import * as nodemailer from 'nodemailer';

export namespace MailService {
    const transporter = nodemailer.createTransport({
        host: process.env.EMAIL_HOST,
        pool: true,
        port: 465,
        secure: true,
        auth: {
            user: process.env.EMAIL_USERNAME,
            pass: process.env.EMAIL_PASSWORD
        },
        tls: {rejectUnauthorized: false}
    });

    export interface MailAttachment {
        filename: string;
        content: string | Buffer;
        contentType?: string;
    }

    export interface SendMailOptions {
        html?: string;
        attachments?: MailAttachment[];
    }

    // Builds a fresh options object per call rather than mutating a shared
    // module-level one - the transporter is pooled, so overlapping sendMail
    // calls (e.g. two guests redeeming at once) previously risked one
    // call's recipient/subject/body being overwritten by another's before
    // transporter.sendMail() read it.
    export const sendMail = async (recipientAddress: string, subject: string, body: string, options?: SendMailOptions) => {
        await transporter.sendMail({
            from: 'noreply@nachklang.art',
            to: recipientAddress,
            subject: subject,
            text: body,
            html: options?.html,
            attachments: options?.attachments
        });
    };
}