v1.0.0

internal/domains/finance/services/invoice_domain_service.go

@@ -0,0 +1,152 @@
+package services
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"tyapi-server/internal/domains/finance/entities"
+	"tyapi-server/internal/domains/finance/value_objects"
+
+	"github.com/shopspring/decimal"
+)
+
+// InvoiceDomainService 发票领域服务接口
+// 职责：处理发票领域的业务规则和计算逻辑，不涉及外部依赖
+type InvoiceDomainService interface {
+	// 验证发票信息完整性
+	ValidateInvoiceInfo(ctx context.Context, info *value_objects.InvoiceInfo, invoiceType value_objects.InvoiceType) error
+
+	// 验证开票金额是否合法（基于业务规则）
+	ValidateInvoiceAmount(ctx context.Context, amount decimal.Decimal, availableAmount decimal.Decimal) error
+
+	// 计算可开票金额（纯计算逻辑）
+	CalculateAvailableAmount(totalRecharged decimal.Decimal, totalGifted decimal.Decimal, totalInvoiced decimal.Decimal) decimal.Decimal
+
+	// 验证发票申请状态转换
+	ValidateStatusTransition(currentStatus entities.ApplicationStatus, targetStatus entities.ApplicationStatus) error
+
+	// 验证发票申请业务规则
+	ValidateInvoiceApplication(ctx context.Context, application *entities.InvoiceApplication) error
+}
+
+// InvoiceDomainServiceImpl 发票领域服务实现
+type InvoiceDomainServiceImpl struct {
+	// 领域服务不依赖仓储，只处理业务规则
+}
+
+// NewInvoiceDomainService 创建发票领域服务
+func NewInvoiceDomainService() InvoiceDomainService {
+	return &InvoiceDomainServiceImpl{}
+}
+
+// ValidateInvoiceInfo 验证发票信息完整性
+func (s *InvoiceDomainServiceImpl) ValidateInvoiceInfo(ctx context.Context, info *value_objects.InvoiceInfo, invoiceType value_objects.InvoiceType) error {
+	if info == nil {
+		return errors.New("发票信息不能为空")
+	}
+
+	switch invoiceType {
+	case value_objects.InvoiceTypeGeneral:
+		return info.ValidateForGeneralInvoice()
+	case value_objects.InvoiceTypeSpecial:
+		return info.ValidateForSpecialInvoice()
+	default:
+		return errors.New("无效的发票类型")
+	}
+}
+
+// ValidateInvoiceAmount 验证开票金额是否合法（基于业务规则）
+func (s *InvoiceDomainServiceImpl) ValidateInvoiceAmount(ctx context.Context, amount decimal.Decimal, availableAmount decimal.Decimal) error {
+	if amount.LessThanOrEqual(decimal.Zero) {
+		return errors.New("开票金额必须大于0")
+	}
+
+	if amount.GreaterThan(availableAmount) {
+		return fmt.Errorf("开票金额不能超过可开票金额，可开票金额：%s", availableAmount.String())
+	}
+
+	// 最小开票金额限制
+	minAmount := decimal.NewFromFloat(0.01) // 最小0.01元
+	if amount.LessThan(minAmount) {
+		return fmt.Errorf("开票金额不能少于%s元", minAmount.String())
+	}
+
+	return nil
+}
+
+// CalculateAvailableAmount 计算可开票金额（纯计算逻辑）
+func (s *InvoiceDomainServiceImpl) CalculateAvailableAmount(totalRecharged decimal.Decimal, totalGifted decimal.Decimal, totalInvoiced decimal.Decimal) decimal.Decimal {
+	// 可开票金额 = 充值金额 - 已开票金额（不包含赠送金额）
+	availableAmount := totalRecharged.Sub(totalInvoiced)
+	if availableAmount.LessThan(decimal.Zero) {
+		availableAmount = decimal.Zero
+	}
+	return availableAmount
+}
+
+// ValidateStatusTransition 验证发票申请状态转换
+func (s *InvoiceDomainServiceImpl) ValidateStatusTransition(currentStatus entities.ApplicationStatus, targetStatus entities.ApplicationStatus) error {
+	// 定义允许的状态转换
+	allowedTransitions := map[entities.ApplicationStatus][]entities.ApplicationStatus{
+		entities.ApplicationStatusPending: {
+			entities.ApplicationStatusCompleted,
+			entities.ApplicationStatusRejected,
+		},
+		entities.ApplicationStatusCompleted: {
+			// 已完成状态不能再转换
+		},
+		entities.ApplicationStatusRejected: {
+			// 已拒绝状态不能再转换
+		},
+	}
+
+	allowedTargets, exists := allowedTransitions[currentStatus]
+	if !exists {
+		return fmt.Errorf("无效的当前状态：%s", currentStatus)
+	}
+
+	for _, allowed := range allowedTargets {
+		if allowed == targetStatus {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("不允许从状态 %s 转换到状态 %s", currentStatus, targetStatus)
+}
+
+// ValidateInvoiceApplication 验证发票申请业务规则
+func (s *InvoiceDomainServiceImpl) ValidateInvoiceApplication(ctx context.Context, application *entities.InvoiceApplication) error {
+	if application == nil {
+		return errors.New("发票申请不能为空")
+	}
+
+	// 验证基础字段
+	if application.UserID == "" {
+		return errors.New("用户ID不能为空")
+	}
+
+	if application.Amount.LessThanOrEqual(decimal.Zero) {
+		return errors.New("申请金额必须大于0")
+	}
+
+	// 验证发票类型
+	if !application.InvoiceType.IsValid() {
+		return errors.New("无效的发票类型")
+	}
+
+	// 验证开票信息
+	if application.CompanyName == "" {
+		return errors.New("公司名称不能为空")
+	}
+
+	if application.TaxpayerID == "" {
+		return errors.New("纳税人识别号不能为空")
+	}
+
+	if application.ReceivingEmail == "" {
+		return errors.New("发票接收邮箱不能为空")
+	}
+
+	return nil
+}