// Package shop 提供店铺管理的业务逻辑服务
// 包含店铺创建、查询、更新、删除等功能
package shop

import (
	"context"

	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/internal/store"
	"github.com/break/junhong_cmp_fiber/internal/store/postgres"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
	"github.com/break/junhong_cmp_fiber/pkg/middleware"
)

// Service 店铺业务服务
type Service struct {
	shopStore *postgres.ShopStore
}

// New 创建店铺服务
func New(shopStore *postgres.ShopStore) *Service {
	return &Service{
		shopStore: shopStore,
	}
}

// Create 创建店铺
func (s *Service) Create(ctx context.Context, req *model.CreateShopRequest) (*model.Shop, error) {
	// 获取当前用户 ID
	currentUserID := middleware.GetUserIDFromContext(ctx)
	if currentUserID == 0 {
		return nil, errors.New(errors.CodeUnauthorized, "未授权访问")
	}

	// 检查店铺编号唯一性
	if req.ShopCode != "" {
		existing, err := s.shopStore.GetByCode(ctx, req.ShopCode)
		if err == nil && existing != nil {
			return nil, errors.New(errors.CodeShopCodeExists, "店铺编号已存在")
		}
	}

	// 计算层级
	level := 1
	if req.ParentID != nil {
		// 验证上级店铺存在
		parent, err := s.shopStore.GetByID(ctx, *req.ParentID)
		if err != nil {
			return nil, errors.New(errors.CodeInvalidParentID, "上级店铺不存在或无效")
		}

		// 计算新店铺的层级
		level = parent.Level + 1

		// 校验层级不超过最大值
		if level > constants.MaxShopLevel {
			return nil, errors.New(errors.CodeShopLevelExceeded, "店铺层级不能超过 7 级")
		}
	}

	// 创建店铺
	shop := &model.Shop{
		ShopName:     req.ShopName,
		ShopCode:     req.ShopCode,
		ParentID:     req.ParentID,
		Level:        level,
		ContactName:  req.ContactName,
		ContactPhone: req.ContactPhone,
		Province:     req.Province,
		City:         req.City,
		District:     req.District,
		Address:      req.Address,
		Status:       constants.StatusEnabled,
	}
	shop.Creator = currentUserID
	shop.Updater = currentUserID

	if err := s.shopStore.Create(ctx, shop); err != nil {
		return nil, err
	}

	return shop, nil
}

// Update 更新店铺信息
func (s *Service) Update(ctx context.Context, id uint, req *model.UpdateShopRequest) (*model.Shop, error) {
	// 获取当前用户 ID
	currentUserID := middleware.GetUserIDFromContext(ctx)
	if currentUserID == 0 {
		return nil, errors.New(errors.CodeUnauthorized, "未授权访问")
	}

	// 查询店铺
	shop, err := s.shopStore.GetByID(ctx, id)
	if err != nil {
		return nil, errors.New(errors.CodeShopNotFound, "店铺不存在")
	}

	// 检查店铺编号唯一性（如果修改了编号）
	if req.ShopCode != nil && *req.ShopCode != shop.ShopCode {
		existing, err := s.shopStore.GetByCode(ctx, *req.ShopCode)
		if err == nil && existing != nil && existing.ID != id {
			return nil, errors.New(errors.CodeShopCodeExists, "店铺编号已存在")
		}
		shop.ShopCode = *req.ShopCode
	}

	// 更新字段
	if req.ShopName != nil {
		shop.ShopName = *req.ShopName
	}
	if req.ContactName != nil {
		shop.ContactName = *req.ContactName
	}
	if req.ContactPhone != nil {
		shop.ContactPhone = *req.ContactPhone
	}
	if req.Province != nil {
		shop.Province = *req.Province
	}
	if req.City != nil {
		shop.City = *req.City
	}
	if req.District != nil {
		shop.District = *req.District
	}
	if req.Address != nil {
		shop.Address = *req.Address
	}

	shop.Updater = currentUserID

	if err := s.shopStore.Update(ctx, shop); err != nil {
		return nil, err
	}

	return shop, nil
}

// Disable 禁用店铺
func (s *Service) Disable(ctx context.Context, id uint) error {
	// 获取当前用户 ID
	currentUserID := middleware.GetUserIDFromContext(ctx)
	if currentUserID == 0 {
		return errors.New(errors.CodeUnauthorized, "未授权访问")
	}

	// 查询店铺
	shop, err := s.shopStore.GetByID(ctx, id)
	if err != nil {
		return errors.New(errors.CodeShopNotFound, "店铺不存在")
	}

	// 更新状态
	shop.Status = constants.StatusDisabled
	shop.Updater = currentUserID

	return s.shopStore.Update(ctx, shop)
}

// Enable 启用店铺
func (s *Service) Enable(ctx context.Context, id uint) error {
	// 获取当前用户 ID
	currentUserID := middleware.GetUserIDFromContext(ctx)
	if currentUserID == 0 {
		return errors.New(errors.CodeUnauthorized, "未授权访问")
	}

	// 查询店铺
	shop, err := s.shopStore.GetByID(ctx, id)
	if err != nil {
		return errors.New(errors.CodeShopNotFound, "店铺不存在")
	}

	// 更新状态
	shop.Status = constants.StatusEnabled
	shop.Updater = currentUserID

	return s.shopStore.Update(ctx, shop)
}

// GetByID 获取店铺详情
func (s *Service) GetByID(ctx context.Context, id uint) (*model.Shop, error) {
	shop, err := s.shopStore.GetByID(ctx, id)
	if err != nil {
		return nil, errors.New(errors.CodeShopNotFound, "店铺不存在")
	}
	return shop, nil
}

// List 查询店铺列表
func (s *Service) List(ctx context.Context, opts *store.QueryOptions, filters map[string]interface{}) ([]*model.Shop, int64, error) {
	return s.shopStore.List(ctx, opts, filters)
}

// GetSubordinateShopIDs 获取下级店铺 ID 列表（包含自己）
func (s *Service) GetSubordinateShopIDs(ctx context.Context, shopID uint) ([]uint, error) {
	return s.shopStore.GetSubordinateShopIDs(ctx, shopID)
}