import { randomUUID } from 'node:crypto';

import { INestApplication, NotFoundException } from '@nestjs/common';
import { PrismaClient, User } from '@prisma/client';
import { afterAll, beforeAll, describe, expect, it } from 'vitest';
import * as Y from 'yjs';

import { createTestApp } from '../testing/test-app';
import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
import { VERSION_RETENTION_DAYS, VersionsService } from './versions.service';

describe.skipIf(!hasTestDb)('VersionsService (db, issue #41)', () => {
  let app: INestApplication;
  let prisma: PrismaClient;
  let versions: VersionsService;
  const suffix = uniqueSuffix();
  let owner: User;
  let pondId: string;
  const pageIds: string[] = [];

  async function createPage(): Promise<string> {
    const id = randomUUID();
    await prisma.page.create({
      data: {
        id,
        pondId,
        title: 'Versioned',
        slug: `p-${id.slice(0, 8)}`,
        ydocState: new Uint8Array(Y.encodeStateAsUpdate(new Y.Doc())),
        sortKey: 'a0',
        createdBy: owner.id,
      },
    });
    pageIds.push(id);
    return id;
  }

  beforeAll(async () => {
    prisma = createTestPrisma();
    app = await createTestApp();
    versions = app.get(VersionsService);

    owner = await prisma.user.create({
      data: {
        username: `ver-owner-${suffix}`,
        email: `ver-owner-${suffix}@example.test`,
        displayName: 'Version Owner',
      },
    });
    const pond = await prisma.pond.create({
      data: {
        slug: `ver-pond-${suffix}`,
        name: 'Version Pond',
        type: 'PERSONAL',
        ownerId: owner.id,
      },
    });
    pondId = pond.id;
  });

  afterAll(async () => {
    if (pageIds.length > 0) await prisma.page.deleteMany({ where: { id: { in: pageIds } } });
    await prisma.pond.deleteMany({ where: { id: pondId } });
    await prisma.user.deleteMany({ where: { id: owner.id } });
    await prisma.$disconnect();
    await app.close();
  });

  it('creates a named version storing label and creator', async () => {
    const pageId = await createPage();
    const view = await versions.createNamed(owner, pageId, { label: 'before restructuring' });

    expect(view).toMatchObject({
      trigger: 'manual',
      label: 'before restructuring',
      createdBy: owner.id,
    });
    const row = await prisma.pageVersion.findUniqueOrThrow({ where: { id: view.id } });
    expect(row.label).toBe('before restructuring');
    expect(row.createdBy).toBe(owner.id);
    expect(row.trigger).toBe('MANUAL');
    expect(row.ydocSnapshot.byteLength).toBeGreaterThan(0);
  });

  it('creates an unnamed manual snapshot when no label is given (#125)', async () => {
    const pageId = await createPage();
    const view = await versions.createNamed(owner, pageId, {});

    expect(view).toMatchObject({ trigger: 'manual', label: null, createdBy: owner.id });
    const row = await prisma.pageVersion.findUniqueOrThrow({ where: { id: view.id } });
    expect(row.label).toBeNull();
  });

  it('captures and clears the pending contributor set', async () => {
    const pageId = await createPage();
    const authorA = randomUUID();
    const authorB = randomUUID();
    await prisma.pagePendingContributor.createMany({
      data: [
        { pageId, userId: authorA },
        { pageId, userId: authorB },
      ],
    });

    const view = await versions.createNamed(owner, pageId, { label: 'snapshot' });
    expect([...view.contributorIds].sort()).toEqual([authorA, authorB].sort());
    // The accumulator is consumed so the next version does not re-attribute them.
    expect(await prisma.pagePendingContributor.count({ where: { pageId } })).toBe(0);
  });

  it('lists versions newest first and renders a version read-only', async () => {
    const pageId = await createPage();
    const first = await versions.createNamed(owner, pageId, { label: 'first' });
    const second = await versions.createNamed(owner, pageId, { label: 'second' });

    const list = await versions.list(owner, pageId);
    expect(list.map((v) => v.id)).toEqual([second.id, first.id]); // newest first

    const content = await versions.getContent(owner, pageId, first.id);
    expect(content.id).toBe(first.id);
    expect(typeof content.html).toBe('string');
    expect(typeof content.markdown).toBe('string');
  });

  // Write-access gating of every history route moved to the route guard
  // with #52 — covered by the permission e2e pack.

  it('restore returns the target version and emits without mutating history', async () => {
    const pageId = await createPage();
    const version = await versions.createNamed(owner, pageId, { label: 'target' });
    const before = await prisma.pageVersion.count({ where: { pageId } });

    // The api side only checks permission and signals collab; it must not delete
    // or alter any version (history is append-only — collab appends pre-restore).
    const restored = await versions.restore(owner, pageId, version.id);
    expect(restored.id).toBe(version.id);
    expect(await prisma.pageVersion.count({ where: { pageId } })).toBe(before);

    await expect(versions.restore(owner, pageId, randomUUID())).rejects.toBeInstanceOf(
      NotFoundException,
    );
  });

  it('thins auto versions beyond the window to the newest per day, keeping the rest', async () => {
    const pageId = await createPage();
    const daysAgo = (days: number, hour: number): Date => {
      const d = new Date();
      d.setDate(d.getDate() - days);
      d.setHours(hour, 0, 0, 0);
      return d;
    };
    const snapshot = new Uint8Array(Y.encodeStateAsUpdate(new Y.Doc()));
    const auto = (createdAt: Date) => ({
      pageId,
      ydocSnapshot: snapshot,
      trigger: 'AUTO' as const,
      contributorIds: [],
      createdAt,
    });

    // Two auto versions on one day beyond the window (older + newer), one auto
    // on another day beyond the window, one manual beyond the window, and one
    // auto inside the window.
    const oldDayOlder = daysAgo(120, 8);
    const oldDayNewer = daysAgo(120, 20);
    const otherOldDay = daysAgo(200, 12);
    await prisma.pageVersion.createMany({
      data: [
        auto(oldDayOlder),
        auto(oldDayNewer),
        auto(otherOldDay),
        { ...auto(daysAgo(150, 10)), trigger: 'MANUAL', label: 'keep me', createdBy: owner.id },
        auto(daysAgo(3, 10)), // within the window
      ],
    });

    const removed = await versions.thinDueVersions();
    expect(removed).toBeGreaterThanOrEqual(1);

    const remaining = await prisma.pageVersion.findMany({
      where: { pageId },
      orderBy: { createdAt: 'asc' },
      select: { trigger: true, createdAt: true, label: true },
    });
    const times = remaining.map((v) => v.createdAt.getTime());
    // The older of the two same-day beyond-window auto versions is gone…
    expect(times).not.toContain(oldDayOlder.getTime());
    // …its newer same-day sibling survives, as does the other-day one.
    expect(times).toContain(oldDayNewer.getTime());
    expect(times).toContain(otherOldDay.getTime());
    // Manual and within-window auto are always kept.
    expect(remaining.some((v) => v.label === 'keep me')).toBe(true);
    expect(remaining.length).toBe(4);
    expect(VERSION_RETENTION_DAYS).toBe(90);
  });
});