import { test, expect, type Page } from "@playwright/test";
import { existsSync, readFileSync, writeFileSync } from "node:fs";
import { createHash } from "node:crypto";
import { resolve } from "node:path";
import { CrystalAssets } from "../src/game/rom/assets";
import { GameWorld } from "../src/game/world/world";

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

/** The version-1 database the singleton player left, with one save. */
async function seedSingleton(page: Page, record: object) {
  await page.evaluate(
    (record) =>
      new Promise<void>((resolve, reject) => {
        const request = indexedDB.open("crystal-native-port", 1);
        request.onupgradeneeded = () =>
          request.result.createObjectStore("saves", { keyPath: "romHash" });
        request.onerror = () => reject(request.error);
        request.onsuccess = () => {
          const db = request.result;
          const transaction = db.transaction("saves", "readwrite");
          const { state, ...fields } = record as { state: number[] };
          transaction
            .objectStore("saves")
            .put({ ...fields, state: new Uint8Array(state) });
          transaction.oncomplete = () => {
            db.close();
            resolve();
          };
          transaction.onerror = () => reject(transaction.error);
        };
      }),
    record,
  );
}

test("save slots: migration, new game, rename, continue, duplicate, delete and import preview", async ({
  page,
}, testInfo) => {
  test.skip(!existsSync(romPath), "Requires a local user-supplied ROM.");
  const errors: string[] = [];
  page.on("pageerror", (error) => errors.push(error.message));
  const bytes = readFileSync(romPath);
  const romHash = createHash("sha1").update(bytes).digest("hex");
  const world = new GameWorld(new CrystalAssets(new Uint8Array(bytes)));
  world.restore({ ...world.save(), name: "GOLD", map: "24:6", x: 6, y: 6 });
  const state = JSON.stringify(world.save());

  await page.goto("/");
  await seedSingleton(page, {
    version: 1,
    romHash,
    coreId: "crystal-native-world-v1",
    savedAt: "2026-10-01T12:00:00.000Z",
    state: [...new TextEncoder().encode(state)],
  });
  await page.reload();
  await page.locator("#rom-file").setInputFiles(romPath);
  await expect(page.locator("#status")).toContainText("saved session is ready");
  const screen = page.locator("#game-screen");
  await expect(screen).toHaveAttribute("data-map", "24:6");

  // The singleton save became the first slot.
  await page.locator("#tab-saves").click();
  const slots = page.locator("#slot-list > li");
  await expect(slots).toHaveCount(1);
  await expect(slots.first()).toHaveAttribute("aria-current", "true");
  await expect(slots.first()).toContainText("Save 1");
  await expect(slots.first()).toContainText("GOLD");
  await expect(
    page.getByRole("button", { name: "Delete Save 1" }),
  ).toBeDisabled();

  // A new game gets its own slot and starts with the introduction.
  await page.locator("#new-game").click();
  await expect(page.locator("#status")).toContainText("“Save 2” created");
  await expect(page.locator("#intro-screen")).toBeVisible();
  await page.locator("#tab-saves").click();
  await expect(slots).toHaveCount(2);
  await expect(
    page.locator('#slot-list > li[aria-current="true"]'),
  ).toContainText("Save 2");

  // Rename the first slot, then continue it.
  await page.getByRole("button", { name: "Rename Save 1" }).click();
  await page.locator("#slot-name").fill("Gold run");
  await page.locator("#slot-dialog-confirm").click();
  await expect(page.locator("#status")).toContainText("Renamed to “Gold run”");
  await page.getByRole("button", { name: "Continue Gold run" }).click();
  await expect(page.locator("#status")).toContainText("“Gold run” is ready");
  await expect(screen).toHaveAttribute("data-map", "24:6");
  await expect(page.locator("#intro-screen")).toBeHidden();

  // Duplicate it, then delete the copy after confirming.
  await page.getByRole("button", { name: "Duplicate Gold run" }).click();
  await expect(page.locator("#status")).toContainText(
    "copied to “Gold run copy”",
  );
  await expect(slots).toHaveCount(3);
  await page.getByRole("button", { name: "Delete Gold run copy" }).click();
  await expect(page.locator("#slot-dialog")).toBeVisible();
  await page
    .locator("#slot-dialog")
    .getByRole("button", { name: "Cancel" })
    .click();
  await expect(slots).toHaveCount(3);
  await page.getByRole("button", { name: "Delete Gold run copy" }).click();
  await page.locator("#slot-dialog-confirm").click();
  await expect(page.locator("#status")).toContainText(
    "“Gold run copy” deleted",
  );
  await expect(slots).toHaveCount(2);

  // The import preview shows the trainer and the slot it conflicts with,
  // and cancelling changes nothing.
  const downloaded = page.waitForEvent("download");
  await page.locator("#backup").click();
  const backup = (await (await downloaded).path())!;
  await page.locator("#save-file").setInputFiles(backup);
  const preview = page.locator("#import-dialog");
  await expect(preview).toBeVisible();
  await expect(preview).toContainText("GOLD · ID No.");
  await expect(preview).toContainText("game data version 3");
  await expect(preview).toContainText("“Gold run”");
  await expect(preview).toContainText("the same progress as this backup");
  await preview.getByRole("button", { name: "Cancel" }).click();
  await expect(slots).toHaveCount(2);

  // A backup for another cartridge is refused without changing any slot.
  const foreign = testInfo.outputPath("foreign.crystal-save.json");
  writeFileSync(
    foreign,
    JSON.stringify({
      ...JSON.parse(readFileSync(backup, "utf8")),
      romHash: "0".repeat(40),
    }),
  );
  await page.locator("#save-file").setInputFiles(foreign);
  await expect(preview).toContainText("different cartridge");
  await expect(page.locator("#import-new")).toHaveCount(0);
  await preview.getByRole("button", { name: "Close" }).click();
  await expect(slots).toHaveCount(2);

  // Importing as a new save adds a slot and continues it.
  await page.locator("#save-file").setInputFiles(backup);
  await page.locator("#import-new").click();
  await expect(page.locator("#status")).toContainText("Backup restored");
  await expect(slots).toHaveCount(3);
  await expect(
    page.locator('#slot-list > li[aria-current="true"]'),
  ).toContainText("GOLD");

  // The last slot played opens after a reload.
  await page.getByRole("button", { name: "Continue Gold run" }).click();
  await expect(page.locator("#status")).toContainText("“Gold run” is ready");
  await page.reload();
  await page.locator("#rom-file").setInputFiles(romPath);
  await expect(page.locator("#status")).toContainText("saved session is ready");
  await page.locator("#tab-saves").click();
  await expect(
    page.locator('#slot-list > li[aria-current="true"]'),
  ).toContainText("Gold run");
  expect(errors).toEqual([]);
});