Some comments from my AI assisted initial review, i still need to go through it in mode detail myself and check it in a few of my micro-services to make sure it doesn't break anything which i will do in the next couple of days.

Design Review: Cassandra Adapter Implementation

Overview

This PR reintroduces the Cassandra adapter using gocqlx/v2. The implementation correctly follows the storage adapter interface and integrates well with the existing codebase. However, the design differs from other adapters in several ways - some are intentional and appropriate for Cassandra/gocqlx, while others should be addressed for consistency.

Design Consistency Analysis

✅ Strengths

1. Adapter Interface Compliance: Correctly implements all required StorageAdapter methods
2. Singleton Pattern: Consistent with other adapters (SQL, DynamoDB, CosmosDB)
3. Error Handling: Uses errors.Join for proper error wrapping
4. Table Metadata: Pre-loads table metadata using gocqlx, which is appropriate for Cassandra
5. Session Management: On-demand session creation with proper cleanup (defer s.Close()) is reasonable for Cassandra

🔄 Design Differences (Intentional vs. Inconsistencies)

1. Initialization Pattern

• Current: Inline initialization in GetCassandraAdapter() with error return
• Other Adapters: Separate OpenConnection() method, no error return
• Impact: API inconsistency - Cassandra is the only adapter that can fail during factory creation
• Recommendation: Consider standardizing factory method signature across adapters, or document why Cassandra differs

2. Connection Management

• Current: On-demand session creation per operation
• Other Adapters: Persistent connections/clients stored in struct
• Impact: Different but acceptable for Cassandra; gocql.ClusterConfig manages connection pool
• Status: ✅ Acceptable design choice

3. Table Metadata Pre-loading

• Current: Pre-loads all table metadata in initializeTableMappers() during initialization
• Other Adapters: Compute table names dynamically from type names
• Impact: Requires keyspace and tables to exist at initialization time
• Status: ✅ Appropriate for gocqlx, but less flexible than other adapters

🐛 Issues Found

Critical Bugs

1. Migration Table Handling (Lines 236, 261)

t, e := c.getTableForItem("migrations")  // ❌ Won't work

• Problem: getTableForItem() expects a struct type, not a string. Passing "migrations" will fail because typeName("migrations") returns empty string.
• Fix: Use direct table lookup: c.tables["migrations"] or create a migration struct type

2. Count Method Returns Wrong Value (Line 395)

return -1, t.SelectBuilder().CountAll().Query(s).BindStruct(dest).ExecRelease()

• Problem: Always returns -1 instead of actual count. The count result is not captured.
• Fix: Capture and return the count value from the query result

3. Wrong Error Variable (Line 272)

return -1, errors.Join(
    fmt.Errorf("failed creating a session"),
    e,  // Should be sErr
)

• Problem: Uses e (from line 261) instead of sErr (from line 268)
• Fix: Change e to sErr

Minor Issues

4. Typo in storage/reflection.go:20

• "fot" should be "for"

5. Max("id") Usage (Line 276)

• Verify that gocqlx/v2 SelectBuilder supports Max() method. May need raw CQL query instead.

💡 Recommendations

High Priority

1. ✅ Fix migration table handling - use direct table lookup or migration struct
2. ✅ Fix Count method - return actual count value
3. ✅ Fix error variable bug in GetLatestMigration()

Medium Priority

4. ⚠️ Consider API consistency - either:
   • Make all factory methods return (Adapter, error), OR
   • Make Cassandra's factory method match others (no error return, handle errors differently)
5. ⚠️ Add unit tests for Cassandra adapter methods, especially edge cases

Low Priority

6. 📝 Fix typo in reflection.go
7. 📝 Verify Max() method usage or use alternative approach for GetLatestMigration()
8. 📝 Consider adding connection pooling documentation explaining why sessions are created per-operation

📊 Overall Assessment

The implementation is solid and follows gocqlx patterns correctly. The main concerns are:

• Three bugs that need fixing (migration table, Count method, error variable)
• API inconsistency in factory method signature
• Some design differences that are acceptable but should be documented

Recommendation: Address the critical bugs before merging. The API consistency issue can be handled in a follow-up if needed, but documenting the differences would be helpful.