wip: vfs implementation

apps/backend/internal/virtualfs/path.go

@@ -0,0 +1,42 @@
+package virtualfs
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"strings"
+
+	"github.com/google/uuid"
+	"github.com/uptrace/bun"
+)
+
+const absolutePathQuery = `WITH RECURSIVE path AS (
+    SELECT id, parent_id, name, 1 as depth
+    FROM vfs_nodes WHERE id = $1 AND deleted_at IS NULL
+    
+    UNION ALL
+    
+    SELECT n.id, n.parent_id, n.name, p.depth + 1
+    FROM vfs_nodes n
+    JOIN path p ON n.id = p.parent_id
+    WHERE n.deleted_at IS NULL
+)
+SELECT name FROM path 
+WHERE EXISTS (SELECT 1 FROM path WHERE parent_id IS NULL)
+ORDER BY depth DESC;`
+
+func JoinPath(parts ...string) string {
+	return strings.Join(parts, "/")
+}
+
+func buildNodeAbsolutePath(ctx context.Context, db *bun.DB, nodeID uuid.UUID) (string, error) {
+	var path []string
+	err := db.NewRaw(absolutePathQuery, nodeID).Scan(ctx, &path)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return "", ErrNodeNotFound
+		}
+		return "", err
+	}
+	return JoinPath(path...), nil
+}