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 { generatePartyMon } from "../src/game/party/pokemon";
import { snorlaxAwake } from "../src/game/scripts/kanto";
import { TEARDOWN_FRAMES } from "../src/game/scripts/magnet-train";
import { SOUND } from "../src/game/audio/constants";
import { settle } from "./world-driver";

const romPath =
  process.env.CRYSTAL_ROM_PATH ?? "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";

describe.skipIf(!existsSync(romPath))("Kanto with the local ROM", () => {
  const bytes = existsSync(romPath) ? new Uint8Array(readFileSync(romPath)) : new Uint8Array();
  const VERMILION = "12:3",
    BILLS_HOUSE = "7:11",
    TRAINER_HOUSE_B1F = "23:7",
    SAFFRON_STATION = "25:9",
    GOLDENROD_STATION = "11:7",
    CELADON_MANSION_3F = "21:14",
    OAKS_LAB = "13:6",
    GOLDENROD = "11:2",
    MOUNT_MOON = "3:85",
    INDIGO_PLATEAU_CENTER = "16:2";
  const LICKITUNG = 108,
    EVERSTONE = 0x70,
    PASS = 0x86,
    EVENT_GOT_EVERSTONE_FROM_BILLS_GRANDPA = 0x320,
    EVENT_SHOWED_LICKITUNG_TO_BILLS_GRANDPA = 0x31b,
    EVENT_ENABLE_DIPLOMA_PRINTING = 0xd6,
    EVENT_RESTORED_POWER_TO_KANTO = 0xcd,
    EVENT_OPENED_MT_SILVER = 0x74f,
    EVENT_TALKED_TO_OAK_IN_KANTO = 0xe1,
    EVENT_BEAT_ELITE_FOUR = 0x44,
    COIN_CASE = 0x36,
    PIKACHU = 25,
    THUNDERBOLT = 85,
    ENGINE_DAILY_MOVE_TUTOR = 94,
    EVENT_BEAT_RIVAL_IN_MT_MOON = 0x319;
  const world = (date = "2026-09-22T12:00:00") => {
    let seed = 33;
    const game = new GameWorld(
      new CrystalAssets(bytes),
      () => new Date(date),
      () => {
        seed = (seed * 1103515245 + 12345) >>> 0;
        return (seed >>> 16) & 255;
      },
    );
    game.state.party = [mon(game, 157, 60)];
    return game;
  };
  const mon = (game: GameWorld, species: number, level = 30) =>
    generatePartyMon(game.assets.pokemon, {
      species,
      level,
      item: 0,
      otId: game.playerId,
      ot: "KAWA",
      dvs: 0x8888,
      caughtData: 0,
    });
  /** Stand at (x, y) on `map` facing `face`, press A and answer. */
  const talk = (
    game: GameWorld,
    map: string,
    x: number,
    y: number,
    face: "up" | "down" | "left" | "right",
    answers: (number | string)[] = [],
  ) => {
    game.warpTo(map, x, y);
    settle(game);
    game.restore({ ...game.save(), x, y, direction: face });
    game.interact();
    const shown = settle(game, answers).join(" ");
    expect(game.notice, game.diagnostic).toBe("");
    return shown;
  };
  /** Run scripts until a battle starts, answering questions with YES. */
  const untilBattle = (game: GameWorld) => {
    const shown: string[] = [];
    for (let tick = 0; tick < 3000 && !game.battle; tick++) {
      expect(game.notice, game.diagnostic).toBe("");
      const dialogue = game.dialogue;
      if (dialogue) {
        const last = dialogue.index === dialogue.pages.length - 1;
        if (!shown.includes(dialogue.pages[dialogue.index])) shown.push(dialogue.pages[dialogue.index]);
        if (last && dialogue.choice) game.choose(1);
        else if (last && dialogue.holdTicks !== undefined) game.tick();
        else game.advanceDialogue();
      } else game.tick();
    }
    return shown.join(" ");
  };
  /** Run a screen that plays on its own to its end, counting its frames. */
  const watch = (game: GameWorld) => {
    let frames = 0;
    for (let tick = 0; tick < 2000 && game.dialogue?.choice?.kind === "screen"; tick++) {
      frames += 2;
      game.tick();
    }
    return frames;
  };

  describe("Vermilion's Snorlax", () => {
    it("wakes only to the Poké Flute channel, from beside it", () => {
      const r = new CrystalAssets(bytes).reader;
      const flute = SOUND.MUSIC_POKE_FLUTE_CHANNEL;
      for (const [x, y] of [[33, 8], [34, 10], [35, 10], [36, 8], [36, 9]])
        expect(snorlaxAwake(r, flute, { x, y })).toBe(1);
      expect(snorlaxAwake(r, flute, { x: 34, y: 11 })).toBe(0);
      expect(snorlaxAwake(r, SOUND.MUSIC_NONE, { x: 34, y: 10 })).toBe(0);
    });
    it("covers two tiles by two and snores until the flute plays", () => {
      const game = world();
      // The big Snorlax at (34, 8) also fills (35, 9): no step there.
      game.warpTo(VERMILION, 36, 9);
      settle(game);
      game.restore({ ...game.save(), x: 36, y: 9, direction: "left" });
      game.move("left");
      settle(game);
      expect({ x: game.x, y: game.y }).toEqual({ x: 36, y: 9 });
      expect(talk(game, VERMILION, 34, 10, "up")).toContain("SNORLAX is snoring\npeacefully…");
      // The Pokégear's radio left on the Poké Flute channel (wMapMusic).
      game.restore({ ...game.save(), x: 34, y: 10, direction: "up" });
      game.sound.engine.mapMusic = SOUND.MUSIC_POKE_FLUTE_CHANNEL;
      game.interact();
      expect(untilBattle(game)).toContain("SNORLAX");
      expect(game.battle?.engine.enemy.mon.species).toBe(143);
      expect(game.battle?.engine.enemy.mon.level).toBe(50);
    });
  });

  it("has Bill's grandpa take a look at a Lickitung for the Everstone", () => {
    const game = world();
    game.state.party.push(mon(game, LICKITUNG));
    // YES to show him, then the party's second Pokémon.
    const shown = talk(game, BILLS_HOUSE, 2, 4, "up", [1, 1]);
    expect(shown).toContain("Hm? You know BILL?");
    expect(shown).toContain("LICKITUNG");
    expect(game.state.events.has(EVENT_SHOWED_LICKITUNG_TO_BILLS_GRANDPA)).toBe(true);
    expect(game.state.events.has(EVENT_GOT_EVERSTONE_FROM_BILLS_GRANDPA)).toBe(true);
    expect(game.state.bag.items.some((slot) => slot.item === EVERSTONE)).toBe(true);
  });

  it("matches the Trainer House's default trainer, CAL", () => {
    const game = world();
    // The receptionist's coordinate event at (7, 3), from the stairs' side.
    game.warpTo(TRAINER_HOUSE_B1F, 8, 3);
    settle(game);
    game.restore({ ...game.save(), x: 8, y: 3, direction: "left" });
    expect(game.move("left")).toBe(true);
    // TrainerHouse returns 0 without a Mystery Gift partner: CAL3.
    expect(untilBattle(game)).toContain("CAL");
    expect(game.battle?.engine.enemy.mon).toBeDefined();
  });

  it("rides the Magnet Train both ways with the PASS once the power is back", () => {
    const game = world();
    game.state.bag.keyItems.push(PASS);
    game.state.events.add(EVENT_RESTORED_POWER_TO_KANTO);
    // Saffron's officer at (9, 9): YES, then the ride to Goldenrod.
    game.warpTo(SAFFRON_STATION, 9, 10);
    settle(game);
    game.restore({ ...game.save(), x: 9, y: 10, direction: "up" });
    game.interact();
    for (let tick = 0; tick < 400 && game.dialogue?.choice?.kind !== "screen"; tick++) {
      if (game.dialogue?.choice) game.choose(1);
      else if (game.dialogue) game.advanceDialogue();
      else game.tick();
    }
    expect(game.dialogue?.choice?.kind).toBe("screen");
    const frames = watch(game);
    // The first run through, its palette frame, the ride and the teardown.
    expect(frames).toBeGreaterThan(300 + TEARDOWN_FRAMES);
    settle(game);
    expect(game.notice, game.diagnostic).toBe("");
    expect(game.mapId).toBe(GOLDENROD_STATION);
    // And back from Goldenrod's officer.
    game.restore({ ...game.save(), x: 9, y: 10, direction: "up" });
    game.interact();
    for (let tick = 0; tick < 400 && game.dialogue?.choice?.kind !== "screen"; tick++) {
      if (game.dialogue?.choice) game.choose(1);
      else if (game.dialogue) game.advanceDialogue();
      else game.tick();
    }
    watch(game);
    settle(game);
    expect(game.mapId).toBe(SAFFRON_STATION);
  });

  it("shows the Diploma for a complete Pokédex, then cannot print it", () => {
    const game = world();
    for (let species = 1; species <= 251; species++) {
      game.state.pokedex.seen.add(species);
      game.state.pokedex.caught.add(species);
    }
    // The game designer at (3, 6), from below.
    game.warpTo(CELADON_MANSION_3F, 3, 7);
    settle(game);
    game.restore({ ...game.save(), x: 3, y: 7, direction: "up" });
    game.interact();
    let diploma = "";
    for (let tick = 0; tick < 400; tick++) {
      const choice = game.dialogue?.choice;
      if (choice?.kind === "screen") {
        diploma = choice.screen.label;
        game.choose("a");
        break;
      }
      if (game.dialogue) game.advanceDialogue();
      else game.tick();
    }
    expect(diploma).toBe(`Diploma: ${game.name}`);
    settle(game);
    expect(game.state.events.has(EVENT_ENABLE_DIPLOMA_PRINTING)).toBe(true);
    // The graphic artist at (3, 4) prints it: no printer, B cancels.
    game.restore({ ...game.save(), x: 3, y: 5, direction: "up" });
    game.interact();
    let printer = "";
    for (let tick = 0; tick < 400; tick++) {
      const choice = game.dialogue?.choice;
      if (choice?.kind === "yesno") game.choose(1);
      else if (choice?.kind === "screen") {
        printer = choice.screen.label;
        game.choose("b");
        break;
      } else if (game.dialogue) game.advanceDialogue();
      else game.tick();
    }
    expect(printer).toMatch(/B/);
    settle(game);
    expect(game.notice, game.diagnostic).toBe("");
  });

  it("has Professor Oak open Mt. Silver for sixteen badges and rate the Pokédex", () => {
    const game = world();
    for (let badge = 0x1b; badge < 0x1b + 16; badge++) game.state.flags.add(badge);
    for (const species of [1, 4, 7, 25]) game.state.pokedex.seen.add(species);
    game.state.pokedex.caught.add(25);
    // Oak at (4, 2), from below.
    const shown = talk(game, OAKS_LAB, 4, 3, "up");
    expect(game.state.events.has(EVENT_TALKED_TO_OAK_IN_KANTO)).toBe(true);
    expect(game.state.events.has(EVENT_OPENED_MT_SILVER)).toBe(true);
    expect(shown).toContain("4 POKéMON seen\n1 POKéMON owned");
    expect(shown).toContain("Look for POKéMON\nin grassy areas!");
  });
  it("has Goldenrod's move tutor teach Thunderbolt for 4000 coins on a Wednesday after the League", () => {
    // 2026-09-23 is a Wednesday.
    const game = world("2026-09-23T12:00:00");
    game.state.party.push(mon(game, PIKACHU, 5));
    game.state.events.add(EVENT_BEAT_ELITE_FOUR);
    game.state.bag.keyItems.push(COIN_CASE);
    game.state.coins = 5000;
    // The tutor at (12, 22), from below.
    game.warpTo(GOLDENROD, 12, 23);
    settle(game);
    expect(game.objects().some((object) => object.x === 12 && object.y === 22)).toBe(true);
    game.restore({ ...game.save(), x: 12, y: 23, direction: "up" });
    game.interact();
    // YES, YES to 4000 coins, THUNDERBOLT, then Typhlosion (NOT ABLE:
    // back to the menu) and Pikachu.
    const party = [0, 1],
      details: string[][] = [];
    for (let tick = 0; tick < 3000 && game.busy; tick++) {
      expect(game.notice, game.diagnostic).toBe("");
      const dialogue = game.dialogue;
      const last = dialogue && dialogue.index === dialogue.pages.length - 1;
      if (last && dialogue.choice?.kind === "yesno") game.choose(1);
      else if (last && dialogue.choice?.kind === "menu" && dialogue.choice.items.includes("THUNDERBOLT"))
        game.choose(dialogue.choice.items.indexOf("THUNDERBOLT"));
      else if (last && dialogue.choice?.kind === "menu") {
        details.push(dialogue.choice.details ?? []);
        game.choose(party.shift()!);
      } else if (dialogue) game.advanceDialogue();
      else game.tick();
    }
    expect(details).toEqual([
      ["NOT ABLE", "ABLE"],
      ["NOT ABLE", "ABLE"],
    ]);
    const pikachu = game.state.party[1];
    expect(pikachu.moves).toContain(THUNDERBOLT);
    expect(game.state.coins).toBe(1000);
    expect(game.state.flags.has(ENGINE_DAILY_MOVE_TUTOR)).toBe(true);
    // Into the Game Corner: gone from the street.
    expect(game.objects().some((object) => object.x === 12 && object.y === 22)).toBe(false);
  });
  describe("the rival in Kanto", () => {
    it("waits in Mt. Moon", () => {
      const game = world();
      // MountMoonRivalEncounterScene, from the Route 3 entrance.
      game.warpTo(MOUNT_MOON, 3, 3);
      expect(untilBattle(game)).toContain(`It's been a while,\n${game.name}.`);
      expect(game.battle).toBeDefined();
    });
    // PlateauRivalBattle1 and 2: Mondays and Wednesdays, after Mt. Moon.
    for (const [date, day, fights] of [
      ["2026-09-21T12:00:00", "a Monday", true],
      ["2026-09-22T12:00:00", "a Tuesday", false],
    ] as const)
      it(`${fights ? "battles" : "stays away"} at Indigo Plateau on ${day}`, () => {
        const game = world(date);
        game.state.events.add(EVENT_BEAT_RIVAL_IN_MT_MOON);
        game.warpTo(INDIGO_PLATEAU_CENTER, 16, 5);
        settle(game);
        game.restore({ ...game.save(), x: 16, y: 5, direction: "up" });
        expect(game.move("up")).toBe(true);
        if (fights) {
          expect(untilBattle(game)).toContain("Hold it.");
          expect(game.battle).toBeDefined();
        } else {
          settle(game);
          expect(game.battle).toBeUndefined();
          expect({ x: game.x, y: game.y }).toEqual({ x: 16, y: 4 });
        }
      });
  });
});