import { describe, expect, it } from "vitest";
import { existsSync, readFileSync } from "node:fs";
import { CrystalAssets } from "../src/game/rom/assets";
import { GameWorld, migrateSave } from "../src/game/world/world";
import { generatePartyMon } from "../src/game/party/pokemon";
import {
  mailMessage,
  validMailMessage,
  type Mail,
} from "../src/game/party/mail";
import { close, menuItems, open, pick, pickItem, until } from "./menu-driver";

const romPath =
  process.env.CRYSTAL_ROM_PATH ??
  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
const POKEMON_CENTER = "26:5",
  CYNDAQUIL = 155,
  PIDGEY = 16,
  EGG = 0xfd;
const POTION = 0x12,
  BERRY = 0xad,
  FLOWER_MAIL = 0x9e,
  SURF_MAIL = 0xb5;

describe("MAIL messages", () => {
  it("hold up to sixteen characters a line, the second after a full first", () => {
    expect(validMailMessage("")).toBe(true);
    expect(validMailMessage("HELLO, CHRIS!")).toBe(true);
    expect(validMailMessage("x".repeat(17))).toBe(false);
    expect(validMailMessage("SHORT\nLINE")).toBe(false);
    expect(validMailMessage(`${"A".repeat(16)}\n${"b".repeat(16)}`)).toBe(true);
    expect(validMailMessage(`${"A".repeat(16)}\nB\nC`)).toBe(false);
    // The mail entry's own characters only.
    expect(validMailMessage("é♂♀¥…× “”[]:;&()")).toBe(true);
    expect(validMailMessage("<PK>")).toBe(false);
    expect(validMailMessage("tab\there")).toBe(false);
    // The second line pads the first to a full line.
    expect(mailMessage("HI", "THERE")).toBe(`HI${" ".repeat(14)}\nTHERE`);
    expect(mailMessage("HI", "")).toBe("HI");
  });
});

describe.skipIf(!existsSync(romPath))("MAIL", () => {
  /** In front of Cherrygrove's PC with two Pokémon, MAIL and a Potion. */
  function fixture() {
    const assets = new CrystalAssets(new Uint8Array(readFileSync(romPath)));
    const world = new GameWorld(
      assets,
      () => new Date("2026-09-25T12:00:00"),
      () => 0x42,
    );
    const mon = (species: number, level: number) =>
      generatePartyMon(assets.pokemon, {
        species,
        level,
        item: 0,
        otId: world.playerId,
        ot: "CHRIS",
        dvs: 0x9abc,
        caughtData: 0,
      });
    world.state.party = [mon(CYNDAQUIL, 8), mon(PIDGEY, 4)];
    world.state.bag.items = [
      { item: POTION, quantity: 1 },
      { item: FLOWER_MAIL, quantity: 2 },
    ];
    world.restore({
      ...world.save(),
      map: POKEMON_CENTER,
      x: 9,
      y: 2,
      direction: "up",
      objects: [],
    });
    return world;
  }
  const letter = (
    world: GameWorld,
    message: string,
    type = FLOWER_MAIL,
  ): Mail => ({
    message,
    author: world.name,
    authorId: world.playerId,
    species: CYNDAQUIL,
    type,
  });
  /** GIVE the MAIL from the pack to the first Pokémon, up to its entry. */
  function give(world: GameWorld) {
    open(world);
    pick(world, "PACK");
    pickItem(world, FLOWER_MAIL);
    pick(world, "GIVE");
    return pick(world, "CYNDAQUIL");
  }
  /** The first Pokémon's MAIL submenu. */
  function mailMenu(world: GameWorld) {
    open(world);
    pick(world, "POKéMON");
    pick(world, "CYNDAQUIL");
    return pick(world, "MAIL");
  }
  /** Turn on the PC and open the player's MAIL BOX. */
  function mailbox(world: GameWorld) {
    world.interact();
    until(world);
    pick(world, `${world.name}'s PC`);
    return pick(world, "MAIL BOX");
  }

  it("writes a message on MAIL given from the pack", () => {
    const world = fixture();
    expect(give(world)).toEqual(["Made CYNDAQUIL hold FLOWER MAIL."]);
    const entry = world.dialogue?.choice;
    expect(entry?.kind === "name" && [entry.mail, entry.max]).toEqual([
      true,
      16,
    ]);
    // The entry keeps its lines; a short first line cannot have a second.
    world.choose("SHORT\nLINE");
    expect(world.dialogue?.choice?.kind).toBe("name");
    world.choose(mailMessage("HELLO FROM", "NEW BARK TOWN!"));
    close(world);
    const mon = world.state.party[0];
    expect(mon.item).toBe(FLOWER_MAIL);
    expect(mon.mail).toEqual(
      letter(world, `HELLO FROM${" ".repeat(6)}\nNEW BARK TOWN!`),
    );
    expect(world.state.bag.items.at(-1)).toEqual({
      item: FLOWER_MAIL,
      quantity: 1,
    });
    // The submenu offers MAIL instead of ITEM, and SWITCH keeps it with
    // the Pokémon.
    open(world);
    pick(world, "POKéMON");
    pick(world, "CYNDAQUIL");
    expect(menuItems(world)).toEqual([
      "STATS",
      "SWITCH",
      "MOVE",
      "MAIL",
      "CANCEL",
    ]);
    pick(world, "SWITCH");
    pick(world, "PIDGEY");
    close(world);
    expect(
      world.state.party.map((mon) => [mon.species, mon.mail?.type]),
    ).toEqual([
      [PIDGEY, undefined],
      [CYNDAQUIL, FLOWER_MAIL],
    ]);
    const saved = world.save();
    world.restore(saved);
    expect(world.save()).toEqual(saved);
  });

  it("swaps a held item for MAIL, which then gets its message", () => {
    const world = fixture();
    world.state.party[0].item = BERRY;
    expect(give(world)).toEqual([
      "CYNDAQUIL is already holding",
      "BERRY. Switch items?",
    ]);
    world.choose(1);
    expect(until(world)).toEqual([
      "Took CYNDAQUIL's BERRY and",
      "made it hold FLOWER MAIL.",
    ]);
    expect(world.dialogue?.choice?.kind).toBe("name");
    world.choose("");
    close(world);
    expect(world.state.party[0].mail).toEqual(letter(world, ""));
    expect(world.state.bag.items.some((slot) => slot.item === BERRY)).toBe(
      true,
    );
  });

  it("reads MAIL, and takes it to the PC or into the pack", () => {
    const world = fixture();
    const mon = world.state.party[0];
    mon.item = FLOWER_MAIL;
    mon.mail = letter(world, "SEE YOU SOON!");
    mailMenu(world);
    expect(menuItems(world)).toEqual(["READ", "TAKE", "QUIT"]);
    world.choose(0); // READ
    expect(world.mailView).toEqual(mon.mail);
    world.advanceDialogue();
    until(world);
    expect(world.mailView).toBeUndefined();
    // B on the letter goes back to the party menu.
    expect(menuItems(world)).toEqual(["CYNDAQUIL", "PIDGEY"]);
    close(world);

    // TAKE: NO, then NO again keeps it.
    mailMenu(world);
    expect(pick(world, "TAKE")).toEqual(["Send the removed MAIL to your PC?"]);
    world.choose(0);
    expect(until(world)[0]).toBe("The MAIL will lose its message. OK?");
    world.choose(0);
    close(world);
    expect(world.state.party[0].mail?.message).toBe("SEE YOU SOON!");

    // To the PC.
    mailMenu(world);
    pick(world, "TAKE");
    world.choose(1);
    expect(until(world)[0]).toBe("The MAIL was sent to your PC.");
    close(world);
    expect(world.state.party[0]).not.toHaveProperty("mail");
    expect(world.state.party[0].item).toBe(0);
    expect(world.state.mailbox).toEqual([letter(world, "SEE YOU SOON!")]);
    const saved = world.save();
    world.restore(saved);
    expect(world.save()).toEqual(saved);
  });

  it("refuses a full MAILBOX, and loses the message in the pack", () => {
    const world = fixture();
    const mon = world.state.party[0];
    mon.item = FLOWER_MAIL;
    mon.mail = letter(world, "HI");
    world.state.mailbox = Array.from({ length: 10 }, () =>
      letter(world, "OLD"),
    );
    mailMenu(world);
    pick(world, "TAKE");
    world.choose(1);
    expect(until(world)[0]).toBe("Your PC's MAILBOX is full.");
    close(world);
    expect(world.state.party[0].mail?.message).toBe("HI");

    // A full pack keeps it on the Pokémon.
    world.state.bag.items = Array.from({ length: 20 }, (_, i) => ({
      item: i + 1,
      quantity: 1,
    }));
    mailMenu(world);
    pick(world, "TAKE");
    world.choose(0);
    until(world);
    world.choose(1);
    expect(until(world)[0]).toBe("There's no space for removing MAIL.");
    close(world);
    expect(world.state.party[0].item).toBe(FLOWER_MAIL);

    world.state.bag.items = [];
    mailMenu(world);
    pick(world, "TAKE");
    world.choose(0);
    until(world);
    world.choose(1);
    expect(until(world)[0]).toBe("MAIL detached from CYNDAQUIL.");
    close(world);
    expect(world.state.party[0]).not.toHaveProperty("mail");
    expect(world.state.bag.items).toEqual([{ item: FLOWER_MAIL, quantity: 1 }]);
  });

  it("keeps a Pokémon holding MAIL out of the boxes", () => {
    const world = fixture();
    const mon = world.state.party[1];
    mon.item = FLOWER_MAIL;
    mon.mail = { ...letter(world, "HI"), species: PIDGEY };
    world.interact();
    until(world);
    pick(world, "BILL's PC");
    until(world);
    pick(world, "DEPOSIT POKéMON");
    pick(world, /^PIDGEY/);
    expect(pick(world, "DEPOSIT")).toContain("Remove MAIL.");
    close(world);
    expect(world.state.party).toHaveLength(2);
  });

  it("reads, packs and attaches MAIL from the PC's MAIL BOX", () => {
    const world = fixture();
    world.state.mailbox = [
      letter(world, "FIRST"),
      { ...letter(world, "SECOND", SURF_MAIL), author: "KRIS" },
      letter(world, "THIRD"),
    ];
    world.state.party.push({
      ...structuredClone(world.state.party[1]),
      species: EGG,
    });
    mailbox(world);
    expect(menuItems(world)).toEqual([
      world.name,
      "KRIS",
      world.name,
      "CANCEL",
    ]);
    pick(world, "KRIS");
    expect(menuItems(world)).toEqual([
      "READ MAIL",
      "PUT IN PACK",
      "ATTACH MAIL",
      "CANCEL",
    ]);
    world.choose(0); // READ MAIL
    expect(world.mailView?.message).toBe("SECOND");
    world.advanceDialogue();
    until(world);

    // PUT IN PACK asks first, then the message is lost.
    pick(world, "KRIS");
    expect(pick(world, "PUT IN PACK")).toEqual([
      "The MAIL's message will be lost. OK?",
    ]);
    world.choose(1);
    expect(until(world)[0]).toBe("The cleared MAIL was put away.");
    expect(menuItems(world)).toEqual([world.name, world.name, "CANCEL"]);

    // ATTACH MAIL: not to an Egg or a Pokémon holding an item.
    pick(world, /./);
    expect(pick(world, "ATTACH MAIL")).toEqual(["Choose a POKéMON."]);
    world.choose(2);
    expect(until(world)[0]).toBe("An EGG can't hold any MAIL.");
    world.choose(0);
    expect(until(world)[0]).toBe("The MAIL was moved from the MAILBOX.");
    close(world);
    expect(world.state.party[0].mail).toEqual(letter(world, "FIRST"));
    expect(world.state.party[0].item).toBe(FLOWER_MAIL);
    expect(world.state.mailbox).toEqual([letter(world, "THIRD")]);
    expect(world.state.bag.items.at(-1)).toEqual({
      item: SURF_MAIL,
      quantity: 1,
    });

    mailbox(world);
    pick(world, world.name);
    pick(world, "ATTACH MAIL");
    world.choose(0);
    expect(until(world)[0]).toBe("It's already hold- ing an item.");
    close(world);
    expect(world.state.mailbox).toHaveLength(1);
  });

  it("saves MAIL with its holder, and refuses MAIL without one", () => {
    const world = fixture();
    const mon = world.state.party[0];
    mon.item = FLOWER_MAIL;
    mon.mail = letter(world, "HI");
    world.state.mailbox = [letter(world, "BOX")];
    const saved = world.save();
    world.restore(saved);
    expect(world.save()).toEqual(saved);
    const { mailbox: _, ...legacy } = saved;
    expect(migrateSave(legacy, () => 0)?.mailbox).toEqual([]);
    const party = (change: (mon: (typeof saved.party)[number]) => void) => {
      const copy = structuredClone(saved);
      change(copy.party[0]);
      return copy;
    };
    for (const invalid of [
      party((mon) => delete mon.mail),
      party((mon) => (mon.item = POTION)),
      party((mon) => (mon.mail!.message = "x".repeat(17))),
      party((mon) => (mon.mail!.type = POTION)),
      {
        ...saved,
        mailbox: Array.from({ length: 11 }, () => letter(world, "")),
      },
    ])
      expect(() => world.restore(invalid)).toThrow("Invalid native save");
  });
});