/**
 * Unit tests for src/services/EventPublisher.ts
 */

import { EventPublisher } from '../../../src/services/EventPublisher';
import { WebhookDeliveryWorker } from '../../../src/workers/WebhookDeliveryWorker';
import { Pool } from 'pg';

jest.mock('../../../src/workers/WebhookDeliveryWorker');
jest.mock('pg');

const MockPool = Pool as jest.MockedClass<typeof Pool>;
const MockWorker = WebhookDeliveryWorker as jest.MockedClass<typeof WebhookDeliveryWorker>;

function makePool(queryImpl?: jest.Mock): jest.Mocked<Pool> {
  const pool = new MockPool() as jest.Mocked<Pool>;
  pool.query = queryImpl ?? jest.fn();
  return pool;
}

function makeWorker(): jest.Mocked<WebhookDeliveryWorker> {
  const worker = new MockWorker({} as never) as jest.Mocked<WebhookDeliveryWorker>;
  worker.enqueue = jest.fn().mockResolvedValue(undefined);
  return worker;
}

const ORG_ID = 'org-abc-123';
const EVENT_TYPE = 'agent.created' as const;
const DATA = { agentId: 'agent-001' };

describe('EventPublisher', () => {
  let pool: jest.Mocked<Pool>;
  let worker: jest.Mocked<WebhookDeliveryWorker>;

  beforeEach(() => {
    jest.clearAllMocks();
    pool = makePool();
    worker = makeWorker();
  });

  describe('publishEvent() — webhook fanout', () => {
    it('should query for active subscriptions and create a delivery record', async () => {
      const subscriptionRows = [{ id: 'sub-001', organization_id: ORG_ID }];
      const deliveryRow = [{ id: 'del-001' }];
      pool.query = jest.fn()
        .mockResolvedValueOnce({ rows: subscriptionRows, rowCount: 1 })
        .mockResolvedValueOnce({ rows: deliveryRow, rowCount: 1 });

      const publisher = new EventPublisher(worker, pool, null);
      await publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA);

      expect(pool.query).toHaveBeenCalledTimes(2);
      expect(pool.query).toHaveBeenNthCalledWith(
        1,
        expect.stringContaining('webhook_subscriptions'),
        [ORG_ID, JSON.stringify([EVENT_TYPE])],
      );
      expect(pool.query).toHaveBeenNthCalledWith(
        2,
        expect.stringContaining('webhook_deliveries'),
        expect.arrayContaining(['sub-001', EVENT_TYPE]),
      );
    });

    it('should enqueue a Bull delivery job for each matching subscription', async () => {
      const subscriptionRows = [{ id: 'sub-001', organization_id: ORG_ID }];
      pool.query = jest.fn()
        .mockResolvedValueOnce({ rows: subscriptionRows, rowCount: 1 })
        .mockResolvedValueOnce({ rows: [{ id: 'del-001' }], rowCount: 1 });

      const publisher = new EventPublisher(worker, pool, null);
      await publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA);

      expect(worker.enqueue).toHaveBeenCalledTimes(1);
      expect(worker.enqueue).toHaveBeenCalledWith(
        expect.objectContaining({
          deliveryId: 'del-001',
          subscriptionId: 'sub-001',
          organizationId: ORG_ID,
        }),
      );
    });

    it('should fan out to multiple subscriptions', async () => {
      const subscriptionRows = [
        { id: 'sub-001', organization_id: ORG_ID },
        { id: 'sub-002', organization_id: ORG_ID },
      ];
      pool.query = jest.fn()
        .mockResolvedValueOnce({ rows: subscriptionRows, rowCount: 2 })
        .mockResolvedValueOnce({ rows: [{ id: 'del-001' }], rowCount: 1 })
        .mockResolvedValueOnce({ rows: [{ id: 'del-002' }], rowCount: 1 });

      const publisher = new EventPublisher(worker, pool, null);
      await publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA);

      expect(worker.enqueue).toHaveBeenCalledTimes(2);
    });

    it('should not enqueue any jobs when no matching subscriptions exist', async () => {
      pool.query = jest.fn().mockResolvedValueOnce({ rows: [], rowCount: 0 });

      const publisher = new EventPublisher(worker, pool, null);
      await publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA);

      expect(worker.enqueue).not.toHaveBeenCalled();
    });

    it('should not throw when subscription DB query fails', async () => {
      pool.query = jest.fn().mockRejectedValueOnce(new Error('DB down'));

      const publisher = new EventPublisher(worker, pool, null);
      await expect(publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA)).resolves.toBeUndefined();
    });

    it('should not throw when delivery insert fails for a subscription', async () => {
      const subscriptionRows = [{ id: 'sub-001', organization_id: ORG_ID }];
      pool.query = jest.fn()
        .mockResolvedValueOnce({ rows: subscriptionRows, rowCount: 1 })
        .mockRejectedValueOnce(new Error('Insert failed'));

      const publisher = new EventPublisher(worker, pool, null);
      await expect(publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA)).resolves.toBeUndefined();
    });
  });

  describe('publishEvent() — Kafka fanout', () => {
    it('should produce to Kafka when kafkaProducer is provided', async () => {
      pool.query = jest.fn().mockResolvedValueOnce({ rows: [], rowCount: 0 });
      const kafkaProducer = { send: jest.fn().mockResolvedValue(undefined) };

      const publisher = new EventPublisher(worker, pool, kafkaProducer as never);
      await publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA);

      expect(kafkaProducer.send).toHaveBeenCalledWith(
        expect.objectContaining({
          topic: 'agentidp-events',
          messages: expect.arrayContaining([
            expect.objectContaining({ key: ORG_ID }),
          ]),
        }),
      );
    });

    it('should not call Kafka when kafkaProducer is null', async () => {
      pool.query = jest.fn().mockResolvedValueOnce({ rows: [], rowCount: 0 });
      const kafkaProducer = { send: jest.fn() };

      const publisher = new EventPublisher(worker, pool, null);
      await publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA);

      expect(kafkaProducer.send).not.toHaveBeenCalled();
    });

    it('should not throw when Kafka produce fails', async () => {
      pool.query = jest.fn().mockResolvedValueOnce({ rows: [], rowCount: 0 });
      const kafkaProducer = { send: jest.fn().mockRejectedValue(new Error('Kafka error')) };

      const publisher = new EventPublisher(worker, pool, kafkaProducer as never);
      await expect(publisher.publishEvent(ORG_ID, EVENT_TYPE, DATA)).resolves.toBeUndefined();
    });
  });
});