import { beforeEach, describe, expect, it } from 'vitest';
import type { Repos } from '../src/db.js';
import type { Config } from '../src/config.js';
import { processEmailJob, processFcmJob, type Deps } from '../src/handlers.js';
import { aNotif, aUser, fakeFcm, fakeMailer, freshRepos, silentLog, testCfg } from './helpers.js';

let repos: Repos;
const baseCfg: Config = testCfg();

beforeEach(async () => {
  repos = await freshRepos();
});

function deps(over: Partial<Deps> = {}): Deps {
  return { cfg: baseCfg, repos, log: silentLog, ...over };
}

describe('FCM handler', () => {
  it('sends push and marks the doc notified (full mode)', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const fcm = fakeFcm({ ok: true, messageId: 'mid-1' });

    await processFcmJob(deps({ fcm }), notif._id.toHexString());

    expect(fcm.calls).toHaveLength(1);
    expect(fcm.calls[0]!.token).toBe('tok-abc');
    const after = await repos.notifications.findOne({ _id: notif._id });
    expect(after?.notified).toBe(true);
    expect(after?.notifiedAt).toBeInstanceOf(Date);
    const send = await repos.sends.findOne({ notificationId: notif._id, channel: 'fcm' });
    expect(send?.status).toBe('sent');
  });

  it('idempotent across a simulated restart: never double-sends', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const fcm = fakeFcm({ ok: true, messageId: 'mid-1' });

    // First run sends and marks notified.
    await processFcmJob(deps({ fcm }), notif._id.toHexString());
    // Simulate a replay/restart: the doc is already notified -> guard skips.
    await processFcmJob(deps({ fcm }), notif._id.toHexString());
    // Even if the notified flag were somehow cleared, the send record blocks it.
    await repos.notifications.updateOne({ _id: notif._id }, { $unset: { notified: '' } });
    await processFcmJob(deps({ fcm }), notif._id.toHexString());

    expect(fcm.calls).toHaveLength(1); // only ONE real send, ever
  });

  it('dry-run does not send and does not mark the doc', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const fcm = fakeFcm({ ok: true, messageId: 'x' });

    await processFcmJob(deps({ cfg: { ...baseCfg, mode: 'dry-run' }, fcm }), notif._id.toHexString());

    expect(fcm.calls).toHaveLength(0);
    const after = await repos.notifications.findOne({ _id: notif._id });
    expect(after?.notified).toBeUndefined();
    expect(await repos.sends.countDocuments({})).toBe(0); // no reservation in dry-run
  });

  it('kill switch stops sending', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const fcm = fakeFcm({ ok: true, messageId: 'x' });

    await processFcmJob(deps({ cfg: { ...baseCfg, killSwitch: true }, fcm }), notif._id.toHexString());

    expect(fcm.calls).toHaveLength(0);
  });

  it('canary sends only to the cohort', async () => {
    const inCohort = aNotif({ userId: 'u1' });
    const outCohort = aNotif({ userId: 'u2', subsId: undefined });
    await repos.notifications.insertMany([inCohort, outCohort]);
    await repos.users.insertMany([aUser({ _id: 'u1' }), aUser({ _id: 'u2' })]);
    const fcm = fakeFcm({ ok: true, messageId: 'x' });
    const cfg = { ...baseCfg, mode: 'canary' as const, canary: { userIds: ['u1'], subsIds: [] } };

    await processFcmJob(deps({ cfg, fcm }), inCohort._id.toHexString());
    await processFcmJob(deps({ cfg, fcm }), outCohort._id.toHexString());

    expect(fcm.calls).toHaveLength(1);
    expect(fcm.calls[0]!.token).toBe('tok-abc');
  });

  it('purges dead FCM tokens and does not retry', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const fcm = fakeFcm({ ok: false, deadToken: true, error: 'messaging/registration-token-not-registered' });

    await processFcmJob(deps({ fcm }), notif._id.toHexString());

    const user = await repos.users.findOne({ _id: 'u1' });
    expect(user?.fireBaseToken).toBeNull();
    expect(user?.fireBaseTokenDeadAt).toBeInstanceOf(Date);
    const send = await repos.sends.findOne({ notificationId: notif._id, channel: 'fcm' });
    expect(send?.status).toBe('dead-token'); // recorded -> won't retry
    const after = await repos.notifications.findOne({ _id: notif._id });
    expect(after?.notified).toBeUndefined(); // not marked as notified
  });

  it('transient error releases the reservation so it can retry', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const fcm = fakeFcm({ ok: false, deadToken: false, error: 'UNAVAILABLE' });

    await expect(processFcmJob(deps({ fcm }), notif._id.toHexString())).rejects.toThrow();
    // reservation released -> a later retry can proceed
    expect(await repos.sends.countDocuments({ notificationId: notif._id })).toBe(0);

    const fcm2 = fakeFcm({ ok: true, messageId: 'ok' });
    await processFcmJob(deps({ fcm: fcm2 }), notif._id.toHexString());
    expect(fcm2.calls).toHaveLength(1);
  });

  it('skips users without a fireBaseToken', async () => {
    const notif = aNotif();
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser({ fireBaseToken: null }));
    const fcm = fakeFcm({ ok: true, messageId: 'x' });

    await processFcmJob(deps({ fcm }), notif._id.toHexString());

    expect(fcm.calls).toHaveLength(0);
    const after = await repos.notifications.findOne({ _id: notif._id });
    expect(after?.notified).toBeUndefined();
  });

  it('enforces the per-user/day limit', async () => {
    await repos.users.insertOne(aUser());
    const cfg = { ...baseCfg, limits: { ...baseCfg.limits, perUserPerDay: 2 } };
    const fcm = fakeFcm({ ok: true, messageId: 'x' });

    // Three pending notifs for the same user.
    const notifs = [aNotif(), aNotif(), aNotif()];
    await repos.notifications.insertMany(notifs);
    for (const n of notifs) {
      await processFcmJob(deps({ cfg, fcm }), n._id.toHexString());
    }

    expect(fcm.calls).toHaveLength(2); // third blocked by limit
  });
});

describe('Email handler', () => {
  it('sends email and marks emailNotified', async () => {
    const notif = aNotif({ type: 'web' });
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const mailer = fakeMailer();

    await processEmailJob(deps({ mailer }), notif._id.toHexString());

    expect(mailer.calls).toHaveLength(1);
    expect(mailer.calls[0]!.to).toBe('ana@example.com');
    expect(mailer.calls[0]!.content.subject.length).toBeGreaterThan(0);
    const after = await repos.notifications.findOne({ _id: notif._id });
    expect(after?.emailNotified).toBe(true);
  });

  it('removes the doc when there is no verified recipient (full mode)', async () => {
    const notif = aNotif({ type: 'web' });
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser({ emails: [{ address: 'ana@example.com', verified: false }] }));
    const mailer = fakeMailer();

    await processEmailJob(deps({ mailer }), notif._id.toHexString());

    expect(mailer.calls).toHaveLength(0);
    expect(await repos.notifications.findOne({ _id: notif._id })).toBeNull(); // removed
  });

  it('does not remove the doc for missing recipient in shadow mode', async () => {
    const notif = aNotif({ type: 'web' });
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser({ emails: [{ address: 'x@y', verified: false }] }));
    const mailer = fakeMailer();

    await processEmailJob(deps({ cfg: { ...baseCfg, mode: 'shadow' }, mailer }), notif._id.toHexString());

    expect(await repos.notifications.findOne({ _id: notif._id })).not.toBeNull();
  });

  it('transient SMTP error releases reservation and rethrows', async () => {
    const notif = aNotif({ type: 'web' });
    await repos.notifications.insertOne(notif);
    await repos.users.insertOne(aUser());
    const mailer = fakeMailer({ fail: true });

    await expect(processEmailJob(deps({ mailer }), notif._id.toHexString())).rejects.toThrow();
    expect(await repos.sends.countDocuments({ notificationId: notif._id })).toBe(0);
  });
});