import nodemailer from 'nodemailer';
import dotenv from 'dotenv';
import {Router} from 'express';

/** @typedef Email
 * @property {string} name - name of sender.
 * @property {string} email - email addr of sender.
 * @property {string} subject - subject of email.
 * @property {string} message - message body of email.
 */

/** @typedef {import("@types/express").Request} Request */
/** @typedef {import("@types/express").Response} Response */
/** @typedef {import("@types/express").NextFunction} NextFunction */
/** @typedef {import("@types/nodemailer").TransportOptions} TransportOptions */

dotenv.config();

const transporter = nodemailer.createTransport(
    /** @type {TransportOptions}*/
    {
        service: 'gmail', // Use Gmail as the email service
        target: process.env.EMAIL_TARGET, // The email address to send the email to
        auth: {
            user: process.env.MAILER_EMAIL_ADDR, // Your Gmail address
            pass: process.env.MAILER_EMAIL_PASS, // Your Gmail password or App Password
        },
    });

await withTimeout(transporter.verify(), 15000)
    .then(() => {
        console.log("Transporter is ready to send emails");
    })
    .catch((error) => console.error("Error verifying transporter:", error));

const router = Router()


router.post('/',
    /**
     * Sends an email using the configured transporter.
     * @param {Request} req
     * @param {Response} res
     * @param {NextFunction} next
     * @return {Promise<e.Response<any, Record<string, any>> | void>}
     */
    async (req, res, next) => {
        try {
            console.debug("made it to sendEmail function");
            let exitonError = false;

            await withTimeout(transporter.verify(), 15000)
                .then(() => {
                    console.debug("Transporter is ready to send emails");
                })
                .catch((error) => {
                    console.error("Error verifying transporter:", error);
                    res.status(500).json({message: 'Failed to verify email transporter'});
                    exitonError = true;
                });
            if (exitonError) return;
            const emailWithZeroWidthSpace = req.body.email.replace(/@/g, '@\u200B').replace(/\./g, ".\u200B"); // Add zero-width space to prevent email scraping
            /** @type {Email} */
            const contact = {
                name: req.body.name,
                email: emailWithZeroWidthSpace, // Add zero-width space to prevent email scraping
                subject: req.body.subject,
                message: req.body.message,
            };

            if (!contact.name || !contact.email || !contact.subject || !contact.message) {
                return res.status(400).json({message: 'To, subject, and text are required'});
            }

            const emailText = `
This email was sent from Li0nhunter's Bot.
Name: ${contact.name}
Email: ${contact.email}
Subject: ${contact.subject}
Message: ${contact.message}

Respond now: mailto:${contact.email}
`

            const emailHtml = `
<div style="max-width:80%;margin:40px auto;background:var(--color-background);border-radius:8px;box-shadow:0 2px 8px rgba(0,0,0,0.14);padding:32px 24px;font-family:Arial,sans-serif;">
  <h1 style="margin-bottom:24px;text-align:center;color:var(--color-text);">You got a message from your website's contact page!</h1>
  <div style="margin-bottom:16px;">
    <label style="display:block;font-size:1rem;font-weight:500;margin-bottom:4px;color:var(--color-text);"><b>Name:</b></label>
    <div style="font-size:1rem;font-weight:500;padding:10px 12px;border:1px solid #333333;border-radius:4px;background:var(--color-form-background);color:var(--color-text);"><b>${contact.name}</b></div>
  </div>
  <div style="margin-bottom:16px;">
    <label style="display:block;font-size:1rem;font-weight:500;margin-bottom:4px;color:var(--color-text);"><b>Email:</b></label>
    <div style="font-size:1rem;font-weight:500;padding:10px 12px;border:1px solid #333333;border-radius:4px;background:var(--color-form-background);color:var(--color-text);"><b>${contact.email}</b></div>
  </div>
  <div style="margin-bottom:16px;">
    <label style="display:block;font-size:1rem;font-weight:500;margin-bottom:4px;color:var(--color-text);"><b>Subject:</b></label>
    <div style="font-size:1rem;font-weight:500;padding:10px 12px;border:1px solid #333333;border-radius:4px;background:var(--color-form-background);color:var(--color-text);"><b>${contact.subject}</b></div>
  </div>
  <div style="margin-bottom:24px;">
    <label style="display:block;font-size:1rem;font-weight:500;margin-bottom:4px;color:var(--color-text);"><b>Message:</b></label>
    <div style="font-size:1rem;font-weight:500;padding:10px 12px;border:1px solid #333333;border-radius:4px;background:var(--color-form-background);color:var(--color-text);white-space:pre-line;"><b>${contact.message}</b></div>
  </div>
  <div style="text-align:center;">
    <a href="mailto:${contact.email}" style="display:inline-block;font-weight:500;color:var(--color-text);background-color:var(--color-form-background);border:1px solid #333333;padding:10px 32px;text-align:center;border-radius:4px;text-decoration:none;font-size:1.1rem;transition:background 0.2s;"><b>Respond now</b></a>
  </div>
  <p style="text-align:center;color:var(--color-text);">This email was sent from Li0nhunter's Bot.</p>
</div>
`;

            const mailOptions = {
                from: `"Li0nhunter's Web Bot" <${process.env.EMAIL_ADDR}>`, // sender address
                to: process.env.EMAIL_TARGET,
                replyTo: contact.email,
                subject: contact.subject, // Subject line
                text: emailText, // plain text body
                html: emailHtml, // html body
            };
            // Set a timeout of 15 seconds (15,000 ms) for sending the email
            await withTimeout(transporter.sendMail(mailOptions), 15000)
                .then((result) => res.status(200).json({data: result, message: 'Email sent successfully'}))
                .catch((error) => {
                    console.error(error);
                    res.status(500).json({message: error.message || 'Failed to send email'});
                });
        } catch (error) {
            next(error);
        }

    });

/**
 * Executes a promise with a timeout.
 * @param {Promise<any>} promise The promise to execute.
 * @param {number} ms The timeout in milliseconds.
 * @throws {Error} If the promise does not resolve within the specified time.
 * @return {Promise<any>}
 */
async function withTimeout(promise, ms) {
    const timeout = new Promise((_, reject) =>
        setTimeout(() => reject(new Error('Operation timed out')), ms)
    );
    return Promise.race([promise, timeout])
}


export default router;