import { HocuspocusProvider } from '@hocuspocus/provider';
import { signCollabToken } from '@dorfteich/shared/token-crypto';
import { pino } from 'pino';
import { afterEach, describe, expect, it } from 'vitest';
import * as Y from 'yjs';

import { createCollabServer } from './server.js';
import { freePort } from './testing/free-port.js';
import { InMemoryPagePersistence } from './testing/fake-persistence.js';

const secret = 'persistence-test-secret-32-chars!!';
const logger = pino({ enabled: false });

/** Poll `predicate` until it is true or the timeout elapses. */
async function waitFor(predicate: () => boolean, timeoutMs = 5000): Promise<void> {
  const deadline = Date.now() + timeoutMs;
  while (Date.now() < deadline) {
    if (predicate()) return;
    await new Promise((resolve) => setTimeout(resolve, 20));
  }
  throw new Error('timed out waiting for condition');
}

describe('collab persistence hooks', () => {
  const cleanups: Array<() => Promise<void> | void> = [];

  afterEach(async () => {
    // Tear down in reverse order (providers before their server).
    for (const cleanup of cleanups.splice(0).reverse()) await cleanup();
  });

  async function startServer(persistence: InMemoryPagePersistence): Promise<string> {
    const server = createCollabServer({
      version: 'test',
      logger,
      tokenSecret: secret,
      pingDatabase: async () => ({ ok: true }),
      persistence,
    });
    const port = await freePort();
    await server.listen(port);
    cleanups.push(() => server.destroy());
    return `ws://127.0.0.1:${port}`;
  }

  function connect(url: string, pageId: string): { provider: HocuspocusProvider; doc: Y.Doc } {
    const doc = new Y.Doc();
    const token = signCollabToken({ userId: `u-${pageId}`, pageId, mode: 'rw' }, secret, 60);
    const provider = new HocuspocusProvider({ url, name: pageId, document: doc, token });
    cleanups.push(() => provider.destroy());
    return { provider, doc };
  }

  it('syncs edits between two read-write clients on the same page', async () => {
    const persistence = new InMemoryPagePersistence();
    const url = await startServer(persistence);
    const pageId = '11111111-1111-1111-1111-111111111111';

    const a = connect(url, pageId);
    const b = connect(url, pageId);

    a.doc.getText('t').insert(0, 'hello from A');

    await waitFor(() => b.doc.getText('t').toString() === 'hello from A');
    expect(b.doc.getText('t').toString()).toBe('hello from A');
  });

  it('persists edits so they survive a collab-server restart', async () => {
    const persistence = new InMemoryPagePersistence();
    const pageId = '22222222-2222-2222-2222-222222222222';

    const url1 = await startServer(persistence);
    const first = connect(url1, pageId);
    first.doc.getText('t').insert(0, 'durable content');

    // Disconnecting the only client triggers an immediate final store.
    await waitFor(() => first.provider.isSynced);
    await first.provider.destroy();
    await waitFor(() => persistence.storeCalls > 0);

    // A brand-new server instance reusing the same persistence must reload it.
    const url2 = await startServer(persistence);
    const second = connect(url2, pageId);
    await waitFor(() => second.doc.getText('t').toString() === 'durable content');
    expect(second.doc.getText('t').toString()).toBe('durable content');
  });

  it('rejects an oversize document and notifies the client via a stateless error', async () => {
    const persistence = new InMemoryPagePersistence();
    persistence.sizeLimit = 10; // any real edit exceeds this
    const url = await startServer(persistence);
    const pageId = '33333333-3333-3333-3333-333333333333';

    const { provider, doc } = connect(url, pageId);
    let statelessPayload: string | undefined;
    provider.on('stateless', ({ payload }: { payload: string }) => {
      statelessPayload = payload;
    });

    doc.getText('t').insert(0, 'this document is over the ceiling');

    await waitFor(() => statelessPayload !== undefined);
    expect(JSON.parse(statelessPayload!)).toMatchObject({
      type: 'error',
      code: 'page_document_too_large',
    });
  });
});