import type { SendMailOptions, Transporter } from "nodemailer";
import type { ReactElement } from "react";
import nodemailer from "nodemailer";
import { render } from "react-email";
import { env } from "@reactive-resume/env/server";

type SendEmailOptions = {
	to: string | string[];
	subject: string;
	text?: string;
	html?: string;
	react?: ReactElement;
	from?: string;
};

const isSmtpEnabled = () => {
	return !!env.SMTP_HOST && !!env.SMTP_USER && !!env.SMTP_PASS && !!env.SMTP_FROM;
};

let cachedTransport: Transporter | undefined;

const getTransport = () => {
	if (!isSmtpEnabled()) return;
	if (cachedTransport) return cachedTransport;

	cachedTransport = nodemailer.createTransport({
		host: env.SMTP_HOST,
		port: env.SMTP_PORT,
		secure: env.SMTP_SECURE,
		auth: {
			// biome-ignore lint/style/noNonNullAssertion: guarded by isSmtpEnabled
			user: env.SMTP_USER!,
			// biome-ignore lint/style/noNonNullAssertion: guarded by isSmtpEnabled
			pass: env.SMTP_PASS!,
		},
	});

	return cachedTransport;
};

export const sendEmail = async (options: SendEmailOptions) => {
	const transport = getTransport();
	const from = options.from ?? env.SMTP_FROM ?? "Reactive Resume <noreply@localhost>";
	const payload: SendMailOptions = {
		to: options.to,
		from,
		subject: options.subject,
		text: options.text,
		html: options.html,
	};

	if (options.react) {
		payload.html = await render(options.react);
		payload.text = options.text ?? (await render(options.react, { plainText: true }));
	}

	if (!payload.text && !payload.html) return;

	if (!transport) {
		console.info("SMTP not configured; skipping email send.", {
			to: payload.to,
			subject: payload.subject,
			text: payload.text,
			html: payload.html,
		});
		return;
	}

	try {
		await transport.sendMail(payload);
	} catch (error) {
		console.error("There was an error sending mail.", error);
	}
};