From c443df01ba97229b30065a2a3f405cb124b4df1a Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Fri, 3 Apr 2026 05:03:59 +0000
Subject: [PATCH] Add debug logging to internal/difc/resource.go

Add logger var and 5 targeted debug log calls to help troubleshoot
DIFC label aggregation for collection filtering:

- CollectionLabeledData.Overall(): log item count before union
- CollectionLabeledData.Overall(): log when collection is empty
- FilteredCollectionLabeledData.Overall(): log accessible vs filtered counts
- FilteredCollectionLabeledData.Overall(): log when no accessible items
- FilteredCollectionLabeledData.ToResult(): log returned item count and filter reason

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 internal/difc/resource.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/internal/difc/resource.go b/internal/difc/resource.go
index fb04f13c..062baa1f 100644
--- a/internal/difc/resource.go
+++ b/internal/difc/resource.go
@@ -1,5 +1,9 @@
 package difc
 
+import "github.com/github/gh-aw-mcpg/internal/logger"
+
+var logResource = logger.New("difc:resource")
+
 // Resource represents an external system with label requirements (deprecated - use LabeledResource)
 type Resource struct {
 	Description string
@@ -104,9 +108,11 @@ type LabeledItem struct {
 func (c *CollectionLabeledData) Overall() *LabeledResource {
 	// Aggregate labels from all items - most restrictive
 	if len(c.Items) == 0 {
+		logResource.Print("CollectionLabeledData.Overall: empty collection, returning empty labels")
 		return NewLabeledResource("empty collection")
 	}
 
+	logResource.Printf("CollectionLabeledData.Overall: aggregating labels from %d items", len(c.Items))
 	overall := NewLabeledResource("collection")
 	for _, item := range c.Items {
 		if item.Labels != nil {
@@ -147,9 +153,11 @@ type FilteredCollectionLabeledData struct {
 func (f *FilteredCollectionLabeledData) Overall() *LabeledResource {
 	// Only aggregate labels from accessible items
 	if len(f.Accessible) == 0 {
+		logResource.Print("FilteredCollectionLabeledData.Overall: no accessible items, returning empty labels")
 		return NewLabeledResource("empty filtered collection")
 	}
 
+	logResource.Printf("FilteredCollectionLabeledData.Overall: aggregating labels from %d accessible items (%d filtered)", len(f.Accessible), len(f.Filtered))
 	overall := NewLabeledResource("filtered collection")
 	for _, item := range f.Accessible {
 		if item.Labels != nil {
@@ -163,6 +171,7 @@ func (f *FilteredCollectionLabeledData) Overall() *LabeledResource {
 
 func (f *FilteredCollectionLabeledData) ToResult() (interface{}, error) {
 	// Return only accessible items
+	logResource.Printf("FilteredCollectionLabeledData.ToResult: returning %d accessible items (filter_reason=%s)", len(f.Accessible), f.FilterReason)
 	result := make([]interface{}, 0, len(f.Accessible))
 	for _, item := range f.Accessible {
 		result = append(result, item.Data)