import os from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { promisify } from "node:util";
import type { Transporter } from "nodemailer";
import nodemailer from "nodemailer";
import type Mail from "nodemailer/lib/mailer/index.js";
import type { Address } from "nodemailer/lib/mailer/index.js";
import type SMTPTransport from "nodemailer/lib/smtp-transport/index.js";
import hbs from "nodemailer-express-handlebars";
import { returnFunc } from "./returnHelper.utils.js";
import { tryCatch } from "./trycatch.utils.js";

interface HandlebarsMailOptions extends Mail.Options {
	template: string;
	context: Record<string, unknown>;
}

interface EmailData {
	email: string;
	subject: string;
	template: string;
	context: Record<string, unknown>;
}

export const sendEmail = async (data: EmailData) => {
	let transporter: Transporter;
	let fromEmail: string | Address;

	if (os.hostname().includes("OLP")) {
		transporter = nodemailer.createTransport({
			service: "gmail",
			auth: {
				user: process.env.EMAIL_USER,
				pass: process.env.EMAIL_PASSWORD, // The 16-character App Password
			},
			//debug: true,
		});

		// update the from email
		fromEmail = process.env.EMAIL_USER as string;

		// update the from email
		fromEmail = `donotreply@alpla.com`;
	} else {
		//create the servers smtp config
		let host = `${os.hostname().replace("VMS006", "")}-smtp.alpla.net`;

		if (os.hostname().includes("VMS036")) {
			host = "USMCD1-smtp.alpla.net";
		}

		transporter = nodemailer.createTransport({
			host: host,
			port: 25,
			rejectUnauthorized: false,
			//secure: false,
			// auth: {
			//   user: "alplaprod",
			//   pass: "obelix",
			// },
			debug: true,
		} as SMTPTransport.Options);

		// update the from email
		fromEmail = `donotreply@alpla.com`;
	}

	// create the handlebars view
	const viewPath = path.resolve(
		path.dirname(fileURLToPath(import.meta.url)),
		"./mailViews",
	);

	const handlebarOptions = {
		viewEngine: {
			extname: ".hbs",
			defaultLayout: "",
			partialsDir: viewPath,
		},
		viewPath: viewPath,
		extName: ".hbs",
	};

	transporter.use("compile", hbs(handlebarOptions));

	const mailOptions: HandlebarsMailOptions = {
		from: fromEmail,
		to: data.email,
		subject: data.subject,
		//text: "You will have a reset token here and only have 30min to click the link before it expires.",
		//html: emailTemplate("Blake's Test", "This is an example with css"),
		template: data.template, // Name of the Handlebars template (e.g., 'welcome.hbs')
		context: data.context,
	};

	// now verify and send the email
	const sendMailPromise = promisify(transporter.sendMail).bind(transporter);

	const { data: mail, error } = await tryCatch(sendMailPromise(mailOptions));

	if (mail) {
		return returnFunc({
			success: true,
			level: "info",
			module: "utils",
			subModule: "sendmail",
			message: `Email was sent to: ${data.email}`,
			data: [],
			notify: false,
		});
	}

	if (error) {
		return returnFunc({
			success: false,
			level: "error",
			module: "utils",
			subModule: "sendmail",
			message: `Error sending Email to : ${data.email}`,
			data: [{ error: error }],
			notify: false,
		});
	}
};