package finance

import (
	"context"
	"fmt"
	"mime/multipart"
	"time"

	"tyapi-server/internal/application/finance/dto"
	"tyapi-server/internal/domains/finance/entities"
	finance_repo "tyapi-server/internal/domains/finance/repositories"
	"tyapi-server/internal/domains/finance/services"
	"tyapi-server/internal/domains/finance/value_objects"
	user_repo "tyapi-server/internal/domains/user/repositories"
	user_service "tyapi-server/internal/domains/user/services"
	"tyapi-server/internal/infrastructure/external/storage"

	"github.com/shopspring/decimal"
	"go.uber.org/zap"
)

// ==================== 用户端发票应用服务 ====================

// InvoiceApplicationService 发票应用服务接口
// 职责：跨域协调、数据聚合、事务管理、外部服务调用
type InvoiceApplicationService interface {
	// ApplyInvoice 申请开票
	ApplyInvoice(ctx context.Context, userID string, req ApplyInvoiceRequest) (*dto.InvoiceApplicationResponse, error)

	// GetUserInvoiceInfo 获取用户发票信息
	GetUserInvoiceInfo(ctx context.Context, userID string) (*dto.InvoiceInfoResponse, error)

	// UpdateUserInvoiceInfo 更新用户发票信息
	UpdateUserInvoiceInfo(ctx context.Context, userID string, req UpdateInvoiceInfoRequest) error

	// GetUserInvoiceRecords 获取用户开票记录
	GetUserInvoiceRecords(ctx context.Context, userID string, req GetInvoiceRecordsRequest) (*dto.InvoiceRecordsResponse, error)

	// DownloadInvoiceFile 下载发票文件
	DownloadInvoiceFile(ctx context.Context, userID string, applicationID string) (*dto.FileDownloadResponse, error)

	// GetAvailableAmount 获取可开票金额
	GetAvailableAmount(ctx context.Context, userID string) (*dto.AvailableAmountResponse, error)
}

// InvoiceApplicationServiceImpl 发票应用服务实现
type InvoiceApplicationServiceImpl struct {
	// 仓储层依赖
	invoiceRepo         finance_repo.InvoiceApplicationRepository
	userInvoiceInfoRepo finance_repo.UserInvoiceInfoRepository
	userRepo            user_repo.UserRepository
	rechargeRecordRepo  finance_repo.RechargeRecordRepository
	walletRepo          finance_repo.WalletRepository

	// 领域服务依赖
	invoiceDomainService    services.InvoiceDomainService
	invoiceAggregateService services.InvoiceAggregateService
	userInvoiceInfoService  services.UserInvoiceInfoService
	userAggregateService    user_service.UserAggregateService

	// 外部服务依赖
	storageService *storage.QiNiuStorageService
	logger         *zap.Logger
}

// NewInvoiceApplicationService 创建发票应用服务
func NewInvoiceApplicationService(
	invoiceRepo finance_repo.InvoiceApplicationRepository,
	userInvoiceInfoRepo finance_repo.UserInvoiceInfoRepository,
	userRepo user_repo.UserRepository,
	userAggregateService user_service.UserAggregateService,
	rechargeRecordRepo finance_repo.RechargeRecordRepository,
	walletRepo finance_repo.WalletRepository,
	invoiceDomainService services.InvoiceDomainService,
	invoiceAggregateService services.InvoiceAggregateService,
	userInvoiceInfoService services.UserInvoiceInfoService,
	storageService *storage.QiNiuStorageService,
	logger *zap.Logger,
) InvoiceApplicationService {
	return &InvoiceApplicationServiceImpl{
		invoiceRepo:             invoiceRepo,
		userInvoiceInfoRepo:     userInvoiceInfoRepo,
		userRepo:                userRepo,
		userAggregateService:    userAggregateService,
		rechargeRecordRepo:      rechargeRecordRepo,
		walletRepo:              walletRepo,
		invoiceDomainService:    invoiceDomainService,
		invoiceAggregateService: invoiceAggregateService,
		userInvoiceInfoService:  userInvoiceInfoService,
		storageService:          storageService,
		logger:                  logger,
	}
}

// ApplyInvoice 申请开票
func (s *InvoiceApplicationServiceImpl) ApplyInvoice(ctx context.Context, userID string, req ApplyInvoiceRequest) (*dto.InvoiceApplicationResponse, error) {
	// 1. 验证用户是否存在
	user, err := s.userRepo.GetByID(ctx, userID)
	if err != nil {
		return nil, err
	}
	if user.ID == "" {
		return nil, fmt.Errorf("用户不存在")
	}

	// 2. 验证发票类型
	invoiceType := value_objects.InvoiceType(req.InvoiceType)
	if !invoiceType.IsValid() {
		return nil, fmt.Errorf("无效的发票类型")
	}

	// 3. 获取用户企业认证信息
	userWithEnterprise, err := s.userAggregateService.GetUserWithEnterpriseInfo(ctx, userID)
	if err != nil {
		return nil, fmt.Errorf("获取用户企业认证信息失败: %w", err)
	}

	// 4. 检查用户是否有企业认证信息
	if userWithEnterprise.EnterpriseInfo == nil {
		return nil, fmt.Errorf("用户未完成企业认证，无法申请开票")
	}

	// 5. 获取用户开票信息
	userInvoiceInfo, err := s.userInvoiceInfoService.GetUserInvoiceInfoWithEnterpriseInfo(
		ctx,
		userID,
		userWithEnterprise.EnterpriseInfo.CompanyName,
		userWithEnterprise.EnterpriseInfo.UnifiedSocialCode,
	)
	if err != nil {
		return nil, err
	}

	// 6. 验证开票信息完整性
	invoiceInfo := value_objects.NewInvoiceInfo(
		userInvoiceInfo.CompanyName,
		userInvoiceInfo.TaxpayerID,
		userInvoiceInfo.BankName,
		userInvoiceInfo.BankAccount,
		userInvoiceInfo.CompanyAddress,
		userInvoiceInfo.CompanyPhone,
		userInvoiceInfo.ReceivingEmail,
	)

	if err := s.userInvoiceInfoService.ValidateInvoiceInfo(ctx, invoiceInfo, invoiceType); err != nil {
		return nil, err
	}

	// 7. 计算可开票金额
	availableAmount, err := s.calculateAvailableAmount(ctx, userID)
	if err != nil {
		return nil, fmt.Errorf("计算可开票金额失败: %w", err)
	}

	// 8. 验证开票金额
	amount, err := decimal.NewFromString(req.Amount)
	if err != nil {
		return nil, fmt.Errorf("无效的金额格式: %w", err)
	}

	if err := s.invoiceDomainService.ValidateInvoiceAmount(ctx, amount, availableAmount); err != nil {
		return nil, err
	}

	// 9. 调用聚合服务申请开票
	aggregateReq := services.ApplyInvoiceRequest{
		InvoiceType: invoiceType,
		Amount:      req.Amount,
		InvoiceInfo: invoiceInfo,
	}

	application, err := s.invoiceAggregateService.ApplyInvoice(ctx, userID, aggregateReq)
	if err != nil {
		return nil, err
	}

	// 10. 构建响应DTO
	return &dto.InvoiceApplicationResponse{
		ID:          application.ID,
		UserID:      application.UserID,
		InvoiceType: application.InvoiceType,
		Amount:      application.Amount,
		Status:      application.Status,
		InvoiceInfo: invoiceInfo,
		CreatedAt:   application.CreatedAt,
	}, nil
}

// GetUserInvoiceInfo 获取用户发票信息
func (s *InvoiceApplicationServiceImpl) GetUserInvoiceInfo(ctx context.Context, userID string) (*dto.InvoiceInfoResponse, error) {
	// 1. 获取用户企业认证信息
	user, err := s.userAggregateService.GetUserWithEnterpriseInfo(ctx, userID)
	if err != nil {
		return nil, fmt.Errorf("获取用户企业认证信息失败: %w", err)
	}

	// 2. 获取企业认证信息
	var companyName, taxpayerID string
	var companyNameReadOnly, taxpayerIDReadOnly bool

	if user.EnterpriseInfo != nil {
		companyName = user.EnterpriseInfo.CompanyName
		taxpayerID = user.EnterpriseInfo.UnifiedSocialCode
		companyNameReadOnly = true
		taxpayerIDReadOnly = true
	}

	// 3. 获取用户开票信息（包含企业认证信息）
	userInvoiceInfo, err := s.userInvoiceInfoService.GetUserInvoiceInfoWithEnterpriseInfo(ctx, userID, companyName, taxpayerID)
	if err != nil {
		return nil, err
	}

	// 4. 构建响应DTO
	return &dto.InvoiceInfoResponse{
		CompanyName:    userInvoiceInfo.CompanyName,
		TaxpayerID:     userInvoiceInfo.TaxpayerID,
		BankName:       userInvoiceInfo.BankName,
		BankAccount:    userInvoiceInfo.BankAccount,
		CompanyAddress: userInvoiceInfo.CompanyAddress,
		CompanyPhone:   userInvoiceInfo.CompanyPhone,
		ReceivingEmail: userInvoiceInfo.ReceivingEmail,
		IsComplete:     userInvoiceInfo.IsComplete(),
		MissingFields:  userInvoiceInfo.GetMissingFields(),
		// 字段权限标识
		CompanyNameReadOnly: companyNameReadOnly, // 公司名称只读（从企业认证信息获取）
		TaxpayerIDReadOnly:  taxpayerIDReadOnly,  // 纳税人识别号只读（从企业认证信息获取）
	}, nil
}

// UpdateUserInvoiceInfo 更新用户发票信息
func (s *InvoiceApplicationServiceImpl) UpdateUserInvoiceInfo(ctx context.Context, userID string, req UpdateInvoiceInfoRequest) error {
	// 1. 获取用户企业认证信息
	user, err := s.userAggregateService.GetUserWithEnterpriseInfo(ctx, userID)
	if err != nil {
		return fmt.Errorf("获取用户企业认证信息失败: %w", err)
	}

	// 2. 检查用户是否有企业认证信息
	if user.EnterpriseInfo == nil {
		return fmt.Errorf("用户未完成企业认证，无法创建开票信息")
	}

	// 3. 创建开票信息对象，公司名称和纳税人识别号从企业认证信息中获取
	invoiceInfo := value_objects.NewInvoiceInfo(
		"", // 公司名称将由服务层从企业认证信息中获取
		"", // 纳税人识别号将由服务层从企业认证信息中获取
		req.BankName,
		req.BankAccount,
		req.CompanyAddress,
		req.CompanyPhone,
		req.ReceivingEmail,
	)

	// 4. 使用包含企业认证信息的方法
	_, err = s.userInvoiceInfoService.CreateOrUpdateUserInvoiceInfoWithEnterpriseInfo(
		ctx,
		userID,
		invoiceInfo,
		user.EnterpriseInfo.CompanyName,
		user.EnterpriseInfo.UnifiedSocialCode,
	)
	return err
}

// GetUserInvoiceRecords 获取用户开票记录
func (s *InvoiceApplicationServiceImpl) GetUserInvoiceRecords(ctx context.Context, userID string, req GetInvoiceRecordsRequest) (*dto.InvoiceRecordsResponse, error) {
	// 1. 验证用户是否存在
	user, err := s.userRepo.GetByID(ctx, userID)
	if err != nil {
		return nil, err
	}
	if user.ID == "" {
		return nil, fmt.Errorf("用户不存在")
	}

	// 2. 获取发票申请记录
	var status entities.ApplicationStatus
	if req.Status != "" {
		status = entities.ApplicationStatus(req.Status)
	}

	// 3. 解析时间范围
	var startTime, endTime *time.Time
	if req.StartTime != "" {
		if t, err := time.Parse("2006-01-02 15:04:05", req.StartTime); err == nil {
			startTime = &t
		}
	}
	if req.EndTime != "" {
		if t, err := time.Parse("2006-01-02 15:04:05", req.EndTime); err == nil {
			endTime = &t
		}
	}

	// 4. 获取发票申请记录（需要更新仓储层方法以支持时间筛选）
	applications, total, err := s.invoiceRepo.FindByUserIDAndStatusWithTimeRange(ctx, userID, status, startTime, endTime, req.Page, req.PageSize)
	if err != nil {
		return nil, err
	}

	// 5. 构建响应DTO
	records := make([]*dto.InvoiceRecordResponse, len(applications))
	for i, app := range applications {
		// 使用快照信息（申请时的开票信息）
		records[i] = &dto.InvoiceRecordResponse{
			ID:             app.ID,
			UserID:         app.UserID,
			InvoiceType:    app.InvoiceType,
			Amount:         app.Amount,
			Status:         app.Status,
			CompanyName:    app.CompanyName,    // 使用快照的公司名称
			TaxpayerID:     app.TaxpayerID,     // 使用快照的纳税人识别号
			BankName:       app.BankName,       // 使用快照的银行名称
			BankAccount:    app.BankAccount,    // 使用快照的银行账号
			CompanyAddress: app.CompanyAddress, // 使用快照的企业地址
			CompanyPhone:   app.CompanyPhone,   // 使用快照的企业电话
			ReceivingEmail: app.ReceivingEmail, // 使用快照的接收邮箱
			FileName:       app.FileName,
			FileSize:       app.FileSize,
			FileURL:        app.FileURL,
			ProcessedAt:    app.ProcessedAt,
			CreatedAt:      app.CreatedAt,
			RejectReason:   app.RejectReason,
		}
	}

	return &dto.InvoiceRecordsResponse{
		Records:    records,
		Total:      total,
		Page:       req.Page,
		PageSize:   req.PageSize,
		TotalPages: (int(total) + req.PageSize - 1) / req.PageSize,
	}, nil
}

// DownloadInvoiceFile 下载发票文件
func (s *InvoiceApplicationServiceImpl) DownloadInvoiceFile(ctx context.Context, userID string, applicationID string) (*dto.FileDownloadResponse, error) {
	// 1. 查找申请记录
	application, err := s.invoiceRepo.FindByID(ctx, applicationID)
	if err != nil {
		return nil, err
	}
	if application == nil {
		return nil, fmt.Errorf("申请记录不存在")
	}

	// 2. 验证权限（只能下载自己的发票）
	if application.UserID != userID {
		return nil, fmt.Errorf("无权访问此发票")
	}

	// 3. 验证状态（只能下载已完成的发票）
	if application.Status != entities.ApplicationStatusCompleted {
		return nil, fmt.Errorf("发票尚未通过审核")
	}

	// 4. 验证文件信息
	if application.FileURL == nil || *application.FileURL == "" {
		return nil, fmt.Errorf("发票文件不存在")
	}

	// 5. 从七牛云下载文件内容
	fileContent, err := s.storageService.DownloadFile(ctx, *application.FileURL)
	if err != nil {
		return nil, fmt.Errorf("下载文件失败: %w", err)
	}

	// 6. 构建响应DTO
	return &dto.FileDownloadResponse{
		FileID:      *application.FileID,
		FileName:    *application.FileName,
		FileSize:    *application.FileSize,
		FileURL:     *application.FileURL,
		FileContent: fileContent,
	}, nil
}

// GetAvailableAmount 获取可开票金额
func (s *InvoiceApplicationServiceImpl) GetAvailableAmount(ctx context.Context, userID string) (*dto.AvailableAmountResponse, error) {
	// 1. 验证用户是否存在
	user, err := s.userRepo.GetByID(ctx, userID)
	if err != nil {
		return nil, err
	}
	if user.ID == "" {
		return nil, fmt.Errorf("用户不存在")
	}

	// 2. 计算可开票金额
	availableAmount, err := s.calculateAvailableAmount(ctx, userID)
	if err != nil {
		return nil, err
	}

	// 3. 获取真实充值金额（支付宝充值+对公转账）和总赠送金额
	realRecharged, totalGifted, totalInvoiced, err := s.getAmountSummary(ctx, userID)
	if err != nil {
		return nil, err
	}

	// 4. 获取待处理申请金额
	pendingAmount, err := s.getPendingApplicationsAmount(ctx, userID)
	if err != nil {
		return nil, err
	}

	// 5. 构建响应DTO
	return &dto.AvailableAmountResponse{
		AvailableAmount:     availableAmount,
		TotalRecharged:      realRecharged, // 使用真实充值金额（支付宝充值+对公转账）
		TotalGifted:         totalGifted,
		TotalInvoiced:       totalInvoiced,
		PendingApplications: pendingAmount,
	}, nil
}

// calculateAvailableAmount 计算可开票金额（私有方法）
func (s *InvoiceApplicationServiceImpl) calculateAvailableAmount(ctx context.Context, userID string) (decimal.Decimal, error) {
	// 1. 获取真实充值金额（支付宝充值+对公转账）和总赠送金额
	realRecharged, totalGifted, totalInvoiced, err := s.getAmountSummary(ctx, userID)
	if err != nil {
		return decimal.Zero, err
	}

	// 2. 获取待处理中的申请金额
	pendingAmount, err := s.getPendingApplicationsAmount(ctx, userID)
	if err != nil {
		return decimal.Zero, err
	}
	fmt.Println("realRecharged", realRecharged)
	fmt.Println("totalGifted", totalGifted)
	fmt.Println("totalInvoiced", totalInvoiced)
	fmt.Println("pendingAmount", pendingAmount)
	// 3. 计算可开票金额：真实充值金额 - 已开票 - 待处理申请
	// 可开票金额 = 真实充值金额（支付宝充值+对公转账） - 已开票金额 - 待处理申请金额
	availableAmount := realRecharged.Sub(totalInvoiced).Sub(pendingAmount)
	fmt.Println("availableAmount", availableAmount)
	// 确保可开票金额不为负数
	if availableAmount.LessThan(decimal.Zero) {
		availableAmount = decimal.Zero
	}

	return availableAmount, nil
}

// getAmountSummary 获取金额汇总（私有方法）
func (s *InvoiceApplicationServiceImpl) getAmountSummary(ctx context.Context, userID string) (decimal.Decimal, decimal.Decimal, decimal.Decimal, error) {
	// 1. 获取用户所有成功的充值记录
	rechargeRecords, err := s.rechargeRecordRepo.GetByUserID(ctx, userID)
	if err != nil {
		return decimal.Zero, decimal.Zero, decimal.Zero, fmt.Errorf("获取充值记录失败: %w", err)
	}

	// 2. 计算真实充值金额（支付宝充值 + 对公转账）和总赠送金额
	var realRecharged decimal.Decimal // 真实充值金额：支付宝充值 + 对公转账
	var totalGifted decimal.Decimal   // 总赠送金额
	for _, record := range rechargeRecords {
		if record.IsSuccess() {
			if record.RechargeType == entities.RechargeTypeGift {
				// 赠送金额不计入可开票金额
				totalGifted = totalGifted.Add(record.Amount)
			} else if record.RechargeType == entities.RechargeTypeAlipay || record.RechargeType == entities.RechargeTypeTransfer {
				// 只有支付宝充值和对公转账计入可开票金额
				realRecharged = realRecharged.Add(record.Amount)
			}
		}
	}

	// 3. 获取用户所有发票申请记录（包括待处理、已完成、已拒绝）
	applications, _, err := s.invoiceRepo.FindByUserID(ctx, userID, 1, 1000) // 获取所有记录
	if err != nil {
		return decimal.Zero, decimal.Zero, decimal.Zero, fmt.Errorf("获取发票申请记录失败: %w", err)
	}

	var totalInvoiced decimal.Decimal
	for _, application := range applications {
		// 计算已完成的发票申请金额
		if application.IsCompleted() {
			totalInvoiced = totalInvoiced.Add(application.Amount)
		}
		// 注意：待处理中的申请金额不计算在已开票金额中，但会在可开票金额计算时被扣除
	}

	return realRecharged, totalGifted, totalInvoiced, nil
}

// getPendingApplicationsAmount 获取待处理申请的总金额（私有方法）
func (s *InvoiceApplicationServiceImpl) getPendingApplicationsAmount(ctx context.Context, userID string) (decimal.Decimal, error) {
	// 获取用户所有发票申请记录
	applications, _, err := s.invoiceRepo.FindByUserID(ctx, userID, 1, 1000)
	if err != nil {
		return decimal.Zero, fmt.Errorf("获取发票申请记录失败: %w", err)
	}

	var pendingAmount decimal.Decimal
	for _, application := range applications {
		// 只计算待处理状态的申请金额
		if application.Status == entities.ApplicationStatusPending {
			pendingAmount = pendingAmount.Add(application.Amount)
		}
	}

	return pendingAmount, nil
}

// ==================== 管理员端发票应用服务 ====================

// AdminInvoiceApplicationService 管理员发票应用服务接口
type AdminInvoiceApplicationService interface {
	// GetPendingApplications 获取发票申请列表（支持筛选）
	GetPendingApplications(ctx context.Context, req GetPendingApplicationsRequest) (*dto.PendingApplicationsResponse, error)

	// ApproveInvoiceApplication 通过发票申请
	ApproveInvoiceApplication(ctx context.Context, applicationID string, file multipart.File, req ApproveInvoiceRequest) error

	// RejectInvoiceApplication 拒绝发票申请
	RejectInvoiceApplication(ctx context.Context, applicationID string, req RejectInvoiceRequest) error

	// DownloadInvoiceFile 下载发票文件（管理员）
	DownloadInvoiceFile(ctx context.Context, applicationID string) (*dto.FileDownloadResponse, error)
}

// AdminInvoiceApplicationServiceImpl 管理员发票应用服务实现
type AdminInvoiceApplicationServiceImpl struct {
	invoiceRepo             finance_repo.InvoiceApplicationRepository
	userInvoiceInfoRepo     finance_repo.UserInvoiceInfoRepository
	userRepo                user_repo.UserRepository
	invoiceAggregateService services.InvoiceAggregateService
	storageService          *storage.QiNiuStorageService
	logger                  *zap.Logger
}

// NewAdminInvoiceApplicationService 创建管理员发票应用服务
func NewAdminInvoiceApplicationService(
	invoiceRepo finance_repo.InvoiceApplicationRepository,
	userInvoiceInfoRepo finance_repo.UserInvoiceInfoRepository,
	userRepo user_repo.UserRepository,
	invoiceAggregateService services.InvoiceAggregateService,
	storageService *storage.QiNiuStorageService,
	logger *zap.Logger,
) AdminInvoiceApplicationService {
	return &AdminInvoiceApplicationServiceImpl{
		invoiceRepo:             invoiceRepo,
		userInvoiceInfoRepo:     userInvoiceInfoRepo,
		userRepo:                userRepo,
		invoiceAggregateService: invoiceAggregateService,
		storageService:          storageService,
		logger:                  logger,
	}
}

// GetPendingApplications 获取发票申请列表（支持筛选）
func (s *AdminInvoiceApplicationServiceImpl) GetPendingApplications(ctx context.Context, req GetPendingApplicationsRequest) (*dto.PendingApplicationsResponse, error) {
	// 1. 解析状态筛选
	var status entities.ApplicationStatus
	if req.Status != "" {
		status = entities.ApplicationStatus(req.Status)
	}

	// 2. 解析时间范围
	var startTime, endTime *time.Time
	if req.StartTime != "" {
		if t, err := time.Parse("2006-01-02 15:04:05", req.StartTime); err == nil {
			startTime = &t
		}
	}
	if req.EndTime != "" {
		if t, err := time.Parse("2006-01-02 15:04:05", req.EndTime); err == nil {
			endTime = &t
		}
	}

	// 3. 获取发票申请记录（支持筛选）
	var applications []*entities.InvoiceApplication
	var total int64
	var err error

	if status != "" {
		// 按状态筛选
		applications, total, err = s.invoiceRepo.FindByStatusWithTimeRange(ctx, status, startTime, endTime, req.Page, req.PageSize)
	} else {
		// 获取所有记录（按时间筛选）
		applications, total, err = s.invoiceRepo.FindAllWithTimeRange(ctx, startTime, endTime, req.Page, req.PageSize)
	}

	if err != nil {
		return nil, err
	}

	// 4. 构建响应DTO
	pendingApplications := make([]*dto.PendingApplicationResponse, len(applications))
	for i, app := range applications {
		// 使用快照信息
		pendingApplications[i] = &dto.PendingApplicationResponse{
			ID:             app.ID,
			UserID:         app.UserID,
			InvoiceType:    app.InvoiceType,
			Amount:         app.Amount,
			Status:         app.Status,
			CompanyName:    app.CompanyName,    // 使用快照的公司名称
			TaxpayerID:     app.TaxpayerID,     // 使用快照的纳税人识别号
			BankName:       app.BankName,       // 使用快照的银行名称
			BankAccount:    app.BankAccount,    // 使用快照的银行账号
			CompanyAddress: app.CompanyAddress, // 使用快照的企业地址
			CompanyPhone:   app.CompanyPhone,   // 使用快照的企业电话
			ReceivingEmail: app.ReceivingEmail, // 使用快照的接收邮箱
			FileName:       app.FileName,
			FileSize:       app.FileSize,
			FileURL:        app.FileURL,
			ProcessedAt:    app.ProcessedAt,
			CreatedAt:      app.CreatedAt,
			RejectReason:   app.RejectReason,
		}
	}

	return &dto.PendingApplicationsResponse{
		Applications: pendingApplications,
		Total:        total,
		Page:         req.Page,
		PageSize:     req.PageSize,
		TotalPages:   (int(total) + req.PageSize - 1) / req.PageSize,
	}, nil
}

// ApproveInvoiceApplication 通过发票申请
func (s *AdminInvoiceApplicationServiceImpl) ApproveInvoiceApplication(ctx context.Context, applicationID string, file multipart.File, req ApproveInvoiceRequest) error {
	// 1. 验证申请是否存在
	application, err := s.invoiceRepo.FindByID(ctx, applicationID)
	if err != nil {
		return err
	}
	if application == nil {
		return fmt.Errorf("发票申请不存在")
	}

	// 2. 验证申请状态
	if application.Status != entities.ApplicationStatusPending {
		return fmt.Errorf("发票申请状态不允许处理")
	}

	// 3. 调用聚合服务处理申请
	aggregateReq := services.ApproveInvoiceRequest{
		AdminNotes: req.AdminNotes,
	}

	return s.invoiceAggregateService.ApproveInvoiceApplication(ctx, applicationID, file, aggregateReq)
}

// RejectInvoiceApplication 拒绝发票申请
func (s *AdminInvoiceApplicationServiceImpl) RejectInvoiceApplication(ctx context.Context, applicationID string, req RejectInvoiceRequest) error {
	// 1. 验证申请是否存在
	application, err := s.invoiceRepo.FindByID(ctx, applicationID)
	if err != nil {
		return err
	}
	if application == nil {
		return fmt.Errorf("发票申请不存在")
	}

	// 2. 验证申请状态
	if application.Status != entities.ApplicationStatusPending {
		return fmt.Errorf("发票申请状态不允许处理")
	}

	// 3. 调用聚合服务处理申请
	aggregateReq := services.RejectInvoiceRequest{
		Reason: req.Reason,
	}

	return s.invoiceAggregateService.RejectInvoiceApplication(ctx, applicationID, aggregateReq)
}

// ==================== 请求和响应DTO ====================

type ApplyInvoiceRequest struct {
	InvoiceType string `json:"invoice_type" binding:"required"` // 发票类型：general/special
	Amount      string `json:"amount" binding:"required"`       // 开票金额
}

type UpdateInvoiceInfoRequest struct {
	CompanyName    string `json:"company_name"`                             // 公司名称（从企业认证信息获取，用户不可修改）
	TaxpayerID     string `json:"taxpayer_id"`                              // 纳税人识别号（从企业认证信息获取，用户不可修改）
	BankName       string `json:"bank_name"`                                // 银行名称
	CompanyAddress string `json:"company_address"`                          // 公司地址
	BankAccount    string `json:"bank_account"`                             // 银行账户
	CompanyPhone   string `json:"company_phone"`                            // 企业注册电话
	ReceivingEmail string `json:"receiving_email" binding:"required,email"` // 发票接收邮箱
}

type GetInvoiceRecordsRequest struct {
	Page      int    `json:"page"`       // 页码
	PageSize  int    `json:"page_size"`  // 每页数量
	Status    string `json:"status"`     // 状态筛选
	StartTime string `json:"start_time"` // 开始时间 (格式: 2006-01-02 15:04:05)
	EndTime   string `json:"end_time"`   // 结束时间 (格式: 2006-01-02 15:04:05)
}

type GetPendingApplicationsRequest struct {
	Page      int    `json:"page"`       // 页码
	PageSize  int    `json:"page_size"`  // 每页数量
	Status    string `json:"status"`     // 状态筛选：pending/completed/rejected
	StartTime string `json:"start_time"` // 开始时间 (格式: 2006-01-02 15:04:05)
	EndTime   string `json:"end_time"`   // 结束时间 (格式: 2006-01-02 15:04:05)
}

type ApproveInvoiceRequest struct {
	AdminNotes string `json:"admin_notes"` // 管理员备注
}

type RejectInvoiceRequest struct {
	Reason string `json:"reason" binding:"required"` // 拒绝原因
}

// DownloadInvoiceFile 下载发票文件（管理员）
func (s *AdminInvoiceApplicationServiceImpl) DownloadInvoiceFile(ctx context.Context, applicationID string) (*dto.FileDownloadResponse, error) {
	// 1. 查找申请记录
	application, err := s.invoiceRepo.FindByID(ctx, applicationID)
	if err != nil {
		return nil, err
	}
	if application == nil {
		return nil, fmt.Errorf("申请记录不存在")
	}

	// 2. 验证状态（只能下载已完成的发票）
	if application.Status != entities.ApplicationStatusCompleted {
		return nil, fmt.Errorf("发票尚未通过审核")
	}

	// 3. 验证文件信息
	if application.FileURL == nil || *application.FileURL == "" {
		return nil, fmt.Errorf("发票文件不存在")
	}

	// 4. 从七牛云下载文件内容
	fileContent, err := s.storageService.DownloadFile(ctx, *application.FileURL)
	if err != nil {
		return nil, fmt.Errorf("下载文件失败: %w", err)
	}

	// 5. 构建响应DTO
	return &dto.FileDownloadResponse{
		FileID:      *application.FileID,
		FileName:    *application.FileName,
		FileSize:    *application.FileSize,
		FileURL:     *application.FileURL,
		FileContent: fileContent,
	}, nil
}