weseek__growi/apps/app/src/server/service/yjs/sync-ydoc.ts

import { Origin, YDocStatus } from '@growi/core';
import type { Document } from 'y-socket.io/dist/server';

import loggerFactory from '~/utils/logger';

import { Revision } from '../../models/revision';

import type { MongodbPersistence } from './extended/mongodb-persistence';

const logger = loggerFactory('growi:service:yjs:sync-ydoc');


// eslint-disable-next-line @typescript-eslint/no-explicit-any
type Delta = Array<{insert?:Array<any>|string, delete?:number, retain?:number}>;

type Context = {
  ydocStatus: YDocStatus,
}

/**
 * Sync the text and the meta data with the latest revision body
 * @param mdb
 * @param doc
 * @param context true to force sync
 */
export const syncYDoc = async(mdb: MongodbPersistence, doc: Document, context: true | Context): Promise<void> => {
  const pageId = doc.name;

  const revision = await Revision
    .findOne(
      // filter
      { pageId },
      // projection
      { body: 1, createdAt: 1, origin: 1 },
      // options
      { sort: { createdAt: -1 } },
    )
    .lean();

  if (revision == null) {
    logger.warn(`Synchronization has been canceled since the revision of the page ('${pageId}') could not be found`);
    return;
  }

  const shouldSync = context === true
    || (() => {
      switch (context.ydocStatus) {
        case YDocStatus.NEW:
          return true;
        case YDocStatus.OUTDATED:
          // should skip when the YDoc is outdated and the latest revision is created by the editor
          return revision.origin !== Origin.Editor;
        default:
          return false;
      }
    })();

  if (shouldSync) {
    logger.debug(`YDoc for the page ('${pageId}') is synced with the latest revision body`);

    const ytext = doc.getText('codemirror');
    const delta: Delta = [];

    if (ytext.length > 0) {
      delta.push({ delete: ytext.length });
    }
    if (revision.body != null) {
      delta.push({ insert: revision.body });
    }

    ytext.applyDelta(delta, { sanitize: false });
  }

  const shouldSyncMeta = context === true
    || context.ydocStatus === YDocStatus.NEW
    || context.ydocStatus === YDocStatus.OUTDATED;

  if (shouldSyncMeta) {
    mdb.setMeta(doc.name, 'updatedAt', revision.createdAt.getTime() ?? Date.now());
  }
};