package logic

import (
	"context"
	"errors"

	"godemo/category/category"
	"godemo/category/internal/model"
	"godemo/category/internal/svc"

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

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

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

func (l *GetCategoryLogic) GetCategory(in *category.GetCategoryRequest) (*category.CategoryInfoResponse, error) {
	// 1. 参数校验
	if in.Id == "" {
		return nil, status.Error(codes.InvalidArgument, "分类ID不能为空")
	}

	// 2. 查询数据库
	categoryData, err := l.svcCtx.CategoryModel.FindOne(l.ctx, in.Id)
	if err != nil {
		if errors.Is(err, model.ErrNotFound) {
			l.Logger.Errorf("分类不存在, ID: %s", in.Id)
			return nil, status.Error(codes.NotFound, "分类不存在")
		}
		l.Logger.Errorf("数据库查询失败: %v", err)
		return nil, status.Error(codes.Internal, "内部错误")
	}

	// 3. 转换响应格式
	return l.convertToResponse(categoryData), nil
}

func (l *GetCategoryLogic) convertToResponse(c *model.Categories) *category.CategoryInfoResponse {
	// 处理可能为空的字段
	var alias, parentID, description string

	if c.Alias.Valid {
		alias = c.Alias.String
	}
	if c.ParentId.Valid {
		parentID = c.ParentId.String
	}
	if c.Description.Valid {
		description = c.Description.String
	}

	// 处理时间戳
	var updatedAt int64
	if c.UpdatedAt.Valid {
		updatedAt = c.UpdatedAt.Time.Unix()
	} else {
		updatedAt = c.CreatedAt.Unix() // 如果未更新过，使用创建时间
	}

	return &category.CategoryInfoResponse{
		Category: &category.CategoryInfo{
			Id:          c.Id,
			SystemId:    c.SystemId,
			Name:        c.Name,
			Alias:       alias,
			ParentId:    parentID,
			Description: description,
			CreatedAt:   c.CreatedAt.Unix(),
			UpdatedAt:   updatedAt,
		},
	}
}