Add holdouts to OptimizelyConfig

This change exposes holdouts in the OptimizelyConfig API, allowing
clients to retrieve holdout information via the config endpoint.

Changes:
- Added OptimizelyHoldout type with id, key, audiences, and variationsMap
- Added Holdouts field to OptimizelyConfig struct
- Added GetHoldoutList() method to ProjectConfig interface
- Implemented getHoldouts() helper to convert holdout entities to OptimizelyHoldouts
- Populated holdouts in NewOptimizelyConfig constructor

This enables Agent and other clients to expose holdout configuration
through their /config endpoints.

Author: Mat001

pkg/config/datafileprojectconfig/config.go

@@ -292,6 +292,11 @@ func (c DatafileProjectConfig) GetHoldoutsForFlag(featureKey string) []entities.
 	return []entities.Holdout{}
 }
 
+// GetHoldoutList returns all holdouts in the project
+func (c DatafileProjectConfig) GetHoldoutList() []entities.Holdout {
+	return c.holdouts
+}
+
 // NewDatafileProjectConfig initializes a new datafile from a json byte array using the default JSON datafile parser
 func NewDatafileProjectConfig(jsonDatafile []byte, logger logging.OptimizelyLogProducer) (*DatafileProjectConfig, error) {
 	datafile, err := Parse(jsonDatafile)

pkg/config/interface.go

@@ -57,6 +57,7 @@ type ProjectConfig interface {
 	GetFlagVariationsMap() map[string][]entities.Variation
 	GetRegion() string
 	GetHoldoutsForFlag(featureKey string) []entities.Holdout
+	GetHoldoutList() []entities.Holdout
 }
 
 // ProjectConfigManager maintains an instance of the ProjectConfig

pkg/config/optimizely_config.go

@@ -42,6 +42,7 @@ type OptimizelyConfig struct {
 	Attributes  []OptimizelyAttribute        `json:"attributes"`
 	Audiences   []OptimizelyAudience         `json:"audiences"`
 	Events      []OptimizelyEvent            `json:"events"`
+	Holdouts    []OptimizelyHoldout          `json:"holdouts"`
 	datafile    string
 }
 
@@ -78,6 +79,14 @@ type OptimizelyEvent struct {
 	ExperimentIds []string `json:"experimentIds"`
 }
 
+// OptimizelyHoldout has holdout info
+type OptimizelyHoldout struct {
+	ID            string                         `json:"id"`
+	Key           string                         `json:"key"`
+	Audiences     string                         `json:"audiences"`
+	VariationsMap map[string]OptimizelyVariation `json:"variationsMap"`
+}
+
 // OptimizelyFeature has feature info
 type OptimizelyFeature struct {
 	ID              string                        `json:"id"`
@@ -365,6 +374,35 @@ func getFeaturesMap(audiencesByID map[string]entities.Audience, mappedExperiment
 	return featuresMap
 }
 
+func getHoldoutAudiences(holdout entities.Holdout, audiencesByID map[string]entities.Audience) string {
+	return getSerializedAudiences(holdout.AudienceConditions, audiencesByID)
+}
+
+func getHoldouts(audiencesByID map[string]entities.Audience, holdouts []entities.Holdout) []OptimizelyHoldout {
+	optimizelyHoldouts := []OptimizelyHoldout{}
+
+	for _, holdout := range holdouts {
+		// Create variations map for this holdout
+		variationsMap := map[string]OptimizelyVariation{}
+		for _, variation := range holdout.Variations {
+			variationsMap[variation.Key] = OptimizelyVariation{
+				ID:             variation.ID,
+				Key:            variation.Key,
+				FeatureEnabled: variation.FeatureEnabled,
+				VariablesMap:   map[string]OptimizelyVariable{}, // Holdouts don't have feature variables
+			}
+		}
+
+		optimizelyHoldouts = append(optimizelyHoldouts, OptimizelyHoldout{
+			ID:            holdout.ID,
+			Key:           holdout.Key,
+			Audiences:     getHoldoutAudiences(holdout, audiencesByID),
+			VariationsMap: variationsMap,
+		})
+	}
+	return optimizelyHoldouts
+}
+
 // NewOptimizelyConfig constructs OptimizelyConfig object
 func NewOptimizelyConfig(projConfig ProjectConfig) *OptimizelyConfig {
 
@@ -405,6 +443,8 @@ func NewOptimizelyConfig(projConfig ProjectConfig) *OptimizelyConfig {
 	variableByIDMap := getVariableByIDMap(featuresList)
 	optimizelyConfig.FeaturesMap = getFeaturesMap(projConfig.GetAudienceMap(), mappedExperiments, featuresList, rolloutIDMap, variableByIDMap)
 
+	optimizelyConfig.Holdouts = getHoldouts(projConfig.GetAudienceMap(), projConfig.GetHoldoutList())
+
 	optimizelyConfig.datafile = projConfig.GetDatafile()
 
 	return optimizelyConfig