Agent-System/internal/ctxmgr/summary_flags.go

package ctxmgr

import (
	"os"
	"strings"
	"sync"
)

const (
	EnvSemanticSummaryShadow  = "SEMANTIC_SUMMARY_SHADOW"
	EnvSemanticSummaryReplace = "SEMANTIC_SUMMARY_REPLACE"
)

// SummaryFeatureFlags controls semantic summary rollout.
// REPLACE is reserved and must remain unwired in PU6 shadow delivery.
type SummaryFeatureFlags struct {
	Shadow  bool
	Replace bool
}

var (
	summaryFlagsMu     sync.RWMutex
	activeSummaryFlags = loadSummaryFlagsFromEnv()
)

func loadSummaryFlagsFromEnv() SummaryFeatureFlags {
	return SummaryFeatureFlags{
		Shadow:  envBoolDefault(EnvSemanticSummaryShadow, false),
		Replace: envBoolDefault(EnvSemanticSummaryReplace, false),
	}
}

func envBoolDefault(key string, def bool) bool {
	v := strings.TrimSpace(os.Getenv(key))
	if v == "" {
		return def
	}
	return v == "1" || strings.EqualFold(v, "true") || strings.EqualFold(v, "yes")
}

// CurrentSummaryFlags returns the active summary feature flags.
func CurrentSummaryFlags() SummaryFeatureFlags {
	summaryFlagsMu.RLock()
	defer summaryFlagsMu.RUnlock()
	return activeSummaryFlags
}

// SemanticSummaryShadowEnabled reports whether shadow semantic summary is on.
func SemanticSummaryShadowEnabled() bool {
	return CurrentSummaryFlags().Shadow
}

// SemanticSummaryReplaceEnabled reports the REPLACE env bit.
// PU6 must not use this to swap the served deterministic narrative.
func SemanticSummaryReplaceEnabled() bool {
	return CurrentSummaryFlags().Replace
}

// SetSummaryFlagsForTest overrides flags in tests.
func SetSummaryFlagsForTest(f SummaryFeatureFlags) {
	summaryFlagsMu.Lock()
	activeSummaryFlags = f
	summaryFlagsMu.Unlock()
}

// ResetSummaryFlagsForTest restores flags from the process environment.
func ResetSummaryFlagsForTest() {
	summaryFlagsMu.Lock()
	activeSummaryFlags = loadSummaryFlagsFromEnv()
	summaryFlagsMu.Unlock()
}