import { afterEach, describe, expect, it, vi } from "vitest";
import {
  existsSync,
  mkdtempSync,
  readFileSync,
  rmSync,
  statSync,
} from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { downloadPrivateRom } from "../scripts/fetch-private-rom.mjs";

const directories: string[] = [];
const secret = "https://private.invalid/crystal?token=never-log-this";
function destination() {
  const directory = mkdtempSync(join(tmpdir(), "crystal-download-"));
  directories.push(directory);
  return join(directory, "private", "crystal.gbc");
}
afterEach(() => {
  for (const directory of directories.splice(0))
    rmSync(directory, { recursive: true, force: true });
});

it("requires HTTPS before making a request", async () => {
  const fetcher = vi.fn();
  await expect(
    downloadPrivateRom("http://private.invalid/game", destination(), fetcher),
  ).rejects.toThrow("HTTPS");
  expect(fetcher).not.toHaveBeenCalled();
});
it("does not disclose the URL in network errors and refuses redirects", async () => {
  const fetcher = vi
    .fn()
    .mockRejectedValue(new Error(`Cannot connect to ${secret}`));
  const path = destination();
  await expect(downloadPrivateRom(secret, path, fetcher)).rejects.toThrow(
    /^Private ROM download failed\./,
  );
  expect(fetcher.mock.calls[0][1].redirect).toBe("error");
  expect(existsSync(path)).toBe(false);
});
it("reports an IP restriction failure without saving the error page", async () => {
  const path = destination();
  await expect(
    downloadPrivateRom(
      secret,
      path,
      async () => new Response("Forbidden", { status: 403 }),
    ),
  ).rejects.toThrow("HTTP 403");
  expect(existsSync(path)).toBe(false);
});
it.each([100, 2 * 1024 * 1024, 2 * 1024 * 1024 + 1])(
  "refuses invalid ROM content of %i bytes",
  async (size) => {
    const path = destination();
    await expect(
      downloadPrivateRom(
        secret,
        path,
        async () => new Response(new Uint8Array(size)),
      ),
    ).rejects.toThrow();
    expect(existsSync(path)).toBe(false);
  },
);

const romPath =
  process.env.CRYSTAL_ROM_PATH ??
  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
describe.skipIf(!existsSync(romPath))("verified private download", () => {
  it("writes the exact verified bytes privately and refuses to overwrite an existing file", async () => {
    const path = destination();
    const rom = readFileSync(romPath);
    const fetcher = async () => new Response(rom);
    await downloadPrivateRom(secret, path, fetcher);
    expect(readFileSync(path).equals(rom)).toBe(true);
    expect(statSync(path).mode & 0o777).toBe(0o600);
    await expect(downloadPrivateRom(secret, path, fetcher)).rejects.toThrow();
    expect(readFileSync(path).equals(rom)).toBe(true);
  });
});