import { beforeAll, describe, expect, it } from "vitest";
import { existsSync, readFileSync } from "node:fs";
import { CrystalAssets } from "../src/game/rom/assets";
import { dexHeight, dexWeight } from "../src/game/rom/pokedex";
import { GameWorld } from "../src/game/world/world";
import { generatePartyMon } from "../src/game/party/pokemon";
import { ENGINE_FLAGS } from "../src/game/rom/profile";
import type { PokedexView } from "../src/game/scripts/pokedex";

const romPath =
  process.env.CRYSTAL_ROM_PATH ??
  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
const pret = ".reference/pokecrystal";
const NEW_BARK_TOWN = "24:4",
  BULBASAUR = 1,
  PIDGEY = 16,
  CHIKORITA = 152,
  BAYLEEF = 153,
  CYNDAQUIL = 155,
  QUILAVA = 156,
  TOTODILE = 158,
  SENTRET = 161,
  HOOTHOOT = 163;

describe("the Pokédex number formats", () => {
  it("prints height and weight over the ROM templates", () => {
    const height = `HT  ?'??"`,
      weight = "WT   ???lb";
    expect(dexHeight(height, 204)).toBe(`HT  2'04"`);
    expect(dexHeight(height, 8)).toBe(`HT  0'08"`);
    expect(dexHeight(height, 1701)).toBe(`HT 17'01"`);
    expect(dexWeight(weight, 150)).toBe("WT  15.0lb");
    expect(dexWeight(weight, 1)).toBe("WT   0.1lb");
    expect(dexWeight(weight, 4760)).toBe("WT 476.0lb");
    // DisplayDexEntry skips a zero word and leaves the question marks.
    expect(dexHeight(height, 0)).toBe(height);
    expect(dexWeight(weight, 0)).toBe(weight);
  });
});

describe.skipIf(!existsSync(romPath))("the Pokédex data", () => {
  let dex!: CrystalAssets["pokedex"];
  beforeAll(() => {
    dex = new CrystalAssets(new Uint8Array(readFileSync(romPath))).pokedex;
  });

  it("reads its strings and the New mode order", () => {
    expect(dex.dexString("String_SEEN")).toBe("SEEN");
    expect(dex.dexString("String_OWN")).toBe("OWN");
    expect(dex.dexString("Pokedex_DrawDexEntryScreenBG.Height")).toBe(`HT  ?'??"`);
    expect(dex.dexString("Pokedex_DrawDexEntryScreenBG.Weight")).toBe("WT   ???lb");
    expect(dex.dexString("Pokedex_DrawDexEntryScreenBG.MenuItems").trim()).toBe(
      "PAGE AREA CRY PRNT",
    );
    expect(dex.notSeenName()).toBe("-----");
    const order = dex.newOrder();
    expect(order.slice(0, 3)).toEqual([CHIKORITA, BAYLEEF, 154]);
    expect([...order].sort((a, b) => a - b)).toEqual(
      Array.from({ length: 251 }, (_, i) => i + 1),
    );
  });

  it("reads an entry's category, measurements and pages", () => {
    const entry = dex.entry(BULBASAUR);
    expect(entry).toMatchObject({ category: "SEED", height: 204, weight: 150 });
    expect(entry.pages[0].split("\n")).toHaveLength(3);
    expect(entry.pages[1].split("\n")).toHaveLength(3);
    for (let species = 1; species <= 251; species++) dex.entry(species);
  });

  it("decodes the question mark picture and its palette", () => {
    expect(dex.questionMarkPic()).toHaveLength(49 * 16);
    // RGB 11, 23, 00 from gfx/pokedex/question_mark.pal.
    expect(dex.questionMarkPalette()[0]).toEqual([90, 189, 0]);
  });
});

describe.skipIf(!existsSync(romPath) || !existsSync(`${pret}/data/pokemon/dex_order_new.asm`))(
  "the Pokédex data against the pinned PRET source",
  () => {
    const read = (path: string) => readFileSync(`${pret}/${path}`, "utf8");
    let dex!: CrystalAssets["pokedex"], species!: Map<string, number>;
    beforeAll(() => {
      dex = new CrystalAssets(new Uint8Array(readFileSync(romPath))).pokedex;
      // constants/pokemon_constants.asm numbers species from 1.
      species = new Map(
        [...read("constants/pokemon_constants.asm").matchAll(/^\s+const (\w+)/gm)].map(
          ([, name], index) => [name, index + 1],
        ),
      );
    });

    it("matches NewPokedexOrder", () => {
      const order = [...read("data/pokemon/dex_order_new.asm").matchAll(/^\s+db (\w+)/gm)].map(
        ([, name]) => species.get(name),
      );
      expect(dex.newOrder()).toEqual(order);
    });

    it("matches every entry in data/pokemon/dex_entries", () => {
      const files = new Map(
        [...read("data/pokemon/dex_entries.asm").matchAll(/^(\w+)::\s+INCLUDE "([^"]+)"/gm)].map(
          ([, label, file]) => [label, file],
        ),
      );
      const labels = [
        ...read("data/pokemon/dex_entry_pointers.asm").matchAll(/^\s+dw (\w+)/gm),
      ].map(([, label]) => label);
      expect(labels).toHaveLength(251);
      labels.forEach((label, index) => {
        const source = read(files.get(label)!);
        const [, category] = /db "([^"]*)@"/.exec(source)!;
        const [, height, weight] = /dw (\d+), (\d+)/.exec(source)!;
        const pages: string[][] = [[]];
        for (const [, command, text] of source.matchAll(/^\s+(db|next|page)\s+"([^"]*)"/gm)) {
          if (text.endsWith("@") && command === "db" && !pages[0].length && text === `${category}@`)
            continue;
          if (command === "page") pages.push([]);
          pages.at(-1)!.push(text.replace(/@$/, "").replaceAll("#", "POKé"));
        }
        expect(dex.entry(index + 1)).toEqual({
          category,
          height: Number(height),
          weight: Number(weight),
          pages: pages.map((lines) => lines.join("\n")),
        });
      });
    });

    it("matches each species' footprint", () => {
      const tops = [
        ...read("gfx/footprints.asm").matchAll(/^INCBIN "([^"]+)",\s+footprint_top/gm),
      ].map(([, file]) => file);
      for (let index = 0; index < 251; index++) {
        const bytes = readFileSync(`${pret}/${tops[index]}`);
        expect(dex.footprint(index + 1), tops[index]).toEqual(
          new Uint8Array(bytes.subarray(0, 32)),
        );
      }
    });
  },
);

describe.skipIf(!existsSync(romPath))("the Pokédex screen", () => {
  const assets = () => new CrystalAssets(new Uint8Array(readFileSync(romPath)));
  function fixture(seen: number[], caught: number[]) {
    const world = new GameWorld(
      assets(),
      () => new Date("2026-09-25T12:00:00"),
      () => 0x42,
    );
    world.state.party = [
      generatePartyMon(world.assets.pokemon, {
        species: CYNDAQUIL,
        level: 8,
        item: 0,
        otId: world.playerId,
        ot: "GOLD",
        dvs: 0x9abc,
        caughtData: 0,
      }),
    ];
    world.restore({
      ...world.save(),
      map: NEW_BARK_TOWN,
      x: 13,
      y: 7,
      direction: "down",
      objects: [],
    });
    world.state.flags.add(ENGINE_FLAGS.pokedex);
    world.state.pokedex.seen = new Set(seen);
    world.state.pokedex.caught = new Set(caught);
    return world;
  }
  function view(world: GameWorld): PokedexView {
    const choice = world.dialogue?.choice;
    if (choice?.kind !== "pokedex")
      throw new Error(`Expected the Pokédex, got ${choice?.kind}`);
    return choice.view;
  }
  function open(world: GameWorld) {
    expect(world.openStartMenu()).toBe(true);
    const choice = world.dialogue?.choice;
    if (choice?.kind !== "menu") throw new Error("Expected the start menu.");
    const index = choice.items.indexOf("POKéDEX");
    expect(index).toBe(0);
    world.choose(index);
    return view(world);
  }
  function press(world: GameWorld, button: "a" | "b" | "up" | "down" | "left" | "right") {
    if (button === "a") world.interact();
    else if (button === "b") world.advanceDialogue();
    else world.moveCursor(button);
  }
  const names = (dex: PokedexView) => dex.rows.map((row) => row.name);

  it("lists the New mode order up to the last seen Pokémon", () => {
    const world = fixture([CHIKORITA, CYNDAQUIL, QUILAVA, PIDGEY], [CYNDAQUIL]);
    const dex = open(world);
    expect(dex).toMatchObject({
      screen: "list",
      seen: 4,
      own: 1,
      cursor: 0,
      scroll: 0,
      labels: { seen: "SEEN", own: "OWN" },
      picture: CHIKORITA,
    });
    // PIDGEY is tenth in New mode, so the list ends there.
    expect(dex.end).toBe(10);
    expect(names(dex)).toEqual([
      "CHIKORITA",
      "-----",
      "-----",
      "CYNDAQUIL",
      "QUILAVA",
      "-----",
      "-----",
    ]);
    expect(dex.rows.map((row) => row.caught)).toEqual([
      false, false, false, true, false, false, false,
    ]);
    // The cursor stops at the last seen Pokémon; an unseen one shows "?".
    press(world, "down");
    expect(view(world)).toMatchObject({ cursor: 1 });
    expect(view(world).picture).toBeUndefined();
    for (let i = 0; i < 12; i++) press(world, "down");
    expect(view(world)).toMatchObject({ cursor: 6, scroll: 3, picture: PIDGEY });
    // Left goes up a page, at most to the top; right goes back down.
    press(world, "left");
    expect(view(world)).toMatchObject({ cursor: 6, scroll: 0 });
    press(world, "right");
    expect(view(world)).toMatchObject({ cursor: 6, scroll: 3 });
  });

  it("ignores A on an unseen Pokémon and opens a seen one's entry", () => {
    const world = fixture([CHIKORITA, CYNDAQUIL], [CYNDAQUIL]);
    open(world);
    press(world, "down");
    press(world, "a");
    expect(view(world).screen).toBe("list");
    press(world, "down");
    press(world, "down");
    press(world, "a");
    const dex = view(world);
    expect(dex.screen).toBe("entry");
    expect(dex.picture).toBe(CYNDAQUIL);
    expect(dex.entry).toMatchObject({
      species: CYNDAQUIL,
      name: "CYNDAQUIL",
      category: "FIRE MOUSE",
      number: "155",
      height: `HT  1'08"`,
      weight: "WT  17.0lb",
      caught: true,
      page: 1,
      actions: ["PAGE", "AREA", "CRY", "PRNT"],
      action: 0,
    });
    expect(dex.entry!.text).toBe(world.assets.pokedex.entry(CYNDAQUIL).pages[0]);
  });

  it("hides measurements and text until the Pokémon is caught", () => {
    const world = fixture([CHIKORITA], []);
    open(world);
    press(world, "a");
    const entry = view(world).entry!;
    expect(entry).toMatchObject({
      name: "CHIKORITA",
      category: "LEAF",
      number: "152",
      height: `HT  ?'??"`,
      weight: "WT   ???lb",
      caught: false,
    });
    expect(entry.text).toBeUndefined();
  });

  it("turns pages, moves the arrow and steps through seen entries", () => {
    const world = fixture(
      [CHIKORITA, CYNDAQUIL, TOTODILE, SENTRET],
      [CHIKORITA, CYNDAQUIL, TOTODILE, SENTRET],
    );
    open(world);
    press(world, "a");
    press(world, "a");
    expect(view(world).entry).toMatchObject({ page: 2 });
    expect(view(world).entry!.text).toBe(world.assets.pokedex.entry(CHIKORITA).pages[1]);
    press(world, "a");
    expect(view(world).entry).toMatchObject({ page: 1 });
    // The arrow stops at PRNT and at PAGE; AREA, CRY and PRNT do nothing.
    for (let i = 0; i < 5; i++) press(world, "right");
    expect(view(world).entry).toMatchObject({ action: 3 });
    press(world, "a");
    expect(view(world).entry).toMatchObject({ action: 3, page: 1 });
    press(world, "left");
    expect(view(world).entry).toMatchObject({ action: 2 });
    press(world, "a");
    press(world, "a");
    expect(view(world).entry).toMatchObject({ page: 1 });
    // Down skips unseen Pokémon and starts the next entry on page 1 with
    // the arrow on PAGE.
    press(world, "down");
    expect(view(world).entry).toMatchObject({ species: CYNDAQUIL, page: 1, action: 0 });
    press(world, "down");
    expect(view(world).entry).toMatchObject({ species: TOTODILE });
    press(world, "down");
    expect(view(world).entry).toMatchObject({ species: SENTRET });
    // SENTRET is 19th in New mode.
    expect(view(world)).toMatchObject({ cursor: 6, scroll: 12 });
    // Past the last seen Pokémon nothing moves.
    press(world, "down");
    expect(view(world).entry).toMatchObject({ species: SENTRET });
    press(world, "up");
    expect(view(world).entry).toMatchObject({ species: TOTODILE });
    // B returns to the list where the entries left the cursor.
    press(world, "b");
    expect(view(world)).toMatchObject({ screen: "list", cursor: 0, scroll: 6 });
  });

  it("leaves to the start menu and reopens on the last entry", () => {
    const world = fixture(
      [CHIKORITA, CYNDAQUIL, PIDGEY, HOOTHOOT],
      [CYNDAQUIL],
    );
    open(world);
    for (let i = 0; i < 9; i++) press(world, "down");
    expect(view(world)).toMatchObject({ picture: PIDGEY });
    press(world, "a");
    press(world, "b");
    press(world, "b");
    expect(world.dialogue?.choice?.kind).toBe("menu");
    // Pokedex_InitCursorPosition scrolls as far as the last page allows
    // (HOOTHOOT is 15th), then moves the cursor to PIDGEY, 10th.
    world.choose(0);
    expect(view(world)).toMatchObject({ screen: "list", picture: PIDGEY, scroll: 8, cursor: 1 });
    // The draft changes nothing, and closing the menu commits the cursor.
    press(world, "b");
    press(world, "b");
    expect(world.dialogue).toBeUndefined();
    expect(open(world)).toMatchObject({ picture: PIDGEY });
  });
});