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 { calcStats, generatePartyMon, maxPP, type PartyMon } from "../src/game/party/pokemon";
import { CHALLENGE, emptyBattleTowerState, loadOpponent } from "../src/game/scripts/battle-tower";
import type { SpecialContext } from "../src/game/scripts/special-context";
import { Playthrough } from "./playthrough-driver";

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

describe.skipIf(!existsSync(romPath))("the Battle Tower with the local ROM", () => {
  const assets = existsSync(romPath)
    ? new CrystalAssets(new Uint8Array(readFileSync(romPath)))
    : undefined;

  const BATTLE_TOWER_1F = "22:11",
    BATTLE_ROOM = "22:12",
    ROUTE_40 = "22:1",
    BATTLE_TOWER_OUTSIDE = "22:16";
  const MEWTWO = 150,
    LUGIA = 249,
    HO_OH = 250,
    RATTATA = 19,
    PIDGEY = 16,
    SENTRET = 161,
    BERRY = 0xad,
    HP_UP = 0x1a,
    CALCIUM = 0x1f,
    LUCKY_PUNCH = 0x1e;
  /** The Challenge/Explanation/Cancel menu's items. */
  const CHALLENGE_ITEM = 0,
    CANCEL_ITEM = 2;

  const mon = (world: GameWorld, species: number, level: number, item = 0): PartyMon =>
    generatePartyMon(assets!.pokemon, {
      species,
      level,
      item,
      otId: world.playerId,
      ot: world.name,
      dvs: 0xffff,
      caughtData: 0,
    });
  /** A playthrough driver in front of the receptionist (7, 7). */
  const driver = (party: (world: GameWorld) => PartyMon[], hallOfFame = true) => {
    const p = new Playthrough(assets!);
    p.world = new GameWorld(assets!, p.now, p.random);
    p.world.state.party = party(p.world);
    p.world.state.hallOfFame = hallOfFame;
    p.world.warpTo(BATTLE_TOWER_1F, 7, 7);
    p.play();
    p.world.restore({ ...p.world.save(), x: 7, y: 7, direction: "up" });
    return p;
  };
  /** A trained Pokémon: full stat experience and chosen moves. */
  const trained = (world: GameWorld, species: number, moves: number[], item = 0): PartyMon => {
    const base = mon(world, species, 100, item);
    const statExp: PartyMon["statExp"] = [65535, 65535, 65535, 65535, 65535];
    const stats = calcStats(assets!.pokemon, species, base.dvs, 100, statExp);
    return {
      ...base,
      statExp,
      stats,
      hp: stats[0],
      moves: moves as PartyMon["moves"],
      pp: moves.map((move) => maxPP(assets!.pokemon, move, 0)) as PartyMon["pp"],
    };
  };
  const PSYCHIC = 94,
    ICE_BEAM = 58,
    THUNDERBOLT = 85,
    FLAMETHROWER = 53,
    AEROBLAST = 177,
    SACRED_FIRE = 221,
    EARTHQUAKE = 89,
    SURF = 57;
  const strong = (world: GameWorld) => [
    trained(world, MEWTWO, [PSYCHIC, ICE_BEAM, THUNDERBOLT, FLAMETHROWER], BERRY),
    trained(world, LUGIA, [AEROBLAST, SURF, ICE_BEAM, EARTHQUAKE]),
    trained(world, HO_OH, [SACRED_FIRE, EARTHQUAKE, THUNDERBOLT, PSYCHIC]),
  ];
  const bt = (p: Playthrough) => p.world.state.battleTower;
  /** Talk to the receptionist and answer her questions. */
  const receptionist = (p: Playthrough, answers: (number | string)[]) => {
    p.world.interact();
    p.play(answers);
    expect(p.world.notice, p.world.diagnostic).toBe("");
  };

  it("names a trainer whose name fills all ten characters", () => {
    // BattleTowerTrainers' sixth entry, ZABOROWSKI, has no "@" of its own.
    let seed = 5;
    const context = {
      reader: assets!.reader,
      data: assets!.pokemon,
      random: () => {
        seed = (seed * 1103515245 + 12345) >>> 0;
        return (seed >>> 16) & 255;
      },
      text: () => ({ player: "KAWA", rival: "SILVER", mom: "MOM", strings: {}, weekday: "SUNDAY" }),
    } as unknown as SpecialContext;
    const names = new Map<number, string>();
    for (let draw = 0; draw < 300 && !names.has(5); draw++) {
      const opponent = loadOpponent(context, { ...emptyBattleTowerState(), levelGroup: 1 });
      names.set(opponent.trainer, opponent.name);
    }
    expect(names.get(5)).toBe("ZABOROWSKI");
  });

  it("is reached from Route 40 through its gate", () => {
    const p = new Playthrough(assets!);
    p.world = new GameWorld(assets!, p.now, p.random);
    p.world.state.party = [mon(p.world, MEWTWO, 50)];
    p.world.warpTo(ROUTE_40, 9, 5);
    p.play();
    p.travel(BATTLE_TOWER_1F, ["22:15", BATTLE_TOWER_OUTSIDE]);
    expect(p.world.mapId).toBe(BATTLE_TOWER_1F);
  });

  it("turns away a party that breaks the rules, saying why", () => {
    // Four Pokémon, two Pidgey holding the same Berry and an Egg.
    const p = driver((world) => [
      mon(world, PIDGEY, 10, BERRY),
      mon(world, PIDGEY, 10, BERRY),
      { ...mon(world, RATTATA, 5), egg: true },
      mon(world, SENTRET, 10),
    ]);
    // The first visit offers the explanation (NO), then the menu.
    receptionist(p, [0, CHALLENGE_ITEM]);
    const shown = p.log.join(" ");
    expect(shown).toContain("Excuse me.\nYou're not ready.");
    expect(shown).toContain("Only three POKéMON\nmay be entered.");
    expect(shown).toContain("The 3 POKéMON\nmust all be\ndifferent kinds.");
    expect(shown).toContain("must not hold the\nsame items.");
    expect(shown).toContain("You can't take an\nEGG!");
    expect(shown).toContain("Please return when\nyou're ready.");
    expect(bt(p).challenge).toBe(CHALLENGE.none);
  });

  it("stops a choice that a party Pokémon's level tops, and an uber below Lv.70", () => {
    const p = driver((world) => [
      mon(world, MEWTWO, 60),
      mon(world, PIDGEY, 30),
      mon(world, SENTRET, 30),
    ]);
    // Challenge, YES to the save, YES to overwrite, then L:30 (Mewtwo is
    // level 60), L:60 (an uber under 70), and CANCEL with YES.
    receptionist(p, [0, CHALLENGE_ITEM, 1, 1, 2, 5, 10, 1, CANCEL_ITEM]);
    const shown = p.log.join(" ");
    expect(shown).toContain("A party POKéMON\ntops this level.");
    expect(shown).toContain("MEWTWO may go\nonly to BATTLE");
    expect(shown).toContain("Cancel your BATTLE\nROOM challenge?");
    expect(p.world.mapId).toBe(BATTLE_TOWER_1F);
  });

  it("offers L:10 to L:40 before the Hall of Fame", () => {
    const p = driver((world) => [mon(world, PIDGEY, 10), mon(world, SENTRET, 10), mon(world, RATTATA, 10)], false);
    p.world.interact();
    // NO to the explanation, Challenge, YES to save, YES to overwrite.
    for (const answer of [0, CHALLENGE_ITEM, 1, 1]) {
      p.toChoice();
      p.world.choose(answer);
    }
    const choice = p.toChoice();
    expect(choice).toMatchObject({ kind: "menu", items: ["L:10", "L:20", "L:30", "L:40", "CANCEL"] });
  });

  it("battles seven trainers, then gives five of a random stat item", () => {
    const p = driver(strong);
    // NO to the explanation, Challenge, YES (save), YES (overwrite), L:100.
    receptionist(p, [0, CHALLENGE_ITEM, 1, 1, 9]);
    expect(p.world.state.battleTower.levelGroup).toBe(10);
    expect(p.world.state.battleTower.quickSave).toMatchObject({ map: BATTLE_TOWER_1F, x: 7, y: 7 });
    // Each win heals the party and asks to go on (YES).
    for (let round = 0; round < 7 && p.world.mapId === BATTLE_ROOM; round++) p.play([1]);
    expect(p.world.notice, p.world.diagnostic).toBe("");
    const shown = p.log.join(" ");
    expect(shown).toContain("Congratulations!");
    expect(p.world.mapId).toBe(BATTLE_TOWER_1F);
    const state = bt(p);
    expect(state.beaten).toBe(7);
    expect(new Set(state.trainers).size).toBe(7);
    expect(state.trainers.every((trainer) => trainer < 70)).toBe(true);
    expect(state.challenge).toBe(CHALLENGE.receivedReward);
    expect(state.reward).toBeGreaterThanOrEqual(HP_UP);
    expect(state.reward).toBeLessThanOrEqual(CALCIUM);
    expect(state.reward).not.toBe(LUCKY_PUNCH);
    expect(p.world.state.bag.items).toContainEqual({ item: state.reward, quantity: 5 });
    // No experience, and LoadPokemonData gave the Berry back after each
    // battle; the party is healed.
    expect(p.world.state.party.map((m) => m.level)).toEqual([100, 100, 100]);
    expect(p.world.state.party[0].item).toBe(BERRY);
    expect(p.world.state.party.every((m) => m.hp === m.stats[0])).toBe(true);
    // The streak's opponents come from the L:100 group of BattleTowerMons.
    expect(state.opponent!.party.every((m) => m.level === 100)).toBe(true);
    // A second talk only says goodbye after the reward.
    p.play();
  });

  it("saves and quits between battles, then resumes the streak", () => {
    const p = driver(strong);
    // After the first win: NO to the next opponent, YES to save and end.
    // Reset continues from the quick save made at the counter, whose scene
    // checks the challenge state and resumes it; the streak then goes on
    // (YES each time) to its seventh trainer.
    receptionist(p, [0, CHALLENGE_ITEM, 1, 1, 9, 0, 1]);
    const shown = p.log.join(" ");
    const saved = shown.indexOf("SAVE and end the\nsession?"),
      waiting = shown.indexOf("We've been waiting");
    expect(saved).toBeGreaterThan(0);
    expect(waiting).toBeGreaterThan(saved);
    // One battle before the reset, six after.
    expect(shown.slice(0, saved).match(/wants to battle!/g)).toHaveLength(1);
    expect(shown.slice(waiting).match(/wants to battle!/g)).toHaveLength(6);
    expect(shown).toContain("Congratulations!");
    expect(bt(p).beaten).toBe(7);
    expect(new Set(bt(p).trainers).size).toBe(7);
    expect(p.world.mapId).toBe(BATTLE_TOWER_1F);
  });

  it("keeps a saved-and-left challenge for the next visit", () => {
    const p = driver(strong);
    p.world.state.battleTower = {
      ...p.world.state.battleTower,
      challenge: CHALLENGE.savedAndLeft,
      beaten: 3,
      savedLevelGroup: 10,
      reward: CALCIUM,
      fileFlags: 2,
      quickSave: {
        map: BATTLE_TOWER_1F,
        x: 7,
        y: 7,
        direction: "up",
        party: structuredClone(p.world.state.party),
        seen: [],
        caught: [],
        unownDex: [],
        firstUnownSeen: 0,
      },
    };
    // A save made in that state and loaded again: the check scene runs.
    p.world.state.scenes[BATTLE_TOWER_1F] = 0;
    p.reload();
    p.play([1, 1, 1, 1]);
    const shown = p.log.join(" ");
    expect(shown).toContain("We've been waiting");
    expect(shown.match(/wants to battle!/g)).toHaveLength(4);
    expect(bt(p).levelGroup).toBe(10);
    expect(p.world.state.bag.items).toContainEqual({ item: CALCIUM, quantity: 5 });
  });

  it("cancels the challenge, or ends it with a loss without a whiteout", () => {
    const p = driver(strong);
    // After the first win: NO, NO (no save), YES (cancel): back to 1F
    // with the challenge gone.
    receptionist(p, [0, CHALLENGE_ITEM, 1, 1, 9, 0, 0, 1]);
    expect(p.world.mapId).toBe(BATTLE_TOWER_1F);
    expect(bt(p).challenge).toBe(CHALLENGE.none);
    expect(p.log.join(" ")).toContain("Cancel your BATTLE\nROOM challenge?");

    const weak = driver((world) => [
      mon(world, PIDGEY, 10),
      mon(world, SENTRET, 10),
      mon(world, RATTATA, 10),
    ]);
    receptionist(weak, [0, CHALLENGE_ITEM, 1, 1, 9]);
    expect(weak.world.notice, weak.world.diagnostic).toBe("");
    expect(weak.world.mapId).toBe(BATTLE_TOWER_1F);
    expect(weak.log.join(" ")).toContain("Thanks for\nvisiting!");
    expect(bt(weak).challenge).toBe(CHALLENGE.none);
    // LoadPokemonData and HealParty: the party is back as it was saved.
    expect(weak.world.state.party.every((m) => m.hp === m.stats[0])).toBe(true);
  });
});