package logic

import (
	"context"
	"strings"
	"time"

	"godemo/category/category"
	"godemo/gateway/internal/svc"
	"godemo/gateway/internal/types"

	"github.com/zeromicro/go-zero/core/logx"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

type GetSystemCategoriesLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewGetSystemCategoriesLogic(ctx context.Context, svcCtx *svc.ServiceContext) *GetSystemCategoriesLogic {
	return &GetSystemCategoriesLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *GetSystemCategoriesLogic) GetSystemCategories(req *types.GetSystemCategoriesReq) (resp *types.ListCategoriesResp, err error) {
	// 1. 验证系统ID
	if strings.TrimSpace(req.SystemID) == "" {
		return nil, status.Error(codes.InvalidArgument, "system_id is required")
	}

	// 2. 准备 RPC 请求
	rpcReq := &category.GetSystemCategoriesRequest{
		SystemId:           req.SystemID,
		IncludeDescendants: req.IncludeDescendants,
	}

	// 添加父分类ID过滤（如果提供）
	if req.ParentID != "" {
		rpcReq.ParentId = req.ParentID
	}

	// 3. 调用 RPC 服务
	rpcResp, rpcErr := l.svcCtx.CategoryRpc.GetSystemCategories(l.ctx, rpcReq)
	if rpcErr != nil {
		st, ok := status.FromError(rpcErr)
		if ok && st.Code() == codes.NotFound {
			// 返回空列表而不是错误
			return &types.ListCategoriesResp{
				Total: 0,
				List:  []types.BaseCategory{},
			}, nil
		}
		l.Logger.Errorf("RPC error: %v", rpcErr)
		return nil, rpcErr
	}

	// 4. 转换响应数据
	categories := make([]types.BaseCategory, 0, len(rpcResp.Categories))
	for _, cat := range rpcResp.Categories {
		// 转换时间格式
		createdAt := ""
		if cat.CreatedAt > 0 {
			createdAt = time.Unix(cat.CreatedAt, 0).Format(time.RFC3339)
		}

		updatedAt := ""
		if cat.UpdatedAt > 0 {
			updatedAt = time.Unix(cat.UpdatedAt, 0).Format(time.RFC3339)
		}

		categories = append(categories, types.BaseCategory{
			ID:          cat.Id,
			SystemID:    cat.SystemId,
			Name:        cat.Name,
			Alias:       cat.Alias,
			ParentID:    cat.ParentId,
			Description: cat.Description,
			CreatedAt:   createdAt,
			UpdatedAt:   updatedAt,
		})
	}

	// 5. 构建响应
	resp = &types.ListCategoriesResp{
		Total: rpcResp.Total,
		List:  categories,
	}

	l.Logger.Infof("Retrieved %d categories for system %s (parent: %s)", len(categories), req.SystemID, req.ParentID)
	return resp, nil
}