package services

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

	"tyapi-server/internal/domains/finance/entities"
	"tyapi-server/internal/domains/finance/events"
	"tyapi-server/internal/domains/finance/repositories"
	"tyapi-server/internal/domains/finance/value_objects"

	"tyapi-server/internal/infrastructure/external/storage"

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

// ApplyInvoiceRequest 申请开票请求
type ApplyInvoiceRequest struct {
	InvoiceType value_objects.InvoiceType  `json:"invoice_type" binding:"required"`
	Amount      string                     `json:"amount" binding:"required"`
	InvoiceInfo *value_objects.InvoiceInfo `json:"invoice_info" binding:"required"`
}

// ApproveInvoiceRequest 通过发票申请请求
type ApproveInvoiceRequest struct {
	AdminNotes string `json:"admin_notes"`
}

// RejectInvoiceRequest 拒绝发票申请请求
type RejectInvoiceRequest struct {
	Reason string `json:"reason" binding:"required"`
}

// InvoiceAggregateService 发票聚合服务接口
// 职责：协调发票申请聚合根的生命周期，调用领域服务进行业务规则验证，发布领域事件
type InvoiceAggregateService interface {
	// 申请开票
	ApplyInvoice(ctx context.Context, userID string, req ApplyInvoiceRequest) (*entities.InvoiceApplication, error)

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

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

// InvoiceAggregateServiceImpl 发票聚合服务实现
type InvoiceAggregateServiceImpl struct {
	applicationRepo     repositories.InvoiceApplicationRepository
	userInvoiceInfoRepo repositories.UserInvoiceInfoRepository
	domainService       InvoiceDomainService
	qiniuStorageService *storage.QiNiuStorageService
	logger              *zap.Logger
	eventPublisher      EventPublisher
}

// EventPublisher 事件发布器接口
type EventPublisher interface {
	PublishInvoiceApplicationCreated(ctx context.Context, event *events.InvoiceApplicationCreatedEvent) error
	PublishInvoiceApplicationApproved(ctx context.Context, event *events.InvoiceApplicationApprovedEvent) error
	PublishInvoiceApplicationRejected(ctx context.Context, event *events.InvoiceApplicationRejectedEvent) error
	PublishInvoiceFileUploaded(ctx context.Context, event *events.InvoiceFileUploadedEvent) error
}

// NewInvoiceAggregateService 创建发票聚合服务
func NewInvoiceAggregateService(
	applicationRepo repositories.InvoiceApplicationRepository,
	userInvoiceInfoRepo repositories.UserInvoiceInfoRepository,
	domainService InvoiceDomainService,
	qiniuStorageService *storage.QiNiuStorageService,
	logger *zap.Logger,
	eventPublisher EventPublisher,
) InvoiceAggregateService {
	return &InvoiceAggregateServiceImpl{
		applicationRepo:     applicationRepo,
		userInvoiceInfoRepo: userInvoiceInfoRepo,
		domainService:       domainService,
		qiniuStorageService: qiniuStorageService,
		logger:              logger,
		eventPublisher:      eventPublisher,
	}
}

// ApplyInvoice 申请开票
func (s *InvoiceAggregateServiceImpl) ApplyInvoice(ctx context.Context, userID string, req ApplyInvoiceRequest) (*entities.InvoiceApplication, error) {
	// 1. 解析金额
	amount, err := decimal.NewFromString(req.Amount)
	if err != nil {
		return nil, fmt.Errorf("无效的金额格式: %w", err)
	}

	// 2. 验证发票信息
	if err := s.domainService.ValidateInvoiceInfo(ctx, req.InvoiceInfo, req.InvoiceType); err != nil {
		return nil, fmt.Errorf("发票信息验证失败: %w", err)
	}

	// 3. 获取用户开票信息
	userInvoiceInfo, err := s.userInvoiceInfoRepo.FindByUserID(ctx, userID)
	if err != nil {
		return nil, fmt.Errorf("获取用户开票信息失败: %w", err)
	}
	if userInvoiceInfo == nil {
		return nil, fmt.Errorf("用户开票信息不存在")
	}

	// 4. 创建发票申请聚合根
	application := entities.NewInvoiceApplication(userID, req.InvoiceType, amount, userInvoiceInfo.ID)

	// 5. 设置开票信息快照
	application.SetInvoiceInfoSnapshot(req.InvoiceInfo)

	// 6. 验证聚合根业务规则
	if err := s.domainService.ValidateInvoiceApplication(ctx, application); err != nil {
		return nil, fmt.Errorf("发票申请业务规则验证失败: %w", err)
	}

	// 7. 保存聚合根
	if err := s.applicationRepo.Create(ctx, application); err != nil {
		return nil, fmt.Errorf("保存发票申请失败: %w", err)
	}

	// 8. 发布领域事件
	event := events.NewInvoiceApplicationCreatedEvent(
		application.ID,
		application.UserID,
		application.InvoiceType,
		application.Amount,
		application.CompanyName,
		application.ReceivingEmail,
	)

	if err := s.eventPublisher.PublishInvoiceApplicationCreated(ctx, event); err != nil {
		// 记录错误但不影响主流程
		fmt.Printf("发布发票申请创建事件失败: %v\n", err)
	}

	return application, nil
}

// ApproveInvoiceApplication 通过发票申请（上传发票）
func (s *InvoiceAggregateServiceImpl) ApproveInvoiceApplication(ctx context.Context, applicationID string, file multipart.File, req ApproveInvoiceRequest) error {
	// 1. 获取发票申请
	application, err := s.applicationRepo.FindByID(ctx, applicationID)
	if err != nil {
		return fmt.Errorf("获取发票申请失败: %w", err)
	}
	if application == nil {
		return fmt.Errorf("发票申请不存在")
	}

	// 2. 验证状态转换
	if err := s.domainService.ValidateStatusTransition(application.Status, entities.ApplicationStatusCompleted); err != nil {
		return fmt.Errorf("状态转换验证失败: %w", err)
	}

	// 3. 处理文件上传
	// 读取文件内容
	fileBytes, err := io.ReadAll(file)
	if err != nil {
		s.logger.Error("读取上传文件失败", zap.Error(err))
		return fmt.Errorf("读取上传文件失败: %w", err)
	}

	// 生成文件名（使用时间戳确保唯一性）
	fileName := fmt.Sprintf("invoice_%s_%d.pdf", applicationID, time.Now().Unix())

	// 上传文件到七牛云
	uploadResult, err := s.qiniuStorageService.UploadFile(ctx, fileBytes, fileName)
	if err != nil {
		s.logger.Error("上传发票文件到七牛云失败", zap.String("file_name", fileName), zap.Error(err))
		return fmt.Errorf("上传发票文件到七牛云失败: %w", err)
	}

	// 从上传结果获取文件信息
	fileID := uploadResult.Key
	fileURL := uploadResult.URL
	fileSize := uploadResult.Size

	// 4. 更新聚合根状态
	application.MarkCompleted("admin_user_id")
	application.SetFileInfo(fileID, fileName, fileURL, fileSize)
	application.AdminNotes = &req.AdminNotes

	// 5. 保存聚合根
	if err := s.applicationRepo.Update(ctx, application); err != nil {
		return fmt.Errorf("更新发票申请失败: %w", err)
	}

	// 6. 发布领域事件
	approvedEvent := events.NewInvoiceApplicationApprovedEvent(
		application.ID,
		application.UserID,
		application.Amount,
		application.ReceivingEmail,
	)

	if err := s.eventPublisher.PublishInvoiceApplicationApproved(ctx, approvedEvent); err != nil {
		s.logger.Error("发布发票申请通过事件失败",
			zap.String("application_id", applicationID),
			zap.Error(err),
		)
		// 事件发布失败不影响主流程，只记录日志
	} else {
		s.logger.Info("发票申请通过事件发布成功",
			zap.String("application_id", applicationID),
		)
	}

	fileUploadedEvent := events.NewInvoiceFileUploadedEvent(
		application.ID,
		application.UserID,
		fileID,
		fileName,
		fileURL,
		application.ReceivingEmail,
		application.CompanyName,
		application.Amount,
		application.InvoiceType,
	)

	if err := s.eventPublisher.PublishInvoiceFileUploaded(ctx, fileUploadedEvent); err != nil {
		s.logger.Error("发布发票文件上传事件失败",
			zap.String("application_id", applicationID),
			zap.Error(err),
		)
		// 事件发布失败不影响主流程，只记录日志
	} else {
		s.logger.Info("发票文件上传事件发布成功",
			zap.String("application_id", applicationID),
		)
	}

	return nil
}

// RejectInvoiceApplication 拒绝发票申请
func (s *InvoiceAggregateServiceImpl) RejectInvoiceApplication(ctx context.Context, applicationID string, req RejectInvoiceRequest) error {
	// 1. 获取发票申请
	application, err := s.applicationRepo.FindByID(ctx, applicationID)
	if err != nil {
		return fmt.Errorf("获取发票申请失败: %w", err)
	}
	if application == nil {
		return fmt.Errorf("发票申请不存在")
	}

	// 2. 验证状态转换
	if err := s.domainService.ValidateStatusTransition(application.Status, entities.ApplicationStatusRejected); err != nil {
		return fmt.Errorf("状态转换验证失败: %w", err)
	}

	// 3. 更新聚合根状态
	application.MarkRejected(req.Reason, "admin_user_id")

	// 4. 保存聚合根
	if err := s.applicationRepo.Update(ctx, application); err != nil {
		return fmt.Errorf("更新发票申请失败: %w", err)
	}

	// 5. 发布领域事件
	event := events.NewInvoiceApplicationRejectedEvent(
		application.ID,
		application.UserID,
		req.Reason,
		application.ReceivingEmail,
	)

	if err := s.eventPublisher.PublishInvoiceApplicationRejected(ctx, event); err != nil {
		fmt.Printf("发布发票申请拒绝事件失败: %v\n", err)
	}

	return nil
}