Add internal engine relocation candidate

internal/engine/render.go

@@ -0,0 +1,46 @@
+package engine
+
+import (
+	"errors"
+	"io"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
+	yamladapter "gitea.maximumdirect.net/eric/ConfigKit/internal/yaml"
+)
+
+var errEffectiveUnavailable = errors.New("configkit: effective configuration is unavailable")
+
+// WriteEffective writes deterministic redacted YAML from the frozen resolved
+// snapshot. The output is intended for inspection and is not promised reloadable.
+// Writer errors, including short writes, are returned and may leave partial output.
+func (r *Result[T]) WriteEffective(output io.Writer) error {
+	if r == nil || r.final == nil || output == nil {
+		return errEffectiveUnavailable
+	}
+	safe := redactedDocument(r.final, r.secrets, Path{})
+	return yamladapter.Write(output, safe)
+}
+
+func redactedDocument(node *document.Node, secret map[string]bool, path Path) *document.Node {
+	result, _ := safeSnapshotDocument(node, secret, path)
+	return result
+}
+
+func pathIsSecret(secret map[string]bool, path Path) bool {
+	if secret[""] {
+		return true
+	}
+	pointer := path.String()
+	for pointer != "" {
+		if secret[pointer] {
+			return true
+		}
+		position := strings.LastIndexByte(pointer, '/')
+		if position <= 0 {
+			break
+		}
+		pointer = pointer[:position]
+	}
+	return false
+}