/**
 * lib/smtp.ts
 * SMTP mail sending via nodemailer + IMAP Sent folder append.
 * Uses user's mailbox credentials for authenticated SMTP.
 */

import nodemailer from "nodemailer";
import { ImapFlow } from "imapflow";
import type { MailCredentials } from "./imap";

const SMTP_HOST = process.env.MAILCOW_API_URL
  ? new URL(process.env.MAILCOW_API_URL).hostname
  : "localhost";
const SMTP_PORT = parseInt(process.env.SMTP_PORT ?? "587");
const IMAP_HOST = SMTP_HOST;
const IMAP_PORT = parseInt(process.env.IMAP_PORT ?? "993");

export interface SendMailOptions {
  to: string;
  cc?: string;
  subject: string;
  html: string;
  text?: string;
  inReplyTo?: string;
  references?: string;
  attachments?: {
    filename: string;
    content: Buffer | string;
    contentType?: string;
  }[];
}

export async function sendMail(
  creds: MailCredentials,
  options: SendMailOptions
): Promise<{ success: boolean; messageId?: string; error?: string }> {
  try {
    const transporter = nodemailer.createTransport({
      host: SMTP_HOST,
      port: SMTP_PORT,
      secure: SMTP_PORT === 465,
      auth: {
        user: creds.email,
        pass: creds.password,
      },
      tls: {
        // Mailcow self-signed cert'e izin ver
        rejectUnauthorized: false,
      },
    });

    const mailOptions = {
      from: creds.email,
      to: options.to,
      cc: options.cc || undefined,
      subject: options.subject,
      html: options.html,
      text: options.text || undefined,
      inReplyTo: options.inReplyTo || undefined,
      references: options.references || undefined,
      attachments: options.attachments?.map((a) => ({
        filename: a.filename,
        content: a.content,
        contentType: a.contentType,
      })),
    };

    const result = await transporter.sendMail(mailOptions);

    // Gönderilen maili Sent klasörüne kaydet (IMAP APPEND)
    try {
      await appendToSent(creds, mailOptions);
    } catch (e) {
      // Sent'e kaydetme başarısız olursa mail yine de gitmiş olur
      console.error("Sent klasörüne kaydetme hatası:", e);
    }

    return { success: true, messageId: result.messageId };
  } catch (err: any) {
    return { success: false, error: err?.message ?? "SMTP hatası" };
  }
}

/**
 * Gönderilen maili IMAP Sent klasörüne kaydet.
 * Mailcow'da Sent klasörü "Sent" olarak adlandırılır.
 */
async function appendToSent(
  creds: MailCredentials,
  mailOptions: Record<string, any>
): Promise<void> {
  // nodemailer ile raw mesaj oluştur
  const transporter = nodemailer.createTransport({ jsonTransport: true });
  const compiled = await transporter.sendMail(mailOptions);
  const rawMessage = JSON.parse(compiled.message);

  // Gerçek raw RFC822 mesajı oluştur
  const buildTransporter = nodemailer.createTransport({ streamTransport: true });
  const built = await buildTransporter.sendMail(mailOptions);
  const chunks: Buffer[] = [];
  for await (const chunk of built.message as any) {
    chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
  }
  const rawBuffer = Buffer.concat(chunks);

  const client = new ImapFlow({
    host: IMAP_HOST,
    port: IMAP_PORT,
    secure: true,
    auth: { user: creds.email, pass: creds.password },
    logger: false,
  });

  await client.connect();
  try {
    // Sent klasörünü bul
    const mailboxes = await client.list();
    let sentPath = "Sent";
    for (const mb of mailboxes) {
      if (mb.specialUse === "\\Sent") {
        sentPath = mb.path;
        break;
      }
    }

    // Mesajı Sent klasörüne ekle (Seen flag ile)
    await client.append(sentPath, rawBuffer, ["\\Seen"]);
  } finally {
    await client.logout();
  }
}