import { HocuspocusProvider } from '@hocuspocus/provider';
import type { CollabTokenClaims } from '@dorfteich/shared';
import { signCollabToken } from '@dorfteich/shared/token-crypto';
import { pino } from 'pino';
import { afterAll, beforeAll, 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 = 'integration-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 = 4000): 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 authentication', () => {
  let server: ReturnType<typeof createCollabServer>;
  let url: string;

  beforeAll(async () => {
    server = createCollabServer({
      version: 'test',
      logger,
      tokenSecret: secret,
      pingDatabase: async () => ({ ok: true }),
      persistence: new InMemoryPagePersistence(),
    });
    const port = await freePort();
    await server.listen(port);
    url = `ws://127.0.0.1:${port}`;
  });

  afterAll(async () => {
    await server.destroy();
  });

  function connect(
    name: string,
    token: string,
  ): {
    provider: HocuspocusProvider;
    doc: Y.Doc;
    authenticated: () => boolean;
    failed: () => boolean;
    synced: () => boolean;
  } {
    const doc = new Y.Doc();
    let authenticated = false;
    let failed = false;
    let synced = false;
    // No WebSocketPolyfill: the provider falls back to Node's global WebSocket.
    const provider = new HocuspocusProvider({
      url,
      name,
      token,
      document: doc,
      onAuthenticated: () => {
        authenticated = true;
      },
      onAuthenticationFailed: () => {
        failed = true;
      },
      onSynced: () => {
        synced = true;
      },
    });
    return {
      provider,
      doc,
      authenticated: () => authenticated,
      failed: () => failed,
      synced: () => synced,
    };
  }

  it('accepts a valid token whose page matches the document', async () => {
    const token = await signCollabToken(
      { userId: 'u1', pageId: 'page-ok', mode: 'rw' },
      secret,
      60,
    );
    const client = connect('page-ok', token);
    await waitFor(client.authenticated);
    expect(client.authenticated()).toBe(true);
    expect(client.failed()).toBe(false);
    client.provider.destroy();
    client.doc.destroy();
  });

  const claims: CollabTokenClaims = { userId: 'u1', pageId: 'page-x', mode: 'rw' };
  const rejectionCases: { label: string; name: string; token: () => Promise<string> }[] = [
    {
      label: 'an expired token',
      name: 'page-x',
      token: () => signCollabToken(claims, secret, -60),
    },
    {
      label: 'a tampered token',
      name: 'page-x',
      token: async () => {
        const [h, p, s = ''] = (await signCollabToken(claims, secret, 60)).split('.');
        // Flip the FIRST signature character — its bits are all significant.
        // The last character is not: its low bits are base64url padding that
        // decoders ignore, so a last-char flip of a signature ending in 'A'
        // decodes to the same bytes and verifies (jose compares decoded
        // bytes, unlike the pre-#188 code that compared encoded strings).
        const flipped = (s.startsWith('A') ? 'B' : 'A') + s.slice(1);
        return `${h}.${p}.${flipped}`;
      },
    },
    {
      label: 'a token minted for a different page',
      name: 'page-y',
      token: () => signCollabToken(claims, secret, 60),
    },
    {
      label: 'a token signed with the wrong secret',
      name: 'page-x',
      token: () => signCollabToken(claims, 'a-completely-different-secret-32c', 60),
    },
  ];

  it.each(rejectionCases)('rejects $label', async ({ name, token }) => {
    const client = connect(name, await token());
    await waitFor(client.failed);
    expect(client.failed()).toBe(true);
    expect(client.authenticated()).toBe(false);
    client.provider.destroy();
    client.doc.destroy();
  });

  it('lets a read-only client receive updates but discards its writes server-side', async () => {
    const page = 'page-shared';
    const rw = connect(
      page,
      await signCollabToken({ userId: 'w', pageId: page, mode: 'rw' }, secret, 60),
    );
    const ro = connect(
      page,
      await signCollabToken({ userId: 'r', pageId: page, mode: 'ro' }, secret, 60),
    );
    await waitFor(() => rw.synced() && ro.synced());

    const rwMap = rw.doc.getMap<string>('m');
    const roMap = ro.doc.getMap<string>('m');

    // A write from the read-write client reaches the read-only client.
    rw.doc.transact(() => rwMap.set('fromRw', 'a'));
    await waitFor(() => roMap.get('fromRw') === 'a');

    // The read-only client writes; the server must drop it.
    ro.doc.transact(() => roMap.set('fromRo', 'b'));
    // Barrier: a second rw write round-trips to ro; by the time it arrives the
    // server has already processed (and dropped) the ro write that preceded it.
    rw.doc.transact(() => rwMap.set('barrier', 'c'));
    await waitFor(() => roMap.get('barrier') === 'c');

    expect(rwMap.get('fromRo')).toBeUndefined();

    rw.provider.destroy();
    ro.provider.destroy();
    rw.doc.destroy();
    ro.doc.destroy();
  });
});