Build identified record inheritance graphs

internal/engine/inheritance_identified.go

@@ -0,0 +1,160 @@
+package engine
+
+import "gitea.maximumdirect.net/eric/ConfigKit/internal/document"
+
+type identifiedInheritanceTemplate struct {
+	item          *document.Node
+	path          Path
+	tuple         string
+	parent        int
+	hasParent     bool
+	cancelled     bool
+	directive     *document.Node
+	directivePath Path
+}
+
+type identifiedInheritanceGraph struct {
+	scope      *document.Node
+	scopePath  Path
+	fields     []string
+	nodes      []identifiedInheritanceTemplate
+	edges      []dependencyEdge
+	byIdentity map[string]int
+}
+
+// analyzeIdentifiedInheritanceGraph validates relationships inside one
+// identified sequence. It prepares a graph only; mapping-sibling expansion
+// remains the active inheritance behavior until the reusable scope executor is
+// activated.
+func analyzeIdentifiedInheritanceGraph(sequence *document.Node, scopePath Path, identityFields []string) (*identifiedInheritanceGraph, []Diagnostic) {
+	if sequence == nil || sequence.Kind != document.Sequence {
+		var primary *Location
+		if sequence != nil {
+			location := publicLocation(sequence.Location)
+			primary = &location
+		}
+		return nil, []Diagnostic{{
+			Code: CodeSequenceInvalid, Severity: SeverityError, Path: scopePath.clone(),
+			Message: "identified inheritance scope must be a sequence", Primary: primary,
+		}}
+	}
+	fields, err := normalizeSequenceIdentityFields(identityFields)
+	if err != nil {
+		location := publicLocation(sequence.Location)
+		return nil, []Diagnostic{{
+			Code: CodeSequenceInvalid, Severity: SeverityError, Path: scopePath.clone(),
+			Message: "identified inheritance scope requires identity fields", Primary: &location,
+		}}
+	}
+	lookup, diagnostics := validateNormalizedSequenceIdentityFrom(
+		sequence, scopePath, fields, sequenceCombinationIdentityCodes, 0,
+	)
+	if len(diagnostics) != 0 {
+		return nil, diagnostics
+	}
+	graph := &identifiedInheritanceGraph{
+		scope: sequence, scopePath: scopePath.clone(), fields: cloneStrings(fields),
+		nodes:      make([]identifiedInheritanceTemplate, len(sequence.Sequence)),
+		byIdentity: make(map[string]int, len(lookup)),
+	}
+	for tuple, record := range lookup {
+		graph.byIdentity[tuple] = record.index
+		graph.nodes[record.index] = identifiedInheritanceTemplate{
+			item: sequence.Sequence[record.index], path: scopePath.Index(record.index), tuple: tuple,
+		}
+	}
+
+	for index := range graph.nodes {
+		node := &graph.nodes[index]
+		directive, found := inheritanceDirective(node.item)
+		if !found {
+			continue
+		}
+		node.directive = directive.Value
+		node.directivePath = node.path.Key(inheritanceKey)
+		referenceLocation := publicLocation(directive.Value.Location)
+		switch directive.Value.Kind {
+		case document.Null:
+			node.cancelled = true
+		case document.Mapping:
+			reference, issues := identifiedInheritanceReference(directive.Value, node.directivePath, fields)
+			if len(issues) != 0 {
+				return nil, issues
+			}
+			parent, exists := graph.byIdentity[reference]
+			if !exists {
+				return nil, []Diagnostic{inheritanceDiagnostic(
+					CodeInheritanceMissing, node.directivePath, referenceLocation, nil,
+					"referenced record does not exist in this collection",
+				)}
+			}
+			node.parent = parent
+			node.hasParent = true
+			graph.edges = append(graph.edges, dependencyEdge{prerequisite: parent, dependent: index})
+		default:
+			return nil, []Diagnostic{inheritanceDiagnostic(
+				CodeInheritanceInvalid, node.directivePath, referenceLocation, nil,
+				"identified record inheritance reference must be a mapping or null",
+			)}
+		}
+	}
+	return graph, nil
+}
+
+func identifiedInheritanceReference(reference *document.Node, path Path, identityFields []string) (string, []Diagnostic) {
+	allowed := make(map[string]struct{}, len(identityFields))
+	for _, field := range identityFields {
+		allowed[field] = struct{}{}
+	}
+	seen := make(map[string]struct{}, len(reference.Mapping))
+	for _, entry := range reference.Mapping {
+		if _, ok := allowed[entry.Key]; !ok {
+			return "", []Diagnostic{inheritanceDiagnostic(
+				CodeInheritanceInvalid, path.Key(entry.Key), publicLocation(entry.Value.Location), nil,
+				"identified record inheritance reference has an unsupported field",
+			)}
+		}
+		seen[entry.Key] = struct{}{}
+	}
+	for _, field := range identityFields {
+		if _, ok := seen[field]; !ok {
+			return "", []Diagnostic{inheritanceDiagnostic(
+				CodeInheritanceInvalid, path.Key(field), publicLocation(reference.Location), nil,
+				"identified record inheritance reference is missing an identity field",
+			)}
+		}
+	}
+	index := newSequenceMappingIndex(reference)
+	tuple, _, missing, invalid := index.identity(identityFields)
+	if missing != "" || invalid >= 0 || invalid == -2 {
+		value := reference
+		fieldPath := path.Key(missing)
+		if invalid >= 0 && invalid < len(reference.Mapping) {
+			value = reference.Mapping[invalid].Value
+			fieldPath = path.Key(reference.Mapping[invalid].Key)
+		}
+		location := publicLocation(value.Location)
+		return "", []Diagnostic{inheritanceDiagnostic(
+			CodeInheritanceInvalid, fieldPath, location, nil,
+			"identified record inheritance identity fields must be scalar values",
+		)}
+	}
+	return tuple, nil
+}
+
+func (graph *identifiedInheritanceGraph) schedule() ([]int, []Diagnostic) {
+	keys := make([]dependencyKey, len(graph.nodes))
+	for index, node := range graph.nodes {
+		keys[index] = dependencyKey{"record", graph.scopePath.String(), node.path.String()}
+	}
+	order, cycle := scheduleDependencies(keys, graph.edges)
+	if len(cycle) == 0 {
+		return order, nil
+	}
+	parent, child := graph.nodes[cycle[0]], graph.nodes[cycle[1]]
+	return nil, []Diagnostic{inheritanceDiagnostic(
+		CodeInheritanceCycle, child.directivePath, publicLocation(child.directive.Location),
+		[]Location{publicLocation(parent.item.Location)},
+		"identified record inheritance contains a cycle",
+	)}
+}