame
    // up to the top of the screen.
    expect(heights.slice(0, 32).every((y) => y === 0)).toBe(true);
    expect(Math.min(...heights)).toBe(-84);
    // MAPSETUP_FLY: Cherrygrove's spawn point, facing down; the icon then
    // comes down from above the screen onto the player.
    expect([world.mapId, world.x, world.y]).toEqual([CHERRYGROVE_CITY, 29, 4]);
    expect(world.flyingIcon?.y).toBeLessThan(-80);
    const landing: number[] = [];
    while (world.busy) {
      landing.push(world.flyingIcon?.y ?? 0);
      world.tick();
    }
    expect(landing.at(-1)).toBe(0);
    expect(world.flyingIcon).toBeUndefined();
    expect(world.poses().find((pose) => pose.id === 0)).toMatchObject({
      direction: "down",
    });
    expect(world.notice, world.diagnostic).toBe("");
    // The flight commits: a save is on Cherrygrove.
    expect(world.save()).toMatchObject({ map: CHERRYGROVE_CITY, x: 29, y: 4 });
  });

  it("refuses to fly to a flypoint that is not ported", () => {
    const { world } = fixture([FLY], ROUTE_29, 50, 10);
    world.state.flags.add(ENGINE_STORMBADGE);
    visit(world, SPAWN_NEW_BARK, SPAWN_CHERRYGROVE, SPAWN_MT_SILVER);
    useMove(world, "FLY");
    for (let press = 0; press < 4 && flyMap(world)?.name !== "SILVER CAVE"; press++)
      world.moveCursor("down");
    expect(flyMap(world)?.name).toBe("SILVER CAVE");
    world.choose("a");
    until(world);
    expect(world.notice).toBe("This destination is not ported yet.");
    close(world);
    expect([world.mapId, world.x, world.y]).toEqual([ROUTE_29, 50, 10]);
  });

  it("teleports outdoors to the last Pokémon Center's town", () => {
    const { world } = fixture([TELEPORT], ROUTE_29, 50, 10);
    // No spawn recorded yet, or indoors: the move cannot be used.
    expect(useMove(world, "TELEPORT")[0]).toBe("Can't use that\nhere.");
    close(world);
    world.state.lastSpawnMap = CHERRYGROVE_CITY;
    const shown = [...useMove(world, "TELEPORT"), ...close(world)];
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown.join("\n")).toContain("Return to the last\nPOKéMON CENTER.");
    expect([world.mapId, world.x, world.y]).toEqual([CHERRYGROVE_CITY, 29, 4]);
    expect(world.poses().find((pose) => pose.id === 0)).toMatchObject({
      direction: "down",
    });
    expect(world.busy).toBe(false);
  });

  it("refuses Teleport indoors", () => {
    const { world } = fixture([TELEPORT], PLAYERS_HOUSE_1F, 7, 4);
    world.state.lastSpawnMap = CHERRYGROVE_CITY;
    expect(useMove(world, "TELEPORT")[0]).toBe("Can't use that\nhere.");
    close(world);
    expect(world.mapId).toBe(PLAYERS_HOUSE_1F);
  });

  /** Walk from Route 31 into Dark Cave, which records the dig warp. */
  function enterDarkCave(moves: number[]) {
    const fixtureWorld = fixture(moves, ROUTE_31, 34, 6, "up", [
      ROUTE_31,
      DARK_CAVE_VIOLET_ENTRANCE,
    ]);
    const { world } = fixtureWorld;
    for (let tick = 0; tick < 40 && world.mapId === ROUTE_31; tick++)
      world.tick("up");
    settle(world);
    expect(world.mapId).toBe(DARK_CAVE_VIOLET_ENTRANCE);
    // EnterMapWarp's SaveDigWarp: Route 31's third warp, the cave entrance.
    expect(world.state.digWarp).toEqual({ map: ROUTE_31, warp: 3 });
    return fixtureWorld;
  }

  it("digs out of a cave to the entrance last used", () => {
    const { world } = enterDarkCave([DIG]);
    // The dig warp is saved with the game.
    const saved = world.save();
    expect(saved.digWarp).toEqual({ map: ROUTE_31, warp: 3 });
    world.restore(saved);
    const shown = [...useMove(world, "DIG"), ...close(world)];
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown.join("\n")).toContain("BIRDY used\nDIG!");
    // MAPSETUP_DOOR onto the cave entrance, which faces the player down;
    // standing on it, the player then walks out.
    expect(world.mapId).toBe(ROUTE_31);
    expect(world.poses().find((pose) => pose.id === 0)).toMatchObject({
      direction: "down",
    });
    for (let tick = 0; tick < 40 && world.y < 6; tick++) world.tick();
    expect([world.x, world.y]).toEqual([34, 6]);
  });

  it("explains that Dig only works in caves", () => {
    const { world } = fixture([DIG], ROUTE_29, 50, 10);
    world.state.digWarp = { map: ROUTE_31, warp: 3 };
    expect(useMove(world, "DIG")[0]).toMatch(/^Can't use that/);
    close(world);
    expect(world.mapId).toBe(ROUTE_29);
  });

  it("uses an Escape Rope in a cave, and only there", () => {
    const { world } = enterDarkCave([]);
    world.state.bag.items = [{ item: ESCAPE_ROPE, quantity: 2 }];
    const useRope = () => {
      expect(world.openStartMenu()).toBe(true);
      until(world);
      pick(world, "PACK");
      const choice = world.dialogue?.choice;
      if (choice?.kind !== "pack") throw new Error("Expected the pack.");
      const pocket = choice.pockets.findIndex(({ entries }) =>
        entries.some((entry) => entry.item === ESCAPE_ROPE),
      );
      world.choosePackEntry(
        pocket,
        choice.pockets[pocket].entries.findIndex(
          (entry) => entry.item === ESCAPE_ROPE,
        ),
      );
      until(world);
      return pick(world, "USE");
    };
    const shown = [...useRope(), ...close(world)];
    expect(world.notice, world.diagnostic).toBe("");
    expect(shown.join("\n")).toMatch(/used an\nESCAPE ROPE/);
    expect(world.mapId).toBe(ROUTE_31);
    expect(world.state.bag.items).toEqual([{ item: ESCAPE_ROPE, quantity: 1 }]);
    // Outdoors it fails silently, then Oak warns; the rope is kept.
    for (let tick = 0; tick < 40 && world.busy; tick++) world.tick();
    expect(useRope()).toEqual([
      "OAK: CHRIS!\nThis isn't the\ntime to use that!",
    ]);
    close(world);
    expect(world.state.bag.items).toEqual([{ item: ESCAPE_ROPE, quantity: 1 }]);
  });

  it("does not record a dig warp into Mount Moon Square or Tin Tower's roof", () => {
    const { assets } = fixture([], ROUTE_29, 50, 10);
    // SaveDigWarp's exclusions name these two outdoor maps.
    expect(assets.map("15:10").location).toBe("Mt.Moon");
    expect(assets.map("15:12").location).toBe("Tin Tower");
    expect(assets.map("15:10").environment).not.toBe(3);
  });
});