Demo/Data/Repository/GroupRepositoryImpl.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using Posechaemost.Data.LocalData;
using Posechaemost.Data.LocalData.Entity;

namespace Posechaemost.Data.Repository
{
    public class GroupRepositoryImpl
    {
        public List<GroupLocalEntity> GetAllGroups() => LocalStaticData.groups;
        public GroupLocalEntity? UpdateGroup(String name) 
        {
            GroupLocalEntity? groupLocal = GetAllGroups()
                    .Where(x => x.Name == name).FirstOrDefault();
            if (groupLocal == null) return null;
            groupLocal.Name = name;
            return groupLocal;
        }

        public GroupLocalEntity? AddGroup(String name, String id)
        {
            GroupLocalEntity? groupLocal = GetAllGroups().FirstOrDefault();
            groupLocal.Name = name;
            groupLocal.Id = int.Parse(id);
            return groupLocal;
        }
    }
}