import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
import {
  act,
  fireEvent,
  render,
  renderHook,
  screen,
} from "@testing-library/react";
import { type ReactNode, useRef } from "react";
import {
  MemoryRouter,
  Route,
  Routes,
  useLocation,
  useNavigate,
} from "react-router";
import { useFading } from "../../hooks/useFading.ts";
import { useFeedCache } from "../../hooks/useFeedCache.ts";
import { useTabParam } from "../../hooks/useTabParam.ts";
import {
  setTitleBadge,
  SITE_NAME,
  useDocumentTitle,
} from "../../hooks/useDocumentTitle.ts";
import { useInfiniteScroll } from "../../hooks/useInfiniteScroll.ts";
import { useScrollLock } from "../../hooks/useScrollLock.ts";
import { useScrollSave } from "../../hooks/useScrollSave.ts";
import { useDefaultFeedTab } from "../../hooks/useDefaultFeedTab.ts";
import { useSoundsEnabled } from "../../hooks/useSoundsEnabled.ts";
import { useDumpCardLink } from "../../hooks/useDumpCardLink.ts";
import { useAnchoredFloat } from "../../hooks/useAnchoredFloat.ts";
import { useHeightTransition } from "../../hooks/useHeightTransition.ts";
import { isDumpVisited } from "../../utils/visited.ts";
import { FakeIntersectionObserver } from "../setup.ts";

afterEach(() => vi.useRealTimers());

describe("useFading", () => {
  beforeEach(() => vi.useFakeTimers());

  test("cooldown for 2s, then dismissing for 350ms, then gone", () => {
    const { result } = renderHook(useFading);
    act(() => result.current.startFading("a"));
    expect(result.current.fading).toEqual({ a: "cooldown" });
    act(() => vi.advanceTimersByTime(2000));
    expect(result.current.fading).toEqual({ a: "dismissing" });
    act(() => vi.advanceTimersByTime(350));
    expect(result.current.fading).toEqual({});
  });

  test("starting twice is one animation", () => {
    const { result } = renderHook(useFading);
    act(() => result.current.startFading("a"));
    act(() => vi.advanceTimersByTime(1000));
    act(() => result.current.startFading("a"));
    act(() => vi.advanceTimersByTime(1000));
    expect(result.current.fading).toEqual({ a: "dismissing" });
  });

  test("cancel during cooldown and during dismissal", () => {
    const { result } = renderHook(useFading);
    act(() => result.current.startFading("a"));
    act(() => result.current.cancelFading("a"));
    expect(result.current.fading).toEqual({});
    act(() => vi.advanceTimersByTime(5000));
    expect(result.current.fading).toEqual({});

    act(() => result.current.startFading("b"));
    act(() => vi.advanceTimersByTime(2100));
    act(() => result.current.cancelFading("b"));
    expect(result.current.fading).toEqual({});
    // Cancelled means it can start over.
    act(() => result.current.startFading("b"));
    expect(result.current.fading).toEqual({ b: "cooldown" });
  });

  test("cancelAll", () => {
    const { result } = renderHook(useFading);
    act(() => {
      result.current.startFading("a");
      result.current.startFading("b");
    });
    act(() => result.current.cancelAll());
    expect(result.current.fading).toEqual({});
  });
});

describe("useFeedCache", () => {
  // A MemoryRouter's first entry is a POP, as after Back.
  const wrapper = () => ({ children }: { children: ReactNode }) => (
    <MemoryRouter>{children}</MemoryRouter>
  );

  test("restores a saved feed on a back/forward (POP) visit", () => {
    const first = renderHook(() => useFeedCache<{ n: number }>("k", (x) => x), {
      wrapper: wrapper(),
    });
    act(() => first.result.current.saveState([{ n: 1 }], 2, true, 300));
    const second = renderHook(
      () => useFeedCache<{ n: number }>("k", (x) => ({ n: x.n * 10 })),
      { wrapper: wrapper() },
    );
    expect(second.result.current.cached).toMatchObject({
      items: [{ n: 10 }],
      page: 2,
      hasMore: true,
      scrollY: 300,
    });
  });

  test("an expired entry is ignored", () => {
    vi.useFakeTimers();
    const first = renderHook(() => useFeedCache("k", (x) => x), {
      wrapper: wrapper(),
    });
    act(() => first.result.current.saveState([], 1, false, 0));
    vi.advanceTimersByTime(11 * 60 * 1000);
    const second = renderHook(() => useFeedCache("k", (x) => x), {
      wrapper: wrapper(),
    });
    expect(second.result.current.cached).toBeNull();
  });

  test("a fresh (PUSH) visit ignores the cache", () => {
    sessionStorage.setItem(
      "k",
      JSON.stringify({
        items: [1],
        page: 1,
        hasMore: false,
        scrollY: 0,
        savedAt: Date.now(),
      }),
    );
    function Probe() {
      const { cached } = useFeedCache("k", (x) => x);
      return <p>{cached ? "cached" : "fresh"}</p>;
    }
    function Home() {
      const navigate = useNavigate();
      return (
        <button type="button" onClick={() => navigate("/feed")}>
          go
        </button>
      );
    }
    render(
      <MemoryRouter>
        <Routes>
          <Route path="/" element={<Home />} />
          <Route path="/feed" element={<Probe />} />
        </Routes>
      </MemoryRouter>,
    );
    fireEvent.click(screen.getByText("go"));
    expect(screen.getByText("fresh")).toBeInTheDocument();
  });

  test("corrupt storage reads as no cache; a full quota doesn't throw", () => {
    sessionStorage.setItem("k", "{");
    const { result } = renderHook(() => useFeedCache("k", (x) => x), {
      wrapper: wrapper(),
    });
    expect(result.current.cached).toBeNull();
    vi.spyOn(Storage.prototype, "setItem").mockImplementation(() => {
      throw new Error("QuotaExceededError");
    });
    expect(() => result.current.saveState([], 1, false, 0)).not.toThrow();
  });
});

describe("useTabParam", () => {
  const TABS = ["dumps", "playlists", "votes"] as const;
  function setup(path: string, state?: unknown) {
    let loc!: ReturnType<typeof useLocation>;
    const hook = renderHook(() => {
      loc = useLocation();
      return useTabParam(TABS, "dumps");
    }, {
      wrapper: ({ children }) => (
        <MemoryRouter
          initialEntries={[{
            pathname: path.split("?")[0],
            search: path.includes("?") ? "?" + path.split("?")[1] : "",
            state,
          }]}
        >
          {children}
        </MemoryRouter>
      ),
    });
    return { hook, loc: () => loc };
  }

  test("reads the tab after /~/", () => {
    expect(setup("/users/ann/~/playlists").hook.result.current[0]).toBe(
      "playlists",
    );
    expect(setup("/users/ann/~/playlists/").hook.result.current[0]).toBe(
      "playlists",
    );
    expect(setup("/users/ann").hook.result.current[0]).toBe("dumps");
    expect(setup("/users/ann/~/bogus").hook.result.current[0]).toBe("dumps");
  });

  test("the default tab collapses to the base path", () => {
    const { hook, loc } = setup("/users/ann/~/votes");
    act(() => hook.result.current[1]("dumps"));
    expect(loc().pathname).toBe("/users/ann");
    act(() => hook.result.current[1]("playlists"));
    expect(loc().pathname).toBe("/users/ann/~/playlists");
  });

  test("at the root the default stays explicit", () => {
    const { hook, loc } = setup("/~/votes");
    act(() => hook.result.current[1]("dumps"));
    expect(loc().pathname).toBe("/~/dumps");
  });

  test("keeps the query string and the entry's state", () => {
    const { hook, loc } = setup("/search?q=cats", { back: "/x" });
    act(() => hook.result.current[1]("votes"));
    expect(loc().pathname).toBe("/search/~/votes");
    expect(loc().search).toBe("?q=cats");
    expect(loc().state).toEqual({ back: "/x" });
  });
});

describe("useDocumentTitle", () => {
  test("composes page, site name and unread badge", () => {
    const { rerender } = renderHook(
      ({ title }: { title: string | null | undefined }) =>
        useDocumentTitle(title),
      { initialProps: { title: "Cats" as string | null | undefined } },
    );
    expect(document.title).toBe(`Cats · ${SITE_NAME}`);
    act(() => setTitleBadge(3));
    expect(document.title).toBe(`(3) Cats · ${SITE_NAME}`);
    act(() => setTitleBadge(150));
    expect(document.title).toBe(`(99+) Cats · ${SITE_NAME}`);
    rerender({ title: null });
    expect(document.title).toBe(`(99+) ${SITE_NAME}`);
    act(() => setTitleBadge(0));
    expect(document.title).toBe(SITE_NAME);
    // undefined leaves it be
    rerender({ title: undefined });
    expect(document.title).toBe(SITE_NAME);
  });

  test("the site name defaults to gerbeur when unsubstituted", () => {
    expect(SITE_NAME).toBe("gerbeur");
  });
});

describe("useInfiniteScroll", () => {
  function Feed({ onMore, enabled }: { onMore: () => void; enabled: boolean }) {
    const ref = useInfiniteScroll(onMore, enabled);
    return <div ref={ref} data-testid="sentinel" />;
  }
  const intersect = (isIntersecting: boolean) => {
    const obs = FakeIntersectionObserver.instances.at(-1)!;
    act(() => obs.report(isIntersecting));
  };

  test("loads more when the sentinel shows, only while enabled", () => {
    const onMore = vi.fn();
    const { rerender } = render(<Feed onMore={onMore} enabled />);
    expect(FakeIntersectionObserver.instances.at(-1)!.elements.size).toBe(1);
    intersect(false);
    expect(onMore).not.toHaveBeenCalled();
    intersect(true);
    expect(onMore).toHaveBeenCalledTimes(1);
    rerender(<Feed onMore={onMore} enabled={false} />);
    intersect(true);
    expect(onMore).toHaveBeenCalledTimes(1);
  });

  // A load that fails re-enables the feed with the sentinel still in view: a
  // browser's new observer reports it at once, and without a pause that's a
  // request loop as fast as the request can fail.
  test("a sentinel that stays in view waits longer each time", () => {
    vi.useFakeTimers();
    const onMore = vi.fn();
    render(<Feed onMore={onMore} enabled />);
    intersect(true);
    expect(onMore).toHaveBeenCalledTimes(1);
    // Reported again right after each load, as a new observer does: how long
    // until the next one?
    const delays: number[] = [];
    for (let i = 0; i < 8; i++) {
      const before = onMore.mock.calls.length;
      intersect(true);
      let waited = 0;
      while (onMore.mock.calls.length === before) {
        act(() => vi.advanceTimersByTime(100));
        waited += 100;
      }
      delays.push(waited);
    }
    expect(delays).toEqual([
      1000,
      2000,
      4000,
      8000,
      16000,
      30000,
      30000,
      30000,
    ]);
  });

  test("re-rendering doesn't restart the wait", () => {
    vi.useFakeTimers();
    const onMore = vi.fn();
    const { rerender } = render(<Feed onMore={onMore} enabled />);
    intersect(true);
    intersect(true);
    act(() => vi.advanceTimersByTime(600));
    // A new onLoadMore (the feed's state changed) remakes the observer.
    rerender(<Feed onMore={() => onMore()} enabled />);
    intersect(true);
    act(() => vi.advanceTimersByTime(400));
    expect(onMore).toHaveBeenCalledTimes(2);
  });

  test("leaving the view, or new items pushing it down, asks at once again", () => {
    vi.useFakeTimers();
    const onMore = vi.fn();
    render(<Feed onMore={onMore} enabled />);
    const at = (top: number) => {
      const obs = FakeIntersectionObserver.instances.at(-1)!;
      act(() => obs.report(true, top));
    };
    at(500);
    at(500);
    expect(onMore).toHaveBeenCalledTimes(1); // waiting
    act(() => FakeIntersectionObserver.instances.at(-1)!.report(false, 500));
    at(500);
    expect(onMore).toHaveBeenCalledTimes(2);
    at(500);
    at(900); // the page grew: that load worked
    expect(onMore).toHaveBeenCalledTimes(3);
  });

  test("a pending retry is dropped when the feed is disabled or unmounted", () => {
    vi.useFakeTimers();
    const onMore = vi.fn();
    const { rerender, unmount } = render(<Feed onMore={onMore} enabled />);
    intersect(true);
    intersect(true);
    rerender(<Feed onMore={onMore} enabled={false} />);
    act(() => vi.advanceTimersByTime(60_000));
    expect(onMore).toHaveBeenCalledTimes(1);
    rerender(<Feed onMore={onMore} enabled />);
    intersect(true); // long overdue: at once
    expect(onMore).toHaveBeenCalledTimes(2);
    intersect(true);
    unmount();
    act(() => vi.advanceTimersByTime(60_000));
    expect(onMore).toHaveBeenCalledTimes(2);
  });
});

describe("useScrollLock", () => {
  function Lock() {
    useScrollLock();
    return null;
  }
  test("counts nested locks", () => {
    const root = document.documentElement;
    const a = render(<Lock />);
    const b = render(<Lock />);
    expect(root.style.overflowY).toBe("hidden");
    a.unmount();
    expect(root.style.overflowY).toBe("hidden");
    b.unmount();
    expect(root.style.overflowY).toBe("");
  });
});

describe("useScrollSave", () => {
  const scrollTo = (y: number) => {
    Object.defineProperty(globalThis, "scrollY", {
      value: y,
      configurable: true,
    });
    globalThis.dispatchEvent(new Event("scroll"));
  };

  test("saves the last position when the page is left, not while scrolling", () => {
    const onSave = vi.fn();
    const { unmount } = renderHook(() => useScrollSave(true, onSave));
    scrollTo(100);
    scrollTo(250);
    expect(onSave).not.toHaveBeenCalled();
    // The next page has already scrolled back up by the time this unmounts.
    Object.defineProperty(globalThis, "scrollY", {
      value: 0,
      configurable: true,
    });
    unmount();
    expect(onSave).toHaveBeenCalledExactlyOnceWith(250);
  });

  test("saves on pagehide, with the latest callback", () => {
    const first = vi.fn();
    const second = vi.fn();
    const { rerender, unmount } = renderHook(
      ({ cb }) => useScrollSave(true, cb),
      { initialProps: { cb: first } },
    );
    scrollTo(40);
    rerender({ cb: second });
    globalThis.dispatchEvent(new Event("pagehide"));
    expect(first).not.toHaveBeenCalled();
    expect(second).toHaveBeenCalledExactlyOnceWith(40);
    unmount();
  });

  test("nothing is tracked or saved while disabled", () => {
    const onSave = vi.fn();
    const { unmount } = renderHook(() => useScrollSave(false, onSave));
    scrollTo(10);
    globalThis.dispatchEvent(new Event("pagehide"));
    unmount();
    expect(onSave).not.toHaveBeenCalled();
  });
});

describe("stored preferences", () => {
  test("useDefaultFeedTab validates and persists", () => {
    localStorage.setItem("default-feed-tab", "bogus");
    const { result } = renderHook(useDefaultFeedTab);
    expect(result.current[0]).toBe("journal");
    act(() => result.current[1]("new"));
    expect(result.current[0]).toBe("new");
    expect(localStorage.getItem("default-feed-tab")).toBe("new");
    expect(renderHook(useDefaultFeedTab).result.current[0]).toBe("new");
  });

  test("useSoundsEnabled", () => {
    const { result } = renderHook(useSoundsEnabled);
    expect(result.current[0]).toBe(true);
    act(() => result.current[1](false));
    expect(result.current[0]).toBe(false);
    expect(localStorage.getItem("sounds")).toBe("off");
  });
});

describe("useDumpCardLink", () => {
  function Card() {
    const link = useDumpCardLink({ id: "d1", slug: "hello" });
    return (
      <div data-testid="card" {...link.cardProps}>
        <a href="/elsewhere">inner link</a>
        <button
          type="button"
          onClick={(e) => {
            if (!link.handledAsNewTab(e)) e.currentTarget.dataset.played = "1";
          }}
        >
          play
        </button>
      </div>
    );
  }
  function setup() {
    const open = vi.spyOn(globalThis, "open").mockImplementation(() => null);
    render(
      <MemoryRouter>
        <Routes>
          <Route path="/" element={<Card />} />
          <Route path="/dumps/:id" element={<p>dump page</p>} />
        </Routes>
      </MemoryRouter>,
    );
    return { open };
  }

  test("a click navigates and marks visited", () => {
    setup();
    fireEvent.click(screen.getByTestId("card"));
    expect(screen.getByText("dump page")).toBeInTheDocument();
    expect(isDumpVisited("d1")).toBe(true);
  });

  test("ctrl/cmd/shift-click opens a new tab", () => {
    const { open } = setup();
    fireEvent.click(screen.getByTestId("card"), { ctrlKey: true });
    expect(open).toHaveBeenCalledWith("/dumps/hello", "_blank", "noopener");
  });

  test("a middle click opens a new tab, except over a link", () => {
    const { open } = setup();
    const mouseDown = new MouseEvent("mousedown", {
      button: 1,
      bubbles: true,
      cancelable: true,
    });
    screen.getByTestId("card").dispatchEvent(mouseDown);
    expect(mouseDown.defaultPrevented).toBe(true);
    fireEvent(
      screen.getByTestId("card"),
      new MouseEvent("auxclick", { button: 1, bubbles: true }),
    );
    expect(open).toHaveBeenCalledTimes(1);
    fireEvent(
      screen.getByText("inner link"),
      new MouseEvent("auxclick", { button: 1, bubbles: true }),
    );
    expect(open).toHaveBeenCalledTimes(1);
    fireEvent(
      screen.getByTestId("card"),
      new MouseEvent("auxclick", { button: 2, bubbles: true }),
    );
    expect(open).toHaveBeenCalledTimes(1);
  });

  test("a modified click on the play button opens the dump instead of playing", () => {
    const { open } = setup();
    const play = screen.getByText("play");
    fireEvent.click(play, { metaKey: true });
    expect(open).toHaveBeenCalledTimes(1);
    expect(play.dataset.played).toBeUndefined();
    fireEvent.click(play);
    expect(play.dataset.played).toBe("1");
  });
});

describe("useAnchoredFloat", () => {
  function Float({ open, top }: { open: boolean; top: number }) {
    const ref = useRef<HTMLDivElement>(null);
    const style = useAnchoredFloat(ref, open, {
      width: 300,
      chromeHeight: 40,
      minContentHeight: 100,
      maxContentHeight: 400,
    });
    return (
      <>
        <div
          ref={(el) => {
            ref.current = el;
            if (el) {
              el.getBoundingClientRect = () =>
                ({
                  top,
                  bottom: top + 20,
                  left: 900,
                  right: 1000,
                  width: 100,
                  height: 20,
                }) as DOMRect;
            }
          }}
        />
        <output data-testid="style">{JSON.stringify(style)}</output>
      </>
    );
  }
  const styleOf = () => JSON.parse(screen.getByTestId("style").textContent!);

  beforeEach(() => {
    vi.stubGlobal("innerWidth", 1024);
    vi.stubGlobal("innerHeight", 768);
  });

  test("null while closed", () => {
    render(<Float open={false} top={100} />);
    expect(styleOf()).toBeNull();
  });

  test("opens below an anchor near the top, clamped into the viewport", () => {
    render(<Float open top={100} />);
    const s = styleOf();
    expect(s.position).toBe("fixed");
    expect(s.top).toBe(124);
    expect(s.bottom).toBe("auto");
    expect(s.left).toBe(1024 - 300 - 8);
    expect(s["--float-max-h"]).toBe("400px");
  });

  test("flips above an anchor near the bottom", () => {
    render(<Float open top={700} />);
    const s = styleOf();
    expect(s.bottom).toBe(768 - 700 + 4);
    expect(s.top).toBe("auto");
  });
});

describe("useHeightTransition", () => {
  test("animates from the old height to the new one when watch changes", () => {
    const animate = vi.spyOn(Element.prototype, "animate");
    let height = 100;
    vi.spyOn(Element.prototype, "getBoundingClientRect").mockImplementation(
      () => ({ height }) as DOMRect,
    );
    function Box({ open }: { open: boolean }) {
      const ref = useHeightTransition<HTMLDivElement>(open);
      return <div ref={ref} />;
    }
    const { rerender } = render(<Box open={false} />);
    height = 250;
    rerender(<Box open />);
    expect(animate).toHaveBeenCalledTimes(1);
    expect(animate.mock.calls[0][0]).toEqual([
      expect.objectContaining({ height: "100px" }),
      expect.objectContaining({ height: "250px" }),
    ]);

    // No change in height, no animation.
    rerender(<Box open={false} />);
    expect(animate).toHaveBeenCalledTimes(1);
  });
});