feat(utils): compute cosine similarity, remove package

src/lib/utils/computeSimilarity.ts

@@ -1,7 +1,22 @@
-import cosineSimilarity from 'compute-cosine-similarity';
-
 const computeSimilarity = (x: number[], y: number[]): number => {
-  return cosineSimilarity(x, y) as number;
+  if (x.length !== y.length)
+    throw new Error('Vectors must be of the same length');
+
+  let dotProduct = 0;
+  let normA = 0;
+  let normB = 0;
+
+  for (let i = 0; i < x.length; i++) {
+    dotProduct += x[i] * y[i];
+    normA += x[i] * x[i];
+    normB += y[i] * y[i];
+  }
+
+  if (normA === 0 || normB === 0) {
+    return 0;
+  }
+
+  return dotProduct / (Math.sqrt(normA) * Math.sqrt(normB));
 };
 
 export default computeSimilarity;