Demo/Data/Repository/PresenceRepositoryImpl.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Posechaemost.Data.LocalData;
using Posechaemost.Data.LocalData.Entity;
using Posechaemost.Domain.Models;

namespace Posechaemost.Data.Repository
{
    public class PresenceRepositoryImpl: IPresenceRepository
    {
        public PresenceRepositoryImpl() {
            GetAllPresences = LocalStaticData.presences;
        }
        public List<PresenceLocalEntity> GetAllPresences
        { get; set; }

        public void AddPresence(PresenceLocalEntity presence)
        {
            PresenceLocalEntity? presenceLocal = GetAllPresences.FirstOrDefault();
            // GroupLocalEntity? group = new GroupLocalEntity();
            presenceLocal.ClassNumber = presence.ClassNumber;
            presence.UserGuid = presence.UserGuid;
            presenceLocal.Date = presence.Date;
            presenceLocal.IsAttendence = presence.IsAttendence;
        }

        public List<PresenceLocalEntity> GetPresenceByGroup(int groupId)
        {
            return GetAllPresences;
        }

        public List<PresenceLocalEntity> GetPresenceByGroupAndDate(int groupId, DateOnly date)
        {
            return GetAllPresences;
        }

        public bool UncheckAttendence(int firstClass, int lastClass, DateOnly date, Guid userGuid)
        {
            var presToUpdate = GetAllPresences
                .Where(x => x.UserGuid == userGuid && x.ClassNumber >= firstClass 
                        && x.ClassNumber <= lastClass && x.Date == date).ToList();

            foreach (var pres in presToUpdate) {
                pres.IsAttendence = false;
            }
            return true;
        }
    }
}