Process text story messages

ts/util/generateBlurHash.ts

@@ -0,0 +1,16 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { encode83 } from 'blurhash/dist/base83';
+
+/* eslint-disable no-bitwise */
+export function generateBlurHash(argb = 4294704123): string {
+  const R = 0xff & (argb >> 16);
+  const G = 0xff & (argb >> 8);
+  const B = 0xff & (argb >> 0);
+
+  const value = (R << 16) + (G << 8) + B;
+
+  return `00${encode83(value, 4)}`;
+}
+/* eslint-enable no-bitwise */