Agent-System/internal/ctxmgr/semantic_shadow.go

package ctxmgr

import (
	"context"
	"os"
	"strings"
)

// SemanticSummaryShadowEnabled reports SEMANTIC_SUMMARY_SHADOW (default off).
func SemanticSummaryShadowEnabled() bool {
	v := strings.TrimSpace(os.Getenv("SEMANTIC_SUMMARY_SHADOW"))
	return v == "1" || strings.EqualFold(v, "true") || strings.EqualFold(v, "yes")
}

// MaybeApplySemanticShadow optionally annotates a deterministic summary when the
// shadow flag is on. It never drops Facts; on "model" failure it keeps the
// deterministic narrative and marks freshness. Summarizer has no tool rights.
func MaybeApplySemanticShadow(ctx context.Context, sum *ChatSummary, authorizedOnly bool) *ChatSummary {
	_ = ctx
	if sum == nil || !SemanticSummaryShadowEnabled() {
		return sum
	}
	if !authorizedOnly {
		// Refuse to summarize unauthorized views.
		out := *sum
		if out.Facts == nil {
			out.Facts = map[string]string{}
		}
		out.Facts["semantic_shadow"] = "skipped_unauthorized_view"
		return &out
	}
	out := *sum
	if out.Facts == nil {
		out.Facts = map[string]string{}
	}
	// Deterministic shadow stub (no external LLM in unit path). Real PI can
	// replace Narrative later behind the same flag; failure keeps deterministic.
	shadow := strings.TrimSpace(out.Narrative)
	if shadow == "" {
		shadow = "（语义摘要影子：无叙事，保留事实槽位）"
	} else if !strings.Contains(shadow, "[shadow]") {
		shadow = "[shadow] " + shadow
	}
	out.Narrative = shadow
	out.Facts["semantic_shadow"] = "applied"
	out.Facts["semantic_shadow_freshness"] = "deterministic_fallback_ok"
	return &out
}