package product

import (
	"context"

	"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"
	product_service "tyapi-server/internal/domains/product/services"
)

// ProductApplicationServiceImpl 产品应用服务实现
// 负责业务流程编排、事务管理、数据转换，不直接操作仓库
type ProductApplicationServiceImpl struct {
	productManagementService *product_service.ProductManagementService
	productSubscriptionService *product_service.ProductSubscriptionService
	logger                    *zap.Logger
}

// NewProductApplicationService 创建产品应用服务
func NewProductApplicationService(
	productManagementService *product_service.ProductManagementService,
	productSubscriptionService *product_service.ProductSubscriptionService,
	logger *zap.Logger,
) ProductApplicationService {
	return &ProductApplicationServiceImpl{
		productManagementService:    productManagementService,
		productSubscriptionService:  productSubscriptionService,
		logger:                      logger,
	}
}

// CreateProduct 创建产品
// 业务流程：1. 构建产品实体 2. 创建产品
func (s *ProductApplicationServiceImpl) CreateProduct(ctx context.Context, cmd *commands.CreateProductCommand) error {
	// 1. 构建产品实体
	product := &entities.Product{
		Name:           cmd.Name,
		Code:           cmd.Code,
		Description:    cmd.Description,
		Content:        cmd.Content,
		CategoryID:     cmd.CategoryID,
		Price:          cmd.Price,
		IsEnabled:      cmd.IsEnabled,
		IsVisible:      cmd.IsVisible,
		IsPackage:      cmd.IsPackage,
		SEOTitle:       cmd.SEOTitle,
		SEODescription: cmd.SEODescription,
		SEOKeywords:    cmd.SEOKeywords,
	}

	// 2. 创建产品
	_, err := s.productManagementService.CreateProduct(ctx, product)
	return err
}

// UpdateProduct 更新产品
// 业务流程：1. 获取现有产品 2. 更新产品信息 3. 保存产品
func (s *ProductApplicationServiceImpl) UpdateProduct(ctx context.Context, cmd *commands.UpdateProductCommand) error {
	// 1. 获取现有产品
	existingProduct, err := s.productManagementService.GetProductByID(ctx, cmd.ID)
	if err != nil {
		return err
	}

	// 2. 更新产品信息
	existingProduct.Name = cmd.Name
	existingProduct.Code = cmd.Code
	existingProduct.Description = cmd.Description
	existingProduct.Content = cmd.Content
	existingProduct.CategoryID = cmd.CategoryID
	existingProduct.Price = cmd.Price
	existingProduct.IsEnabled = cmd.IsEnabled
	existingProduct.IsVisible = cmd.IsVisible
	existingProduct.IsPackage = cmd.IsPackage
	existingProduct.SEOTitle = cmd.SEOTitle
	existingProduct.SEODescription = cmd.SEODescription
	existingProduct.SEOKeywords = cmd.SEOKeywords

	// 3. 保存产品
	return s.productManagementService.UpdateProduct(ctx, existingProduct)
}

// DeleteProduct 删除产品
// 业务流程：1. 删除产品
func (s *ProductApplicationServiceImpl) DeleteProduct(ctx context.Context, cmd *commands.DeleteProductCommand) error {
	return s.productManagementService.DeleteProduct(ctx, cmd.ID)
}

// ListProducts 获取产品列表
// 业务流程：1. 获取产品列表 2. 构建响应数据
func (s *ProductApplicationServiceImpl) ListProducts(ctx context.Context, query *appQueries.ListProductsQuery) (*responses.ProductListResponse, error) {
	// 根据查询条件获取产品列表
	var products []*entities.Product
	var err error

	if query.CategoryID != "" {
		products, err = s.productManagementService.GetProductsByCategory(ctx, query.CategoryID)
	} else if query.IsVisible != nil && *query.IsVisible {
		products, err = s.productManagementService.GetVisibleProducts(ctx)
	} else if query.IsEnabled != nil && *query.IsEnabled {
		products, err = s.productManagementService.GetEnabledProducts(ctx)
	} else {
		// 默认获取可见产品
		products, err = s.productManagementService.GetVisibleProducts(ctx)
	}

	if err != nil {
		return nil, err
	}

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

	return &responses.ProductListResponse{
		Total: int64(len(items)),
		Page:  query.Page,
		Size:  query.PageSize,
		Items: items,
	}, nil
}

// GetProductsByIDs 根据ID列表获取产品
// 业务流程：1. 获取产品列表 2. 构建响应数据
func (s *ProductApplicationServiceImpl) GetProductsByIDs(ctx context.Context, query *appQueries.GetProductsByIDsQuery) ([]*responses.ProductInfoResponse, error) {
	// 这里需要扩展领域服务来支持批量获取
	// 暂时返回空列表
	return []*responses.ProductInfoResponse{}, nil
}

// GetSubscribableProducts 获取可订阅产品列表
// 业务流程：1. 获取启用产品 2. 过滤可订阅产品 3. 构建响应数据
func (s *ProductApplicationServiceImpl) GetSubscribableProducts(ctx context.Context, query *appQueries.GetSubscribableProductsQuery) ([]*responses.ProductInfoResponse, error) {
	products, err := s.productManagementService.GetEnabledProducts(ctx)
	if err != nil {
		return nil, err
	}

	// 过滤可订阅的产品
	var subscribableProducts []*entities.Product
	for _, product := range products {
		if product.CanBeSubscribed() {
			subscribableProducts = append(subscribableProducts, product)
		}
	}

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

	return items, nil
}

// GetProductByID 根据ID获取产品
// 业务流程：1. 获取产品信息 2. 构建响应数据
func (s *ProductApplicationServiceImpl) GetProductByID(ctx context.Context, query *appQueries.GetProductQuery) (*responses.ProductInfoResponse, error) {
	product, err := s.productManagementService.GetProductWithCategory(ctx, query.ID)
	if err != nil {
		return nil, err
	}

	return s.convertToProductInfoResponse(product), nil
}

// GetProductStats 获取产品统计信息
// 业务流程：1. 获取产品统计 2. 构建响应数据
func (s *ProductApplicationServiceImpl) GetProductStats(ctx context.Context) (*responses.ProductStatsResponse, error) {
	stats, err := s.productSubscriptionService.GetProductStats(ctx)
	if err != nil {
		return nil, err
	}

	return &responses.ProductStatsResponse{
		TotalProducts:   stats["total"],
		EnabledProducts: stats["enabled"],
		VisibleProducts: stats["visible"],
		PackageProducts: 0, // 需要单独统计
	}, nil
}

// convertToProductInfoResponse 转换为产品信息响应
func (s *ProductApplicationServiceImpl) convertToProductInfoResponse(product *entities.Product) *responses.ProductInfoResponse {
	response := &responses.ProductInfoResponse{
		ID:            product.ID,
		Name:          product.Name,
		Code:          product.Code,
		Description:   product.Description,
		Content:       product.Content,
		CategoryID:    product.CategoryID,
		Price:         product.Price,
		IsEnabled:     product.IsEnabled,
		IsVisible:     product.IsVisible,
		IsPackage:     product.IsPackage,
		SEOTitle:      product.SEOTitle,
		SEODescription: product.SEODescription,
		SEOKeywords:   product.SEOKeywords,
		CreatedAt:     product.CreatedAt,
		UpdatedAt:     product.UpdatedAt,
	}

	// 添加分类信息
	if product.Category != nil {
		response.Category = s.convertToCategoryInfoResponse(product.Category)
	}

	return response
}

// convertToCategoryInfoResponse 转换为分类信息响应
func (s *ProductApplicationServiceImpl) convertToCategoryInfoResponse(category *entities.ProductCategory) *responses.CategoryInfoResponse {
	return &responses.CategoryInfoResponse{
		ID:          category.ID,
		Name:        category.Name,
		Description: category.Description,
		IsEnabled:   category.IsEnabled,
		CreatedAt:   category.CreatedAt,
		UpdatedAt:   category.UpdatedAt,
	}
}