Expose sequence identity registrations through the facade

sequence_identity.go

@@ -0,0 +1,74 @@
+package configkit
+
+import "gitea.maximumdirect.net/eric/ConfigKit/internal/engine"
+
+// SequenceSelector identifies a sequence destination through literal mapping
+// keys and arbitrary mapping-key segments. A zero selector identifies the root.
+type SequenceSelector []SequenceSelectorSegment
+
+// SequenceSelectorSegment is one literal mapping key or wildcard mapping key.
+// Its zero value is the literal empty key.
+type SequenceSelectorSegment struct {
+	key           string
+	anyMappingKey bool
+}
+
+// SequenceLiteralKey selects a literal mapping key, including an empty key or
+// the literal string "*".
+func SequenceLiteralKey(key string) SequenceSelectorSegment {
+	return SequenceSelectorSegment{key: key}
+}
+
+// SequenceAnyMappingKey selects any single mapping key.
+func SequenceAnyMappingKey() SequenceSelectorSegment {
+	return SequenceSelectorSegment{anyMappingKey: true}
+}
+
+// SequenceIdentity records the identity fields used for strict sequence
+// composition and identified-record parent lookup. It does not add final-result
+// identity validation; that check remains the application's responsibility.
+type SequenceIdentity struct {
+	exactPath      bool
+	path           Path
+	selector       SequenceSelector
+	identityFields []string
+}
+
+// SequenceIdentityAt registers identity fields at an exact mapping path. The
+// path and fields are copied; invalid paths and empty field sets are reported
+// during load validation.
+func SequenceIdentityAt(path Path, fields ...string) SequenceIdentity {
+	return SequenceIdentity{
+		exactPath:      true,
+		path:           path.clone(),
+		identityFields: append([]string(nil), fields...),
+	}
+}
+
+// SequenceIdentityMatching registers identity fields at destinations matched by
+// selector. Literal and wildcard selector segments are copied. Empty field sets
+// are reported during load validation.
+func SequenceIdentityMatching(selector SequenceSelector, fields ...string) SequenceIdentity {
+	return SequenceIdentity{
+		selector:       append(SequenceSelector(nil), selector...),
+		identityFields: append([]string(nil), fields...),
+	}
+}
+
+func toEngineSequenceIdentity(identity SequenceIdentity) engine.SequenceIdentityRegistrationInput {
+	registration := engine.SequenceIdentityRegistrationInput{
+		IdentityFields: append([]string(nil), identity.identityFields...),
+	}
+	if identity.exactPath {
+		path := toEnginePath(identity.path.clone())
+		registration.ExactPath = &path
+		return registration
+	}
+	registration.Selector = make([]engine.SequenceIdentitySelectorSegment, len(identity.selector))
+	for index, segment := range identity.selector {
+		registration.Selector[index] = engine.SequenceIdentitySelectorSegment{
+			Key: segment.key, AnyMappingKey: segment.anyMappingKey,
+		}
+	}
+	return registration
+}