// @vitest-environment happy-dom
import { act, cleanup, fireEvent, render, screen, waitFor } from "@testing-library/react";
import { useState } from "react";
import { afterEach, describe, expect, it, vi } from "vitest";

import { DirAutocomplete } from "./DirAutocomplete.js";

vi.mock("../../api.js", () => ({
  listDir: vi.fn(),
}));

import { listDir } from "../../api.js";

const mockListDir = vi.mocked(listDir);

afterEach(() => {
  cleanup();
  vi.clearAllMocks();
});

function Harness({ initial = "" }: { initial?: string }) {
  const [value, setValue] = useState(initial);
  return <DirAutocomplete value={value} onChange={setValue} placeholder="cwd" />;
}

// `fireEvent.focus`/`.blur` dispatch the event without moving the browser's
// real focus, so `document.activeElement` (which the dropdown's fetch guards
// against) never changes — calling the DOM method directly does both.
function focus(el: HTMLElement): void {
  act(() => el.focus());
}
function blur(el: HTMLElement): void {
  act(() => el.blur());
}

describe("DirAutocomplete", () => {
  it("lists entries matching the trailing segment on focus", async () => {
    mockListDir.mockResolvedValue({ path: "/home/n", entries: ["alpha", "beta"] });
    render(<Harness initial="/home/n/al" />);

    focus(screen.getByPlaceholderText("cwd"));

    expect(await screen.findByRole("option", { name: "alpha/" })).not.toBeNull();
    expect(screen.queryByRole("option", { name: "beta/" })).toBeNull();
  });

  it("Tab commits the highlighted entry and does not close the field", async () => {
    mockListDir.mockResolvedValue({ path: "/home/n", entries: ["alpha"] });
    render(<Harness initial="/home/n/a" />);
    const input = screen.getByPlaceholderText("cwd") as HTMLInputElement;
    focus(input);
    await screen.findByRole("option", { name: "alpha/" });

    fireEvent.keyDown(input, { key: "Tab" });

    expect(input.value).toBe("/home/n/alpha/");
  });

  it("arrows move the highlight and Enter accepts it without submitting", async () => {
    mockListDir.mockResolvedValue({ path: "/home/n", entries: ["alpha", "beta"] });
    render(<Harness initial="/home/n/" />);
    const input = screen.getByPlaceholderText("cwd") as HTMLInputElement;
    focus(input);
    await screen.findByRole("option", { name: "alpha/" });

    fireEvent.keyDown(input, { key: "ArrowDown" });
    const notPrevented = fireEvent.keyDown(input, { key: "Enter" });

    expect(input.value).toBe("/home/n/beta/");
    expect(notPrevented).toBe(false); // preventDefault called -> event "processed"
  });

  it("Escape closes the dropdown and stops the key from bubbling", async () => {
    mockListDir.mockResolvedValue({ path: "/home/n", entries: ["alpha"] });
    const onKeyDown = vi.fn();
    render(
      <div onKeyDown={onKeyDown}>
        <Harness initial="/home/n/a" />
      </div>,
    );
    const input = screen.getByPlaceholderText("cwd");
    focus(input);
    await screen.findByRole("option", { name: "alpha/" });

    fireEvent.keyDown(input, { key: "Escape" });

    await waitFor(() => expect(screen.queryByRole("option")).toBeNull());
    expect(onKeyDown).not.toHaveBeenCalled();
  });

  it("does not reopen on refocus until the operator types again", async () => {
    mockListDir.mockResolvedValue({ path: "/home/n", entries: ["alpha"] });
    render(<Harness initial="/home/n/a" />);
    const input = screen.getByPlaceholderText("cwd");
    focus(input);
    await screen.findByRole("option", { name: "alpha/" });
    fireEvent.keyDown(input, { key: "Escape" });
    await waitFor(() => expect(screen.queryByRole("option")).toBeNull());

    blur(input);
    focus(input);

    await new Promise((r) => setTimeout(r, 10));
    expect(screen.queryByRole("option")).toBeNull();

    fireEvent.change(input, { target: { value: "/home/n/al" } });
    expect(await screen.findByRole("option", { name: "alpha/" })).not.toBeNull();
  });
});