Refactor code structure and remove redundant changes

src-old/hooks/useVersionComparison.ts

@@ -0,0 +1,56 @@
+import { useState, useEffect } from 'react';
+import { supabase } from '@/lib/supabaseClient';
+import type { EntityType, VersionDiff } from '@/types/versioning';
+import { handleError } from '@/lib/errorHandler';
+
+/**
+ * Hook to compare two versions of an entity and get the diff
+ * Uses the relational version tables for type-safe comparison
+ */
+export function useVersionComparison(
+  entityType: EntityType,
+  fromVersionId: string | null,
+  toVersionId: string | null
+) {
+  const [diff, setDiff] = useState<VersionDiff | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    if (!fromVersionId || !toVersionId || !entityType) {
+      setDiff(null);
+      return;
+    }
+
+    async function fetchDiff() {
+      setLoading(true);
+      setError(null);
+
+      try {
+        // Use the database function to get diff
+        const { data, error: rpcError } = await supabase.rpc('get_version_diff', {
+          p_entity_type: entityType,
+          p_from_version_id: fromVersionId || '',
+          p_to_version_id: toVersionId || ''
+        });
+
+        if (rpcError) throw rpcError;
+
+        setDiff(data as VersionDiff);
+      } catch (err) {
+        handleError(err, { 
+          action: 'Compare Versions',
+          metadata: { entityType, fromVersionId, toVersionId }
+        });
+        setError(err instanceof Error ? err.message : 'Failed to compare versions');
+        setDiff(null);
+      } finally {
+        setLoading(false);
+      }
+    }
+
+    fetchDiff();
+  }, [entityType, fromVersionId, toVersionId]);
+
+  return { diff, loading, error };
+}