#74 refactored createAllSpeakers() to delete/create speakers only when needed

Author: fcamblor

cloud/functions/src/functions/firestore/services/event-utils.ts

@@ -6,10 +6,10 @@ import DocumentSnapshot = firestore.DocumentSnapshot;
 import {getAllSpaceIds} from "./space-utils";
 import {resolvedEventFirestorePath, resolvedEventsFirestorePath} from "../../../../../../shared/utilities/event-utils";
 import {AllInOneTalkStats} from "../../../../../../shared/event-stats";
-import {getEventTalks} from "./talk-utils";
 import {detailedTalksToSpeakersLineup} from "../../../models/Event";
 import {DetailedTalk} from "../../../../../../shared/daily-schedule.firestore";
 import {toValidFirebaseKey} from "../../../../../../shared/utilities/firebase.utils";
+import {arrayDiff} from "../../../../../../shared/utilities/arrays.utils";
 
 
 export async function getAllEventsDocs(opts: { includePrivateSpaces: boolean } = { includePrivateSpaces: false }) {
@@ -57,9 +57,12 @@ export async function createAllSpeakers(eventTalks: DetailedTalk[], maybeSpaceTo
   const eventSpeakersColl = db.collection(`${eventRootPath}/speakers`)
   const existingSpeakerDocs = await eventSpeakersColl.listDocuments()
 
-  // delete all then re-create all
-  await Promise.all(existingSpeakerDocs.map(speakerDoc => speakerDoc.delete()))
-  await Promise.all(lineupSpeakers.map(lineupSpeaker => db.doc(`${eventRootPath}/speakers/${toValidFirebaseKey(lineupSpeaker.id)}`).set(lineupSpeaker)))
+  const speakersDiff = arrayDiff(existingSpeakerDocs, lineupSpeakers, doc => doc.id, sp => sp.id);
+  await Promise.all([
+    ...speakersDiff.elementsToRemove.map(docToRemove => docToRemove.delete()),
+    ...speakersDiff.elementsToAdd.map(lineupSpeakerToAdd => db.doc(`${eventRootPath}/speakers/${toValidFirebaseKey(lineupSpeakerToAdd.id)}`).set(lineupSpeakerToAdd)),
+    ...speakersDiff.elementsAlreadyPresent.map(async ({ origin: speakerDoc, target: lineupSpeaker }) => speakerDoc.update(lineupSpeaker)),
+  ])
 
   return { createdSpeakers: lineupSpeakers }
 }