实现套餐生效条件覆盖与购买快照

internal/domain/package/terms.go

@@ -0,0 +1,65 @@
+// Package package 提供套餐生命周期领域规则。
+package packagedomain
+
+import (
+	"github.com/break/junhong_cmp_fiber/internal/model"
+	"github.com/break/junhong_cmp_fiber/pkg/constants"
+	"github.com/break/junhong_cmp_fiber/pkg/errors"
+)
+
+// TermsSnapshot 套餐购买时不可变计时条款。
+type TermsSnapshot struct {
+	ExpiryBase     string
+	CalendarType   string
+	DurationMonths int
+	DurationDays   int
+}
+
+// ResolveTermsSnapshot 解析并校验套餐购买时计时条款。
+func ResolveTermsSnapshot(pkg *model.Package, allocation *model.ShopPackageAllocation) (TermsSnapshot, error) {
+	if pkg == nil {
+		return TermsSnapshot{}, errors.New(errors.CodeInvalidParam, "套餐计时条款缺失")
+	}
+	expiryBase := pkg.ExpiryBase
+	if allocation != nil && allocation.ExpiryBaseOverride != nil {
+		expiryBase = *allocation.ExpiryBaseOverride
+	}
+	if expiryBase != constants.PackageExpiryBaseFromActivation && expiryBase != constants.PackageExpiryBaseFromPurchase {
+		return TermsSnapshot{}, errors.New(errors.CodeInvalidParam, "套餐生效条件无效")
+	}
+	if pkg.CalendarType == constants.PackageCalendarTypeNaturalMonth {
+		if pkg.DurationMonths <= 0 {
+			return TermsSnapshot{}, errors.New(errors.CodeInvalidParam, "套餐自然月时长无效")
+		}
+		return TermsSnapshot{ExpiryBase: expiryBase, CalendarType: pkg.CalendarType, DurationMonths: pkg.DurationMonths}, nil
+	}
+	if pkg.CalendarType == constants.PackageCalendarTypeByDay && pkg.DurationDays > 0 {
+		return TermsSnapshot{ExpiryBase: expiryBase, CalendarType: pkg.CalendarType, DurationDays: pkg.DurationDays}, nil
+	}
+	return TermsSnapshot{}, errors.New(errors.CodeInvalidParam, "套餐按天时长无效")
+}
+
+// Apply 将计时条款写入套餐使用记录。
+func (s TermsSnapshot) Apply(usage *model.PackageUsage) {
+	usage.ExpiryBaseSnapshot = s.ExpiryBase
+	usage.CalendarTypeSnapshot = s.CalendarType
+	usage.DurationMonthsSnapshot = s.DurationMonths
+	usage.DurationDaysSnapshot = s.DurationDays
+}
+
+// IsValid 判断快照是否完整有效。
+func (s TermsSnapshot) IsValid() bool {
+	if s.ExpiryBase != constants.PackageExpiryBaseFromActivation && s.ExpiryBase != constants.PackageExpiryBaseFromPurchase {
+		return false
+	}
+	return (s.CalendarType == constants.PackageCalendarTypeNaturalMonth && s.DurationMonths > 0) ||
+		(s.CalendarType == constants.PackageCalendarTypeByDay && s.DurationDays > 0)
+}
+
+// TermsSnapshotFromUsage 从使用记录读取计时条款。
+func TermsSnapshotFromUsage(usage *model.PackageUsage) TermsSnapshot {
+	return TermsSnapshot{
+		ExpiryBase: usage.ExpiryBaseSnapshot, CalendarType: usage.CalendarTypeSnapshot,
+		DurationMonths: usage.DurationMonthsSnapshot, DurationDays: usage.DurationDaysSnapshot,
+	}
+}