(updated)notes.ts

import * as functions from "firebase-functions";
import * as admin from "firebase-admin";
import { INote, IUser, NoteModel } from "firebasenoteapptypes";
import { AlgoliaSearch } from "../algolia";

const index = new AlgoliaSearch("Notes");

export const NoteCreated = functions.firestore
  .document("Notes/{NoteId}")
  .onCreate(async (snapshot, context) => {
    const note = snapshot.data() as INote;

    await index.store(new NoteModel(note));

    const userRef = admin
      .firestore()
      .collection("Users")
      .doc(note.Author);

    return admin
      .firestore()
      .runTransaction(t =>
        t.get(userRef).then(doc => {
          const user = doc.data() as IUser;
          return t.set(
            userRef,
            {
              NumNotes: user.NumNotes + 1
            },
            { merge: true }
          );
        })
      )
      .catch(e => console.log("TRANSACTION ERROR: ", e));
  });

function diffTags(params: { before?: string[]; after?: string[] }) {
  if (params.before && params.after) {
    if (params.before.length !== params.after.length) {
      return true;
    }

    let isDifferent = false;

    const a = params.after.sort();
    const b = params.before.sort();

    for (let i = 0; i < a.length; i++) {
      if (a[i] !== b[i]) {
        isDifferent = true;
        break;
      }
    }

    return isDifferent;
  } else {
    return true;
  }
}

export const NoteUpdated = functions.firestore
  .document("Notes/{NoteId}")
  .onUpdate(async (change, context) => {
    const before = change.before.data() as INote;
    const after = change.after.data() as INote;

    if (
      before.Title !== after.Title ||
      before.Note !== after.Note ||
      diffTags({ before: before.Tags, after: after.Tags })
    ) {
      await index.store(new NoteModel(after));
    }

    return Promise.resolve(null);
  });

export const NoteDeleted = functions.firestore
  .document("Notes/{NoteId}")
  .onDelete(async (snapshot, context) => {
    const note = snapshot.data() as INote;

    await index.delete(context.params.NoteId);

    const userRef = admin.firestore().doc(`Users/${note.Author}`);

    return admin
      .firestore()
      .runTransaction(t =>
        t.get(userRef).then(doc => {
          const user = doc.data() as IUser;
          return t.update(userRef, {
            NumNotes: user.NumNotes - 1
          });
        })
      )
      .catch(e => console.log("TRANSACTION ERROR: ", e));
  });