// @vitest-environment jsdom
//
// ChannelsProvider's tab-history behaviour: setView pushes a `_chTab` history entry + persists the tab,
// and a genuine browser Back (popstate carrying `_chTab`) restores + re-persists it. This wiring was
// re-routed through useAccountPersistedState in R13 S2b, so it's exercised here rather than only by hand E2E.
//
// Uses REAL storage (jsdom localStorage/sessionStorage) with the tab's account pinned to 1, so
// useAccountPersistedState / useSortState / useFilterState all resolve their account-scoped keys; only
// navigationContext (the sole runtime dependency) is mocked, pinned to the channels page.
import { describe, it, expect, beforeEach, vi } from "vitest";
import { renderHook, act, render as renderRoot } from "@testing-library/react";
import { useEffect, useRef, type ReactNode } from "react";

vi.mock("./navigationContext", () => ({
  useNavigation: () => ({ page: "channels" }),
  useNavigationActions: () => ({ setPage: vi.fn() }),
}));

import { ChannelsProvider } from "./ChannelsProvider";
import { useChannels, useChannelsActions } from "./channelsContext";

const wrapper = ({ children }: { children: ReactNode }) => (
  <ChannelsProvider>{children}</ChannelsProvider>
);
const render = () => renderHook(() => ({ ...useChannels(), ...useChannelsActions() }), { wrapper });
const VIEW_KEY = "siftlode.channelsView.1"; // account-scoped (accountKey suffixes the pinned id)

beforeEach(() => {
  localStorage.clear();
  sessionStorage.setItem("siftlode.activeAccount", "1"); // pin the tab's account
  // Reset BOTH the history state and the query string: setView only owns an entry on the channels page,
  // and the S8 URL mirror writes ctab/csort/cf — a stale key left by a prior test would be read back by
  // this provider's mount-time URL seed and change the starting tab.
  window.history.replaceState({ sfPage: "channels" }, "", "/");
});

describe("ChannelsProvider tab history", () => {
  it("setView pushes a _chTab history entry and persists the tab", () => {
    const { result } = render();
    expect(result.current.view).toBe("subscribed"); // default

    act(() => result.current.setView("hidden"));

    expect(result.current.view).toBe("hidden");
    expect(window.history.state).toMatchObject({ sfPage: "channels", _chTab: "hidden" });
    expect(localStorage.getItem(VIEW_KEY)).toBe("hidden");
  });

  it("does NOT push a new entry when re-selecting the current tab", () => {
    const { result } = render();
    const spy = vi.spyOn(window.history, "pushState");
    act(() => result.current.setView("subscribed")); // already the current tab
    expect(spy).not.toHaveBeenCalled();
    spy.mockRestore();
  });

  it("a genuine Back (popstate carrying _chTab) restores and re-persists that tab", () => {
    const { result } = render();
    act(() => result.current.setView("blocked"));
    expect(result.current.view).toBe("blocked");

    // Browser Back to an entry stamped with a different tab.
    act(() =>
      window.dispatchEvent(new PopStateEvent("popstate", { state: { _chTab: "discovery" } })),
    );

    expect(result.current.view).toBe("discovery");
    expect(localStorage.getItem(VIEW_KEY)).toBe("discovery");
  });

  it("ignores a popstate for an entry outside the manager (no _chTab)", () => {
    const { result } = render();
    act(() => result.current.setView("hidden"));
    act(() => window.dispatchEvent(new PopStateEvent("popstate", { state: { sfPage: "feed" } })));
    expect(result.current.view).toBe("hidden"); // unchanged
  });
});

describe("ChannelsProvider — S8 shareable URL", () => {
  it("seeds tab + sort + filters from a shared manager link at mount (URL wins over stored)", () => {
    // Stored view says "blocked"; the shared link says "hidden" + a sort + a filter → the URL wins.
    localStorage.setItem(VIEW_KEY, "blocked");
    const cf = encodeURIComponent(JSON.stringify({ sync: "needsFull" }));
    window.history.replaceState(
      { sfPage: "channels" },
      "",
      `/?ctab=hidden&csort=priority:desc&cf=${cf}`,
    );
    const { result } = render();
    expect(result.current.view).toBe("hidden");
    expect(result.current.sort).toEqual({ key: "priority", dir: "desc" });
    expect(result.current.filters).toEqual({ sync: "needsFull" });
  });

  it("mirrors the tab into the address bar and clears it back to the default", () => {
    const { result } = render();
    act(() => result.current.setView("blocked"));
    expect(new URLSearchParams(window.location.search).get("ctab")).toBe("blocked");
    // Back to the default tab clears the key (only non-defaults are emitted).
    act(() => result.current.setView("subscribed"));
    expect(new URLSearchParams(window.location.search).has("ctab")).toBe(false);
  });

  it("a PARTIAL shared link does not clobber the account's stored sort/filters", () => {
    // Regression: the seed's base for the OMITTED dimensions used to be read as defaults, and
    // persisting the seed overwrote the account's real stored sort + filter map.
    localStorage.setItem(
      "siftlode.channelSort.1",
      JSON.stringify({ key: "subscribers", dir: "desc" }),
    );
    localStorage.setItem("siftlode.channelsFilterMap.1", JSON.stringify({ sync: "needsFull" }));
    window.history.replaceState({ sfPage: "channels" }, "", "/?ctab=hidden"); // only the tab in the URL

    const { result } = render();

    // The present dim (tab) is adopted from the link...
    expect(result.current.view).toBe("hidden");
    // ...but the omitted sort + filters keep the account's real stored values, in state AND storage.
    expect(result.current.sort).toEqual({ key: "subscribers", dir: "desc" });
    expect(result.current.filters).toEqual({ sync: "needsFull" });
    expect(JSON.parse(localStorage.getItem("siftlode.channelSort.1")!)).toEqual({
      key: "subscribers",
      dir: "desc",
    });
    expect(JSON.parse(localStorage.getItem("siftlode.channelsFilterMap.1")!)).toEqual({
      sync: "needsFull",
    });
  });
});

// --- the focus-a-channel intent is consumed, not masked -------------------------------------------
// `focusChannel` sends the user to the manager with its name filter seeded. The manager is a page
// chunk: it unmounts on every navigation away, and on opening a channel page (which does not even
// change `page`), and its seeding effect runs again on each mount. So the "already applied" marker
// has to live in the PROVIDER — inside the page it would reset with the page and re-apply an intent
// from earlier in the session over whatever the user has typed into the search box since.
describe("ChannelsProvider — the focus-a-channel intent", () => {
  /** Stands in for Channels.tsx:287-297 — the same effect, the same consume call. */
  function Manager() {
    const { focusName, focusToken } = useChannels();
    const { setSearch, consumeFocus } = useChannelsActions();
    const nameRef = useRef(focusName);
    nameRef.current = focusName;
    useEffect(() => {
      const name = nameRef.current;
      if (!name) return;
      setSearch(name);
      consumeFocus();
    }, [focusToken, setSearch, consumeFocus]);
    return null;
  }

  function Harness({ mounted }: { mounted: boolean }) {
    return <>{mounted && <Manager />}</>;
  }

  it("seeds the search box once, and a later visit does not re-seed it", () => {
    let api!: ReturnType<typeof useChannels> & ReturnType<typeof useChannelsActions>;
    function Probe() {
      api = { ...useChannels(), ...useChannelsActions() };
      return null;
    }
    const { rerender } = renderRoot(
      <ChannelsProvider>
        <Probe />
        <Harness mounted />
      </ChannelsProvider>,
    );

    act(() => api.focusChannel("Kurzgesagt"));
    expect(api.search).toBe("Kurzgesagt");

    // The user looks for something else instead.
    act(() => api.setSearch("veritasium"));

    // Leave the manager (the page chunk unmounts) and come back.
    rerender(
      <ChannelsProvider>
        <Probe />
        <Harness mounted={false} />
      </ChannelsProvider>,
    );
    rerender(
      <ChannelsProvider>
        <Probe />
        <Harness mounted />
      </ChannelsProvider>,
    );

    expect(api.search).toBe("veritasium");
  });

  it("re-seeds when the channel is focused again — the token is the intent", () => {
    let api!: ReturnType<typeof useChannels> & ReturnType<typeof useChannelsActions>;
    function Probe() {
      api = { ...useChannels(), ...useChannelsActions() };
      return null;
    }
    renderRoot(
      <ChannelsProvider>
        <Probe />
        <Harness mounted />
      </ChannelsProvider>,
    );

    act(() => api.focusChannel("Kurzgesagt"));
    act(() => api.setSearch("veritasium"));
    act(() => api.focusChannel("Kurzgesagt")); // the same channel, a new intent
    expect(api.search).toBe("Kurzgesagt");
  });
});