/**
 * Tests de la route GET /api/events/sse — R3.1.b.
 *
 * Stratégie : on construit une app Hono de test avec un container fake.
 * Le `subscribeToStream` est mocké pour injecter des events contrôlés.
 * On lit le ReadableStream SSE et on vérifie les events reçus.
 *
 * Vitest fake timers permettent de déclencher le heartbeat sans attendre 25s.
 */

import { Hono } from 'hono';
import { logger as honoLogger } from 'hono/logger';
import type { Redis } from 'ioredis';
import pino from 'pino';
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import type { RedisCache } from '../../src/adapters/redis-cache.js';
import type { RealtimeEvent } from '../../src/domain/event.js';
import type { Container } from '../../src/lib/container.js';
import { setContainer } from '../../src/lib/container.js';
import { type AuthVariables, authMiddleware } from '../../src/middleware/auth.js';
import { errorHandler } from '../../src/middleware/error-handler.js';
import { eventsRoutes } from '../../src/routes/events.js';

// ---------------------------------------------------------------------------
// Mock event-bus — contrôle complet sur subscribeToStream
// ---------------------------------------------------------------------------

vi.mock('../../src/lib/event-bus.js', async (importOriginal) => {
  const original = await importOriginal<typeof import('../../src/lib/event-bus.js')>();
  return {
    ...original,
    subscribeToStream: vi.fn(),
  };
});

import { subscribeToStream } from '../../src/lib/event-bus.js';
const mockSubscribeToStream = vi.mocked(subscribeToStream);

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

const silentLogger = pino({ level: 'silent' });

const ADMIN_TOKEN = 'brg_admin_events_test';
const NO_SCOPE_TOKEN = 'brg_no_scope_events_test';

function buildFakeRedis(): RedisCache {
  return {
    getClient: () => ({}) as Redis,
    invalidatePattern: async () => 0,
    checkRateLimit: async () => true,
  } as unknown as RedisCache;
}

function buildTestContainer(): Container {
  const tokensMap = new Map([
    [ADMIN_TOKEN, { token: ADMIN_TOKEN, name: 'test-admin', scopes: ['admin:*'] }],
    [NO_SCOPE_TOKEN, { token: NO_SCOPE_TOKEN, name: 'test-no-scope', scopes: ['read:tables'] }],
  ]);

  return {
    config: {
      nodeEnv: 'test',
      port: 0,
      logLevel: 'fatal',
      baserowApiUrl: 'http://localhost',
      baserowApiToken: 'fake',
      redisUrl: 'redis://localhost',
      baserowWebhookSecret: 'fake_secret_at_least_16_chars',
      rateLimitGlobalMax: 10_000,
      rateLimitGlobalWindow: 60,
      rateLimitMutationMax: 10_000,
      rateLimitMutationWindow: 60,
      streamMaxLen: 10_000,
    },
    baserow: {} as unknown,
    redis: buildFakeRedis(),
    repos: {} as unknown,
    tokens: tokensMap,
    oidc: null,
    docmostJwt: null,
    groupsScopesMap: {},
    logger: silentLogger,
  } as unknown as Container;
}

function buildEventsApp(): Hono<{ Variables: AuthVariables }> {
  const container = buildTestContainer();
  setContainer(container);

  const app = new Hono<{ Variables: AuthVariables }>();
  app.use('*', honoLogger());
  app.onError(errorHandler);

  const eventsRouter = new Hono<{ Variables: AuthVariables }>();
  eventsRouter.use(
    '*',
    authMiddleware({
      tokens: container.tokens,
      oidc: null,
      docmostJwt: null,
      groupsScopesMap: {},
      logger: silentLogger,
    }),
  );
  eventsRouter.route('/events', eventsRoutes);
  app.route('/api', eventsRouter);

  return app;
}

/**
 * Lit N events SSE depuis un ReadableStream. Timeout après `timeoutMs` ms.
 * Retourne les events parsés (lignes `event:` + `data:` extraites).
 */
async function readSseEvents(
  stream: ReadableStream<Uint8Array>,
  n: number,
  timeoutMs = 3_000,
): Promise<Array<{ event: string; data: string; id?: string }>> {
  const decoder = new TextDecoder();
  const events: Array<{ event: string; data: string; id?: string }> = [];
  const reader = stream.getReader();

  let buffer = '';
  let currentEvent = '';
  let currentData = '';
  let currentId: string | undefined;

  const deadline = Date.now() + timeoutMs;

  try {
    while (events.length < n && Date.now() < deadline) {
      const { value, done } = await reader.read();
      if (done) break;
      buffer += decoder.decode(value, { stream: true });

      // Parse SSE format : blocs séparés par \n\n.
      const parts = buffer.split('\n\n');
      buffer = parts.pop() ?? '';

      for (const block of parts) {
        currentEvent = '';
        currentData = '';
        currentId = undefined;
        for (const line of block.split('\n')) {
          if (line.startsWith('event: ')) currentEvent = line.slice(7);
          else if (line.startsWith('data: ')) currentData = line.slice(6);
          else if (line.startsWith('id: ')) currentId = line.slice(4);
        }
        if (currentEvent) {
          events.push({ event: currentEvent, data: currentData, id: currentId });
        }
      }
    }
  } finally {
    reader.cancel();
  }

  return events;
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

describe('GET /api/events/sse', () => {
  let app: Hono<{ Variables: AuthVariables }>;

  beforeEach(() => {
    app = buildEventsApp();
    mockSubscribeToStream.mockReset();
  });

  afterEach(() => {
    setContainer(null);
    vi.restoreAllMocks();
  });

  it('retourne 401 sans auth', async () => {
    const res = await app.request('/api/events/sse');
    expect(res.status).toBe(401);
  });

  it('retourne les headers SSE corrects sur connexion authentifiée', async () => {
    // subscribeToStream se termine immédiatement (pas d'events).
    mockSubscribeToStream.mockResolvedValue(undefined);

    const res = await app.request('/api/events/sse', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    expect(res.status).toBe(200);
    expect(res.headers.get('Content-Type')).toContain('text/event-stream');
    expect(res.headers.get('Cache-Control')).toBe('no-cache');
    expect(res.headers.get('Connection')).toBe('keep-alive');
  });

  it('livre les events publiés via subscribeToStream', async () => {
    const events: RealtimeEvent[] = [
      { type: 'row.created', tableId: 1, rowId: 10 },
      { type: 'row.updated', tableId: 1, rowId: 10, row: { name: 'Alice' } },
    ];

    mockSubscribeToStream.mockImplementation(async (opts) => {
      for (let i = 0; i < events.length; i++) {
        await opts.onEvent(`event-id-${i + 1}`, events[i]);
      }
    });

    const res = await app.request('/api/events/sse', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });
    expect(res.status).toBe(200);

    if (!res.body) throw new Error('SSE response has no body');
    const received = await readSseEvents(res.body, 2);
    expect(received).toHaveLength(2);
    expect(received[0].event).toBe('row.created');
    expect(received[0].id).toBe('event-id-1');
    const data0 = JSON.parse(received[0].data);
    expect(data0.tableId).toBe(1);
    expect(data0.rowId).toBe(10);

    expect(received[1].event).toBe('row.updated');
    const data1 = JSON.parse(received[1].data);
    expect(data1.row).toEqual({ name: 'Alice' });
  });

  it('passe le filtre ?tables= à subscribeToStream', async () => {
    mockSubscribeToStream.mockResolvedValue(undefined);

    await app.request('/api/events/sse?tables=10,20', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    expect(mockSubscribeToStream).toHaveBeenCalledOnce();
    const callOpts = mockSubscribeToStream.mock.calls[0][0];
    expect(callOpts.filter.tableIds).toEqual(new Set([10, 20]));
  });

  it('passe le filtre ?views= à subscribeToStream', async () => {
    mockSubscribeToStream.mockResolvedValue(undefined);

    await app.request('/api/events/sse?views=5,6', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    const callOpts = mockSubscribeToStream.mock.calls[0][0];
    expect(callOpts.filter.viewIds).toEqual(new Set([5, 6]));
  });

  it('passe Last-Event-ID à subscribeToStream comme fromId', async () => {
    mockSubscribeToStream.mockResolvedValue(undefined);

    await app.request('/api/events/sse', {
      headers: {
        Authorization: `Bearer ${ADMIN_TOKEN}`,
        'Last-Event-ID': '1234567890-0',
      },
    });

    const callOpts = mockSubscribeToStream.mock.calls[0][0];
    expect(callOpts.fromId).toBe('1234567890-0');
  });

  it('fromId est null quand pas de Last-Event-ID', async () => {
    mockSubscribeToStream.mockResolvedValue(undefined);

    await app.request('/api/events/sse', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    const callOpts = mockSubscribeToStream.mock.calls[0][0];
    expect(callOpts.fromId).toBeNull();
  });

  it('envoie un event error SSE si subscribeToStream throw une erreur fatale', async () => {
    mockSubscribeToStream.mockRejectedValue(new Error('Redis max retries exceeded'));

    const res = await app.request('/api/events/sse', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });
    expect(res.status).toBe(200); // SSE stream reste 200 même en cas d'erreur.

    if (!res.body) throw new Error('SSE response has no body');
    const received = await readSseEvents(res.body, 1, 2_000);
    const errorEvent = received.find((e) => e.event === 'error');
    expect(errorEvent).toBeDefined();
    const data = JSON.parse(errorEvent?.data ?? '{}');
    expect(data.message).toContain('reconnect');
  });

  it('heartbeat : vérifie que subscribeToStream reçoit un signal valide', async () => {
    // On ne peut pas tester le heartbeat sans fake timers sur setInterval.
    // On vérifie que l'abort signal est proprement transmis et que la fn est appelée.
    mockSubscribeToStream.mockImplementation(async (opts) => {
      // Vérifie que le signal est un AbortSignal.
      expect(opts.signal).toBeInstanceOf(AbortSignal);
    });

    await app.request('/api/events/sse', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    expect(mockSubscribeToStream).toHaveBeenCalledOnce();
  });

  it('filtre ?tables= avec valeurs invalides ignorées', async () => {
    mockSubscribeToStream.mockResolvedValue(undefined);

    await app.request('/api/events/sse?tables=10,abc,0,-5,20', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    const callOpts = mockSubscribeToStream.mock.calls[0][0];
    // Seules les valeurs entières positives sont conservées.
    expect(callOpts.filter.tableIds).toEqual(new Set([10, 20]));
  });

  it('heartbeat envoie un event ping via setInterval', async () => {
    // Utilise les fake timers pour déclencher setInterval sans attendre 25s réels.
    vi.useFakeTimers();

    // subscribeToStream bloque le temps que l'on avance les timers + reçoit le ping.
    let resolveSubscribe!: () => void;
    const subscribePromise = new Promise<void>((resolve) => {
      resolveSubscribe = resolve;
    });

    mockSubscribeToStream.mockImplementation(async () => {
      // Attend que le test avance les timers.
      await subscribePromise;
    });

    // Collecte les events SSE reçus en parallèle.
    const responsePromise = app.request('/api/events/sse', {
      headers: { Authorization: `Bearer ${ADMIN_TOKEN}` },
    });

    // Avance les timers de 25s pour déclencher le heartbeat.
    await vi.advanceTimersByTimeAsync(25_000);

    // Libère subscribeToStream pour fermer le stream proprement.
    resolveSubscribe();
    const res = await responsePromise;

    vi.useRealTimers();

    expect(res.status).toBe(200);
    if (!res.body) throw new Error('SSE response has no body');
    const received = await readSseEvents(res.body, 1, 2_000);
    const pingEvent = received.find((e) => e.event === 'ping');
    expect(pingEvent).toBeDefined();
  });
});