RocketChat/Rocket.Chat

import type { IRocketChatRecord } from '@rocket.chat/core-typings';
import type { ChangeStreamDeleteDocument, ChangeStreamInsertDocument, ChangeStreamUpdateDocument } from 'mongodb';

import type { RealTimeData } from './DatabaseWatcher';

export function convertChangeStreamPayload(
    event:
        | ChangeStreamInsertDocument<IRocketChatRecord>
        | ChangeStreamUpdateDocument<IRocketChatRecord>
        | ChangeStreamDeleteDocument<IRocketChatRecord>,
): RealTimeData<IRocketChatRecord> | void {
    switch (event.operationType) {
        case 'insert':
            return {
                action: 'insert',
                clientAction: 'inserted',
                id: event.documentKey._id,
                data: event.fullDocument,
            };
        case 'update':
            const diff: Record<string, any> = {
                ...event.updateDescription.updatedFields,
                ...(event.updateDescription.removedFields || []).reduce((unset, removedField) => {
                    return {
                        ...unset,
                        [removedField]: undefined,
                    };
                }, {}),
            };

            const unset: Record<string, number> = (event.updateDescription.removedFields || []).reduce((unset, removedField) => {
                return {
                    ...unset,
                    [removedField]: 1,
                };
            }, {});

            return {
                action: 'update',
                clientAction: 'updated',
                id: event.documentKey._id,
                data: event.fullDocument,
                diff,
                unset,
            };
        case 'delete':
            return {
                action: 'remove',
                clientAction: 'removed',
                id: event.documentKey._id,
            };
    }
}