// @vitest-environment jsdom
//
// Back to a page whose item changed lists while it was away. The notification center holds a row
// that asked for the reader in "Needs you" for the visit; on the next visit the same row, read now,
// sits in the stream below. The restore matched the unnamed list by its place, missed the name there
// and fell back to the saved index — the focus landed on the neighbour, and Enter opened the wrong
// notification. Its own file: listNav keeps module-level state.
import { afterEach, describe, expect, it, vi } from "vitest";
import { act, cleanup, render } from "@testing-library/react";
import { useRef } from "react";

import { navItemAttrs, navPosition, restoreNavPosition, useListNav } from "./listNav";

afterEach(cleanup);

function List({ items }: { items: string[] }) {
  const ref = useRef<HTMLDivElement>(null);
  useListNav(ref, { enabled: true });
  return (
    <div ref={ref}>
      {items.map((t, i) => (
        <div key={`${t}-${i}`} {...navItemAttrs(i, t)}>
          <button data-nav-open="">{t}</button>
        </div>
      ))}
    </div>
  );
}

const Page = ({ lists }: { lists: string[][] }) => (
  <main>
    {lists.map((items, i) => (
      <List key={i} items={items} />
    ))}
  </main>
);

const button = (name: string) =>
  [...document.querySelectorAll("button")].find((b) => b.textContent === name)!;
const focused = () => document.activeElement?.closest("[data-nav-index]")?.textContent;
const wait = (ms: number) => act(() => new Promise((r) => setTimeout(r, ms)));

async function leaveAndReturn(before: string[][], from: string, after: string[][]) {
  const { unmount } = render(<Page lists={before} />);
  button(from).focus();
  const pos = navPosition()!;
  unmount(); // the page switch
  render(<Page lists={after} />); // Back
  const cancel = restoreNavPosition(pos);
  await wait(120);
  cancel();
}

describe("Back to an item that moved to another list", () => {
  it("finds it by its name in the list it moved to, not its neighbour at the old place", async () => {
    await leaveAndReturn([["subscribed", "download"], ["older"]], "subscribed", [
      ["download"],
      ["subscribed", "older"],
    ]);
    expect(focused()).toBe("subscribed");
  });

  it("finds it when the list it left is gone altogether", async () => {
    await leaveAndReturn([["subscribed"], ["older"]], "subscribed", [["subscribed", "older"]]);
    expect(focused()).toBe("subscribed");
  });

  it("does not guess between two items of that name elsewhere: the saved place", async () => {
    await leaveAndReturn([["twin", "download"], ["older"]], "twin", [
      ["download"],
      ["twin", "older", "twin"],
    ]);
    expect(focused()).toBe("download");
  });

  it("brings an item found in another list into view; one in its own list stays put", async () => {
    // The scroll restore put the page where the item WAS: found elsewhere, it would hold the focus
    // off screen.
    const reveal = vi.fn();
    Element.prototype.scrollIntoView = reveal;
    await leaveAndReturn([["subscribed", "download"], ["older"]], "subscribed", [
      ["download"],
      ["subscribed", "older"],
    ]);
    expect(reveal).toHaveBeenCalledTimes(1);
    cleanup();
    reveal.mockClear();
    await leaveAndReturn([["subscribed", "download"]], "download", [["download", "subscribed"]]);
    expect(focused()).toBe("download");
    expect(reveal).not.toHaveBeenCalled();
  });
});