import webPush from "web-push";
import { and, eq, inArray } from "drizzle-orm";
import { db } from "@/lib/db";
import logger from "@/lib/logger";
import { pushSubscriptions } from "./schema";

function ensureVapidConfigured() {
  const subject = process.env["VAPID_SUBJECT"];
  const publicKey = process.env["VAPID_PUBLIC_KEY"];
  const privateKey = process.env["VAPID_PRIVATE_KEY"];
  if (!subject || !publicKey || !privateKey) {
    throw new Error("VAPID_SUBJECT, VAPID_PUBLIC_KEY, and VAPID_PRIVATE_KEY must be set");
  }
  webPush.setVapidDetails(subject, publicKey, privateKey);
}

export async function sendPushToEndpoint(
  endpoint: string,
  payload: { title: string; body: string; url?: string },
) {
  ensureVapidConfigured();
  const [sub] = await db
    .select()
    .from(pushSubscriptions)
    .where(eq(pushSubscriptions.endpoint, endpoint))
    .limit(1);
  if (!sub) return;
  try {
    await webPush.sendNotification(
      { endpoint: sub.endpoint, keys: { p256dh: sub.p256dh, auth: sub.auth } },
      JSON.stringify({ title: payload.title, body: payload.body, url: payload.url ?? "/" }),
    );
  } catch (err) {
    const status = (err as { statusCode?: number }).statusCode;
    if (status === 404 || status === 410) {
      await db.delete(pushSubscriptions).where(eq(pushSubscriptions.endpoint, endpoint));
    } else {
      logger.error({ err }, "push delivery failed");
    }
  }
}

export async function sendPush(
  userId: string,
  payload: { title: string; body: string; url?: string },
) {
  ensureVapidConfigured();

  const subs = await db
    .select()
    .from(pushSubscriptions)
    .where(eq(pushSubscriptions.userId, userId));

  if (subs.length === 0) return;

  const staleIds: string[] = [];

  await Promise.allSettled(
    subs.map(async (sub) => {
      try {
        await webPush.sendNotification(
          { endpoint: sub.endpoint, keys: { p256dh: sub.p256dh, auth: sub.auth } },
          JSON.stringify({ title: payload.title, body: payload.body, url: payload.url ?? "/" }),
        );
      } catch (err) {
        const status = (err as { statusCode?: number }).statusCode;
        if (status === 404 || status === 410) {
          staleIds.push(sub.id);
        } else {
          logger.error({ err }, "push delivery failed");
        }
      }
    }),
  );

  if (staleIds.length > 0) {
    await db
      .delete(pushSubscriptions)
      .where(and(eq(pushSubscriptions.userId, userId), inArray(pushSubscriptions.id, staleIds)));
  }
}