Add normalize report diagnostics

internal/normalize/build.go

@@ -12,31 +12,57 @@ import (
 	"gitea.maximumdirect.net/eric/seriatim/schema"
 )
 
+// BuildResult contains normalize output plus deterministic transformation diagnostics.
+type BuildResult struct {
+	Output                 any
+	SortingChanged         bool
+	IDsReassigned          bool
+	SegmentsWithCategories int
+}
+
 // Build converts parsed normalize input into a selected seriatim output schema.
-func Build(parsed ParsedTranscript, cfg config.NormalizeConfig) (any, error) {
+func Build(parsed ParsedTranscript, cfg config.NormalizeConfig) (BuildResult, error) {
 	ordered := sortedSegments(parsed.Segments)
+	sortingChanged := didSortingChangeOrder(ordered)
+	idsReassigned := didReassignIDs(ordered)
+	segmentsWithCategories := countSegmentsWithCategories(ordered)
 
 	switch cfg.OutputSchema {
 	case config.OutputSchemaMinimal:
 		output := buildMinimal(ordered)
 		if err := schema.ValidateMinimalTranscript(output); err != nil {
-			return nil, fmt.Errorf("validate normalize output: %w", err)
+			return BuildResult{}, fmt.Errorf("validate normalize output: %w", err)
 		}
-		return output, nil
+		return BuildResult{
+			Output:                 output,
+			SortingChanged:         sortingChanged,
+			IDsReassigned:          idsReassigned,
+			SegmentsWithCategories: segmentsWithCategories,
+		}, nil
 	case config.OutputSchemaIntermediate:
 		output := buildIntermediate(ordered)
 		if err := schema.ValidateIntermediateTranscript(output); err != nil {
-			return nil, fmt.Errorf("validate normalize output: %w", err)
+			return BuildResult{}, fmt.Errorf("validate normalize output: %w", err)
 		}
-		return output, nil
+		return BuildResult{
+			Output:                 output,
+			SortingChanged:         sortingChanged,
+			IDsReassigned:          idsReassigned,
+			SegmentsWithCategories: segmentsWithCategories,
+		}, nil
 	case config.OutputSchemaFull:
 		output := buildFull(ordered, cfg)
 		if err := schema.ValidateTranscript(output); err != nil {
-			return nil, fmt.Errorf("validate normalize output: %w", err)
+			return BuildResult{}, fmt.Errorf("validate normalize output: %w", err)
 		}
-		return output, nil
+		return BuildResult{
+			Output:                 output,
+			SortingChanged:         sortingChanged,
+			IDsReassigned:          idsReassigned,
+			SegmentsWithCategories: segmentsWithCategories,
+		}, nil
 	default:
-		return nil, fmt.Errorf("unsupported output schema %q", cfg.OutputSchema)
+		return BuildResult{}, fmt.Errorf("unsupported output schema %q", cfg.OutputSchema)
 	}
 }
 
@@ -156,3 +182,35 @@ func copyIntPtr(value *int) *int {
 	copied := *value
 	return &copied
 }
+
+func didSortingChangeOrder(segments []InputSegment) bool {
+	for index, segment := range segments {
+		if segment.InputIndex != index {
+			return true
+		}
+	}
+	return false
+}
+
+func didReassignIDs(segments []InputSegment) bool {
+	if len(segments) == 0 {
+		return false
+	}
+	for index, segment := range segments {
+		newID := index + 1
+		if segment.OriginalID == nil || *segment.OriginalID != newID {
+			return true
+		}
+	}
+	return false
+}
+
+func countSegmentsWithCategories(segments []InputSegment) int {
+	count := 0
+	for _, segment := range segments {
+		if len(segment.Categories) > 0 {
+			count++
+		}
+	}
+	return count
+}