import { INestApplication } from '@nestjs/common';
import { PrismaClient, User } from '@prisma/client';
import request from 'supertest';
import { afterAll, beforeAll, describe, expect, it } from 'vitest';

import { DigestService } from './digest.service';
import { NotificationsService } from './notifications.service';
import { createTestApp, sessionCookieOf } from '../testing/test-app';
import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
import { UsersService } from '../users/users.service';

const HOUR = 60 * 60 * 1000;

/**
 * E-mail digests (issue #95): grouping into exactly one mail, the cadence
 * windows with time travel, the session-free unsubscribe link, and the
 * send-time permission re-check.
 */
describe.skipIf(!hasTestDb)('notification digests (e2e, issue #95)', () => {
  let app: INestApplication;
  let prisma: PrismaClient;
  let digest: DigestService;
  const suffix = uniqueSuffix();
  const password = 'gebuendelt statt einzeln 1';
  const users: Record<string, User> = {};
  const cookies: Record<string, string> = {};
  let pondId: string;
  let pageId: string;

  const api = () => request(app.getHttpServer());

  async function makeUser(handle: string): Promise<void> {
    const service = app.get(UsersService);
    const username = `di-${handle}-${suffix}`;
    const user = await service.createUser({
      username,
      email: `${username}@example.org`,
      displayName: `Di ${handle}`,
      password,
      locale: 'de',
    });
    await service.markEmailVerified(user.id);
    users[handle] = user;
    cookies[handle] = sessionCookieOf(
      await api()
        .post('/api/v1/auth/login')
        .send({ usernameOrEmail: username, password })
        .expect(200),
    );
  }

  /** Fan out an event and backdate the resulting unmailed notifications. */
  async function seedEvent(type: 'page_changed' | 'comment_added', ageMs: number): Promise<void> {
    await app.get(NotificationsService).fanoutPageEvent(type, pageId, [users.owner!.id]);
    await prisma.notification.updateMany({
      where: { userId: users.watcher!.id, mailedAt: null },
      data: { createdAt: new Date(Date.now() - ageMs) },
    });
  }

  async function outboxFor(handle: string): Promise<{ subject: string; textBody: string }[]> {
    return prisma.mailOutbox.findMany({
      where: { toAddress: users[handle]!.email },
      orderBy: { createdAt: 'asc' },
      select: { subject: true, textBody: true },
    });
  }

  beforeAll(async () => {
    prisma = createTestPrisma();
    await prisma.rateLimit.deleteMany({});
    app = await createTestApp();
    digest = app.get(DigestService);
    for (const handle of ['owner', 'watcher']) await makeUser(handle);

    const pond = await prisma.pond.create({
      data: {
        slug: `di-pond-${suffix}`,
        name: 'Digest Pond',
        type: 'SHARED',
        ownerId: users.owner!.id,
      },
    });
    pondId = pond.id;
    await prisma.roleGrant.create({
      data: {
        pondId,
        subjectType: 'USER',
        subjectId: users.owner!.id,
        role: 'POND_ADMIN',
        scopeType: 'POND',
        effect: 'ALLOW',
        createdBy: users.owner!.id,
      },
    });
    const page = await api()
      .post(`/api/v1/ponds/${pondId}/pages`)
      .set('Cookie', cookies.owner!)
      .send({ title: 'Digest target' })
      .expect(201);
    pageId = (page.body as { id: string }).id;
    // The watcher joins as a reader through the API (permission cache!).
    await api()
      .post(`/api/v1/ponds/${pondId}/members`)
      .set('Cookie', cookies.owner!)
      .send({ usernameOrEmail: `di-watcher-${suffix}`, role: 'reader' })
      .expect(201);
    await api().put(`/api/v1/watches/page/${pageId}`).set('Cookie', cookies.watcher!).expect(200);
  });

  afterAll(async () => {
    const ids = Object.values(users).map((u) => u.id);
    await prisma.mailOutbox.deleteMany({
      where: { toAddress: { in: Object.values(users).map((u) => u.email) } },
    });
    await prisma.notification.deleteMany({ where: { userId: { in: ids } } });
    await prisma.watch.deleteMany({ where: { userId: { in: ids } } });
    await prisma.comment.deleteMany({ where: { page: { pondId } } });
    await prisma.roleGrant.deleteMany({ where: { pondId } });
    await prisma.page.deleteMany({ where: { pondId } });
    await prisma.pond.deleteMany({ where: { id: pondId } });
    await prisma.auditEntry.deleteMany({ where: { actorId: { in: ids } } });
    await prisma.session.deleteMany({ where: { userId: { in: ids } } });
    await prisma.userIdentity.deleteMany({ where: { userId: { in: ids } } });
    await prisma.user.deleteMany({ where: { id: { in: ids } } });
    await prisma.$disconnect();
    await app.close();
  });

  it('groups two edits and a comment into exactly one localized mail', async () => {
    await seedEvent('page_changed', 2 * HOUR);
    await seedEvent('page_changed', 2 * HOUR);
    await seedEvent('comment_added', 2 * HOUR);

    expect(await digest.runOnce()).toBe(1);
    const mails = await outboxFor('watcher');
    expect(mails).toHaveLength(1);
    expect(mails[0]!.subject).toContain('3');
    expect(mails[0]!.textBody).toContain('Digest Pond');
    expect(mails[0]!.textBody).toContain('Digest target');
    expect(mails[0]!.textBody).toContain('2 Änderungen');
    expect(mails[0]!.textBody).toContain('1 Kommentar');
    expect(mails[0]!.textBody).toContain('Di owner');
    expect(mails[0]!.textBody).toContain('/api/v1/notifications/unsubscribe?token=');

    // Mailed, not read — and never mailed twice.
    const rows = await prisma.notification.findMany({ where: { userId: users.watcher!.id } });
    expect(rows.every((row) => row.mailedAt !== null && row.readAt === null)).toBe(true);
    expect(await digest.runOnce()).toBe(0);
    expect(await outboxFor('watcher')).toHaveLength(1);
  });

  it("respects 'off' and batches 'daily' across the day", async () => {
    await api()
      .patch('/api/v1/users/me')
      .set('Cookie', cookies.watcher!)
      .send({ digestFrequency: 'off' })
      .expect(200);
    await seedEvent('page_changed', 3 * HOUR);
    expect(await digest.runOnce()).toBe(0);
    expect(await outboxFor('watcher')).toHaveLength(1); // unchanged

    // Daily: a 3 h old batch is not due yet, a > 24 h old one is.
    await api()
      .patch('/api/v1/users/me')
      .set('Cookie', cookies.watcher!)
      .send({ digestFrequency: 'daily' })
      .expect(200);
    expect(await digest.runOnce()).toBe(0);
    expect(await digest.runOnce(new Date(Date.now() + 25 * HOUR))).toBe(1);
    expect(await outboxFor('watcher')).toHaveLength(2);
  });

  it('unsubscribes via the signed link without creating a session', async () => {
    await api()
      .patch('/api/v1/users/me')
      .set('Cookie', cookies.watcher!)
      .send({ digestFrequency: 'hourly' })
      .expect(200);

    const token = digest.unsubscribeToken(users.watcher!.id);
    const res = await api().get(`/api/v1/notifications/unsubscribe?token=${token}`).expect(200);
    expect(res.headers['set-cookie']).toBeUndefined();
    expect(res.text).toContain('Digest-Mails deaktiviert');
    const user = await prisma.user.findUniqueOrThrow({ where: { id: users.watcher!.id } });
    expect(user.digestFrequency).toBe('off');

    // Tampered and garbage tokens are rejected.
    await api().get(`/api/v1/notifications/unsubscribe?token=${token}x`).expect(400);
    await api().get('/api/v1/notifications/unsubscribe?token=nonsense').expect(400);
    await api().get('/api/v1/notifications/unsubscribe').expect(400);
  });

  it('re-checks permission at send time: revoked content never reaches the mail', async () => {
    await api()
      .patch('/api/v1/users/me')
      .set('Cookie', cookies.watcher!)
      .send({ digestFrequency: 'hourly' })
      .expect(200);
    await seedEvent('page_changed', 2 * HOUR);

    // Revoke the watcher's membership through the API (cache-safe).
    await api()
      .delete(`/api/v1/ponds/${pondId}/members/${users.watcher!.id}`)
      .set('Cookie', cookies.owner!)
      .expect(204);

    const before = await outboxFor('watcher');
    expect(await digest.runOnce()).toBe(0);
    expect(await outboxFor('watcher')).toHaveLength(before.length);
    // The batch still counts as handled — no retry loop on revoked content.
    const rows = await prisma.notification.findMany({
      where: { userId: users.watcher!.id, mailedAt: null },
    });
    expect(rows).toHaveLength(0);
  });
});