initial version

src/fetchEvents.ts

@@ -0,0 +1,125 @@
+import { Event } from 'nostr-tools';
+import { localStorageGetItem, localStorageSetItem } from './LocalStorage';
+import { publishEventToRelay, requestMyProfileFromRelays } from './RelayManagement';
+
+export const lastFetchDate = ():number | null => {
+  const d = localStorageGetItem('my-profile-last-fetch-date');
+  if (d === null) return null;
+  return Number(d);
+};
+let fetchedthissession: boolean = false;
+export const updateLastFetchDate = ():void => {
+  fetchedthissession = true;
+  localStorageSetItem('my-profile-last-fetch-date', Date.now().toString());
+};
+
+export const lastUpdateDate = ():number | null => {
+  const d = localStorageGetItem('my-profile-last-update-date');
+  if (d === null) return null;
+  return Number(d);
+};
+
+export const updateLastUpdateDate = ():void => {
+  localStorageSetItem('my-profile-last-update-date', Date.now().toString());
+};
+
+export const isUptodate = ():boolean => fetchedthissession;
+// const f = lastFetchDate();
+// // uptodate - fetched within 10 seconds
+// return !(f === null || f < (Date.now() - 10000));
+
+export const hadLatest = ():boolean => {
+  if (!isUptodate()) return false;
+  const f = lastFetchDate();
+  const u = lastUpdateDate();
+  // hadlatest - last update was no more than 10 seconds before fetch complete
+  return !(u === null || f === null || u > (f - 10000));
+};
+
+/**
+ * storeMyProfileEvent
+ * @returns true if stored and false duplicate, wrong kind or wrong pubkey
+ */
+export const storeMyProfileEvent = (event:Event): boolean => {
+  // thrown on no pubkey in localStorage
+  if (localStorageGetItem('pubkey') === null) {
+    throw new Error('storeMyProfileEvent no pubkey in localStorage');
+  }
+  // return false if...
+  if (
+    // event is of an unsupported kind
+    !(event.kind === 0 || event.kind === 2 || event.kind === 10002 || event.kind === 3)
+    // or fron a different pubkey
+    || event.pubkey !== localStorageGetItem('pubkey')
+  ) return false;
+
+  const arrayname = `my-profile-event-${event.kind}`;
+  const ls = localStorageGetItem(arrayname);
+  // if localStorage my-profile-event-[kind] doesnt exist, create it with new event in.
+  if (ls === null) localStorageSetItem(arrayname, JSON.stringify([event]));
+  else {
+    const a = JSON.parse(ls) as Event[];
+    // if event is already stored return false
+    if (a.some((e) => e.id === event.id)) return false;
+    // add event, store array
+    a.push(event);
+    localStorageSetItem(arrayname, JSON.stringify(a));
+  }
+  // update last updated date
+  updateLastUpdateDate();
+  // return true as event saved
+  return true;
+};
+
+export const fetchCachedProfileEventHistory = (
+  kind: 0 | 2 | 10002 | 3,
+): null | [Event, ...Event[]] => {
+  // get data from local storage
+  const arrayname = `my-profile-event-${kind}`;
+  const ls = localStorageGetItem(arrayname);
+  // if no events are cached return null
+  if (ls === null) return null;
+
+  const a = JSON.parse(ls) as [Event, ...Event[]];
+  // return as Events array
+  return a.sort((x, y) => y.created_at - x.created_at);
+};
+
+export const fetchCachedProfileEvent = (kind: 0 | 2 | 10002 | 3): null | Event => {
+  const a = fetchCachedProfileEventHistory(kind);
+  if (a === null) return null;
+  // return Event in array with most recent created_at date
+  return a[0];
+};
+
+/** get my latest profile events either from cache (if isUptodate) or from relays */
+export const fetchMyProfileEvents = async (
+  pubkey:string,
+  profileEventProcesser: (event: Event) => void,
+): Promise<void> => {
+  // get events from relays, store them and run profileEventProcesser
+  if (!isUptodate()) {
+    /**
+     * TODO also run this if we havn't checked for x minutes and we aren't already
+     * listening on my write relays
+     */
+    await requestMyProfileFromRelays(pubkey, (event: Event) => {
+      storeMyProfileEvent(event);
+      profileEventProcesser(event);
+    });
+    // update last-fetch-from-relays date
+    updateLastFetchDate();
+  } else {
+    // for kinds 0, 2, 10002 and 3
+    [0, 2, 10002, 3].forEach((k) => {
+      const e = fetchCachedProfileEvent(k as 0 | 2 | 10002 | 3);
+      if (e !== null) profileEventProcesser(e);
+    });
+  }
+};
+
+export const publishEvent = async (event:Event):Promise<boolean> => {
+  const r = await publishEventToRelay(event);
+  if (r) storeMyProfileEvent(event);
+  return r;
+};