/**
 * Service d'envoi d'emails via SMTP avec nodemailer
 */

import nodemailer from 'nodemailer';
import type { Transporter } from 'nodemailer';

interface EmailParams {
  to: string;
  subject: string;
  html: string;
  attachments?: Array<{
    filename: string;
    content: string;
    contentType: string;
  }>;
}

interface SMTPConfig {
  host: string;
  port: number;
  secure: 'none' | 'tls' | 'ssl';
  user: string;
  password: string;
  fromEmail: string;
  fromName: string;
}

/**
 * Crée un transporteur nodemailer à partir de la configuration SMTP
 */
function createTransporter(config: SMTPConfig): Transporter {
  const secure = config.secure === 'ssl'; // true pour SSL (port 465), false pour TLS/STARTTLS
  
  return nodemailer.createTransport({
    host: config.host,
    port: config.port,
    secure: secure,
    auth: {
      user: config.user,
      pass: config.password,
    },
    // Options supplémentaires pour améliorer la compatibilité
    tls: {
      // Ne pas échouer sur les certificats invalides (à utiliser avec précaution en production)
      rejectUnauthorized: false,
    },
  });
}

/**
 * Envoie un email via SMTP
 */
export async function sendViaSMTP(params: EmailParams, config: SMTPConfig): Promise<boolean> {
  try {
    const transporter = createTransporter(config);

    // Préparer les pièces jointes
    console.log(`[SMTP] Nombre de pièces jointes reçues: ${params.attachments?.length || 0}`);
    if (params.attachments) {
      params.attachments.forEach((att, idx) => {
        console.log(`[SMTP] Attachment ${idx + 1}: ${att.filename}, contentType: ${att.contentType}, size: ${att.content.length} chars`);
      });
    }
    
    const attachments = params.attachments?.map(att => ({
      filename: att.filename,
      content: att.content,
      encoding: 'base64' as const,
      contentType: att.contentType,
    }));
    
    console.log(`[SMTP] Nombre de pièces jointes préparées pour nodemailer: ${attachments?.length || 0}`);

    // Envoyer l'email
    const mailOptions = {
      from: `${config.fromName} <${config.fromEmail}>`,
      to: params.to,
      subject: params.subject,
      html: params.html,
      attachments: attachments,
    };
    
    console.log(`[SMTP] Envoi de l'email avec ${mailOptions.attachments?.length || 0} pièce(s) jointe(s)`);
    const info = await transporter.sendMail(mailOptions);

    console.log('[Email] Email envoyé via SMTP:', info.messageId);
    return true;
  } catch (error) {
    console.error('[Email] Erreur lors de l\'envoi via SMTP:', error);
    return false;
  }
}

/**
 * Teste la connexion SMTP
 */
export async function testSMTPConnection(config: SMTPConfig): Promise<{ success: boolean; message: string }> {
  try {
    const transporter = createTransporter(config);
    
    // Vérifier la connexion
    await transporter.verify();
    
    return {
      success: true,
      message: 'Connexion SMTP réussie',
    };
  } catch (error) {
    console.error('[Email] Erreur de connexion SMTP:', error);
    return {
      success: false,
      message: error instanceof Error ? error.message : 'Erreur de connexion SMTP',
    };
  }
}