Initial DDC release

internal/libraries/libraries.go

@@ -0,0 +1,57 @@
+package libraries
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+var ErrUnknownDestination = errors.New("destination is not a first level folder of a library root")
+
+type Destination struct {
+	Name string `json:"name"`
+	Root string `json:"root"`
+	Path string `json:"path"`
+}
+
+func Discover(roots []string) []Destination {
+	destinations := []Destination{}
+	for _, root := range roots {
+		entries, err := os.ReadDir(root)
+		if err != nil {
+			continue
+		}
+		for _, entry := range entries {
+			if !entry.IsDir() || strings.HasPrefix(entry.Name(), ".") {
+				continue
+			}
+			destinations = append(destinations, Destination{
+				Name: entry.Name(),
+				Root: root,
+				Path: filepath.Join(root, entry.Name()),
+			})
+		}
+	}
+	return destinations
+}
+
+func Resolve(roots []string, requested string) (Destination, error) {
+	cleaned := filepath.Clean(requested)
+	name := filepath.Base(cleaned)
+	if strings.HasPrefix(name, ".") {
+		return Destination{}, ErrUnknownDestination
+	}
+
+	for _, root := range roots {
+		if filepath.Dir(cleaned) != root {
+			continue
+		}
+		info, err := os.Lstat(cleaned)
+		if err != nil || !info.IsDir() {
+			return Destination{}, ErrUnknownDestination
+		}
+		return Destination{Name: name, Root: root, Path: cleaned}, nil
+	}
+	return Destination{}, ErrUnknownDestination
+}