Merge remote-tracking branch 'origin/master'

svc/product_series_auto_scheduler.go

@@ -533,6 +533,7 @@ func productSeriesApplyVariant(ctx context.Context, pg *sql.DB, v productSeriesA
 	if err != nil {
 		return 0, 1, err
 	}
+	appliedFallback := false
 	if !ready {
 		if productSeriesFallbackLogEnabled() {
 			log.Printf("[ProductSeriesFallback] skip_not_ready product=%s color=%s dim3=%s", strings.TrimSpace(v.ProductCode), strings.TrimSpace(v.ColorCode), strings.TrimSpace(v.Dim3Code))
@@ -607,6 +608,30 @@ func productSeriesApplyVariant(ctx context.Context, pg *sql.DB, v productSeriesA
 					return 0, 1, err
 				}
 				if len(existingIDs) > 0 {
+					// Optional grace window: if we recently applied non-fallback rules for this variant,
+					// don't immediately flap back to fallback due to a transient/partial stock snapshot.
+					graceMin := envIntRange("PRODUCT_SERIES_FALLBACK_GRACE_MINUTES", 2, 0, 60)
+					if graceMin > 0 {
+						rowKey := productSeriesAutoKey(v.ProductCode, v.ColorCode, v.Dim3Code)
+						kind, at, err := productSeriesLoadLastApplyState(ctx, pg, rowKey)
+						if err != nil {
+							return 0, 1, err
+						}
+						if kind == "rules" && time.Since(at) < time.Duration(graceMin)*time.Minute {
+							// keep existing mapping as-is for now
+							if productSeriesFallbackLogEnabled() {
+								log.Printf("[ProductSeriesFallback] grace_skip product=%s color=%s dim3=%s grace_min=%d last_rules_at=%s",
+									strings.TrimSpace(v.ProductCode),
+									strings.TrimSpace(v.ColorCode),
+									strings.TrimSpace(v.Dim3Code),
+									graceMin,
+									at.Format(time.RFC3339),
+								)
+							}
+							return 0, 0, nil
+						}
+					}
+
 					anyStillValid := false
 					for _, sid := range existingIDs {
 						// If we can't find the rule definition in memory, assume it's a manual/unknown mapping and keep it.
@@ -641,6 +666,7 @@ func productSeriesApplyVariant(ctx context.Context, pg *sql.DB, v productSeriesA
 			}
 			// Use the fallback series as the single selected rule.
 			selected = []productSeriesAutoRule{{SeriesID: fallbackID}}
+			appliedFallback = true
 		} else {
 			if productSeriesFallbackLogEnabled() {
 				log.Printf("[ProductSeriesFallback] missing_fallback product=%s color=%s dim3=%s fallback_code=%s", strings.TrimSpace(v.ProductCode), strings.TrimSpace(v.ColorCode), strings.TrimSpace(v.Dim3Code), strings.TrimSpace(fallbackCode))
@@ -676,11 +702,27 @@ VALUES ($1, $2, $3, $4)
 	if err := tx.Commit(); err != nil {
 		return 0, 0, err
 	}
+	// Track what we last applied for this variant to reduce flapping and help ops debugging.
+	rowKey := productSeriesAutoKey(v.ProductCode, v.ColorCode, v.Dim3Code)
+	kind := "rules"
+	if appliedFallback {
+		kind = "fallback"
+	}
+	ids := make([]string, 0, len(selected))
+	for _, r := range selected {
+		ids = append(ids, fmt.Sprintf("%d", r.SeriesID))
+	}
+	_, _ = pg.ExecContext(ctx, `
+INSERT INTO mk_product_series_apply_state (row_key, last_apply_at, last_apply_kind, last_series_ids, updated_at)
+VALUES ($1, now(), $2, $3, now())
+ON CONFLICT (row_key) DO UPDATE
+SET last_apply_at=EXCLUDED.last_apply_at,
+    last_apply_kind=EXCLUDED.last_apply_kind,
+    last_series_ids=EXCLUDED.last_series_ids,
+    updated_at=now()
+`, rowKey, kind, strings.Join(ids, ","))
+
 	if productSeriesDebugMatch(v) {
-		ids := make([]string, 0, len(selected))
-		for _, r := range selected {
-			ids = append(ids, fmt.Sprintf("%d", r.SeriesID))
-		}
 		log.Printf("[ProductSeriesDebug] wrote=%d product=%s color=%s dim3=%s series_ids=%s",
 			len(selected),
 			strings.TrimSpace(v.ProductCode),
@@ -692,6 +734,23 @@ VALUES ($1, $2, $3, $4)
 	return len(selected), 0, nil
 }
 
+func productSeriesLoadLastApplyState(ctx context.Context, pg *sql.DB, rowKey string) (kind string, at time.Time, err error) {
+	var k string
+	var t time.Time
+	err = pg.QueryRowContext(ctx, `
+SELECT COALESCE(last_apply_kind,''), COALESCE(last_apply_at, now())
+FROM mk_product_series_apply_state
+WHERE row_key=$1
+`, rowKey).Scan(&k, &t)
+	if err == sql.ErrNoRows {
+		return "", time.Time{}, nil
+	}
+	if err != nil {
+		return "", time.Time{}, err
+	}
+	return k, t, nil
+}
+
 func productSeriesFindRuleByID(rules []productSeriesAutoRule, seriesID int64) (productSeriesAutoRule, bool) {
 	for _, r := range rules {
 		if r.SeriesID == seriesID {