import { test, expect, type Page } from '@playwright/test';

/**
 * Fully deterministic end-to-end test. The Playwright webServer boots the real
 * stack (Vite → Express) with LLM_STUB=1, so the backend uses the deterministic
 * turn simulator in server/stub.ts.
 *
 * Batched-round model: actions and diplomatic messages are queued in
 * `game.pending` (no turn advance, no LLM call); a single "Jump forward"
 * commits the whole batch in one LLM turn. The stub emits one event per
 * queued item (action → military/success, diplomacy → diplomatic/partial) or
 * one political "The world moves on" event when the round is empty. It always
 * sets the player's military to (current + 5, clamped) and allies the player
 * with the first other nation, advancing the date by 2 days.
 */
test.describe('History — deterministic simulation (LLM_STUB=1)', () => {
  test('scenario → nation → queue action + diplomacy → jump, with predicted stat changes', async ({ page }) => {
    test.setTimeout(120000);
    await page.goto('/');

    // Home: the scenario grid loads with all 5 presets.
    const presetCards = page.getByTestId('preset-card');
    await expect(presetCards.first()).toBeVisible();
    await expect(presetCards).toHaveCount(5);

    // Start the first scenario (World War II, 1939).
    await presetCards.first().getByRole('button', { name: 'Play' }).click();

    // Nation select: the world brief is shown, then we lead the United Kingdom.
    await expect(page.getByTestId('world-background')).toBeVisible();
    await page
      .getByTestId('nation-card-uk')
      .getByRole('button', { name: 'Play as United Kingdom' })
      .click();

    // Game screen mounts: map, command deck, and event feed all present; turn 1.
    await expect(page.getByTestId('world-map')).toBeVisible();
    await expect(page.getByTestId('action-panel')).toBeVisible();
    await expect(page.getByTestId('event-feed-panel')).toBeVisible();
    await expect(page.getByTestId('turn-count')).toHaveText('1');

    // The dossier shows the player's four stat bars (value-colored, animated).
    await expect(page.getByTestId('stat-military')).toBeVisible();
    await expect(page.getByTestId('stat-economy')).toBeVisible();
    await expect(page.getByTestId('stat-stability')).toBeVisible();
    await expect(page.getByTestId('stat-population')).toBeVisible();

    // The player (UK) starts at military 80, date 1939-09-01, no events yet.
    const military = page.getByTestId('stat-military');
    const date = page.getByTestId('game-date');
    await expect(military).toHaveText('80');
    await expect(date).toHaveText('1939-09-01');
    await expect(page.getByTestId('event-item')).toHaveCount(0);

    // The map legend is auto-generated from the region map: all 7 nations of the
    // scenario own at least one region, including the player (United Kingdom).
    await expect(page.getByTestId('map-legend-item')).toHaveCount(7, { timeout: 15000 });
    await expect(page.getByTestId('map-legend-item').filter({ hasText: 'United Kingdom' })).toBeVisible();

    // --- Queue an action (no turn advance, no LLM call) ---
    await page.getByTestId('action-textarea').fill('Mobilize the home guard and fortify Dover');
    await page.getByTestId('add-action').click();

    // The pending list shows one queued action; turn and date are unchanged.
    await expect(page.getByTestId('pending-item')).toHaveCount(1);
    await expect(page.getByTestId('pending-item').first()).toHaveAttribute('data-kind', 'action');
    await expect(page.getByTestId('pending-item').first()).toContainText('Mobilize the home guard and fortify Dover');
    await expect(page.getByTestId('turn-count')).toHaveText('1');
    await expect(date).toHaveText('1939-09-01');
    await expect(page.getByTestId('event-item')).toHaveCount(0);
    // The "Your move" window's title badge shows the pending count.
    await expect(page.getByTestId('title-queued')).toHaveText('1 queued');

    // --- Queue a diplomatic message (no turn advance, no LLM call) ---
    await page.getByTestId('tab-diplo').click();
    await page.getByTestId('chat-target').click();
    await page.getByRole('option', { name: 'United States' }).click();
    await page.getByTestId('chat-message').fill('We propose a mutual defense pact');
    await page.getByTestId('add-diplomacy').click();

    // The pending list now shows two items (action + diplomacy); turn still 1.
    await expect(page.getByTestId('pending-item')).toHaveCount(2);
    await expect(page.getByTestId('pending-item').first()).toHaveAttribute('data-kind', 'action');
    await expect(page.getByTestId('pending-item').nth(1)).toHaveAttribute('data-kind', 'diplomacy');
    await expect(page.getByTestId('pending-item').nth(1)).toContainText('→ United States');
    await expect(page.getByTestId('pending-item').nth(1)).toContainText('We propose a mutual defense pact');
    await expect(page.getByTestId('turn-count')).toHaveText('1');
    await expect(date).toHaveText('1939-09-01');
    await expect(page.getByTestId('event-item')).toHaveCount(0);
    await expect(page.getByTestId('title-queued')).toHaveText('2 queued');

    // --- Jump forward: commit the whole pending round in a single LLM turn ---
    // The button sits at the bottom of the scrollable "Your move" window body
    // (max-h-[72vh] overflow-y-auto) and may be outside the page viewport; a
    // native DOM click bypasses Playwright's viewport actionability check.
    await page
      .getByTestId('jump-forward')
      .evaluate((el) => (el as HTMLElement).click());

    // Turn advances to 2, date to 1939-09-03 (+2 days), military 80 → 85.
    await expect(page.getByTestId('turn-count')).toHaveText('2', { timeout: 20000 });
    await expect(military).toHaveText('85', { timeout: 20000 });
    await expect(date).toHaveText('1939-09-03', { timeout: 20000 });

    // Two events were emitted (one per queued item): one military, one diplomatic.
    await expect(page.getByTestId('event-item')).toHaveCount(2);

    // The pending queue is now empty — the round was committed and cleared.
    await expect(page.getByTestId('pending-empty')).toBeVisible();
    await expect(page.getByTestId('title-queued')).not.toBeVisible();

    // Newest first: the diplomatic event (2nd queued item) sits on top, the
    // military event (1st queued item) is second.
    await expect(page.getByTestId('event-item').first().getByTestId('event-type')).toHaveText('diplomatic');
    await expect(page.getByTestId('event-item').first().getByTestId('event-outcome')).toHaveText('partial');
    await expect(page.getByTestId('event-item').nth(1).getByTestId('event-type')).toHaveText('military');
    await expect(page.getByTestId('event-item').nth(1).getByTestId('event-outcome')).toHaveText('success');
  });
});

/**
 * Save / resume across a page refresh. The active game's id is persisted in
 * localStorage, so a reload (or the home screen's "Resume last game" button)
 * must drop the user straight back into the same game — same turn, same stats,
 * same map — rather than resetting to the home screen. Deterministic under the
 * stub (UK military starts at 80 and +5 per committed turn).
 */
test.describe('History — save / resume across a page refresh', () => {
  async function createUkGameAtTurn2(page: Page): Promise<void> {
    await page.goto('/');
    await page.getByTestId('preset-card').first().waitFor({ timeout: 15000 });
    await page.getByTestId('preset-card').first().getByRole('button', { name: 'Play' }).click();
    await page
      .getByTestId('nation-card-uk')
      .getByRole('button', { name: 'Play as United Kingdom' })
      .click();

    // Game screen mounts at turn 1 (UK military starts at 80).
    await expect(page.getByTestId('world-map')).toBeVisible();
    await expect(page.getByTestId('turn-count')).toHaveText('1');
    await expect(page.getByTestId('stat-military')).toHaveText('80');

    // Queue one action onto the pending round, then jump forward: the stub
    // bumps UK military to 85 and advances to turn 2.
    await page.getByTestId('action-textarea').fill('Reinforce the Atlantic convoys');
    await page.getByTestId('add-action').click();
    await expect(page.getByTestId('pending-item')).toHaveCount(1);
    await page.getByTestId('jump-forward').click();
    await expect(page.getByTestId('turn-count')).toHaveText('2', { timeout: 20000 });
    await expect(page.getByTestId('stat-military')).toHaveText('85', { timeout: 20000 });
  }

  test('auto-resumes into the same game after a page reload', async ({ page }) => {
    await createUkGameAtTurn2(page);

    // Reload: the persisted active game id must restore the game — not home.
    await page.reload();

    await expect(page.getByTestId('world-map')).toBeVisible();
    await expect(page.getByTestId('turn-count')).toHaveText('2', { timeout: 20000 });
    await expect(page.getByTestId('stat-military')).toHaveText('85', { timeout: 20000 });
    // The player's identity is restored in the header…
    await expect(page.getByTestId('player-nation')).toHaveText('United Kingdom');
    // …and the map legend is regenerated from the persisted region map.
    await expect(page.getByTestId('map-legend-item').first()).toBeVisible({ timeout: 15000 });
  });

  test('explicitly resumes a saved game from the home screen', async ({ page }) => {
    await createUkGameAtTurn2(page);

    // Back to the home screen: the "Resume last game" affordance is present.
    await page.getByTestId('back-to-scenarios').click();
    await expect(page.getByTestId('resume-last')).toBeVisible();

    // Resuming drops back into the same game, at the saved turn.
    await page.getByTestId('resume-last').click();
    await expect(page.getByTestId('world-map')).toBeVisible();
    await expect(page.getByTestId('turn-count')).toHaveText('2', { timeout: 20000 });
    await expect(page.getByTestId('stat-military')).toHaveText('85', { timeout: 20000 });
    await expect(page.getByTestId('player-nation')).toHaveText('United Kingdom');
  });
});

/**
 * URL deep-linking (issue #3). The active game's id lives in the URL fragment:
 * home is `#/` and an active game is `#/game/<id>`. A fresh page navigated to
 * that hash loads that exact game; a bad/missing id falls back to home and
 * clears the hash; returning to home clears it. A browser context is fresh per
 * test, so localStorage is isolated, but the e2e webServer shares one SQLite
 * (`data/e2e`) across tests — so each test captures the *specific* id of the
 * game it creates (via the POST /api/games response) rather than assuming "the
 * only game".
 */

/**
 * Start the first scenario (World War II) and pick the United Kingdom, returning
 * the freshly created game's id (read from the POST /api/games response). Leaves
 * the caller on the game screen at turn 1.
 */
async function createUkGame(page: Page): Promise<string> {
  await page.goto('/');
  await page.getByTestId('preset-card').first().waitFor({ timeout: 15000 });
  await page.getByTestId('preset-card').first().getByRole('button', { name: 'Play' }).click();
  await expect(page.getByTestId('world-background')).toBeVisible();
  const [resp] = await Promise.all([
    page.waitForResponse(
      (r) => r.request().method() === 'POST' && new URL(r.url()).pathname === '/api/games',
    ),
    page
      .getByTestId('nation-card-uk')
      .getByRole('button', { name: 'Play as United Kingdom' })
      .click(),
  ]);
  const body = (await resp.json()) as { game: { id: string } };
  return body.game.id;
}

/** Poll until `location.hash` equals `expected` (hash writes happen in effects). */
async function waitHash(page: Page, expected: string): Promise<void> {
  await page.waitForFunction(
    (exp) => window.location.hash === exp,
    expected,
    { timeout: 15000 },
  );
}

test.describe('History — URL deep-linking (#/game/<id>)', () => {
  test('creating a game puts its id in the URL', async ({ page }) => {
    test.setTimeout(60000);
    const id = await createUkGame(page);

    // The game screen mounts at turn 1; the URL-sync effect writes the deep link.
    await expect(page.getByTestId('world-map')).toBeVisible();
    await expect(page.getByTestId('turn-count')).toHaveText('1');
    await expect(page.getByTestId('player-nation')).toHaveText('United Kingdom');
    await waitHash(page, `#/game/${id}`);
  });

  test('a fresh page deep-links to the exact saved game', async ({ page, context }) => {
    test.setTimeout(60000);
    const id = await createUkGame(page);
    await waitHash(page, `#/game/${id}`);
    const origin = await page.evaluate(() => location.origin);

    // A brand-new page navigated straight to the deep link must load that exact
    // game (matching id, preset, and player) — the URL hash takes precedence over
    // the (shared) localStorage, so this is deterministic.
    const page2 = await context.newPage();
    await page2.goto(`${origin}/#/game/${id}`);
    await expect(page2.getByTestId('world-map')).toBeVisible();
    await expect(page2.getByTestId('turn-count')).toHaveText('1');
    await expect(page2.getByTestId('player-nation')).toHaveText('United Kingdom');
    await waitHash(page2, `#/game/${id}`);
    await page2.close();
  });

  test('a bad game id falls back to the home screen and clears the hash', async ({
    page,
    context,
  }) => {
    test.setTimeout(60000);
    await page.goto('/');
    const origin = await page.evaluate(() => location.origin);

    // A fresh page navigated to a non-existent id must not crash: it lands on the
    // home screen and the bad hash is cleared to `#/`.
    const page2 = await context.newPage();
    await page2.goto(`${origin}/#/game/does-not-exist-xyz`);
    await expect(page2.getByTestId('preset-card').first()).toBeVisible({ timeout: 20000 });
    await waitHash(page2, '#/');
    await page2.close();
  });

  test('returning to home from a game clears the hash to #/', async ({ page }) => {
    test.setTimeout(60000);
    const id = await createUkGame(page);
    await expect(page.getByTestId('world-map')).toBeVisible();
    await waitHash(page, `#/game/${id}`);

    // "← Scenarios" returns to the home screen; the URL-sync effect clears the hash.
    await page.getByTestId('back-to-scenarios').click();
    await expect(page.getByTestId('preset-card').first()).toBeVisible({ timeout: 15000 });
    await waitHash(page, '#/');
  });
});