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

vi.mock("react-i18next", async (importOriginal) => {
  const actual = await importOriginal<typeof import("react-i18next")>();
  return {
    ...actual,
    useTranslation: () => ({
      t: (k: string, o?: Record<string, unknown>) =>
        o && "from" in o ? `${k}:${String(o.from)}-${String(o.to)}` : k,
      i18n: { language: "en" },
    }),
  };
});
vi.mock("../../lib/history", () => ({ useBackToClose: () => {} }));

import YearPicker from "./YearPicker";

afterEach(cleanup);

// Eight years over three decades, 1987 and 2014 without titles.
const YEARS = [
  { year: 2026, count: 3 },
  { year: 2024, count: 9 },
  { year: 2023, count: 1 },
  { year: 2021, count: 4 },
  { year: 2020, count: 2 },
  { year: 2015, count: 5 },
  { year: 2013, count: 7 },
  { year: 1985, count: 6 },
];

const open = () => fireEvent.click(screen.getByRole("button", { name: /sidebar\.year\.more/ }));

describe("YearPicker", () => {
  it("shows the six newest years as chips, the selected one kept beside them", () => {
    render(<YearPicker years={YEARS} selected={1985} onPick={() => {}} />);
    const chips = screen.getAllByRole("button", { pressed: false }).map((b) => b.textContent);
    expect(chips.slice(0, 6)).toEqual(["20263", "20249", "20231", "20214", "20202", "20155"]);
    expect(screen.getByRole("button", { pressed: true }).textContent).toBe("19856");
  });

  it("lays every year out by decade in the dialog; a year without titles is not a choice", () => {
    render(<YearPicker years={YEARS} onPick={() => {}} />);
    open();
    const dialog = screen.getByRole("dialog");
    const rows = within(dialog).getAllByRole("group", { name: /sidebar\.year\.decade/ });
    expect(rows.map((r) => r.getAttribute("aria-label"))).toEqual([
      "sidebar.year.decade:2020-2029",
      "sidebar.year.decade:2010-2019",
      "sidebar.year.decade:1980-1989",
    ]);
    const in1980s = within(rows[2]!)
      .getAllByRole("button")
      .map((b) => b.dataset.year);
    expect(in1980s).toEqual(["1985"]);
    expect(rows[1]!.querySelector('[data-year="2014"]')).toBeNull();
  });

  it("sorted by count, the busiest year comes first", () => {
    render(<YearPicker years={YEARS} onPick={() => {}} />);
    open();
    fireEvent.click(screen.getByRole("button", { name: "sidebar.year.sortCount" }));
    const order = within(screen.getByRole("dialog"))
      .getAllByRole("button")
      .map((b) => b.dataset.year)
      .filter(Boolean);
    expect(order.slice(0, 3)).toEqual(["2024", "2013", "1985"]);
  });

  it("a pick in the dialog names the year and closes it; the selected year again clears it", () => {
    const onPick = vi.fn();
    const { rerender } = render(<YearPicker years={YEARS} onPick={onPick} />);
    open();
    fireEvent.click(screen.getByRole("dialog").querySelector('[data-year="1985"]')!);
    expect(onPick).toHaveBeenLastCalledWith(1985);
    expect(screen.queryByRole("dialog")).toBeNull();

    rerender(<YearPicker years={YEARS} selected={2024} onPick={onPick} />);
    fireEvent.click(screen.getByRole("button", { pressed: true }));
    expect(onPick).toHaveBeenLastCalledWith(undefined);
  });

  it("offers More… while a year with titles is not among the chips, the kept selection aside", () => {
    // Seven years, and a selected year with no titles kept beside the six newest: 2013 is hidden.
    render(<YearPicker years={YEARS.slice(0, 7)} selected={1999} onPick={() => {}} />);
    expect(screen.getByRole("button", { name: "sidebar.year.more" })).toBeTruthy();
  });

  it("More… is a plain chip: the ellipsis says a dialog follows, no chevron", () => {
    render(<YearPicker years={YEARS} onPick={() => {}} />);
    expect(
      screen.getByRole("button", { name: "sidebar.year.more" }).querySelector("svg"),
    ).toBeNull();
  });

  it("clearing the kept older year hands the focus on, not to <body>", () => {
    const { rerender } = render(<YearPicker years={YEARS} selected={1985} onPick={() => {}} />);
    const kept = screen.getByRole("button", { pressed: true });
    kept.focus();
    fireEvent.click(kept);
    rerender(<YearPicker years={YEARS} onPick={() => {}} />);
    expect(document.activeElement).toBe(screen.getByRole("button", { name: "sidebar.year.more" }));
  });

  it("a decade row is named once: its caption is not read again", () => {
    render(<YearPicker years={YEARS} onPick={() => {}} />);
    open();
    const row = screen.getAllByRole("group", { name: /sidebar\.year\.decade/ })[0]!;
    expect(row.firstElementChild?.getAttribute("aria-hidden")).toBe("true");
  });

  it("a cell carries its count under the year, compact", () => {
    render(<YearPicker years={[...YEARS, { year: 2025, count: 17243 }]} onPick={() => {}} />);
    open();
    const cell = screen.getByRole("dialog").querySelector<HTMLElement>('[data-year="2025"]')!;
    expect(cell.textContent).toBe("202517.2K");
  });

  it("the arrows walk the cells: along a decade, then down to the next one", () => {
    render(<YearPicker years={YEARS} onPick={() => {}} />);
    open();
    const dialog = screen.getByRole("dialog");
    dialog.querySelector<HTMLElement>('[data-year="2020"]')!.focus();
    press("ArrowRight");
    expect((document.activeElement as HTMLElement).dataset.year).toBe("2021");
    press("ArrowDown");
    expect((document.activeElement as HTMLElement).dataset.year).toMatch(/^201/);
  });
});

/** A keydown where a real one starts: on whatever holds focus, bubbling to the window listener. */
function press(key: string): void {
  act(() => {
    (document.activeElement ?? document.body).dispatchEvent(
      new KeyboardEvent("keydown", { key, bubbles: true, cancelable: true }),
    );
  });
}