backend\index.js

let webpush = require("web-push");


const publicKey =
  "Your-public-key";
const privateKey = "Your-private-key";

/*
  config - webpush
*/

webpush.setVapidDetails(
  "mailto:youremail@gmail.com",
  publicKey,
  privateKey
);

/*
endpoint- create post
*/
app.post("/blog", (request, response) => {
  response.set("Access-Control-Allow-Origin", "*");

  let uuid = UUID();
  let fields = {};
  let fileData = {};

  const bb = busboy({ headers: request.headers });
  bb.on("file", (name, file, info) => {
    const { filename, encoding, mimeType } = info;

    let filepath = path.join(os.tmpdir(), filename);
    file.pipe(fs.createWriteStream(filepath));
    fileData = { filepath, mimeType };
  });
  bb.on("field", (name, val, info) => {
    console.log(`Field [${name}]: value: %j`, val);
    fields[name] = val;
  });
  bb.on("close", () => {
    db.collection("blogs")
      .doc(fields.id)
      .set({
        id: fields.id,
        title: fields.title,
        content: fields.content,
        created_at: parseInt(fields.created_at),
        updated_at: parseInt(fields.created_at),
        image_url: fields.image_url,
        liked: fields.liked,
        favorite: fields.favorite,
      })
      .then(() => {
        sendPushNotification();
        response.send("blog added: " + fields.id);
      });
    function sendPushNotification() {
      let subscriptions = [];
      db.collection("subscriptions")
        .get()
        .then((snapshot) => {
          snapshot.forEach((doc) => {
            subscriptions.push(doc.data());
          });
          return subscriptions;
        })
        .then((subscriptions) => {
          subscriptions.forEach((subscription) => {
            const pushSubscription = {
              endpoint: subscription.endpoint,
              keys: {
                auth: subscription.keys.auth,
                p256dh: subscription.keys.p256dh,
              },
            };
            let pushContent = {
              title: "New Blog Created!",
              body: "New Blog Added! Check it out!",
              openUrl: "/#/",
            };
            let pushContentStringified = JSON.stringify(pushContent);
            try {
              webpush.sendNotification(
                pushSubscription,
                pushContentStringified
              );
              console.log("Notification Send");
            } catch (error) {
              console.error("Error sending push notification:", error);
            }
          });
        });
    }
  });

  request.pipe(bb);
});

/*
  endpoint - createSubscription
*/
app.post("/createSubscription", (request, response) => {
  response.set("Access-Control-Allow-Origin", "*");
  db.collection("subscriptions")
    .add(request.query)
    .then((docRef) => {
      response.send({
        message: "Subscription added!",
        postData: request.query,
      });
    });
});