import { createTransport, type Transporter } from 'nodemailer';
import { env } from '../../config/env.js';

let transporter: Transporter | null = null;

function getTransporter(): Transporter {
  if (!transporter) {
    if (!env.SMTP_USER || !env.SMTP_PASS) {
      console.warn('[EMAIL] SMTP not configured. Emails will be logged to console.');
      return {
        sendMail: async (opts: any) => {
          console.log('[EMAIL] Would send:', { to: opts.to, subject: opts.subject });
          return { messageId: 'mock' };
        },
      } as any;
    }

    transporter = createTransport({
      host: env.SMTP_HOST,
      port: parseInt(env.SMTP_PORT),
      secure: false, // Upgrade to TLS via STARTTLS
      requireTLS: true, // Reject if STARTTLS is not available
      auth: {
        user: env.SMTP_USER,
        pass: env.SMTP_PASS,
      },
    });
  }
  return transporter;
}

async function sendEmail(to: string, subject: string, html: string) {
  const transport = getTransporter();
  try {
    await transport.sendMail({
      from: env.SMTP_FROM,
      to,
      subject,
      html,
      text: html.replace(/<[^>]*>/g, ''),
    });
  } catch (error) {
    console.error('[EMAIL] Error sending email:', error);
    // Don't throw — email failure shouldn't break the main flow
  }
}

export const emailService = {
  sendWelcome: async (to: string, data: { nombre: string; email: string; tempPassword: string }) => {
    const { welcomeEmail } = await import('./templates/welcome.js');
    await sendEmail(to, 'Bienvenido a Horux360', welcomeEmail(data));
  },

  sendFielNotification: async (data: { clienteNombre: string; clienteRfc: string }) => {
    const { fielNotificationEmail } = await import('./templates/fiel-notification.js');
    await sendEmail(env.ADMIN_EMAIL, `[${data.clienteNombre}] subió su FIEL`, fielNotificationEmail(data));
  },

  sendPaymentConfirmed: async (to: string, data: { nombre: string; amount: number; plan: string; date: string }) => {
    const { paymentConfirmedEmail } = await import('./templates/payment-confirmed.js');
    await sendEmail(to, 'Confirmación de pago - Horux360', paymentConfirmedEmail(data));
  },

  sendPaymentFailed: async (to: string, data: { nombre: string; amount: number; plan: string }) => {
    const { paymentFailedEmail } = await import('./templates/payment-failed.js');
    await sendEmail(to, 'Problema con tu pago - Horux360', paymentFailedEmail(data));
    await sendEmail(env.ADMIN_EMAIL, `Pago fallido: ${data.nombre}`, paymentFailedEmail(data));
  },

  sendSubscriptionExpiring: async (to: string, data: { nombre: string; plan: string; expiresAt: string }) => {
    const { subscriptionExpiringEmail } = await import('./templates/subscription-expiring.js');
    await sendEmail(to, 'Tu suscripción vence en 5 días', subscriptionExpiringEmail(data));
  },

  sendSubscriptionCancelled: async (to: string, data: { nombre: string; plan: string }) => {
    const { subscriptionCancelledEmail } = await import('./templates/subscription-cancelled.js');
    await sendEmail(to, 'Suscripción cancelada - Horux360', subscriptionCancelledEmail(data));
    await sendEmail(env.ADMIN_EMAIL, `Suscripción cancelada: ${data.nombre}`, subscriptionCancelledEmail(data));
  },

  sendNewClientAdmin: async (data: {
    clienteNombre: string;
    clienteRfc: string;
    adminEmail: string;
    adminNombre: string;
    tempPassword: string;
    databaseName: string;
    plan: string;
  }) => {
    const { newClientAdminEmail } = await import('./templates/new-client-admin.js');
    await sendEmail(env.ADMIN_EMAIL, `Nuevo cliente: ${data.clienteNombre} (${data.clienteRfc})`, newClientAdminEmail(data));
  },
};