/**
 * Copyright (c) 2026 Niolla
 * All rights reserved.
 *
 * This source code is proprietary and confidential.
 * Unauthorized copying, modification, distribution, or use
 * of this file, via any medium, is strictly prohibited.
 */

// app/utils/mailer.util.js



const nodemailer = require("nodemailer");
const fs = require("fs");
const path = require("path");
const mailConfig = require("../config/mail.config");

const transporter = nodemailer.createTransport({
  host: mailConfig.host,
  port: mailConfig.port,
  secure: mailConfig.secure,
  auth: mailConfig.auth,
});

if (process.env.NODE_ENV !== "test" && process.env.ENABLE_MAIL === "true") {
  transporter.verify((err) => {
    if (err) console.error("Mail server connection failed", { message: err.message });
    else console.log("Mail server ready");
  });
}

// Utility to load template and replace placeholders
const loadTemplate = (templateName, variables = {}) => {
  if (!/^[a-zA-Z0-9_-]+$/.test(templateName)) throw new Error("Invalid email template");
  const templatePath = path.join(__dirname, "../templates/emails", `${templateName}.html`);
  let template = fs.readFileSync(templatePath, "utf-8");

  Object.keys(variables).forEach((key) => {
    const regex = new RegExp(`{{${key}}}`, "g");
    const escaped = String(variables[key] ?? "").replace(/[&<>"']/g, (char) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;" })[char]);
    template = template.replace(regex, escaped);
  });

  return template;
};

const send = async ({ to, subject, templateName, templateVars = {}, text }) => {
  if (process.env.ENABLE_MAIL !== "true") {
    throw new Error("Email functionality is not enabled");
  }
  const html = templateName ? loadTemplate(templateName, templateVars) : undefined;

  const mailOptions = {
    from: mailConfig.from,
    to,
    subject,
    text,
    html,
  };

  try {
    const info = await transporter.sendMail(mailOptions);
    console.log("Email sent:", info.messageId);
    return info;
  } catch (err) {
    console.error("Error sending email:", err);
    throw err;
  }
};

const sendMail = async (options) => {
  const today = new Date();

  // Full formatted date: "January 1, 2026"
  const formattedDate = today.toLocaleDateString("en-US", {
    year: "numeric",
    month: "long",
    day: "numeric",
  });

  // Only year: "2026"
  const currentYear = today.getFullYear();

  const templateVars = {
    ...options.templateVars, // keep existing vars
    currentDate: formattedDate,
    currentYear: currentYear,
  };

  return send({ ...options, templateVars });
};


module.exports = { sendMail, loadTemplate };