// tests/content/navigation-tracking.test.ts
//
// Phase 4 Plan 04-01 Wave 0 RED — Audit P1 #14 contract pins.
//
// Site under test (src/content/index.ts:99-109): `handleNavigation` closure
// inside setupNavigationLogging emits navigation UserEvent with
// `meta: { previousUrl: history.state?.url || 'unknown' }`. In practice no
// modern SPA populates history.state.url, so the field is permanently
// 'unknown' — useless for support reproducing where the operator came from.
//
// Phase 4 Plan 04-01 fix (RESEARCH.md §"Specifics" + 04-PATTERNS.md):
//   - ADD module-scope `let previousUrl = window.location.href;`
//   - In handleNavigation, swap-then-emit:
//       const fromUrl = previousUrl;
//       const toUrl = window.location.href;
//       previousUrl = toUrl;
//       addUserEvent({ ..., meta: { previousUrl: fromUrl } });
//
// 3-test contract per 04-01-PLAN.md acceptance criteria:
//   * Test A: popstate after location mutation → UserEvent.meta.previousUrl
//             === the prior href (NOT 'unknown').
//   * Test B: hashchange → same semantics.
//   * Test C: history.pushState wrap continues to fire navigation handler
//             AND meta.previousUrl carries the prior URL (regression guard
//             for the pushState/replaceState patch path).
//
// Scaffold: same Node-env stub pattern as fetch-interception.test.ts.

import { describe, it, expect, vi, beforeEach } from 'vitest';
import type { UserEvent } from '../../src/shared/types';

// Stub rrweb so the content-script's `import { record } from 'rrweb'` doesn't
// pull rrweb's ESM bundle through vitest's CJS transform pipeline (rrweb's
// lib/*.js is plain ESM and crashes with "exports is not defined" under the
// vitest worker default transform). The stubbed record() is a no-op for the
// navigation tests — they only exercise setupNavigationLogging.
vi.mock('rrweb', () => ({
  record: (_opts: unknown) => () => {},
}));

// ────────────────────────────────────────────────────────────────────────────

interface OnMessageCallback {
  (msg: unknown, sender: unknown, sendResponse: (r: unknown) => void): boolean | void;
}

interface ContentChromeStub {
  runtime: {
    sendMessage: ReturnType<typeof vi.fn>;
    onMessage: {
      addListener: ReturnType<typeof vi.fn>;
      _callbacks: OnMessageCallback[];
    };
  };
}

interface FakeWindowHandle {
  setHref(next: string): void;
  dispatch(type: string): void;
}

interface FakeHistoryHandle {
  callPushState(url?: string): void;
  callReplaceState(url?: string): void;
}

interface GlobalWithContentRealm {
  chrome?: ContentChromeStub;
  window?: unknown;
  document?: unknown;
  history?: unknown;
  Request?: unknown;
  setInterval?: unknown;
  XMLHttpRequest?: unknown;
}

function buildContentChromeStub(): ContentChromeStub {
  const stub: ContentChromeStub = {
    runtime: {
      sendMessage: vi.fn().mockResolvedValue(undefined),
      onMessage: { addListener: vi.fn(), _callbacks: [] },
    },
  };
  stub.runtime.onMessage.addListener.mockImplementation((cb: OnMessageCallback) => {
    stub.runtime.onMessage._callbacks.push(cb);
  });
  return stub;
}

function installFakeDom(initialHref: string): {
  windowHandle: FakeWindowHandle;
  historyHandle: FakeHistoryHandle;
} {
  const navigationListeners: Record<string, Array<(ev: unknown) => void>> = {};
  const documentListeners: Record<string, Array<(ev: unknown) => void>> = {};

  const fakeLocation = { href: initialHref };

  const fakeWindow = {
    location: fakeLocation,
    fetch: undefined as unknown,
    addEventListener(type: string, listener: (ev: unknown) => void): void {
      const bucket = navigationListeners[type] ?? [];
      bucket.push(listener);
      navigationListeners[type] = bucket;
    },
    dispatchEvent(ev: { type: string }): boolean {
      const bucket = navigationListeners[ev.type] ?? [];
      for (const fn of bucket) fn(ev);
      return true;
    },
  };

  const fakeDocument = {
    readyState: 'complete',
    addEventListener(type: string, listener: (ev: unknown) => void): void {
      const bucket = documentListeners[type] ?? [];
      bucket.push(listener);
      documentListeners[type] = bucket;
    },
    dispatchEvent(ev: { type: string }): boolean {
      const bucket = documentListeners[ev.type] ?? [];
      for (const fn of bucket) fn(ev);
      return true;
    },
  };

  const fakeHistory = {
    state: null,
    pushState(_state: unknown, _title: string, url?: string): void {
      if (url !== undefined) fakeLocation.href = url;
    },
    replaceState(_state: unknown, _title: string, url?: string): void {
      if (url !== undefined) fakeLocation.href = url;
    },
  };

  class FakeRequest {
    public url: string;
    constructor(input: string | { url?: string }, _init?: unknown) {
      if (typeof input === 'string') this.url = input;
      else if (input && typeof input.url === 'string') this.url = input.url;
      else this.url = '';
    }
  }

  const g = globalThis as unknown as GlobalWithContentRealm;
  g.window = fakeWindow;
  g.document = fakeDocument;
  g.history = fakeHistory;
  g.Request = FakeRequest;
  g.setInterval = (() => 0) as unknown as typeof setInterval;
  g.XMLHttpRequest = class FakeXHR {
    open(): void {}
    send(): void {}
    addEventListener(): void {}
  } as unknown as typeof XMLHttpRequest;

  return {
    windowHandle: {
      setHref(next: string): void {
        fakeLocation.href = next;
      },
      dispatch(type: string): void {
        fakeWindow.dispatchEvent({ type });
      },
    },
    historyHandle: {
      callPushState(url?: string): void {
        // Use the (potentially wrapped) history.pushState assigned by the
        // content script's setupNavigationLogging override.
        (globalThis as unknown as GlobalWithContentRealm).history; // ensure read
        const h = (globalThis as unknown as { history: { pushState: (s: unknown, t: string, u?: string) => void } }).history;
        h.pushState({}, '', url);
      },
      callReplaceState(url?: string): void {
        const h = (globalThis as unknown as { history: { replaceState: (s: unknown, t: string, u?: string) => void } }).history;
        h.replaceState({}, '', url);
      },
    },
  };
}

function uninstallFakeDom(): void {
  const g = globalThis as unknown as GlobalWithContentRealm;
  delete g.window;
  delete g.document;
  delete g.history;
  delete g.Request;
  delete g.setInterval;
  delete g.XMLHttpRequest;
}

function captureUserEvents(stub: ContentChromeStub): UserEvent[] {
  let captured: UserEvent[] = [];
  const handler = stub.runtime.onMessage._callbacks[0];
  handler(
    { type: 'GET_RRWEB_EVENTS' },
    {},
    (response: unknown) => {
      const r = response as { userEvents?: UserEvent[] };
      captured = r.userEvents ?? [];
    },
  );
  return captured;
}

// ────────────────────────────────────────────────────────────────────────────

describe('Audit P1 #14 — navigation URL tracking uses module-level previousUrl', () => {
  beforeEach(() => {
    vi.resetModules();
    uninstallFakeDom();
  });

  // ──────────────────────────────────────────────────────────────────────
  // Test A — RED today, GREEN after fix:
  // popstate dispatch after a location mutation → UserEvent.meta.previousUrl
  // === prior href, NOT 'unknown'.
  // ──────────────────────────────────────────────────────────────────────
  it('A: popstate captures the previous URL (NOT "unknown")', async () => {
    const stub = buildContentChromeStub();
    (globalThis as unknown as GlobalWithContentRealm).chrome = stub;
    const startHref = 'https://example.com/start';
    const { windowHandle } = installFakeDom(startHref);

    await import('../../src/content/index');
    for (let i = 0; i < 8; i += 1) await Promise.resolve();

    // Operator navigates to /next; popstate fires.
    windowHandle.setHref('https://example.com/next');
    windowHandle.dispatch('popstate');
    for (let i = 0; i < 8; i += 1) await Promise.resolve();

    const events = captureUserEvents(stub);
    const nav = events.find((e) => e.type === 'navigation');
    expect(nav).toBeDefined();
    const previousUrl = (nav?.meta as { previousUrl?: unknown } | undefined)?.previousUrl;
    expect(previousUrl).toBe(startHref);
    expect(previousUrl).not.toBe('unknown');
  });

  // ──────────────────────────────────────────────────────────────────────
  // Test B — RED today, GREEN after fix:
  // hashchange via same module-level previousUrl mechanism.
  // ──────────────────────────────────────────────────────────────────────
  it('B: hashchange captures the previous URL', async () => {
    const stub = buildContentChromeStub();
    (globalThis as unknown as GlobalWithContentRealm).chrome = stub;
    const startHref = 'https://example.com/page';
    const { windowHandle } = installFakeDom(startHref);

    await import('../../src/content/index');
    for (let i = 0; i < 8; i += 1) await Promise.resolve();

    // Operator hash-jumps.
    windowHandle.setHref('https://example.com/page#section-2');
    windowHandle.dispatch('hashchange');
    for (let i = 0; i < 8; i += 1) await Promise.resolve();

    const events = captureUserEvents(stub);
    const nav = events.find((e) => e.type === 'navigation');
    expect(nav).toBeDefined();
    const previousUrl = (nav?.meta as { previousUrl?: unknown } | undefined)?.previousUrl;
    expect(previousUrl).toBe(startHref);
    expect(previousUrl).not.toBe('unknown');
  });

  // ──────────────────────────────────────────────────────────────────────
  // Test C — REGRESSION + module-state guard:
  // history.pushState wraps still fire navigation events AND meta.previousUrl
  // honors the prior module state (NOT the freshly-pushed URL — that would
  // mean previousUrl was mutated before reading fromUrl).
  // ──────────────────────────────────────────────────────────────────────
  it('C: history.pushState wrap emits navigation with prior URL as previousUrl', async () => {
    const stub = buildContentChromeStub();
    (globalThis as unknown as GlobalWithContentRealm).chrome = stub;
    const startHref = 'https://example.com/initial';
    const { historyHandle } = installFakeDom(startHref);

    await import('../../src/content/index');
    for (let i = 0; i < 8; i += 1) await Promise.resolve();

    historyHandle.callPushState('https://example.com/after-push');
    for (let i = 0; i < 8; i += 1) await Promise.resolve();

    const events = captureUserEvents(stub);
    const navs = events.filter((e) => e.type === 'navigation');
    expect(navs.length).toBeGreaterThanOrEqual(1);
    const lastNav = navs[navs.length - 1];
    const previousUrl = (lastNav.meta as { previousUrl?: unknown } | undefined)?.previousUrl;
    // The prior URL (startHref) must be what meta.previousUrl carries — NOT
    // the freshly-pushed href (that's `value` / `url`).
    expect(previousUrl).toBe(startHref);
    expect(previousUrl).not.toBe('https://example.com/after-push');
    expect(previousUrl).not.toBe('unknown');
  });
});