import { NextRequest, NextResponse } from "next/server";
import { getUsers } from "@/lib/users";

/**
 * app/api/webhooks/mail/route.ts
 * 
 * Webhook endpoint for incoming mail notifications (e.g. from Rspamd or Mailcow).
 * Sends notifications to Telegram based on the recipient email.
 */

export async function POST(req: NextRequest) {
  try {
    const data = await req.json();
    
    // Extract basic info from the incoming payload
    const aliciMail = (data.to || data.rcpt || "").toLowerCase().trim();
    const sender = data.from || "Bilinmiyor";
    const subject = data.subject || "(Konu Yok)";
    
    console.log(`[Mail Webhook] Yeni mail geldi: ${sender} -> ${aliciMail}`);

    // 1. Find which USER_X owns this mail address via JSON mapping
    // Format: MAIL_USER_MAPPINGS='{"email1@domain.com":"USER_0", "email2@domain.com":"USER_1"}'
    const mappingsRaw = process.env.MAIL_USER_MAPPINGS || "{}";
    let ownerUserKey: string | undefined = undefined;
    
    try {
      const mappings = JSON.parse(mappingsRaw);
      ownerUserKey = mappings[aliciMail];
    } catch (e) {
      console.error("[Mail Webhook] MAIL_USER_MAPPINGS JSON ayrıştırma hatası:", e);
    }

    if (ownerUserKey) {
      // 2. Get that USER's Telegram ID (e.g., USER_0_TELEGRAM_ID)
      const tgIdKey = `${ownerUserKey}_TELEGRAM_ID`;
      const targetChatId = process.env[tgIdKey];

      if (targetChatId && process.env.TELEGRAM_BOT_TOKEN) {
        const message = `🔔 *Yeni Mail Geldi!*\n\n📧 *Alıcı:* ${aliciMail}\n👤 *Gönderen:* ${sender}\n📝 *Konu:* ${subject}`;
        
        const telegramUrl = `https://api.telegram.org/bot${process.env.TELEGRAM_BOT_TOKEN}/sendMessage`;
        
        const res = await fetch(telegramUrl, {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({
            chat_id: targetChatId,
            text: message,
            parse_mode: "Markdown",
          }),
        });

        if (!res.ok) {
          const errorText = await res.text();
          console.error(`[Mail Webhook] Telegram API hatası: ${res.status} ${errorText}`);
        } else {
          console.log(`[Webhook] Bildirim ${ownerUserKey} kullanıcısına (ID: ${targetChatId}) gönderildi.`);
        }
      }
    } else {
      console.log(`[Webhook] Sahibi bilinmeyen veya eşleşmeyen mail: ${aliciMail}`);
    }

    return NextResponse.json({ status: "ok" });
  } catch (error: any) {
    console.error(`[Mail Webhook] Hata: ${error.message}`);
    return NextResponse.json({ error: "İşlem başarısız" }, { status: 500 });
  }
}