Files
clip-sync/internal/transfer/transfer.go
T

84 lines
2.1 KiB
Go

// Package transfer handles binary content (images, files) transfer between
// clip-sync peers. It is kept separate from the text clipboard path so that
// text sync remains simple and safe; binary content is sent explicitly and is
// written to disk on the receiving side only when enabled.
package transfer
import (
"encoding/base64"
"fmt"
"mime"
"os"
"path/filepath"
"time"
)
// File is the wire payload for a transferred binary object.
type File struct {
Name string `json:"name"`
Mime string `json:"mime"`
Data string `json:"data"` // base64-encoded content
Ts int64 `json:"ts"`
Origin string `json:"origin"`
}
// ReadFile reads a file from disk and encodes it as a transfer.File payload.
func ReadFile(path, origin string) (*File, error) {
data, err := os.ReadFile(path)
if err != nil {
return nil, err
}
mimeType := mime.TypeByExtension(filepath.Ext(path))
if mimeType == "" {
mimeType = "application/octet-stream"
}
return &File{
Name: filepath.Base(path),
Mime: mimeType,
Data: base64.StdEncoding.EncodeToString(data),
Ts: time.Now().UnixNano(),
Origin: origin,
}, nil
}
// Decode returns the raw bytes of the file.
func (f *File) Decode() ([]byte, error) {
if f.Data == "" {
return nil, fmt.Errorf("transfer: empty data")
}
return base64.StdEncoding.DecodeString(f.Data)
}
// SaveTo writes the decoded content to the given directory, sanitizing the
// file name to avoid path traversal. It returns the written path.
func (f *File) SaveTo(dir string) (string, error) {
data, err := f.Decode()
if err != nil {
return "", err
}
if err := os.MkdirAll(dir, 0755); err != nil {
return "", err
}
name := filepath.Base(f.Name)
if name == "." || name == "" || name == string(filepath.Separator) {
name = "received.bin"
}
// Avoid overwriting existing files: append a numeric suffix if needed.
dest := filepath.Join(dir, name)
for i := 1; ; i++ {
if _, err := os.Stat(dest); os.IsNotExist(err) {
break
}
ext := filepath.Ext(name)
base := name[:len(name)-len(ext)]
dest = filepath.Join(dir, fmt.Sprintf("%s (%d)%s", base, i, ext))
}
return dest, os.WriteFile(dest, data, 0644)
}