RocketChat/Rocket.Chat

import type { IMessage, IUser } from '@rocket.chat/core-typings';
import { Messages, Users } from '@rocket.chat/models';
import moment from 'moment';

import * as Mailer from '../../../app/mailer/server/api';
import { settings } from '../../../app/settings/server';
import { Message } from '../../../app/ui-utils/server';
import { getMomentLocale } from '../getMomentLocale';

export async function sendViaEmail(
    data: {
        rid: string;
        toUsers: string[];
        toEmails: string[];
        subject: string;
        messages: string[];
        language: string;
    },
    user: IUser,
): Promise<{
    missing: string[];
}> {
    const emails = data.toEmails.map((email) => email.trim()).filter(Boolean);

    const missing = [...data.toUsers].filter(Boolean);

    (
        await Users.findUsersByUsernames(data.toUsers, {
            projection: { 'username': 1, 'emails.address': 1 },
        }).toArray()
    ).forEach((user: IUser) => {
        const emailAddress = user.emails?.[0].address;

        if (!emailAddress) {
            return;
        }

        if (!Mailer.checkAddressFormat(emailAddress)) {
            throw new Error('error-invalid-email');
        }

        const found = missing.indexOf(String(user.username));
        if (found !== -1) {
            missing.splice(found, 1);
        }

        emails.push(emailAddress);
    });

    const email = user.emails?.[0]?.address;
    const lang = data.language || user.language || 'en';

    const localMoment = moment();

    if (lang !== 'en') {
        const localeFn = await getMomentLocale(lang);
        if (localeFn) {
            Function(localeFn).call({ moment });
            localMoment.locale(lang);
        }
    }

    const html = (
        await Messages.findByRoomIdAndMessageIds(data.rid, data.messages, {
            sort: { ts: 1 },
        }).toArray()
    )
        .map((message: IMessage) => {
            const dateTime = moment(message.ts).locale(lang).format('L LT');
            return `<p style='margin-bottom: 5px'><b>${
                message.u.username
            }</b> <span style='color: #aaa; font-size: 12px'>${dateTime}</span><br/>${Message.parse(message, data.language)}</p>`;
        })
        .join('');

    await Mailer.send({
        to: emails,
        from: settings.get('From_Email'),
        replyTo: email,
        subject: data.subject,
        html,
    });

    return { missing };
}