import webpush from "web-push";
import { db, pushSubscriptions, eq } from "@epicure/db";

let vapidInitialized = false;
function ensureVapid() {
  if (vapidInitialized) return;
  const pub = process.env.NEXT_PUBLIC_VAPID_PUBLIC_KEY;
  const priv = process.env.VAPID_PRIVATE_KEY;
  if (!pub || !priv) throw new Error("VAPID keys not configured");
  webpush.setVapidDetails("mailto:contact@epicure.app", pub, priv);
  vapidInitialized = true;
}

export async function sendPushNotification(
  userId: string,
  notification: { title: string; body: string; url?: string }
): Promise<void> {
  ensureVapid();
  const subs = await db
    .select()
    .from(pushSubscriptions)
    .where(eq(pushSubscriptions.userId, userId));

  const payload = JSON.stringify({
    title: notification.title,
    body: notification.body,
    url: notification.url ?? "/",
  });

  await Promise.allSettled(
    subs.map((sub) =>
      webpush.sendNotification(
        { endpoint: sub.endpoint, keys: { p256dh: sub.p256dh, auth: sub.auth } },
        payload
      )
    )
  );
}