refactor: deterministic shuffle algorithm

Author: canerakdas

apps/site/components/Common/Partners/utils.ts

@@ -5,6 +5,24 @@ import type {
   Partners,
 } from '#site/types/partners.js';
 
+// Fisher-Yates shuffle algorithm with a seed for deterministic results
+function shuffle(array: Array<Partners>, seed: number): Array<Partners> {
+  const shuffled = [...array];
+  const hash = crypto.createHash('sha256').update(String(seed)).digest();
+
+  for (let i = shuffled.length - 1; i > 0; i--) {
+    // Use hash bytes to generate deterministic "random" index
+    const hashIndex = (i + seed) % 32;
+    // Normalize to 0-1
+    const randomValue = hash[hashIndex] / 255;
+
+    const j = Math.floor(randomValue * (i + 1));
+    [shuffled[i], shuffled[j]] = [shuffled[j], shuffled[i]];
+  }
+
+  return shuffled;
+}
+
 function randomPartnerList(
   partners: Array<Partners>,
   config: RandomPartnerListConfig
@@ -19,15 +37,7 @@ function randomPartnerList(
     ? partners.filter(p => p.categories.includes(category))
     : partners;
 
-  // Create a hash from the seed to use for consistent randomization
-  const hash = crypto.createHash('sha256').update(String(seed)).digest();
-
-  // Sort partners using the hash to ensure same results for the same seed
-  const sorted = filtered.sort(
-    (a, b) => hash[a.name.charCodeAt(0) % 32] - hash[b.name.charCodeAt(0) % 32]
-  );
-
-  return sorted.slice(0, pick ?? sorted.length);
+  return shuffle(filtered, seed).slice(0, pick ?? filtered.length);
 }
 
 export { randomPartnerList };