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, validPartyMon } from "../src/game/party/pokemon";
import { C } from "../src/game/battle/constants";
import { battleFixtureWorld, ENCOUNTER_WALK } from "./battle-fixture";
import { settle } from "./world-driver";

const romPath =
  process.env.CRYSTAL_ROM_PATH ?? "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
const ROUTE_29 = "24:3",
  DUDE = 2,
  RATTATA = 19,
  PIDGEY = 16;
const EVENT_GOT_A_POKEMON_FROM_ELM = 26,
  EVENT_GAVE_MYSTERY_EGG_TO_ELM = 31,
  EVENT_DUDE_TALKED_TO_YOU = 65,
  EVENT_LEARNED_TO_CATCH_POKEMON = 66;

describe.skipIf(!existsSync(romPath))("the catching tutorial and capture in the world", () => {
  const assets = () => new CrystalAssets(new Uint8Array(readFileSync(romPath)));
  /** After returning the Egg: Route 29 is in its catching-tutorial scene. */
  const tutorialWorld = (position = { x: 54, y: 8 }) => {
    let seed = 3;
    const world = new GameWorld(assets(), () => new Date("2026-09-24T12:00:00"), () => {
      seed = (seed * 1103515245 + 12345) >>> 0;
      return (seed >>> 16) & 255;
    });
    const mon = generatePartyMon(world.assets.pokemon, {
      species: 158, level: 8, item: 0, otId: world.playerId, ot: "CHRIS", dvs: 0xffff, caughtData: 0,
    });
    world.state.party = [mon];
    world.state.pokedex.seen.add(158);
    world.state.pokedex.caught.add(158);
    for (const event of [EVENT_GOT_A_POKEMON_FROM_ELM, EVENT_GAVE_MYSTERY_EGG_TO_ELM])
      world.state.events.add(event);
    world.state.bag.balls = [{ item: C.POKE_BALL, quantity: 5 }];
    world.restore({ ...world.save(), map: ROUTE_29, ...position, direction: "left", scenes: { [ROUTE_29]: 1 } });
    return world;
  };
  const dude = (world: GameWorld) => world.objects().find((object) => object.id === DUDE)!;

  it.each([
    [8, "Tutorial1"],
    [9, "Tutorial2"],
  ])("runs the Dude's demonstration from the trigger at y=%i (%s)", (y) => {
    const world = tutorialWorld({ x: 54, y });
    const before = world.save();
    expect(world.move("left")).toBe(true);
    const pages = settle(world).join("\n").replace(/\n/g, " ");
    expect(world.notice, world.diagnostic).toBe("");
    expect(pages).toContain("show you how to catch POKéMON?");
    expect(pages).toContain("That's how you do it");
    expect(world.state.events.has(EVENT_DUDE_TALKED_TO_YOU)).toBe(true);
    expect(world.state.events.has(EVENT_LEARNED_TO_CATCH_POKEMON)).toBe(true);
    expect(world.state.scenes[ROUTE_29]).toBe(0);
    // Only the Pokédex sighting remains; the Dude's catch is not kept.
    expect(world.state.pokedex.seen.has(RATTATA)).toBe(true);
    expect(world.state.pokedex.caught.has(RATTATA)).toBe(false);
    expect(world.state.party).toEqual(before.party);
    expect(world.state.bag).toEqual(before.bag);
    expect(dude(world)).toMatchObject({ x: 50, y: 12 });
    // Nothing replays after reload.
    world.restore(world.save());
    expect(settle(world)).toEqual([]);
  });

  it("shows the battle as the Dude with automatic messages", () => {
    const world = tutorialWorld();
    expect(world.move("left")).toBe(true);
    const messages: string[] = [];
    for (let tick = 0; tick < 5000 && !world.battle; tick++) {
      if (world.dialogue?.choice) world.choose(1);
      else if (world.dialogue) world.advanceDialogue();
      else world.tick();
    }
    expect(world.battle?.engine.player.mon).toBeUndefined();
    // A save during the battle holds the state before the scene.
    const saved = world.save();
    expect(saved.events).not.toContain(EVENT_DUDE_TALKED_TO_YOU);
    expect(saved.pokedex.seen).not.toContain(RATTATA);
    while (world.battle) {
      const text = world.battle.message?.text;
      if (text && messages.at(-1) !== text) messages.push(text);
      expect(world.battle.prompt).toBeUndefined();
      expect(world.battle.message?.prompt).not.toBe(true);
      world.tick();
    }
    expect(messages.map((text) => text.replace(/\n/g, " "))).toEqual([
      "Wild RATTATA appeared!",
      "DUDE used the POKé BALL.",
      "Gotcha! RATTATA was caught!",
    ]);
    settle(world);
    expect(world.notice, world.diagnostic).toBe("");
    // Reloading the mid-battle save replays the whole scene.
    world.restore(saved);
    expect(world.x).toBe(54);
    expect(world.move("left")).toBe(true);
    settle(world);
    expect(world.state.events.has(EVENT_LEARNED_TO_CATCH_POKEMON)).toBe(true);
  });

  it("lets the player decline, then offers the demonstration again when talked to", () => {
    const world = tutorialWorld();
    expect(world.move("left")).toBe(true);
    const declined = settle(world, [0]).join("\n").replace(/\n/g, " ");
    expect(world.notice, world.diagnostic).toBe("");
    expect(declined).toContain("Oh. Fine, then");
    expect(world.state.scenes[ROUTE_29]).toBe(0);
    expect(world.state.events.has(EVENT_LEARNED_TO_CATCH_POKEMON)).toBe(false);
    expect(dude(world)).toMatchObject({ x: 50, y: 12 });

    // CatchingTutorialDudeScript: stand below him and talk.
    world.restore({ ...world.save(), x: 50, y: 13, direction: "up" });
    world.interact();
    const pages = settle(world).join("\n").replace(/\n/g, " ");
    expect(world.notice, world.diagnostic).toBe("");
    expect(pages).toContain("That's how you do it");
    expect(world.state.events.has(EVENT_LEARNED_TO_CATCH_POKEMON)).toBe(true);
    expect(world.state.pokedex.seen.has(RATTATA)).toBe(true);
  });

  it("catches a wild Pokémon through the world and keeps it after reload", () => {
    const world = battleFixtureWorld(assets());
    world.state.bag.balls = [{ item: C.POKE_BALL, quantity: 10 }];
    for (const direction of ENCOUNTER_WALK) expect(world.move(direction)).toBe(true);
    expect(world.battle).toBeDefined();
    let named = false;
    for (let tick = 0; tick < 20_000 && world.busy; tick++) {
      const view = world.battle;
      if (!view) {
        if (world.dialogue) world.advanceDialogue();
        else world.tick();
        continue;
      }
      const prompt = view.prompt;
      if (prompt?.kind === "action")
        world.battleAction({ action: "item", item: C.POKE_BALL, slot: 0 });
      else if (prompt?.kind === "yesno") world.battleChoose(1);
      else if (prompt?.kind === "name") {
        expect(prompt.title).toBe("PIDGEY'S\nNICKNAME?");
        world.battleName("PIDGE");
        named = true;
      } else if (view.message?.prompt) world.interact();
      else world.tick();
    }
    expect(world.notice, world.diagnostic).toBe("");
    expect(named).toBe(true);
    expect(world.state.party).toHaveLength(2);
    const caught = world.state.party[1];
    expect(caught).toMatchObject({ species: PIDGEY, nickname: "PIDGE", level: 3, ot: world.name });
    // SetCaughtData: day (2 << 6 | level), Chris, New Bark Town's landmark.
    expect(caught.caughtData >> 8).toBe((2 << 6) | 3);
    expect(caught.caughtData & 0x80).toBe(0);
    expect(caught.caughtData & 0x7f).toBe(world.assets.map("24:7").landmark);
    expect(world.state.pokedex.caught.has(PIDGEY)).toBe(true);
    expect(world.state.bag.balls[0].quantity).toBeLessThan(10);
    const saved = world.save();
    world.restore(saved);
    expect(world.save()).toEqual(saved);
    expect(validPartyMon(world.assets.pokemon, world.state.party[1])).toBe(true);
  });

  it("rolls back the whole battle when a full party would need the PC", () => {
    const world = battleFixtureWorld(assets());
    const mon = world.state.party[0];
    world.state.party = Array.from({ length: 6 }, () => structuredClone(mon));
    world.state.bag.balls = [{ item: C.POKE_BALL, quantity: 10 }];
    const before = world.save();
    for (const direction of ENCOUNTER_WALK) expect(world.move(direction)).toBe(true);
    world.battleAction({ action: "item", item: C.POKE_BALL, slot: 0 });
    for (let tick = 0; tick < 200 && world.battle; tick++) {
      if (world.battle.prompt?.kind === "action")
        world.battleAction({ action: "item", item: C.POKE_BALL, slot: 0 });
      else if (world.battle.message?.prompt) world.interact();
      else world.tick();
    }
    expect(world.battle).toBeUndefined();
    expect(world.notice).toMatch(/not been ported/);
    expect(world.state.bag).toEqual({ ...before.bag });
    expect(world.state.party).toHaveLength(6);
  });
});