package product

import (
	"context"

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

	"tyapi-server/internal/application/product/dto/commands"
	appQueries "tyapi-server/internal/application/product/dto/queries"
	"tyapi-server/internal/application/product/dto/responses"
	"tyapi-server/internal/domains/product/entities"
	repoQueries "tyapi-server/internal/domains/product/repositories/queries"
	product_service "tyapi-server/internal/domains/product/services"
	user_repositories "tyapi-server/internal/domains/user/repositories"
)

// SubscriptionApplicationServiceImpl 订阅应用服务实现
// 负责业务流程编排、事务管理、数据转换，不直接操作仓库
type SubscriptionApplicationServiceImpl struct {
	productSubscriptionService *product_service.ProductSubscriptionService
	userRepo                   user_repositories.UserRepository
	logger                     *zap.Logger
}

// NewSubscriptionApplicationService 创建订阅应用服务
func NewSubscriptionApplicationService(
	productSubscriptionService *product_service.ProductSubscriptionService,
	userRepo user_repositories.UserRepository,
	logger *zap.Logger,
) SubscriptionApplicationService {
	return &SubscriptionApplicationServiceImpl{
		productSubscriptionService: productSubscriptionService,
		userRepo:                   userRepo,
		logger:                     logger,
	}
}

// UpdateSubscriptionPrice 更新订阅价格
// 业务流程：1. 获取订阅 2. 更新价格 3. 保存订阅
func (s *SubscriptionApplicationServiceImpl) UpdateSubscriptionPrice(ctx context.Context, cmd *commands.UpdateSubscriptionPriceCommand) error {
	return s.productSubscriptionService.UpdateSubscriptionPrice(ctx, cmd.ID, cmd.Price)
}

// BatchUpdateSubscriptionPrices 一键改价
// 业务流程：1. 获取用户所有订阅 2. 根据范围筛选 3. 批量更新价格
func (s *SubscriptionApplicationServiceImpl) BatchUpdateSubscriptionPrices(ctx context.Context, cmd *commands.BatchUpdateSubscriptionPricesCommand) error {
	subscriptions, _, err := s.productSubscriptionService.ListSubscriptions(ctx, &repoQueries.ListSubscriptionsQuery{
		UserID:   cmd.UserID,
		Page:     1,
		PageSize: 1000,
	})
	if err != nil {
		return err
	}

	// 根据范围筛选订阅
	var targetSubscriptions []*entities.Subscription
	for _, sub := range subscriptions {
		if cmd.Scope == "all" {
			// 所有订阅都修改
			targetSubscriptions = append(targetSubscriptions, sub)
		} else if cmd.Scope == "undiscounted" {
			// 只修改未打折的订阅（价格等于产品原价）
			if sub.Product != nil && sub.Price.Equal(sub.Product.Price) {
				targetSubscriptions = append(targetSubscriptions, sub)
			}
		}
	}

	// 批量更新价格
	for _, sub := range targetSubscriptions {
		if sub.Product != nil {
			// 计算折扣后的价格
			discountRatio := cmd.Discount / 10
			newPrice := sub.Product.Price.Mul(decimal.NewFromFloat(discountRatio))
			// 四舍五入到2位小数
			newPrice = newPrice.Round(2)

			err := s.productSubscriptionService.UpdateSubscriptionPrice(ctx, sub.ID, newPrice.InexactFloat64())
			if err != nil {
				s.logger.Error("批量更新订阅价格失败",
					zap.String("subscription_id", sub.ID),
					zap.Error(err))
				// 继续处理其他订阅，不中断整个流程
			}
		}
	}

	return nil
}

// CreateSubscription 创建订阅
// 业务流程：1. 创建订阅
func (s *SubscriptionApplicationServiceImpl) CreateSubscription(ctx context.Context, cmd *commands.CreateSubscriptionCommand) error {
	_, err := s.productSubscriptionService.CreateSubscription(ctx, cmd.UserID, cmd.ProductID)
	return err
}

// GetSubscriptionByID 根据ID获取订阅
// 业务流程：1. 获取订阅信息 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) GetSubscriptionByID(ctx context.Context, query *appQueries.GetSubscriptionQuery) (*responses.SubscriptionInfoResponse, error) {
	subscription, err := s.productSubscriptionService.GetSubscriptionByID(ctx, query.ID)
	if err != nil {
		return nil, err
	}

	return s.convertToSubscriptionInfoResponse(subscription), nil
}

// ListSubscriptions 获取订阅列表（管理员用）
// 业务流程：1. 获取订阅列表 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) ListSubscriptions(ctx context.Context, query *appQueries.ListSubscriptionsQuery) (*responses.SubscriptionListResponse, error) {
	repoQuery := &repoQueries.ListSubscriptionsQuery{
		Page:        query.Page,
		PageSize:    query.PageSize,
		UserID:      query.UserID, // 管理员可以按用户筛选
		Keyword:     query.Keyword,
		SortBy:      query.SortBy,
		SortOrder:   query.SortOrder,
		CompanyName: query.CompanyName,
		ProductName: query.ProductName,
		StartTime:   query.StartTime,
		EndTime:     query.EndTime,
	}
	subscriptions, total, err := s.productSubscriptionService.ListSubscriptions(ctx, repoQuery)
	if err != nil {
		return nil, err
	}
	items := make([]responses.SubscriptionInfoResponse, len(subscriptions))
	for i := range subscriptions {
		resp := s.convertToSubscriptionInfoResponse(subscriptions[i])
		if resp != nil {
			items[i] = *resp // 解引用指针
		}
	}
	return &responses.SubscriptionListResponse{
		Total: total,
		Page:  query.Page,
		Size:  query.PageSize,
		Items: items,
	}, nil
}

// ListMySubscriptions 获取我的订阅列表（用户用）
// 业务流程：1. 获取用户订阅列表 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) ListMySubscriptions(ctx context.Context, userID string, query *appQueries.ListSubscriptionsQuery) (*responses.SubscriptionListResponse, error) {
	repoQuery := &repoQueries.ListSubscriptionsQuery{
		Page:        query.Page,
		PageSize:    query.PageSize,
		UserID:      userID, // 强制设置为当前用户ID
		Keyword:     query.Keyword,
		SortBy:      query.SortBy,
		SortOrder:   query.SortOrder,
		CompanyName: query.CompanyName,
		ProductName: query.ProductName,
		StartTime:   query.StartTime,
		EndTime:     query.EndTime,
	}
	subscriptions, total, err := s.productSubscriptionService.ListSubscriptions(ctx, repoQuery)
	if err != nil {
		return nil, err
	}
	items := make([]responses.SubscriptionInfoResponse, len(subscriptions))
	for i := range subscriptions {
		resp := s.convertToSubscriptionInfoResponse(subscriptions[i])
		if resp != nil {
			items[i] = *resp // 解引用指针
		}
	}
	return &responses.SubscriptionListResponse{
		Total: total,
		Page:  query.Page,
		Size:  query.PageSize,
		Items: items,
	}, nil
}

// GetUserSubscriptions 获取用户订阅
// 业务流程：1. 获取用户订阅 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) GetUserSubscriptions(ctx context.Context, query *appQueries.GetUserSubscriptionsQuery) ([]*responses.SubscriptionInfoResponse, error) {
	subscriptions, err := s.productSubscriptionService.GetUserSubscriptions(ctx, query.UserID)
	if err != nil {
		return nil, err
	}

	// 转换为响应对象
	items := make([]*responses.SubscriptionInfoResponse, len(subscriptions))
	for i := range subscriptions {
		items[i] = s.convertToSubscriptionInfoResponse(subscriptions[i])
	}

	return items, nil
}

// GetProductSubscriptions 获取产品订阅
// 业务流程：1. 获取产品订阅 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) GetProductSubscriptions(ctx context.Context, query *appQueries.GetProductSubscriptionsQuery) ([]*responses.SubscriptionInfoResponse, error) {
	// 这里需要扩展领域服务来支持按产品查询订阅
	// 暂时返回空列表
	return []*responses.SubscriptionInfoResponse{}, nil
}

// GetSubscriptionUsage 获取订阅使用情况
// 业务流程：1. 获取订阅使用情况 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) GetSubscriptionUsage(ctx context.Context, subscriptionID string) (*responses.SubscriptionUsageResponse, error) {
	subscription, err := s.productSubscriptionService.GetSubscriptionByID(ctx, subscriptionID)
	if err != nil {
		return nil, err
	}

	return &responses.SubscriptionUsageResponse{
		ID:        subscription.ID,
		ProductID: subscription.ProductID,
		APIUsed:   subscription.APIUsed,
	}, nil
}

// GetSubscriptionStats 获取订阅统计信息
// 业务流程：1. 获取订阅统计 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) GetSubscriptionStats(ctx context.Context) (*responses.SubscriptionStatsResponse, error) {
	stats, err := s.productSubscriptionService.GetSubscriptionStats(ctx)
	if err != nil {
		return nil, err
	}

	return &responses.SubscriptionStatsResponse{
		TotalSubscriptions: stats["total_subscriptions"].(int64),
		TotalRevenue:       stats["total_revenue"].(float64),
	}, nil
}

// GetMySubscriptionStats 获取我的订阅统计信息
// 业务流程：1. 获取用户订阅统计 2. 构建响应数据
func (s *SubscriptionApplicationServiceImpl) GetMySubscriptionStats(ctx context.Context, userID string) (*responses.SubscriptionStatsResponse, error) {
	stats, err := s.productSubscriptionService.GetUserSubscriptionStats(ctx, userID)
	if err != nil {
		return nil, err
	}

	return &responses.SubscriptionStatsResponse{
		TotalSubscriptions: stats["total_subscriptions"].(int64),
		TotalRevenue:       stats["total_revenue"].(float64),
	}, nil
}

// convertToSubscriptionInfoResponse 转换为订阅信息响应
func (s *SubscriptionApplicationServiceImpl) convertToSubscriptionInfoResponse(subscription *entities.Subscription) *responses.SubscriptionInfoResponse {
	// 查询用户信息
	var userInfo *responses.UserSimpleResponse
	if subscription.UserID != "" {
		user, err := s.userRepo.GetByIDWithEnterpriseInfo(context.Background(), subscription.UserID)
		if err == nil {
			companyName := "未知公司"
			if user.EnterpriseInfo != nil {
				companyName = user.EnterpriseInfo.CompanyName
			}
			userInfo = &responses.UserSimpleResponse{
				ID:          user.ID,
				CompanyName: companyName,
				Phone:       user.Phone,
			}
		}
	}

	var productResponse *responses.ProductSimpleResponse
	if subscription.Product != nil {
		productResponse = s.convertToProductSimpleResponse(subscription.Product)
	}

	return &responses.SubscriptionInfoResponse{
		ID:        subscription.ID,
		UserID:    subscription.UserID,
		ProductID: subscription.ProductID,
		Price:     subscription.Price.InexactFloat64(),
		User:      userInfo,
		Product:   productResponse,
		APIUsed:   subscription.APIUsed,
		CreatedAt: subscription.CreatedAt,
		UpdatedAt: subscription.UpdatedAt,
	}
}

// convertToProductSimpleResponse 转换为产品简单信息响应
func (s *SubscriptionApplicationServiceImpl) convertToProductSimpleResponse(product *entities.Product) *responses.ProductSimpleResponse {
	var categoryResponse *responses.CategorySimpleResponse
	if product.Category != nil {
		categoryResponse = s.convertToCategorySimpleResponse(product.Category)
	}

	return &responses.ProductSimpleResponse{
		ID:          product.ID,
		OldID:       product.OldID,
		Name:        product.Name,
		Code:        product.Code,
		Description: product.Description,
		Price:       product.Price.InexactFloat64(),
		Category:    categoryResponse,
		IsPackage:   product.IsPackage,
	}
}

// convertToCategorySimpleResponse 转换为分类简单信息响应
func (s *SubscriptionApplicationServiceImpl) convertToCategorySimpleResponse(category *entities.ProductCategory) *responses.CategorySimpleResponse {
	if category == nil {
		return nil
	}

	return &responses.CategorySimpleResponse{
		ID:   category.ID,
		Name: category.Name,
	}
}