Сделал не доработанную, но рабочую бизнес логику

Hotel/Hotel.sln

@@ -3,11 +3,13 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.9.34622.214
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotelView", "HotelView\HotelView.csproj", "{BEF2955E-B161-42D6-9385-D06D31FA5CF8}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotelView", "HotelView\HotelView.csproj", "{BEF2955E-B161-42D6-9385-D06D31FA5CF8}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotelDataModels", "HotelDataModels\HotelDataModels.csproj", "{311319D0-3CD8-48F0-8258-017FBD83728D}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotelDataModels", "HotelDataModels\HotelDataModels.csproj", "{311319D0-3CD8-48F0-8258-017FBD83728D}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotelContracts", "HotelContracts\HotelContracts.csproj", "{85D5192D-24CF-48CD-800F-BE5E02B738B6}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HotelContracts", "HotelContracts\HotelContracts.csproj", "{85D5192D-24CF-48CD-800F-BE5E02B738B6}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotelBusinessLogic", "HotelBusinessLogic\HotelBusinessLogic.csproj", "{66786012-F68B-4515-9C19-4C97049F9C49}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -27,6 +29,10 @@ Global
 		{85D5192D-24CF-48CD-800F-BE5E02B738B6}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{85D5192D-24CF-48CD-800F-BE5E02B738B6}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{85D5192D-24CF-48CD-800F-BE5E02B738B6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{66786012-F68B-4515-9C19-4C97049F9C49}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{66786012-F68B-4515-9C19-4C97049F9C49}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{66786012-F68B-4515-9C19-4C97049F9C49}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{66786012-F68B-4515-9C19-4C97049F9C49}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

Hotel/HotelBusinessLogic/BookingLogic.cs

@@ -0,0 +1,99 @@
+using HotelContracts.BindingModels;
+using HotelContracts.BusinessLogicsContracts;
+using HotelContracts.SearchModels;
+using HotelContracts.StoragesContracts;
+using HotelContracts.ViewModels;
+using HotelDataModels.Enums;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HotelBusinessLogic
+{
+    public class BookingLogic : IBookingLogic
+    {
+        private readonly IBookingStorage _bookingStorage;
+
+        public BookingLogic(IBookingStorage bookingStorage)
+        {
+            _bookingStorage = bookingStorage;
+        }
+        public BookingViewModel? ReadElement(BookingSearchModel model)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+
+            var element = _bookingStorage.GetElement(model);
+            if (element == null)
+            {
+                return null;
+            }
+            return element;
+        }
+
+        public List<BookingViewModel>? ReadList(BookingSearchModel? model)
+        {
+            var list = model == null ? _bookingStorage.GetFullList() : _bookingStorage.GetFilteredList(model);
+            if (list == null)
+            {
+                return null;
+            }
+            return list;
+        }
+
+        public bool Create(BookingBindingModel model)
+        {
+            CheckModel(model);
+            if (_bookingStorage.Insert(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Delete(BookingBindingModel model)
+        {
+            CheckModel(model, false);
+            if (_bookingStorage.Delete(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Update(BookingBindingModel model)
+        {
+            CheckModel(model);
+            if (_bookingStorage.Update(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        private void CheckModel(BookingBindingModel model, bool withParams = true)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+            if (!withParams)
+            {
+                return;
+            }
+            if (model.RoomId <= 0)
+            {
+                throw new ArgumentNullException("Некорректный идентификатор комнаты", nameof(model.RoomId));
+            }
+            if (model.ClientId <= 0)
+            {
+                throw new ArgumentNullException("Некорректный идентификатор клиента", nameof(model.ClientId));
+            }
+
+        }
+    }
+}

Hotel/HotelBusinessLogic/ClientLogic.cs

@@ -0,0 +1,106 @@
+using HotelContracts.BindingModels;
+using HotelContracts.BusinessLogicsContracts;
+using HotelContracts.SearchModels;
+using HotelContracts.StoragesContracts;
+using HotelContracts.ViewModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HotelBusinessLogic
+{
+    public class ClientLogic : IClientLogic
+    {
+        private readonly IClientStorage _clientStorage;
+
+        public ClientLogic(IClientStorage clientStorage)
+        {
+            _clientStorage = clientStorage;
+        }
+        public ClientViewModel? ReadElement(ClientSearchModel model)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+
+            var element = _clientStorage.GetElement(model);
+            if (element == null)
+            {
+                return null;
+            }
+            return element;
+        }
+
+        public List<ClientViewModel>? ReadList(ClientSearchModel? model)
+        {
+            var list = model == null ? _clientStorage.GetFullList() : _clientStorage.GetFilteredList(model);
+            if (list == null)
+            {
+                return null;
+            }
+            return list;
+        }
+
+        public bool Create(ClientBindingModel model)
+        {
+            CheckModel(model);
+            if (_clientStorage.Insert(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Delete(ClientBindingModel model)
+        {
+            CheckModel(model, false);
+            if (_clientStorage.Delete(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Update(ClientBindingModel model)
+        {
+            CheckModel(model);
+            if (_clientStorage.Update(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        private void CheckModel(ClientBindingModel model, bool withParams = true)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+            if (!withParams)
+            {
+                return;
+            }
+            if (string.IsNullOrEmpty(model.Name))
+            {
+                throw new ArgumentNullException("Нет имени клиента", nameof(model.Name));
+            }
+            if (string.IsNullOrEmpty(model.Surname))
+            {
+                throw new ArgumentNullException("Нет фамилии клиента", nameof(model.Surname));
+            }
+            if (string.IsNullOrEmpty(model.PhoneNumber))
+            {
+                throw new ArgumentNullException("Нет номера телефона", nameof(model.PhoneNumber));
+            }
+            if (string.IsNullOrEmpty(model.Password))
+            {
+                throw new ArgumentNullException("Нет пароля", nameof(model.Password));
+            }
+
+        }
+    }
+}

Hotel/HotelBusinessLogic/HotelBusinessLogic.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\HotelContracts\HotelContracts.csproj" />
+    <ProjectReference Include="..\HotelDataModels\HotelDataModels.csproj" />
+  </ItemGroup>
+
+</Project>

Hotel/HotelBusinessLogic/PostLogic.cs

@@ -0,0 +1,95 @@
+using HotelContracts.BindingModels;
+using HotelContracts.BusinessLogicsContracts;
+using HotelContracts.SearchModels;
+using HotelContracts.StoragesContracts;
+using HotelContracts.ViewModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HotelBusinessLogic
+{
+    public class PostLogic : IPostLogic
+    {
+        private readonly IPostStorage _postStorage;
+
+        public PostLogic(IPostStorage postStorage)
+        {
+            _postStorage = postStorage;
+        }
+        public PostViewModel? ReadElement(PostSearchModel model)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+
+            var element = _postStorage.GetElement(model);
+            if (element == null)
+            {
+                return null;
+            }
+            return element;
+        }
+
+        public List<PostViewModel>? ReadList(PostSearchModel? model)
+        {
+            var list = model == null ? _postStorage.GetFullList() : _postStorage.GetFilteredList(model);
+            if (list == null)
+            {
+                return null;
+            }
+            return list;
+        }
+
+        public bool Create(PostBindingModel model)
+        {
+            CheckModel(model);
+            if (_postStorage.Insert(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Delete(PostBindingModel model)
+        {
+            CheckModel(model, false);
+            if (_postStorage.Delete(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Update(PostBindingModel model)
+        {
+            CheckModel(model);
+            if (_postStorage.Update(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        private void CheckModel(PostBindingModel model, bool withParams = true)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+            if (!withParams)
+            {
+                return;
+            }
+            if (string.IsNullOrEmpty(model.PostName))
+            {
+                throw new ArgumentNullException("Нужно заполнить поле должности", nameof(model.PostName));
+            }
+         
+
+        }
+    }
+}

Hotel/HotelBusinessLogic/RoomLogic.cs

@@ -0,0 +1,114 @@
+using HotelContracts.BindingModels;
+using HotelContracts.BusinessLogicsContracts;
+using HotelContracts.SearchModels;
+using HotelContracts.StoragesContracts;
+using HotelContracts.ViewModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HotelBusinessLogic
+{
+    public class RoomLogic : IRoomLogic
+    {
+        private readonly IRoomStorage _roomStorage;
+
+        public RoomLogic(IRoomStorage roomStorage)
+        {
+            _roomStorage = roomStorage;
+        }
+        public RoomViewModel? ReadElement(RoomSearchModel model)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+
+            var element = _roomStorage.GetElement(model);
+            if (element == null)
+            {
+                return null;
+            }
+            return element;
+        }
+
+        public List<RoomViewModel>? ReadList(RoomSearchModel? model)
+        {
+            var list = model == null ? _roomStorage.GetFullList() : _roomStorage.GetFilteredList(model);
+            if (list == null)
+            {
+                return null;
+            }
+            return list;
+        }
+
+        public bool Create(RoomBindingModel model)
+        {
+            CheckModel(model);
+            if (_roomStorage.Insert(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Delete(RoomBindingModel model)
+        {
+            CheckModel(model, false);
+            if (_roomStorage.Delete(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Update(RoomBindingModel model)
+        {
+            CheckModel(model);
+            if (_roomStorage.Update(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        private void CheckModel(RoomBindingModel model, bool withParams = true)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+            if (!withParams)
+            {
+                return;
+            }
+            if (string.IsNullOrEmpty(model.Condition))
+            {
+                throw new ArgumentNullException("Нет поля состояние", nameof(model.Condition));
+            }
+            if (model.WorkerId <= 0)
+            {
+                throw new ArgumentNullException("Некорректный идентификатор рабочего", nameof(model.WorkerId));
+            }
+            if (model.Number <= 0)
+            {
+                throw new ArgumentNullException("нет поля номера", nameof(model.Number));
+            }
+            if (model.Floor <= 0)
+            {
+                throw new ArgumentNullException("нет поля этаж", nameof(model.Floor));
+            }
+            if (model.NumberOfBeds <= 0)
+            {
+                throw new ArgumentNullException("нет поля количество спальных мест", nameof(model.NumberOfBeds));
+            }
+            if (model.Cost <= 0)
+            {
+                throw new ArgumentNullException("нет поля цены", nameof(model.Cost));
+            }
+
+        }
+    }
+}

Hotel/HotelBusinessLogic/WorkerLogic.cs

@@ -0,0 +1,115 @@
+using HotelContracts.BindingModels;
+using HotelContracts.BusinessLogicsContracts;
+using HotelContracts.SearchModels;
+using HotelContracts.StoragesContracts;
+using HotelContracts.ViewModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HotelBusinessLogic
+{
+    public class WorkerLogic : IWorkerLogic
+    {
+        private readonly IWorkerStorage _workerStorage;
+
+        public WorkerLogic(IWorkerStorage workerStorage)
+        {
+            _workerStorage = workerStorage;
+        }
+        public WorkerViewModel? ReadElement(WorkerSearchModel model)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+
+            var element = _workerStorage.GetElement(model);
+            if (element == null)
+            {
+                return null;
+            }
+            return element;
+        }
+
+        public List<WorkerViewModel>? ReadList(WorkerSearchModel? model)
+        {
+            var list = model == null ? _workerStorage.GetFullList() : _workerStorage.GetFilteredList(model);
+            if (list == null)
+            {
+                return null;
+            }
+            return list;
+        }
+
+        public bool Create(WorkerBindingModel model)
+        {
+            CheckModel(model);
+            if (_workerStorage.Insert(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Delete(WorkerBindingModel model)
+        {
+            CheckModel(model, false);
+            if (_workerStorage.Delete(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        public bool Update(WorkerBindingModel model)
+        {
+            CheckModel(model);
+            if (_workerStorage.Update(model) == null)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        private void CheckModel(WorkerBindingModel model, bool withParams = true)
+        {
+            if (model == null)
+            {
+                throw new ArgumentNullException(nameof(model));
+            }
+            if (!withParams)
+            {
+                return;
+            }
+            if (string.IsNullOrEmpty(model.Phone))
+            {
+                throw new ArgumentNullException("Нет поля номер телефона", nameof(model.Phone));
+            }
+            if (string.IsNullOrEmpty(model.FIO))
+            {
+                throw new ArgumentNullException("Нет поля ФИО", nameof(model.FIO));
+            }
+            if (model.PostId <= 0)
+            {
+                throw new ArgumentNullException("Некорректный идентификатор должности", nameof(model.PostId));
+            }
+            if (model.WorkExperience < 0)
+            {
+                throw new ArgumentNullException("Рабочий опыт не может быть меньше 0", nameof(model.WorkExperience));
+            }
+            if (model.PostId <= 0)
+            {
+                throw new ArgumentNullException("Некорректный идентификатор должности", nameof(model.PostId));
+            }
+            if (model.Salary <= 0)
+            {
+                throw new ArgumentNullException("Зарплата не может быть меньше 0", nameof(model.Salary));
+            }
+
+
+        }
+    }
+}