WIP

server-new/internal/adapters/fs_utils.go

@@ -0,0 +1,78 @@
+package adapters
+
+import (
+	"errors"
+	"mime"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+func SafeRel(root, requested string) (string, error) {
+	s := requested
+	if after, ok := strings.CutPrefix(s, "/"); ok {
+		s = after
+	}
+	full := filepath.Join(root, filepath.FromSlash(s))
+	rel, err := filepath.Rel(root, full)
+	if err != nil {
+		return "", err
+	}
+	if rel == "." {
+		return "/", nil
+	}
+	sep := string(filepath.Separator)
+	if strings.HasPrefix(rel, "..") || strings.Contains(rel, ".."+sep) {
+		return "", errors.New("path escapes root")
+	}
+	return "/" + filepath.ToSlash(rel), nil
+}
+
+func ResponsePath(root, full string) string {
+	rel, err := filepath.Rel(root, full)
+	if err != nil || rel == "." {
+		return "/"
+	}
+	return "/" + filepath.ToSlash(rel)
+}
+
+func sizeOrZero(fi os.FileInfo) int64 {
+	if fi == nil {
+		return 0
+	}
+	return fi.Size()
+}
+
+func modTimeOrZero(fi os.FileInfo) time.Time {
+	if fi == nil {
+		return time.Time{}
+	}
+	return fi.ModTime()
+}
+
+var textPlainExtensions = map[string]bool{
+	".txt":  true,
+	".log":  true,
+	".json": true,
+	".yaml": true,
+	".yml":  true,
+	".toml": true,
+	".xml":  true,
+	".csv":  true,
+}
+
+func contentTypeFor(name string) string {
+	ext := strings.ToLower(filepath.Ext(name))
+	switch ext {
+	case ".md", ".markdown", ".mdown":
+		return "application/markdown"
+	}
+	if ct := mime.TypeByExtension(ext); ct != "" {
+		return ct
+	}
+	if textPlainExtensions[ext] {
+		return "text/plain; charset=utf-8"
+	}
+	return "application/octet-stream"
+}