import { NextRequest, NextResponse } from "next/server";
import { createServiceClient } from "@/lib/supabase";
import { sendeRegistrierungsBestaetigung } from "@/lib/mailer";

export async function POST(req: NextRequest) {
  let body: { email?: string; password?: string; firma?: string };
  try {
    body = await req.json();
  } catch {
    return NextResponse.json({ error: "Ungültige Eingabe" }, { status: 422 });
  }

  const { email, password, firma } = body;
  if (!email || !password || password.length < 8) {
    return NextResponse.json({ error: "Ungültige Eingabe" }, { status: 422 });
  }

  const appUrl = process.env.APP_URL ?? "https://mbo-tech-it.de";
  const db = createServiceClient();

  const { data: linkData, error } = await db.auth.admin.generateLink({
    type: "signup",
    email,
    password,
    options: {
      data: { firma: firma ?? "" },
      redirectTo: `${appUrl}/auth/callback`,
    },
  });

  if (error) {
    if (
      error.message.includes("already registered") ||
      error.message.includes("already been registered")
    ) {
      return NextResponse.json({ error: "already_registered" }, { status: 409 });
    }
    console.error("[Registrierung] Fehler:", error.message);
    return NextResponse.json({ error: error.message }, { status: 500 });
  }

  const bestaetigungsLink = linkData.properties?.action_link;
  if (!bestaetigungsLink) {
    return NextResponse.json({ error: "Kein Bestätigungslink erhalten" }, { status: 500 });
  }

  await sendeRegistrierungsBestaetigung({ email, firma, bestaetigungsLink });

  return NextResponse.json({ success: true });
}