import { apolloClient } from "@/vue-apollo";
import { provideApolloClient, useQuery } from "@vue/apollo-composable";
import { WEB_PUSH } from "../graphql/config";
import { IConfig } from "../types/config.model";

function urlBase64ToUint8Array(base64String: string): Uint8Array {
  const padding = "=".repeat((4 - (base64String.length % 4)) % 4);
  const base64 = (base64String + padding).replace(/-/g, "+").replace(/_/g, "/");

  const rawData = window.atob(base64);
  const outputArray = new Uint8Array(rawData.length);

  for (let i = 0; i < rawData.length; ++i) {
    outputArray[i] = rawData.charCodeAt(i);
  }
  return outputArray;
}

export async function subscribeUserToPush(): Promise<PushSubscription | null> {
  const { onResult } = provideApolloClient(apolloClient)(() =>
    useQuery<{ config: IConfig }>(WEB_PUSH)
  );

  return new Promise((resolve, reject) => {
    onResult(async ({ data }) => {
      if (data?.config?.webPush?.enabled && data?.config?.webPush?.publicKey) {
        const subscribeOptions = {
          userVisibleOnly: true,
          applicationServerKey: urlBase64ToUint8Array(
            data?.config?.webPush?.publicKey
          ),
        };
        const registration = await navigator.serviceWorker.ready;
        try {
          const pushSubscription =
            await registration.pushManager.subscribe(subscribeOptions);
          console.debug("Received PushSubscription: ", pushSubscription);
          resolve(pushSubscription);
        } catch (e) {
          console.error("Error while subscribing to push notifications", e);
        }
      }
      reject(null);
    });
  });
}

export async function unsubscribeUserToPush(): Promise<string | undefined> {
  console.debug("performing unsubscribeUserToPush");
  const registration = await navigator.serviceWorker.ready;
  console.debug("found registration", registration);
  const subscription = await registration.pushManager?.getSubscription();
  console.debug("found subscription", subscription);
  if (subscription && (await subscription?.unsubscribe()) === true) {
    console.debug("done unsubscription");
    return subscription?.endpoint;
  }
  console.debug("went wrong");
  return undefined;
}