/* eslint-disable @typescript-eslint/no-unsafe-assignment */
import type { Transporter } from 'nodemailer';
import { createTransport } from 'nodemailer';
import { ErrorReporterProxy as ErrorReporter, LoggerProxy as Logger } from 'n8n-workflow';
import config from '@/config';
import type { MailData, SendEmailResult } from './Interfaces';
import type SMTPConnection from 'nodemailer/lib/smtp-connection';

export class NodeMailer {
	private transport?: Transporter;

	async init(): Promise<void> {
		const transportConfig: SMTPConnection.Options = {
			host: config.getEnv('userManagement.emails.smtp.host'),
			port: config.getEnv('userManagement.emails.smtp.port'),
			secure: config.getEnv('userManagement.emails.smtp.secure'),
		};

		if (
			config.getEnv('userManagement.emails.smtp.auth.user') &&
			config.getEnv('userManagement.emails.smtp.auth.pass')
		) {
			transportConfig.auth = {
				user: config.getEnv('userManagement.emails.smtp.auth.user'),
				pass: config.getEnv('userManagement.emails.smtp.auth.pass'),
			};
		}

		this.transport = createTransport(transportConfig);
	}

	async verifyConnection(): Promise<void> {
		if (!this.transport) {
			await this.init();
		}
		const host = config.getEnv('userManagement.emails.smtp.host');
		const user = config.getEnv('userManagement.emails.smtp.auth.user');
		const pass = config.getEnv('userManagement.emails.smtp.auth.pass');

		try {
			await this.transport?.verify();
		} catch (error) {
			const message: string[] = [];
			if (!host) message.push('SMTP host not defined (N8N_SMTP_HOST).');
			if (!user) message.push('SMTP user not defined (N8N_SMTP_USER).');
			if (!pass) message.push('SMTP pass not defined (N8N_SMTP_PASS).');
			throw message.length ? new Error(message.join(' '), { cause: error }) : error;
		}
	}

	async sendMail(mailData: MailData): Promise<SendEmailResult> {
		if (!this.transport) {
			await this.init();
		}
		let sender = config.getEnv('userManagement.emails.smtp.sender');
		const user = config.getEnv('userManagement.emails.smtp.auth.user');

		if (!sender && user.includes('@')) {
			sender = user;
		}

		try {
			await this.transport?.sendMail({
				from: sender,
				to: mailData.emailRecipients,
				subject: mailData.subject,
				text: mailData.textOnly,
				html: mailData.body,
			});
			Logger.verbose(
				`Email sent successfully to the following recipients: ${mailData.emailRecipients.toString()}`,
			);
		} catch (error) {
			ErrorReporter.error(error);
			Logger.error('Failed to send email', { recipients: mailData.emailRecipients, error });
			throw error;
		}

		return { emailSent: true };
	}
}