# Complete Implementation Plan for Onyx Phase 1

## Milestone 1: Action Log and onx init

### Action Log Implementation

13. **Create oplog binary format** (`internal/storage/oplog.go`)
    ```go
    type OplogEntry struct {
        ID           uint64
        ParentID     uint64
        Timestamp    int64
        Command      string
        StateBefore  map[string]string
        StateAfter   map[string]string
    }
    ```

14. **Implement oplog writer** (`internal/storage/oplog_writer.go`)
    - `OpenOplog(path string) (*OplogWriter, error)`
    - `AppendEntry(entry *OplogEntry) error`
    - Use binary encoding (gob or protobuf)
    - Implement file locking for concurrent access

15. **Implement oplog reader** (`internal/storage/oplog_reader.go`)
    - `ReadLastEntry() (*OplogEntry, error)`
    - `ReadEntry(id uint64) (*OplogEntry, error)`
    - `GetUndoStack() ([]*OplogEntry, error)`

16. **Create transactional wrapper** (`internal/core/transaction.go`)
    ```go
    func ExecuteWithTransaction(repo *Repository, cmd string, 
        fn func() error) error {
        // 1. Capture state_before
        // 2. Create oplog entry
        // 3. Execute fn()
        // 4. Capture state_after
        // 5. Finalize oplog entry
        // 6. Handle rollback on error
    }
    ```

### onx init Command

17. **Implement init command** (`internal/commands/init.go`)
    - Create .git directory (via go-git)
    - Create .onx directory structure
    - Initialize empty oplog file
    - Create default workstreams.json
    - Create workspace pointer file
    - Add .onx to .gitignore

18. **Create CLI structure** (`cmd/onx/main.go`)
    ```go
    func main() {
        rootCmd := &cobra.Command{
            Use:   "onx",
            Short: "The iPhone of Version Control",
        }
        rootCmd.AddCommand(commands.InitCmd())
        rootCmd.Execute()
    }
    ```

### onx undo Command

19. **Implement undo logic** (`internal/commands/undo.go`)
    - Read last oplog entry
    - Restore all refs from state_before
    - Update workspace pointer
    - Mark entry as undone in oplog
    - Perform git checkout to restore working directory

20. **Add undo tests** (`internal/commands/undo_test.go`)
    - Test undo after init
    - Test sequential undos
    - Test undo with nothing to undo