Add ForkType type alias for improved type safety

- Replace [4]byte with ForkType in ForkInfoList struct
- Update constants ForkTypeDATA and ForkTypeMACR to use ForkType
- Add String() method to ForkType for better debugging
- Improve consistency with existing type patterns (FieldType, TranType)
- Clean up unused code and improve documentation

3 files changed, 26 insertions, 60 deletions

diff --git a/hotline/file_resume_data.go b/hotline/file_resume_data.go
index 5dfd2d8..80f5fe5 100644
--- a/hotline/file_resume_data.go
+++ b/hotline/file_resume_data.go
@@ -3,38 +3,54 @@ package hotline
 import (
 	"bytes"
 	"encoding/binary"
+	"fmt"
 )
 
 // FileResumeData is sent when a client or server would like to resume a transfer from an offset
 type FileResumeData struct {
 	Format       [4]byte  // "RFLT"
 	Version      [2]byte  // Always 1
-	RSVD         [34]byte // Unused
+	RSVD         [34]byte // Present in the Hotline protocol docs, but unused.  Left here for documentation purposes.
 	ForkCount    [2]byte  // Length of ForkInfoList.  Either 2 or 3 depending on whether file has a resource fork
 	ForkInfoList []ForkInfoList
+}
+
+// ForkType represents a 4-byte fork type identifier
+type ForkType [4]byte
 
-	//readOffset int // TODO
+// String returns a string representation of the fork type
+func (ft ForkType) String() string {
+	return fmt.Sprintf("%c%c%c%c", ft[0], ft[1], ft[2], ft[3])
 }
 
 type ForkInfoList struct {
-	Fork     [4]byte // "DATA" or "MACR"
-	DataSize [4]byte // offset from which to resume the transfer of data
-	RSVDA    [4]byte // Unused
-	RSVDB    [4]byte // Unused
+	Fork     ForkType // "DATA" or "MACR"
+	DataSize [4]byte  // offset from which to resume the transfer of data
+	RSVDA    [4]byte  // Present in the Hotline protocol docs, but unused.  Left here for documentation purposes.
+	RSVDB    [4]byte  // Present in the Hotline protocol docs, but unused.  Left here for documentation purposes.
 }
 
+var (
+	ForkTypeDATA = ForkType{0x44, 0x41, 0x54, 0x41} // DATA: Data fork
+	ForkTypeMACR = ForkType{0x4d, 0x41, 0x43, 0x52} // MACR: Mac resource fork
+)
+
 func NewForkInfoList(b []byte) *ForkInfoList {
 	return &ForkInfoList{
-		Fork:     [4]byte{0x44, 0x41, 0x54, 0x41},
+		Fork:     ForkTypeDATA,
 		DataSize: [4]byte{b[0], b[1], b[2], b[3]},
 		RSVDA:    [4]byte{},
 		RSVDB:    [4]byte{},
 	}
 }
 
+var (
+	FormatRFLT = [4]byte{0x52, 0x46, 0x4C, 0x54} // File resume format: "RFLT" (?)
+)
+
 func NewFileResumeData(list []ForkInfoList) *FileResumeData {
 	return &FileResumeData{
-		Format:       [4]byte{0x52, 0x46, 0x4C, 0x54}, // RFLT
+		Format:       FormatRFLT,
 		Version:      [2]byte{0, 1},
 		RSVD:         [34]byte{},
 		ForkCount:    [2]byte{0, uint8(len(list))},
@@ -42,31 +58,6 @@ func NewFileResumeData(list []ForkInfoList) *FileResumeData {
 	}
 }
 
-//
-//func (frd *FileResumeData) Read(p []byte) (int, error) {
-//	buf := slices.Concat(
-//		frd.Format[:],
-//		frd.Version[:],
-//		frd.RSVD[:],
-//		frd.ForkCount[:],
-//	)
-//	for _, fil := range frd.ForkInfoList {
-//		buf = append(buf, fil...)
-//		_ = binary.Write(&buf, binary.LittleEndian, fil)
-//	}
-//
-//	var buf bytes.Buffer
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.Format)
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.Version)
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.RSVD)
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.ForkCount)
-//	for _, fil := range frd.ForkInfoList {
-//		_ = binary.Write(&buf, binary.LittleEndian, fil)
-//	}
-//
-//	return buf.Bytes(), nil
-//}
-
 func (frd *FileResumeData) BinaryMarshal() ([]byte, error) {
 	var buf bytes.Buffer
 	_ = binary.Write(&buf, binary.LittleEndian, frd.Format)
diff --git a/hotline/file_transfer.go b/hotline/file_transfer.go
index 701259a..521b963 100644
--- a/hotline/file_transfer.go
+++ b/hotline/file_transfer.go
@@ -172,23 +172,6 @@ type folderUpload struct {
 	FileNamePath  []byte
 }
 
-//func (fu *folderUpload) Write(p []byte) (int, error) {
-//	if len(p) < 7 {
-//		return 0, errors.New("buflen too short")
-//	}
-//	copy(fu.DataSize[:], p[0:2])
-//	copy(fu.IsFolder[:], p[2:4])
-//	copy(fu.PathItemCount[:], p[4:6])
-//
-//	fu.FileNamePath = make([]byte, binary.BigEndian.Uint16(fu.DataSize[:])-4) // -4 to subtract the path separator bytes TODO: wat
-//	n, err := io.ReadFull(rwc, fu.FileNamePath)
-//	if err != nil {
-//		return 0, err
-//	}
-//
-//	return n + 6, nil
-//}
-
 // pathSegmentScanner implements bufio.SplitFunc for parsing path segments
 func pathSegmentScanner(data []byte, _ bool) (advance int, token []byte, err error) {
 	if len(data) < 3 {
@@ -269,12 +252,6 @@ func (fh *FileHeader) Read(p []byte) (int, error) {
 }
 
 func DownloadHandler(w io.Writer, fullPath string, fileTransfer *FileTransfer, fs FileStore, rLogger *slog.Logger, preserveForks bool) error {
-	//s.Stats.DownloadCounter += 1
-	//s.Stats.DownloadsInProgress += 1
-	//defer func() {
-	//	s.Stats.DownloadsInProgress -= 1
-	//}()
-
 	var dataOffset int64
 	if fileTransfer.FileResumeData != nil {
 		dataOffset = int64(binary.BigEndian.Uint32(fileTransfer.FileResumeData.ForkInfoList[0].DataSize[:]))
@@ -520,7 +497,6 @@ func DownloadFolderHandler(rwc io.ReadWriter, fullPath string, fileTransfer *Fil
 			return fmt.Errorf("error opening file: %w", err)
 		}
 
-		// wr := bufio.NewWriterSize(rwc, 1460)
 		if _, err = io.Copy(rwc, io.TeeReader(file, fileTransfer.bytesSentCounter)); err != nil {
 			return fmt.Errorf("error sending file: %w", err)
 		}
@@ -576,7 +552,6 @@ func UploadFolderHandler(rwc io.ReadWriter, fullPath string, fileTransfer *FileT
 		//s.Stats.UploadCounter += 1
 
 		var fu folderUpload
-		// TODO: implement io.Writer on folderUpload and replace this
 		if _, err := io.ReadFull(rwc, fu.DataSize[:]); err != nil {
 			return err
 		}
@@ -586,7 +561,7 @@ func UploadFolderHandler(rwc io.ReadWriter, fullPath string, fileTransfer *FileT
 		if _, err := io.ReadFull(rwc, fu.PathItemCount[:]); err != nil {
 			return err
 		}
-		fu.FileNamePath = make([]byte, binary.BigEndian.Uint16(fu.DataSize[:])-4) // -4 to subtract the path separator bytes TODO: wat
+		fu.FileNamePath = make([]byte, binary.BigEndian.Uint16(fu.DataSize[:])-4) // -4 to subtract the length of the DataSize and IsFolder fields
 		if _, err := io.ReadFull(rwc, fu.FileNamePath); err != nil {
 			return err
 		}
diff --git a/hotline/file_wrapper.go b/hotline/file_wrapper.go
index b13e0dc..b6aff94 100644
--- a/hotline/file_wrapper.go
+++ b/hotline/file_wrapper.go
@@ -85,7 +85,7 @@ func (f *fileWrapper) rsrcForkSize() (s [4]byte) {
 
 func (f *fileWrapper) rsrcForkHeader() FlatFileForkHeader {
 	return FlatFileForkHeader{
-		ForkType: [4]byte{0x4D, 0x41, 0x43, 0x52}, // "MACR"
+		ForkType: ForkTypeMACR,
 		DataSize: f.rsrcForkSize(),
 	}
 }