RocketChat/Rocket.Chat

import type { IMessage, IRoom } from '@rocket.chat/core-typings';
import type { ServerMethods } from '@rocket.chat/ddp-client';
import { Messages } from '@rocket.chat/models';
import { check } from 'meteor/check';
import { Meteor } from 'meteor/meteor';

import { canAccessRoomIdAsync } from '../../app/authorization/server/functions/canAccessRoom';
import { normalizeMessagesForUser } from '../../app/utils/server/lib/normalizeMessagesForUser';

declare module '@rocket.chat/ddp-client' {
    // eslint-disable-next-line @typescript-eslint/naming-convention
    interface ServerMethods {
        loadNextMessages(rid: IRoom['_id'], end?: Date, limit?: number): Promise<{ messages: IMessage[] }>;
    }
}

Meteor.methods<ServerMethods>({
    async loadNextMessages(rid, end, limit = 20) {
        check(rid, String);
        check(limit, Number);

        if (!Meteor.userId()) {
            throw new Meteor.Error('error-invalid-user', 'Invalid user', {
                method: 'loadNextMessages',
            });
        }

        if (!rid) {
            throw new Meteor.Error('error-invalid-room', 'Invalid room', { method: 'loadNextMessages' });
        }

        const fromId = Meteor.userId();

        if (!fromId || !(await canAccessRoomIdAsync(rid, fromId))) {
            throw new Meteor.Error('error-not-allowed', 'Not allowed', { method: 'loadNextMessages' });
        }

        let records;
        if (end) {
            records = await Messages.findVisibleByRoomIdAfterTimestamp(rid, end, {
                sort: {
                    ts: 1,
                },
                limit,
            }).toArray();
        } else {
            records = await Messages.findVisibleByRoomId(rid, {
                sort: {
                    ts: 1,
                },
                limit,
            }).toArray();
        }

        return {
            messages: await normalizeMessagesForUser(records, fromId),
        };
    },
});