import formData from "npm:form-data@4.0.0";

import MailgunClient from "npm:mailgun.js@9.1.0";

interface Mailgun {

  api_key: string;

}

export async function main(

  mailgunConfig: Mailgun,

  domain: string,

  from: string,

  to: string[],

  subject: string,

  templateName: string,

  replyTo?: string,

  substitutions: Record<string, string>,

) {

  const mailgun = new MailgunClient(formData);

  const mg = mailgun.client({ username: "api", key: mailgunConfig.api_key });

  try {

    const result = await mg.messages.create(domain, {

      from,

      to,

      subject,

      template: templateName,

      "h:X-Mailgun-Variables": JSON.stringify(substitutions),

      ...(replyTo && { "h:Reply-To": replyTo }),

    });

    return result;

  } catch (error) {

    console.error(error);

    throw error;

  }

}