import { describe, expect, it } from "vitest";
import { existsSync, readFileSync } from "node:fs";
import { CrystalAssets } from "../src/game/rom/assets";
import { C } from "../src/game/battle/constants";
import { OW } from "../src/game/world/constants";
import { trainerFixtureWorld } from "./trainer-fixture";
import { migrateSave, type GameWorld } from "../src/game/world/world";
import { DecorationData } from "../src/game/world/decorations";

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

const fixture = (tail?: number[], lose = false, winText = false) =>
  trainerFixtureWorld(new CrystalAssets(new Uint8Array(readFileSync(romPath))), tail, lose, winText);

function finish(world: GameWorld) {
  const messages: string[] = [];
  for (let tick = 0; tick < 10000; tick++) {
    const view = world.battle;
    if (view) {
      if (view.message) messages.push(view.message.text);
      if (view.prompt?.kind === "action") world.battleAction({ action: "fight", move: 0 });
      else if (view.prompt?.kind === "yesno") world.battleChoose(1);
      else if (view.prompt?.kind === "forget") world.battleChoose(3);
      else if (view.prompt?.kind === "stats" || view.message?.prompt) world.interact();
      else world.tick();
    } else if (world.dialogue) world.advanceDialogue();
    else if (world.busy) world.tick();
    else return messages.join("\n");
  }
  throw new Error(`Trainer battle did not settle: ${world.diagnostic}`);
}

describe.skipIf(!existsSync(romPath))("scripted trainer world transactions", () => {
  it("commits Joey's ROM reward, party experience, sighting and postbattle event together", () => {
    const world = fixture();
    const before = world.save();
    world.interact();
    expect(world.battle).toBeDefined();
    expect(world.save()).toEqual(before);
    const messages = finish(world);
    expect(world.notice, world.diagnostic).toBe("");
    expect(messages).toContain("JOEY");
    expect(world.state.money).toBe(before.money + 64);
    expect(world.state.party[0].exp).toBeGreaterThan(before.party[0].exp);
    expect(world.state.pokedex.seen.has(19)).toBe(true);
    expect(world.state.events.has(256)).toBe(true);
    const saved = world.save();
    world.restore(saved);
    expect(world.save()).toEqual(saved);
  });

  it("reads scripted win text from the script bank's ROM pointer", () => {
    const world = fixture(undefined, false, true);
    world.interact();
    const messages = finish(world);
    expect(world.notice, world.diagnostic).toBe("");
    expect(messages).toContain("Ack! I lost again!");
    expect(messages.indexOf("Ack! I lost again!")).toBeLessThan(messages.lastIndexOf("64"));
  });

  it("caps trainer rewards at the money limit", () => {
    const world = fixture();
    world.state.money = C.MAX_MONEY - 1;
    world.interact();
    finish(world);
    expect(world.notice, world.diagnostic).toBe("");
    expect(world.state.money).toBe(C.MAX_MONEY);
  });

  it("sends some of the reward to Mom", () => {
    const world = fixture();
    world.state.flags.add(OW.ENGINE_MOM_SAVING_MONEY);
    world.state.momsMoney = 100;
    const before = world.save();
    world.interact();
    const messages = finish(world);
    expect(world.notice, world.diagnostic).toBe("");
    expect(messages).toContain("Sent some to MOM!");
    expect(world.state.money).toBe(before.money + 48);
    expect(world.state.momsMoney).toBe(116);
    expect(world.state.momItemTriggerBalance).toBe(OW.MOM_MONEY);
  });

  describe("Mom's purchases (MomTriesToBuySomething)", () => {
    const SUPER_POTION = 0x11,
      MOM_ITEMS_1 = [
        [SUPER_POTION, 600],
        [0x09, 90], // ANTIDOTE
        [0x05, 180], // POKE_BALL
        [0x13, 450], // ESCAPE_ROPE
        [0x04, 500], // GREAT_BALL
      ];
    /** Beat Joey while Mom saves a quarter (¥16) of his ¥64; returns the
     * pages of the call that follows, if any. */
    function win(world: GameWorld, momsMoney: number) {
      world.state.flags.add(OW.ENGINE_MOM_SAVING_MONEY);
      world.state.momsMoney = momsMoney - 16;
      world.interact();
      const pages: string[] = [];
      // The queued call starts at the next PlayerEvents.
      let idle = 0;
      for (let tick = 0; tick < 10000; tick++) {
        const view = world.battle;
        if (view) {
          if (view.prompt?.kind === "action") world.battleAction({ action: "fight", move: 0 });
          else if (view.prompt?.kind === "stats" || view.message?.prompt) world.interact();
          else world.tick();
          continue;
        }
        const dialogue = world.dialogue;
        if (dialogue) {
          const page = dialogue.pages[dialogue.index].replace(/\n/g, " ");
          if (pages.at(-1) !== page) pages.push(page);
          if (dialogue.holdTicks !== undefined) world.tick();
          else world.advanceDialogue();
        } else if (world.busy || idle++ < 2) world.tick();
        else {
          expect(world.notice, world.diagnostic).toBe("");
          return pages;
        }
      }
      throw new Error(`Trainer battle did not settle: ${world.diagnostic}`);
    }

    it("buys MomItems_2's next item once her savings reach its trigger", () => {
      const world = fixture();
      const pcItems = world.state.pcItems.map((slot) => ({ ...slot }));
      const pages = win(world, 900);
      expect(pages).toEqual([
        "Hi, CHRIS! How are you?",
        "I found a useful item shopping, so",
        "I bought it with your money. Sorry!",
        "It's in your PC. You'll like it!",
        "Click!",
        "……",
      ]);
      expect(world.state.momsMoney).toBe(300);
      expect(world.state.momItem).toBe(1);
      expect(world.state.pcItems).toEqual([...pcItems, { item: SUPER_POTION, quantity: 1 }]);
      // MomItems_2's next trigger is ¥4000.
      expect(win(world, 3999)).toEqual([]);
      expect(world.state.momItem).toBe(1);
      const saved = world.save();
      expect([saved.momItem, saved.momItemTriggerBalance]).toEqual([1, 4600]);
    });

    it("buys a random MomItems_1 item when her savings land on a ¥2300 step", () => {
      const world = fixture();
      world.state.momItem = 1;
      const pages = win(world, 2300);
      expect(pages[1]).toBe("I found a useful item shopping, so");
      const bought = world.state.pcItems.at(-1)!;
      const entry = MOM_ITEMS_1.find(([item]) => item === bought.item);
      expect(entry).toBeDefined();
      expect(world.state.momsMoney).toBe(2300 - entry![1]);
      expect(world.state.momItem).toBe(1);
      expect(world.state.momItemTriggerBalance).toBe(4600);
    });

    it("raises the ¥2300 step past her savings without buying anything", () => {
      const world = fixture();
      world.state.momItem = 1;
      expect(win(world, 2400)).toEqual([]);
      expect(world.state.momsMoney).toBe(2400);
      expect(world.state.momItemTriggerBalance).toBe(4600);
    });

    it("sends dolls to the player's room", () => {
      const world = fixture();
      world.state.momItem = 3; // ¥10000: the Charmander doll for ¥1800.
      const pages = win(world, 10000);
      expect(pages.slice(0, 4)).toEqual([
        "Hi, CHRIS! How are you?",
        "While shopping today, I saw this adorable doll, so",
        "I bought it with your money. Sorry!",
        "It's in your room. You'll love it!",
      ]);
      expect(world.state.momsMoney).toBe(8200);
      expect(world.state.momItem).toBe(4);
      const doll = new DecorationData(world.assets.reader, world.assets.pokemon);
      const charmander = Array.from({ length: 52 }, (_, i) => i + 1).find(
        (id) => doll.name(id) === "CHARMANDER DOLL",
      )!;
      expect(world.state.events.has(doll.attribute(charmander).event)).toBe(true);
    });

    it("buys nothing while the PC is full", () => {
      const world = fixture();
      world.state.pcItems = Array.from({ length: 50 }, (_, i) => ({ item: 0x20 + i, quantity: 1 }));
      expect(win(world, 900)).toEqual([]);
      expect(world.state.momsMoney).toBe(900);
      expect(world.state.momItem).toBe(0);
    });

    it("migrates saves made before her purchases", () => {
      const world = fixture();
      const { momItem: _, momItemTriggerBalance: __, ...old } = world.save();
      const migrated = migrateSave(old, () => 0)!;
      expect([migrated.momItem, migrated.momItemTriggerBalance]).toEqual([0, OW.MOM_MONEY]);
      world.restore(migrated);
      expect(() => world.restore({ ...migrated, momItem: 11 })).toThrow();
    });
  });

  it("rolls back reward, experience and sightings if the following script is unsupported", () => {
    const world = fixture([0xff]);
    const before = world.save();
    world.interact();
    finish(world);
    expect(world.notice).toContain("not been ported");
    expect(world.save()).toEqual(before);
  });

  it("restores a midbattle save without partially paying the reward", () => {
    const world = fixture();
    const before = world.save();
    world.interact();
    for (let tick = 0; tick < 1000 && !world.battle?.prompt; tick++) {
      if (world.battle?.message?.prompt) world.interact();
      else world.tick();
    }
    expect(world.save()).toEqual(before);
    world.restore(before);
    expect(world.battle).toBeUndefined();
    expect(world.save()).toEqual(before);
  });

  it("CANLOSE scripts receive LOSE in wScriptVar without forcing a whiteout", () => {
    // ifequal LOSE, .lost; invalid; .lost: setevent 256; end
    const world = fixture([0x91], true);
    const clerk = world.assets.map("26:4").objects[0];
    const start = clerk.script + 12; // after winlosstext/loadtrainer/loadvar/startbattle
    const target = ((start + 5) % 0x4000) + 0x4000;
    world.assets.reader.bytes.set([0x06, 1, target & 255, target >> 8, 0xff, 0x33, 0, 1, 0x91], start);
    const before = world.save();
    world.interact();
    const messages = finish(world);
    expect(world.notice, world.diagnostic).toBe("");
    expect(world.state.events.has(256)).toBe(true);
    expect(world.state.money).toBe(before.money);
    expect(world.save().map).toBe(before.map);
    expect(messages).not.toMatch(/whited\s+out/i);
  });
});