cal.pub0.org/lib/emails/invitation.ts

import {serverConfig} from "../serverConfig";
import nodemailer from 'nodemailer';

export default function createInvitationEmail(data: any, options: any = {}) {
  return sendEmail(data, {
    provider: {
      transport: serverConfig.transport,
      from: serverConfig.from,
    },
    ...options
  });
}

const sendEmail = (invitation: any, {
  provider,
}) => new Promise( (resolve, reject) => {
  const { transport, from } = provider;

  nodemailer.createTransport(transport).sendMail(
    {
      from: `Calendso <${from}>`,
      to: invitation.toEmail,
      subject: `${invitation.from} invited you to join ${invitation.teamName}`,
      html: html(invitation),
      text: text(invitation),
    },
    (error) => {
      if (error) {
        console.error("SEND_INVITATION_NOTIFICATION_ERROR", invitation.toEmail, error);
        return reject(new Error(error));
      }
      return resolve();
    });
});

const html = (invitation: any) => `
  <table style="width: 100%;">
  <tr>
    <td>
      <center>
      <table style="width: 640px; border: 1px solid gray; padding: 15px; margin: 0 auto; text-align: left;">
      <tr>
      <td>
    Hi,<br />
    <br />
    ${invitation.from} invited you to join the team "${invitation.teamName}" in Calendso.<br />
    <br />
    <table border="0" cellpadding="0" cellspacing="0" role="presentation" style="border-collapse:separate;line-height:100%;">
      <tr>
        <td>
          <div>
            <!--[if mso]>
              <v:roundrect xmlns:v="urn:schemas-microsoft-com:vml" xmlns:w="urn:schemas-microsoft-com:office:word" href="${process.env.BASE_URL}/settings/teams" style="height:40px;v-text-anchor:middle;width:130px;" arcsize="5%" strokecolor="#19cca3" fillcolor="#19cca3;width: 130;">
                 <w:anchorlock/>
                 <center style="color:#ffffff;font-family:Helvetica, sans-serif;font-size:18px; font-weight: 600;">Join team</center>
               </v:roundrect>
    
            <![endif]-->
              <a href="${process.env.BASE_URL}/settings/teams" style="display: inline-block; mso-hide:all; background-color: #19cca3; color: #FFFFFF; border:1px solid #19cca3; border-radius: 6px; line-height: 220%; width: 200px; font-family: Helvetica, sans-serif; font-size:18px; font-weight:600; text-align: center; text-decoration: none; -webkit-text-size-adjust:none;  " target="_blank">Join team</a>
              </a>
            </div>
        </td>
      </tr>
    </table><br />
    If you prefer not to use "${invitation.toEmail}" as your Calendso email or already have a Calendso account, please request another invitation to that email.
    </td>
    </tr>
    </table>
    </center>
    </td>
    </tr>
  </table>
`;

// just strip all HTML and convert <br /> to \n
const text = (evt: any) => html(evt).replace('<br />', "\n").replace(/<[^>]+>/g, '');