暂存一下,防止丢失

internal/domain/cardobservation/traffic.go

@@ -0,0 +1,92 @@
+package cardobservation
+
+import (
+	"math"
+	"time"
+
+	"github.com/break/junhong_cmp_fiber/pkg/errors"
+)
+
+// TrafficObservation 是领域层接收的标准运营商流量读数。
+type TrafficObservation struct {
+	CardID           uint
+	GatewayReadingMB float64
+	ResetDay         int
+	Metadata         ObservationMetadata
+}
+
+// CardTrafficSnapshot 是流量规则需要的最小卡快照。
+type CardTrafficSnapshot struct {
+	CardID                uint
+	DataUsageMB           int64
+	CurrentMonthUsageMB   float64
+	CurrentMonthStartDate *time.Time
+	LastMonthTotalMB      float64
+	LastGatewayReadingMB  float64
+}
+
+// TrafficDecision 描述一次流量观测应持久化的最终值。
+type TrafficDecision struct {
+	IncrementMB           float64
+	ReadingAccepted       bool
+	CrossMonth            bool
+	DataUsageMB           int64
+	CurrentMonthUsageMB   float64
+	CurrentMonthStartDate time.Time
+	LastMonthTotalMB      float64
+	LastGatewayReadingMB  float64
+}
+
+// ApplyTraffic 应用运营商重置、跨月和异常下降保护规则。
+func ApplyTraffic(snapshot CardTrafficSnapshot, observation TrafficObservation) (TrafficDecision, error) {
+	if err := validateObservationMetadata(observation.CardID, observation.Metadata); err != nil {
+		return TrafficDecision{}, err
+	}
+	if math.IsNaN(observation.GatewayReadingMB) || math.IsInf(observation.GatewayReadingMB, 0) || observation.GatewayReadingMB < 0 {
+		return TrafficDecision{}, errors.New(errors.CodeInvalidParam, "流量观测读数无效")
+	}
+	if observation.ResetDay < 1 || observation.ResetDay > 31 {
+		return TrafficDecision{}, errors.New(errors.CodeInvalidParam, "运营商流量重置日无效")
+	}
+	now := observation.Metadata.ObservedAt
+	monthStart := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
+	decision := TrafficDecision{
+		ReadingAccepted: true, DataUsageMB: snapshot.DataUsageMB,
+		CurrentMonthUsageMB: snapshot.CurrentMonthUsageMB, CurrentMonthStartDate: monthStart,
+		LastMonthTotalMB: snapshot.LastMonthTotalMB, LastGatewayReadingMB: observation.GatewayReadingMB,
+	}
+	increment := observation.GatewayReadingMB - snapshot.LastGatewayReadingMB
+	if increment < 0 {
+		if isTrafficResetWindow(now, observation.ResetDay) {
+			increment = observation.GatewayReadingMB
+		} else {
+			increment = 0
+			decision.ReadingAccepted = false
+			decision.LastGatewayReadingMB = snapshot.LastGatewayReadingMB
+		}
+	}
+	decision.IncrementMB = increment
+	decision.CrossMonth = snapshot.CurrentMonthStartDate == nil || snapshot.CurrentMonthStartDate.Before(monthStart)
+	if decision.CrossMonth {
+		decision.LastMonthTotalMB = snapshot.CurrentMonthUsageMB
+		decision.CurrentMonthUsageMB = increment
+	} else if increment > 0 {
+		decision.CurrentMonthUsageMB += increment
+	}
+	if increment > 0 {
+		decision.DataUsageMB += int64(increment)
+	}
+	return decision, nil
+}
+
+func validateObservationMetadata(cardID uint, metadata ObservationMetadata) error {
+	return validateObservation(RealnameObservation{CardID: cardID, Verified: true, Metadata: metadata})
+}
+
+func isTrafficResetWindow(now time.Time, resetDay int) bool {
+	if now.Day() == resetDay {
+		return true
+	}
+	resetDate := time.Date(now.Year(), now.Month(), resetDay, 0, 0, 0, 0, now.Location())
+	return now.Day() == resetDate.AddDate(0, 0, -1).Day()
+}