// useOnboardingChecklist — the hook's own wiring (#396, #409).
//
// The reducer, the loader, the follower and the derivation are tested in
// useOnboardingChecklist.test.ts; renderToStaticMarkup runs no effect, so what
// the hook does with React would stay unguarded. Here React's hooks come from
// the shared harness (src/test/hookHarness.ts): the hook runs as a plain
// function, its state, memos and callbacks survive from one render to the
// next as in a mounted provider, its reducer is applied, and `commit()` runs
// its effects as React does. The onboarding service is mocked.

import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";

vi.mock("react", async (orig) => (await import("../test/hookHarness")).fakeReact(await orig()));
const ctx = vi.hoisted(() => ({ pathname: "/" }));
vi.mock("react-router-dom", () => ({ useLocation: () => ({ pathname: ctx.pathname }) }));
vi.mock("./useEntitlement", () => ({ useEntitlement: () => ({ allowed: true, ready: true }) }));
vi.mock("../services/logService", () => ({ logInfo: vi.fn(), logWarn: vi.fn(), logError: vi.fn() }));
vi.mock("../services/onboardingService", () => ({
  getOnboardingSnapshot: vi.fn(),
  initializeGuidedPath: vi.fn(),
  hideChecklist: vi.fn(),
  showChecklist: vi.fn(),
  skipStep: vi.fn(),
  resumeStep: vi.fn(),
}));

import { hookHarness } from "../test/hookHarness";
import {
  useOnboardingChecklist,
  initialOnboardingChecklistState,
  onboardingChecklistReducer,
  type OnboardingChecklistState,
} from "./useOnboardingChecklist";
import { notifyDataChanged } from "../services/dataEvents";
import { logError } from "../services/logService";
import {
  getOnboardingSnapshot,
  hideChecklist,
  initializeGuidedPath,
  resumeStep,
  showChecklist,
  skipStep,
  type OnboardingSnapshot,
} from "../services/onboardingService";

const harness = hookHarness();

const snapshot: OnboardingSnapshot = {
  counters: { sources: 1, imports: 1, manualCategorized: 0, budgetEntries: 0, transactions: 12 },
  importFolderSet: true,
  hidden: false,
  skipped: [],
};

const ready: OnboardingChecklistState = [
  { type: "LOAD_START", seq: 1 } as const,
  { type: "LOAD_DONE", seq: 1, snapshot } as const,
].reduce(onboardingChecklistReducer, initialOnboardingChecklistState);

/** One render of the mounted provider. */
const render = () => harness.render(useOnboardingChecklist);

/** The state the provider mounts with: its `useReducer` is its first React hook. */
const mountWith = (state: OnboardingChecklistState) => {
  harness.slots[0] = state;
};

/** Lets the loader's promises settle. */
const flush = async () => {
  for (let i = 0; i < 10; i++) await Promise.resolve();
};

const actionsOfType = (type: string) =>
  harness.dispatch.mock.calls.map((c) => c[0] as { type: string }).filter((a) => a.type === type);

beforeEach(() => {
  harness.clear();
  ctx.pathname = "/";
  vi.mocked(getOnboardingSnapshot).mockReset().mockResolvedValue(snapshot);
  vi.mocked(initializeGuidedPath).mockReset().mockResolvedValue({ hidden: false });
  for (const write of [hideChecklist, showChecklist, skipStep, resumeStep]) {
    vi.mocked(write).mockReset().mockResolvedValue(undefined);
  }
  vi.mocked(logError).mockReset();
});

afterEach(() => {
  harness.unmount();
  vi.useRealTimers();
});

describe("useOnboardingChecklist — wiring (#396)", () => {
  it("reads at mount, through rule D9, and again whenever the route changes", async () => {
    ctx.pathname = "/import";
    render();
    harness.commit();
    await flush();
    expect(initializeGuidedPath).toHaveBeenCalledTimes(1);
    expect(getOnboardingSnapshot).toHaveBeenCalledTimes(1);
    expect(harness.dispatch.mock.calls.map((c) => c[0])).toEqual([
      { type: "LOAD_START", seq: 1 },
      { type: "LOAD_DONE", seq: 1, snapshot },
    ]);

    // The loaded state renders: same route, no new read.
    const loaded = render();
    harness.commit();
    await flush();
    expect(loaded.status).toBe("ready");
    expect(getOnboardingSnapshot).toHaveBeenCalledTimes(1);

    // A new route: React runs the read again.
    ctx.pathname = "/transactions";
    render();
    harness.commit();
    await flush();
    expect(getOnboardingSnapshot).toHaveBeenCalledTimes(2);
    expect(initializeGuidedPath).toHaveBeenCalledTimes(1);
  });

  it("re-reads 150 ms after a burst of data events, and its cleanup unsubscribes", async () => {
    render();
    harness.commit();
    await flush();
    vi.useFakeTimers();
    harness.dispatch.mockReset();

    // A route change re-runs the read, not the follower: one subscription only.
    ctx.pathname = "/reports";
    render();
    harness.commit();
    await flush();
    harness.dispatch.mockReset();

    notifyDataChanged();
    notifyDataChanged();
    vi.advanceTimersByTime(149);
    expect(actionsOfType("LOAD_START")).toHaveLength(0);
    vi.advanceTimersByTime(1);
    expect(actionsOfType("LOAD_START")).toHaveLength(1);
    await flush();

    harness.unmount();
    notifyDataChanged();
    vi.advanceTimersByTime(300);
    expect(actionsOfType("LOAD_START")).toHaveLength(1);
  });

  it("stores a card latch that changed during render, and only then", () => {
    mountWith({ ...ready, cardPage: "/import" });
    ctx.pathname = "/reports";
    render();
    expect(harness.dispatch.mock.calls).toEqual([[{ type: "SET_CARD_PAGE", cardPage: null }]]);

    // The reducer applied it: the next render finds the latch stored.
    harness.dispatch.mockReset();
    expect(render().cardPage).toBeNull();
    expect(harness.dispatch).not.toHaveBeenCalled();
  });

  it("shares the derived next step and mode with the state", () => {
    mountWith(ready);
    ctx.pathname = "/reports";
    const value = render();
    expect(value.status).toBe("ready");
    expect(value.nextStep?.key).toBe("manualCategory");
    expect(value.mode).toBe("banner");
    expect(value.cardPage).toBeNull();
    expect(value.checklist?.done).toBe(4);
  });

  it("each action writes its preference first, then updates the state", async () => {
    mountWith(ready);
    const value = render();
    await value.hide();
    await value.show();
    await value.skip("budget");
    await value.resume("budget");

    expect(hideChecklist).toHaveBeenCalledTimes(1);
    expect(showChecklist).toHaveBeenCalledTimes(1);
    expect(skipStep).toHaveBeenCalledWith("budget");
    expect(resumeStep).toHaveBeenCalledWith("budget");
    expect(harness.dispatch.mock.calls.map((c) => c[0])).toEqual([
      { type: "HIDE" },
      { type: "SHOW" },
      { type: "SKIP", key: "budget" },
      { type: "RESUME", key: "budget" },
    ]);
    const hideDispatch = harness.dispatch.mock.invocationCallOrder[0];
    expect(vi.mocked(hideChecklist).mock.invocationCallOrder[0]).toBeLessThan(hideDispatch);
  });

  it("an action whose write fails leaves the state alone and logs", async () => {
    mountWith(ready);
    const value = render();
    vi.mocked(hideChecklist).mockRejectedValueOnce(new Error("database is locked"));
    vi.mocked(skipStep).mockRejectedValueOnce(new Error("database is locked"));
    await value.hide();
    await value.skip("source");
    expect(harness.dispatch).not.toHaveBeenCalled();
    expect(logError).toHaveBeenCalledTimes(2);
    expect(render().hidden).toBe(false);
  });

  it("refresh is the loader itself", async () => {
    const value = render();
    await value.refresh();
    expect(getOnboardingSnapshot).toHaveBeenCalledTimes(1);
    expect(actionsOfType("LOAD_DONE")).toHaveLength(1);
  });
});

describe("useOnboardingChecklist — what survives a render (#409)", () => {
  it("keeps one loader for the provider's life: refresh, the value and the reads stay put", async () => {
    mountWith(ready);
    ctx.pathname = "/reports";
    const first = render();
    harness.commit();
    await flush();
    const reads = vi.mocked(getOnboardingSnapshot).mock.calls.length;

    const second = render();
    harness.commit();
    await flush();
    expect(second.refresh).toBe(first.refresh);
    // Nothing changed: the shared value keeps its identity, so no consumer re-renders.
    expect(second).toBe(first);
    // A new loader would re-run the read effect at every render: a loop of reads.
    expect(getOnboardingSnapshot).toHaveBeenCalledTimes(reads);
  });

  it("'Skip' moves the next step on the next render, without a re-read", async () => {
    mountWith(ready);
    ctx.pathname = "/reports";
    const before = render();
    expect(before.nextStep?.key).toBe("manualCategory");

    await before.skip("manualCategory");
    const after = render();
    expect(getOnboardingSnapshot).not.toHaveBeenCalled();
    expect(after.checklist).not.toBe(before.checklist);
    expect(after.nextStep?.key).toBe("budget");
  });

  it("a change of mode alone reaches the consumers", () => {
    // An empty profile: the dashboard shows its own empty state, other pages the banner.
    mountWith({ ...ready, counters: { ...snapshot.counters, transactions: 0 } });
    ctx.pathname = "/";
    const dashboard = render();
    ctx.pathname = "/reports";
    const reports = render();
    expect(reports.checklist).toBe(dashboard.checklist);
    expect(reports.nextStep).toBe(dashboard.nextStep);
    expect(reports.cardPage).toBe(dashboard.cardPage);
    expect(reports.mode).not.toBe(dashboard.mode);
    expect(reports.mode).toBe("banner");
  });
});