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

import { createTestApp } from '../testing/test-app';
import { createTestPrisma, grantOwnerAdmin, hasTestDb, uniqueSuffix } from '../testing/test-db';
import { PagesService } from './pages.service';

describe.skipIf(!hasTestDb)('PagesService.reposition (db, issue #45)', () => {
  let app: INestApplication;
  let prisma: PrismaClient;
  let pages: PagesService;
  const suffix = uniqueSuffix();
  let owner: User;
  let pondId: string;

  /** Current manual order of the pond's pages, as the sidebar would render it. */
  async function manualOrder(): Promise<string[]> {
    const list = await pages.list(owner, pondId);
    return list.map((p) => p.title);
  }

  async function pageIdByTitle(title: string): Promise<string> {
    const p = await prisma.page.findFirstOrThrow({ where: { pondId, title } });
    return p.id;
  }

  beforeAll(async () => {
    prisma = createTestPrisma();
    app = await createTestApp();
    pages = app.get(PagesService);

    owner = await prisma.user.create({
      data: {
        username: `pos-owner-${suffix}`,
        email: `pos-owner-${suffix}@example.test`,
        displayName: 'Position Owner',
      },
    });
    const pond = await prisma.pond.create({
      data: {
        slug: `pos-pond-${suffix}`,
        name: 'Position Pond',
        type: 'PERSONAL',
        ownerId: owner.id,
      },
    });
    pondId = pond.id;
    await grantOwnerAdmin(prisma, pondId, owner.id);
    // Manual mode so `list` orders by sort_key.
    await prisma.pond.update({
      where: { id: pondId },
      data: { settings: { sidebarSort: 'manual' } },
    });

    // Four pages created in order A, B, C, D (each appended at the end).
    for (const title of ['A', 'B', 'C', 'D']) {
      await pages.create(owner, pondId, { title });
    }
  });

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

  it('starts in creation order', async () => {
    expect(await manualOrder()).toEqual(['A', 'B', 'C', 'D']);
  });

  it('moves a page and the new order is server-ordered (persisted for everyone)', async () => {
    const d = await pageIdByTitle('D');
    const a = await pageIdByTitle('A');
    const b = await pageIdByTitle('B');
    // Move D to sit between A and B → A, D, B, C.
    await pages.reposition(owner, d, { afterId: a, beforeId: b });
    expect(await manualOrder()).toEqual(['A', 'D', 'B', 'C']);

    // A fresh read (any other user's view) sees the same order — it lives in
    // sort_key, not client state.
    const reread = (await pages.list(owner, pondId)).map((p) => p.title);
    expect(reread).toEqual(['A', 'D', 'B', 'C']);
  });

  it('moves a page to the very top (afterId null)', async () => {
    const c = await pageIdByTitle('C');
    const a = await pageIdByTitle('A');
    await pages.reposition(owner, c, { afterId: null, beforeId: a });
    expect(await manualOrder()).toEqual(['C', 'A', 'D', 'B']);
  });

  it('keeps the manual order when the sort mode changes (just not applied)', async () => {
    await prisma.pond.update({
      where: { id: pondId },
      data: { settings: { sidebarSort: 'alpha' } },
    });
    expect(await manualOrder()).toEqual(['A', 'B', 'C', 'D']); // alpha ignores sort_key

    await prisma.pond.update({
      where: { id: pondId },
      data: { settings: { sidebarSort: 'manual' } },
    });
    // The manual order from before is intact — switching modes never rewrote keys.
    expect(await manualOrder()).toEqual(['C', 'A', 'D', 'B']);
  });
});