feat: percentile indicator

src/core/blitz/getWN8Percentile.ts

@@ -0,0 +1,21 @@
+import { Percentile } from '../../constants/percentiles.js';
+
+const WN8_PERCENTILES: [number, Percentile][] = [
+  [0, Percentile.VeryBad],
+  [300, Percentile.Bad],
+  [450, Percentile.BelowAverage],
+  [650, Percentile.Average],
+  [900, Percentile.AboveAverage],
+  [1200, Percentile.Good],
+  [1600, Percentile.VeryGood],
+  [2000, Percentile.Great],
+  [2450, Percentile.Unicum],
+  [2900, Percentile.SuperUnicum],
+];
+
+export default function getWN8Percentile(WN8: number) {
+  const lastIndex = WN8_PERCENTILES.findLastIndex(
+    ([WN8Listing]) => WN8Listing <= WN8,
+  );
+  return WN8_PERCENTILES[lastIndex === -1 ? 0 : lastIndex][1];
+}