import { afterAll, beforeAll, beforeEach, describe, expect, it } from 'vitest';
import type { Queue } from 'bullmq';
import type { MongoMemoryServer } from 'mongodb-memory-server';
import type { Repos } from '../src/db.js';
import type { Config } from '../src/config.js';
import { createPoller } from '../src/poller.js';
import { pendingFilter } from '../src/poller.js';
import type { Channel, SendJob } from '../src/types.js';
import { aNotif, silentLog, startMongo } from './helpers.js';

let server: MongoMemoryServer;
let repos: Repos;
let baseCfg: Config;

beforeAll(async () => {
  const s = await startMongo();
  server = s.server;
  repos = s.repos;
  baseCfg = s.cfg;
});
afterAll(async () => {
  await repos.close();
  await server.stop();
});
beforeEach(async () => {
  await repos.notifications.deleteMany({});
});

/** Fake queue recording add() calls. */
function fakeQueues() {
  const added: Record<Channel, SendJob[]> = { fcm: [], email: [] };
  const make = (ch: Channel) =>
    ({
      async add(_name: string, job: SendJob) {
        added[ch].push(job);
      },
    }) as unknown as Queue<SendJob>;
  return { queues: { fcm: make('fcm'), email: make('email') } as Record<Channel, Queue<SendJob>>, added };
}

describe('pendingFilter', () => {
  it('uses the CORRECT field names (old cron had a typo)', () => {
    expect(pendingFilter('fcm')).toEqual({ type: 'mobile', notified: { $ne: true } });
    expect(pendingFilter('email')).toEqual({ type: 'web', emailNotified: { $ne: true } });
  });
});

describe('poller.runOnce', () => {
  it('enqueues only pending docs of owned channels and claims them', async () => {
    await repos.notifications.insertMany([
      aNotif({ type: 'mobile' }), // pending fcm
      aNotif({ type: 'mobile', notified: true }), // already done
      aNotif({ type: 'web' }), // pending email
      aNotif({ type: 'web', emailNotified: true }), // already done
    ]);
    const { queues, added } = fakeQueues();
    const poller = createPoller(baseCfg, repos, queues, silentLog);

    const res = await poller.runOnce();

    expect(res).toEqual({ fcm: 1, email: 1 });
    expect(added.fcm).toHaveLength(1);
    expect(added.email).toHaveLength(1);
    // claimedBy provenance set
    expect(await repos.notifications.countDocuments({ claimedBy: baseCfg.serviceName })).toBe(2);
  });

  it('only polls owned channels', async () => {
    await repos.notifications.insertMany([aNotif({ type: 'mobile' }), aNotif({ type: 'web' })]);
    const { queues, added } = fakeQueues();
    const cfg = { ...baseCfg, ownedChannels: ['fcm'] as Channel[] };
    const poller = createPoller(cfg, repos, queues, silentLog);

    const res = await poller.runOnce();

    expect(res.fcm).toBe(1);
    expect(added.email).toHaveLength(0);
  });

  it('circuit breaker halts on oversized batch', async () => {
    const many = Array.from({ length: 5 }, () => aNotif({ type: 'mobile' }));
    await repos.notifications.insertMany(many);
    const { queues, added } = fakeQueues();
    const cfg = { ...baseCfg, ownedChannels: ['fcm'] as Channel[], limits: { ...baseCfg.limits, maxPerBatch: 3 } };
    const poller = createPoller(cfg, repos, queues, silentLog);

    const res = await poller.runOnce();

    // Batch of 5 > max 3 -> nothing enqueued, poller halted.
    expect(res.fcm).toBe(0);
    expect(added.fcm).toHaveLength(0);
  });
});