public interface IRepository<TModel> : IDisposable
    {
        /// <summary>
        /// Вернуть коллекцию объектов, но не более 100 шт первых.
        /// </summary>
        /// <returns></returns>
        IEnumerable<TModel> GetList(int countItems = 100);

        IEnumerable<TModel> GetList(int page, int pageSize);

        /// <summary>
        /// Вернуть кол-во всех объектов
        /// </summary>
        /// <returns></returns>
        long Count();

        TModel GetById(long id);

        TModel Insert(TModel model);

        TModel Update(TModel model);

        void Delete(TModel model);

    }

    public abstract class BaseRepository<TModel, TEntity> : IRepository<TModel> 
        where TEntity : class 
        where TModel :class 
    {
        protected readonly DbContext DB;
        protected readonly ObjectsMapper<TEntity, TModel> MapperModel = ObjectMapperManager.DefaultInstance.GetMapper<TEntity, TModel>();
        protected readonly ObjectsMapper<TModel, TEntity> MapperEntity = ObjectMapperManager.DefaultInstance.GetMapper<TModel, TEntity>();

        public BaseRepository(DbContext db)
        {
            DB = db;
        }

        public BaseRepository()
        {
            DB = new RiskControlDb();
        }

        public virtual IEnumerable<TModel> GetList(int countItems = 100)
        {
            var entityQuery = DB.Set<TEntity>().AsQueryable();
            var entityList = Count() > countItems ? entityQuery.Take(countItems).ToList() : entityQuery.ToList();

            return entityList.Select(entity => MapperModel.Map(entity));
        }

        public IEnumerable<TModel> GetList(int page, int pageSize)
        {
            var list = DB.Set<TEntity>().AsQueryable();
            var count = Count();
            var pageCount = (count%pageSize == 0) ? count/pageSize : count/pageSize + 1;

            return list.Skip((page - 1)*pageSize).Take(pageSize).ToList().Select(entity => MapperModel.Map(entity));
        }

        public virtual long Count()
        {
            return DB.Set<TEntity>().LongCount();
        }
        
        public virtual TModel GetById(long id)
        {
            var collection = DB.Set<TEntity>();
            return MapperModel.Map(collection.Find(id));
        }

        public virtual TModel Insert(TModel model)
        {
            var entity = MapperEntity.Map(model);
            DB.Set<TEntity>().Add(entity);
            DB.SaveChanges();

            return MapperModel.Map(entity);
        }

        public virtual TModel Update(TModel model)
        {
            var entity = MapperEntity.Map(model);
            DB.Entry(entity).State = EntityState.Modified;
            DB.SaveChanges();

            return MapperModel.Map(entity);
        }

        public virtual void Delete(TModel model)
        {
            DB.Set<TEntity>().Remove(MapperEntity.Map(model));
            DB.SaveChanges();
        }

        public virtual void Dispose()
        {
            DB.Dispose();
        }
    }

public class BranchRepository : BaseRepository<BranchModel, BranchEntity>
    {
        
    }

public class ClientModel
    {
        public int Id { get; set; }

        public string NameShort { get; set; }

        public string AddressFirst { get; set; }

        public string Phone { get; set; }

        public string Email { get; set; }

        public string DefaultDocument { get; set; }

        public string Branch { get; set; }

        public ICollection<DocumentModel> Documents { get; set; }
    }

    public class BranchModel
    {
        public int Id { get; set; }

        public string Brief { get; set; }

        public string Description { get; set; }

    }

    public class DocumentModel
    {
        public int Id { get; set; }

        public string Name { get; set; }
    }

    public class Client
    {
        public int Id { get; set; }

        public string NameShort { get; set; }
        
        public string AddressFirst { get; set; }
        
        public string Phone { get; set; }
        
        public string Email { get; set; }

        public string BranchId { get; set; }

        public Branch Branch { get; set; }

        public virtual ICollection<Document> Documents { get; set; }
    }

    public class Branch
    {
        public int Id { get; set; }

        public string Brief { get; set; }

        public string Description { get; set; }

        internal bool IsDelete { get; set; }

        public virtual ICollection<Client> Clients { get; set; }
    }

    public class Document
    {
        public int Id { get; set; }

        public string Name { get; set; }

        public int ClientId { get; set; }

        public Client Client { get; set; }
    }

    public class SampleDb : DbContext
    {
        public DbSet<Client> Clients { get; set; }
        public DbSet<Branch> Branches { get; set; }
        public DbSet<Document> Document { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<Client>().HasRequired(c => c.Branch);
            modelBuilder.Entity<Document>().HasRequired(c => c.Client);
        }
    }