fix: no double fetch and caching

src/core/blitz/getRatingsLeague.ts

@@ -0,0 +1,23 @@
+import { LeagueTop } from '../../commands/ratings';
+import { Region } from '../../constants/regions';
+import { patientFetch } from '../blitzkrieg/patientFetch';
+import { withCORSProxy } from '../blitzkrieg/withCORSProxy';
+import regionToRegionSubdomain from './regionToRegionSubdomain';
+
+export async function getRatingsLeague(
+  region: Region,
+  league: number,
+  usePatientFetcher = false,
+) {
+  const fetcher = usePatientFetcher ? patientFetch : fetch;
+  const response = await fetcher(
+    withCORSProxy(
+      `https://${regionToRegionSubdomain(
+        region,
+      )}.wotblitz.com/en/api/rating-leaderboards/league/${league}/top/`,
+    ),
+  );
+  const json = (await response.json()) as LeagueTop;
+
+  return json;
+}

src/core/blitzkrieg/patientFetch.ts

@@ -0,0 +1,14 @@
+export async function patientFetch(url: string, timeout = 1 * 60 * 1000) {
+  let patientResponse: Response;
+
+  while (patientResponse! === undefined) {
+    try {
+      patientResponse = await fetch(url);
+    } catch (error) {
+      console.warn(`Failed to fetch ${url}; retrying in ${timeout}ms...`);
+      await new Promise((resolve) => setTimeout(resolve, timeout));
+    }
+  }
+
+  return patientResponse;
+}