src/InternshipSystem.Api/Commands/UpdateRegistrationForm.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using IdentityServer4.Extensions;
+using InternshipSystem.Core;
+using InternshipSystem.Core.Entity.Internship;
+
+namespace InternshipSystem.Api.Commands
+{
+    public class UpdateRegistrationForm
+    {
+        public UpdateCompany? Company { get; set; }
+        public DateTime? Start { get; set; }
+        public DateTime? End { get; set; }
+        public UpdateMentor? Mentor { get; set; }
+        public List<Internship> Subjects { get; set; }
+        public InternshipType Type { get; set; }
+    }
+
+    public struct UpdateMentor
+    {
+        public string FirstName { get; set; }
+        public string LastName { get; set; }
+        public string Email { get; set; }
+        public string PhoneNumber { get; set; }
+    }
+
+    public struct UpdateCompany
+    {
+        public long? Id { get; set; }
+        public string Nip { get; set; }
+        public string Name { get; set; }
+        public UpdateBranchOffice? BranchOffice { get; set; }
+
+        public bool IsCustomUpdate => !Nip.IsNullOrEmpty() || !Name.IsNullOrEmpty();
+    }
+
+    public struct UpdateBranchOffice
+    {
+        public long? Id { get; set; }
+        public string Street { get; set; }
+        public string Building { get; set; }
+        public string City { get; set; }
+        public string PostalCode { get; set; }
+        public string Country { get; set; }
+
+        public bool IsCustomUpdate => !string.IsNullOrEmpty(Street) ||
+                                      !string.IsNullOrEmpty(Building) ||
+                                      !string.IsNullOrEmpty(City) ||
+                                      !string.IsNullOrEmpty(PostalCode) ||
+                                      !string.IsNullOrEmpty(Country);
+    }
+}

src/InternshipSystem.Api/Controllers/InternshipRegistrationController.cs

@@ -1,13 +1,11 @@
-using System.Threading;
+using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
-using InternshipSystem.Api.Queries;
+using InternshipSystem.Api.Commands;
 using InternshipSystem.Api.Security;
-using InternshipSystem.Core.Commands;
+using InternshipSystem.Api.UseCases;
 using InternshipSystem.Repository;
 using Microsoft.AspNetCore.Authorization;
-using InternshipSystem.Api.Security;
-using InternshipSystem.Api.Services;
-using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -17,17 +15,16 @@ namespace InternshipSystem.Api.Controllers
     [Route("internshipRegistration")]
     public class InternshipRegistrationController : ControllerBase
     {
-        private readonly IInternshipService _internshipService;
+        private readonly InternshipDbContext _dbContext;
 
-        public InternshipRegistrationController(IInternshipService internshipService)
+        public InternshipRegistrationController(InternshipDbContext dbContext)
         {
-            _internshipService = internshipService;
+            _dbContext = dbContext;
         }
         
         /// <summary>
         /// Validate and add filled internship registration form 
         /// </summary>
-        /// <param name="updateRegistration">Internship registration data</param>
         /// <response code="200">If registration form was successfully added</response>
         /// <response code="400">If the provided registration query was malformed</response>
         /// <response code="401">This action is only available for authorized student registered for current edition</response>
@@ -35,19 +32,33 @@ namespace InternshipSystem.Api.Controllers
         [ProducesResponseType(StatusCodes.Status200OK)]
         [ProducesResponseType(StatusCodes.Status400BadRequest)]
         [ProducesResponseType(StatusCodes.Status401Unauthorized)]
-        [Authorize]
-        public async Task<ActionResult> SubmitRegistrationForm([FromBody] RegistrationFormQuery registrationQuery, 
-            [FromServices] User user, CancellationToken cancellationToken)
+        [Authorize(Policy = Policies.RegisteredOnly)]
+        public async Task<ActionResult> SubmitRegistrationForm(
+            UpdateRegistrationForm registrationCommand, 
+            [FromServices] User user, 
+            CancellationToken cancellationToken)
         {
-            var validator = new RegistrationFormQuery.Validator();
-            var validationResult = await validator.ValidateAsync(registrationQuery, cancellationToken);
+            var edition = await _dbContext.Editions.FirstAsync(e => e.Id == user.EditionId, cancellationToken);
 
-            if (!validationResult.IsValid)
-            {
-                return BadRequest(validationResult.ToString());
-            }
+            var internshipRegistration =
+                await _dbContext
+                    .Entry(edition)
+                    .Collection(e => e.Internships)
+                    .Query()
+                    .Where(i => i.Student.Id == user.PersonNumber)
+                    .Select(i => i.InternshipRegistration)
+                        .Include(r => r.BranchAddress)
+                        .Include(r => r.Company)
+                        .ThenInclude(c => c.Branches)
+                    .FirstAsync(cancellationToken);
             
-            return await _internshipService.SubmitRegistration(registrationQuery, user.PersonNumber, cancellationToken);
+            var useCase = new UpdateInternshipRegistrationUseCase(_dbContext, internshipRegistration, edition, user);
+            
+            var result = await useCase.UpdateInternshipRegistration(registrationCommand, cancellationToken);
+            
+            await _dbContext.SaveChangesAsync(cancellationToken);
+
+            return Ok(result);
         }
     }
 }

src/InternshipSystem.Api/Services/IInternshipService.cs

@@ -7,9 +7,6 @@ namespace InternshipSystem.Api.Services
 {
     public interface IInternshipService
     {
-        Task<ActionResult> SubmitRegistration(RegistrationFormQuery registrationQuery, long personNumber,
-            CancellationToken cancellationToken);
-        
         Task<ActionResult> AddDocumentToInternship(DocumentPublishRequest documentRequest, long personNumber,
             CancellationToken cancellationToken);
     }

src/InternshipSystem.Api/Services/InternshipService.cs

@@ -21,63 +21,6 @@ namespace InternshipSystem.Api.Services
             Mapper = mapper;
         }
 
-        public async Task<ActionResult> SubmitRegistration(RegistrationFormQuery registrationQuery, long personNumber, 
-            CancellationToken cancellationToken)
-        {
-            var edition = await _context.Editions.FindAsync(personNumber);
-
-            var internship = await _context.Entry(edition)
-                .Collection(e => e.Internships)
-                .Query()
-                .SingleAsync(i => i.Student.Id == personNumber, cancellationToken);
-
-            var internshipRegistration = internship.InternshipRegistration;
-
-            if (registrationQuery.Company != null)
-            {
-                var company = registrationQuery.Company.Id.HasValue
-                    ? await _context.Companies.SingleAsync(c => c.Id == registrationQuery.Company.Id,
-                        cancellationToken: cancellationToken)
-                    : Company.CreateCompany(registrationQuery.Company.Nip, registrationQuery.Company.Name);
-
-                internshipRegistration.UpdateCompany(company);
-            }
-
-            var officeForm = registrationQuery.BranchOffice;
-            if (officeForm != null)
-            {
-                BranchOffice branch;
-                
-                if (officeForm.Id.HasValue)
-                { 
-                    branch = await _context.Entry(internshipRegistration.Company)
-                            .Collection(c => c.Branches)
-                            .Query()
-                            .SingleAsync(o => o.Id == officeForm.Id, cancellationToken: cancellationToken);
-                }
-                else
-                {
-                    branch = BranchOffice.CreateBranch(officeForm.Country, officeForm.City, officeForm.PostalCode,
-                        officeForm.Street, officeForm.Building);
-                    internshipRegistration.Company.AddBranchOffice(branch);
-                }
-                
-                internshipRegistration.UpdateBranch(branch);
-            }
-
-            internshipRegistration.Start = registrationQuery.Start ?? internshipRegistration.Start;
-            internshipRegistration.End = registrationQuery.End ?? internshipRegistration.End;
-
-            if (registrationQuery.Type != null && edition.IsInternshipTypeAllowed(registrationQuery.Type))
-            {
-                return new BadRequestObjectResult("Edition doesn't have this type of employment in available employments type");
-            }
-            
-            internshipRegistration.Type = registrationQuery.Type ?? internshipRegistration.Type;
-           
-            await _context.SaveChangesAsync(cancellationToken);
-            return new OkResult();
-        }
 
         public async Task<ActionResult> AddDocumentToInternship(DocumentPublishRequest documentRequest, long personNumber,
             CancellationToken cancellationToken)

src/InternshipSystem.Api/UseCases/UpdateInternshipRegistrationUseCase.cs

@@ -0,0 +1,129 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using IdentityServer4.Extensions;
+using InternshipSystem.Api.Commands;
+using InternshipSystem.Api.Security;
+using InternshipSystem.Core;
+using InternshipSystem.Core.UglyOrmArtifacts;
+using InternshipSystem.Repository;
+using Microsoft.EntityFrameworkCore;
+
+namespace InternshipSystem.Api.UseCases
+{
+    public class UpdateInternshipRegistrationUseCase
+    {
+        private readonly InternshipDbContext _dbContext;
+        private readonly Edition _edition;
+        private readonly User _user;
+        private readonly InternshipRegistration subjectRegistration;
+
+        public UpdateInternshipRegistrationUseCase(InternshipDbContext dbContext,
+            InternshipRegistration internshipRegistration, Edition edition, User user)
+        {
+            _dbContext = dbContext;
+            _edition = edition;
+            _user = user;
+            subjectRegistration = internshipRegistration;
+        }
+
+        public async Task<string> UpdateInternshipRegistration(
+            UpdateRegistrationForm registrationCommand,
+            CancellationToken cancellationToken)
+        {
+            subjectRegistration.Start = registrationCommand.Start ?? subjectRegistration.Start;
+            subjectRegistration.End = registrationCommand.End ?? subjectRegistration.End;
+            subjectRegistration.Type = registrationCommand.Type ?? subjectRegistration.Type;
+
+            if (registrationCommand.Mentor.HasValue)
+            {
+                UpdateMentor(registrationCommand.Mentor.Value);
+            }
+
+            if (!registrationCommand.Subjects.IsNullOrEmpty())
+            {
+                UpdateSubjects(registrationCommand.Subjects);
+            }
+
+            if (registrationCommand.Company.HasValue)
+            {
+                await UpdateCompanyAndBranch(registrationCommand.Company.Value, cancellationToken);
+            }
+
+            return subjectRegistration.ValidateStatus(_edition);
+        }
+
+        private async Task UpdateCompanyAndBranch(UpdateCompany companyUpdate, CancellationToken cancellationToken)
+        {
+            var company = subjectRegistration.Company;
+
+            if (companyUpdate.Id.HasValue)
+            {
+                company = await _dbContext.Companies
+                    .Include(c => c.Branches)
+                    .FirstAsync(c => c.Id == companyUpdate.Id.Value, cancellationToken);
+            }
+            else if (companyUpdate.IsCustomUpdate)
+            {
+                company = await _dbContext.Companies
+                              .Include(c => c.Branches)
+                              .SingleOrDefaultAsync(c => c.Provider == _user.PersonNumber, cancellationToken)
+                          ?? Company.CreateCompany(companyUpdate.Nip, companyUpdate.Name, _user.PersonNumber);
+
+                company.Name = companyUpdate.Name ?? company.Name;
+                company.Nip = companyUpdate.Nip ?? company.Nip;
+            }
+
+            if (companyUpdate.BranchOffice.HasValue)
+            {
+                var branchUpdate = companyUpdate.BranchOffice.Value;
+
+                var branch = subjectRegistration.BranchAddress;
+
+                if (branchUpdate.Id.HasValue)
+                {
+                    branch = company.Branches.First(b => b.Id == branchUpdate.Id.Value);
+                }
+                else if (branchUpdate.IsCustomUpdate)
+                {
+                    branch = company.Branches.FirstOrDefault(b => b.Provider == _user.PersonNumber);
+
+                    if (branch == null)
+                    {
+                        branch = BranchOffice.CreateBranch(branchUpdate.Country, branchUpdate.City, branchUpdate.PostalCode,
+                            branchUpdate.Street, branchUpdate.Building, _user.PersonNumber);
+                        company.AddBranchOffice(branch);
+                    }
+
+                    branch.Address.Country = branchUpdate.Country ?? branch.Address.Country;
+                    branch.Address.City = branchUpdate.City ?? branch.Address.City;
+                    branch.Address.PostalCode = branchUpdate.PostalCode ?? branch.Address.PostalCode;
+                    branch.Address.Street = branchUpdate.Country ?? branch.Address.Street;
+                    branch.Address.Building = branchUpdate.Building ?? branch.Address.Building;
+                }
+
+                subjectRegistration.BranchAddress = branch;
+            }
+
+            subjectRegistration.Company = company;
+        }
+
+        private void UpdateSubjects(IEnumerable<Internship> subjects)
+        {
+            subjectRegistration.Subjects = 
+                subjects
+                    .Select(i => new ProgramSubject
+                    {
+                        Registration = subjectRegistration,
+                        InternshipSubjectId = i.Id
+                    })
+                    .ToList();
+        }
+
+        private void UpdateMentor(UpdateMentor mentorUpdate)
+        {
+            subjectRegistration.Mentor.UpdateInformation(mentorUpdate.FirstName, mentorUpdate.LastName, mentorUpdate.Email, mentorUpdate.PhoneNumber);
+        }
+    }
+}

src/InternshipSystem.Core/Commands/UpdateRegistrationForm.cs

@@ -1,33 +0,0 @@
-using System;
-using InternshipSystem.Core.Entity.Internship;
-
-namespace InternshipSystem.Core.Commands
-{
-    public class UpdateRegistrationForm
-    {
-        public UpdateCompany? Company { get; set; }
-        public DateTime? Start { get; set; }
-        public DateTime? End { get; set; }
-        public InternshipType? Type { get; set; }
-    }
-
-    public struct UpdateCompany
-    {
-        public long? Id { get; set; }
-        public string Nip { get; set; }
-        public string Name { get; set; }
-        public UpdateBranchOffice? BranchOffice { get; set; }
-        
-        public bool IsUpdate => Id.HasValue;
-    }
-
-    public struct UpdateBranchOffice
-    {
-        public long? Id { get; set; }
-        public string Street { get; set; }
-        public string Building { get; set; }
-        public string City { get; set; }
-        public string PostalCode { get; set; }
-        public string Country { get; set; }
-    }
-}

src/InternshipSystem.Core/Entity/BranchOffice.cs

@@ -1,20 +1,28 @@
-namespace InternshipSystem.Core
+using FluentValidation;
+using FluentValidation.Validators;
+
+namespace InternshipSystem.Core
 {
     public class BranchOffice
     {
         public BranchOffice()
         {
         }
-        private BranchOffice(BranchAddress address)
+        
+        private BranchOffice(BranchAddress address, long provider)
         {
             Address = address;
+            Provider = provider;
         }
 
         public long Id { get; set; }
 
         public BranchAddress Address { get; set; }
 
-        public static BranchOffice CreateBranch(string country, string city, string postalCode, string street, string building)
+        public long Provider { get; set; }
+
+        public static BranchOffice CreateBranch(string country, string city, string postalCode, string street,
+            string building, long provider = 0)
         {
             var address = new BranchAddress
             {
@@ -25,7 +33,16 @@
                  PostalCode = postalCode
             };
             
-            return new BranchOffice(address);
+            return new BranchOffice(address, provider);
+        }
+
+        public class Validator : AbstractValidator<BranchOffice>
+        {
+            public Validator()
+            {
+                RuleFor(x => x.Address)
+                    .SetValidator(new BranchAddress.Validator());
+            }
         }
     }
 }

src/InternshipSystem.Core/Entity/Company.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
-using InternshipSystem.Core.Commands;
+using FluentValidation;
+using FluentValidation.Validators;
 
 namespace InternshipSystem.Core
 {
@@ -11,25 +12,28 @@ namespace InternshipSystem.Core
         public string Name { get; set; }
         public List<BranchOffice> Branches { get; set; }
 
-        public static Company CreateCompany(string nip, string name) =>
+        public long Provider { get; set; }
+
+        public static Company CreateCompany(string nip, string name, long provider = 0) =>
             new Company
             {
                 Nip = nip,
-                Name = name
+                Name = name,
+                Provider = provider
             };
 
-        public void AddBranchAddress(BranchAddress branch)
-        {
-        }
-
         public void AddBranchOffice(BranchOffice createBranch)
         {
             Branches.Add(createBranch);
         }
 
-        public static Company CreateCompany(UpdateCompany updateCompany)
+        public class Validator : AbstractValidator<Company>
         {
-            throw new NotImplementedException();
+            public Validator()
+            {
+                RuleFor(x => x.Nip).NotNull();
+                RuleFor(x => x.Name).NotNull();
+            }
         }
     }
 }

src/InternshipSystem.Core/Entity/Internship/Internship.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using InternshipSystem.Core.Commands;
 using InternshipSystem.Core.ValueObject;
 
 namespace InternshipSystem.Core
@@ -51,38 +50,5 @@ namespace InternshipSystem.Core
 
             return internship;
         }
-
-        public void UpdateInternshipRegistration(UpdateRegistrationForm updateRegistration)
-        {
-            var start = updateRegistration.Start ?? InternshipRegistration.Start;
-            var end = updateRegistration.End ?? InternshipRegistration.End;
-
-            if (!Edition.IsDateDuringEdition(start, end))
-            {
-                throw new ArgumentOutOfRangeException(nameof(InternshipRegistration.Start) + nameof(InternshipRegistration.End),"Date outside of edition boundaries");
-            }
-
-            var internshipType = updateRegistration.Type ?? InternshipRegistration.Type;
-
-            if (!Edition.IsInternshipTypeAllowed(internshipType))
-            {
-                throw new ArgumentException("Internship type not allowed for this edition", nameof(updateRegistration.Type));
-            }
-
-            var company = InternshipRegistration.Company;
-            if (company == null)
-            {
-                if (!updateRegistration.Company.HasValue)
-                {
-                    throw new ArgumentException("Company");
-                }
-
-                company = Company.CreateCompany(updateRegistration.Company.Value);
-                
-                
-            }
-            
-            InternshipRegistration.Update(start, end, internshipType);
-        }
     }
 }

src/InternshipSystem.Core/Entity/Internship/InternshipRegistration.cs

@@ -1,5 +1,9 @@
 using System;
+using System.Collections.Generic;
+using FluentValidation;
+using FluentValidation.Results;
 using InternshipSystem.Core.Entity.Internship;
+using InternshipSystem.Core.UglyOrmArtifacts;
 
 namespace InternshipSystem.Core
 {
@@ -10,6 +14,8 @@ namespace InternshipSystem.Core
         public BranchOffice BranchAddress { get; set; }
         public DateTime Start { get; set; }
         public DateTime End { get; set; }
+        public Mentor Mentor { get; set; }
+        public List<ProgramSubject> Subjects { get; set; }
         public InternshipType Type { get; set; }
         public DocumentState State { get; set; }
         
@@ -18,21 +24,44 @@ namespace InternshipSystem.Core
             return new InternshipRegistration();
         }
 
-        public void Update(DateTime start, DateTime end, InternshipType internshipType)
+
+        public string ValidateStatus(Edition edition)
         {
-            Start = start;
-            End = end;
-            Type = internshipType;
+            var validator = new Validator(edition);
+
+            var result = validator.Validate(this);
+
+            State = result.IsValid ? DocumentState.Submitted : DocumentState.Draft;
+
+            return result.ToString();
         }
 
-        public void UpdateCompany(Company newCompany)
+        public class Validator : AbstractValidator<InternshipRegistration>
         {
-            Company = newCompany;
+            public Validator(Edition edition)
+            {
+                RuleFor(x => x.Company)
+                    .SetValidator(new Company.Validator())
+                    .NotNull();
+                RuleFor(x => x.BranchAddress)
+                    .SetValidator(new BranchOffice.Validator())
+                    .NotNull();
+                RuleFor(x => x.Mentor)
+                    .SetValidator(new Mentor.Validate())
+                    .NotNull();
+                RuleFor(x => x.Subjects)
+                    .NotEmpty();
+                RuleFor(x => x.Type)
+                    .NotNull();
+                RuleFor(x => x.Start)
+                    .GreaterThanOrEqualTo(edition.EditionStart)
+                    .LessThan(x => x.End)
+                    .NotEmpty();
+                RuleFor(x => x.End)
+                    .LessThanOrEqualTo(edition.EditionFinish)
+                    .GreaterThan(x => x.Start)
+                    .NotEmpty();
             }
-
-        public void UpdateBranch(BranchOffice branch)
-        {
-            BranchAddress = branch;
         }
     }
 }

src/InternshipSystem.Core/InternshipSystem.Core.csproj

@@ -5,4 +5,8 @@
         <LangVersion>latest</LangVersion>
     </PropertyGroup>
 
+    <ItemGroup>
+      <PackageReference Include="FluentValidation" Version="9.1.2" />
+    </ItemGroup>
+
 </Project>

src/InternshipSystem.Core/UglyOrmArtifacts/ProgramSubject.cs

@@ -4,8 +4,8 @@ namespace InternshipSystem.Core.UglyOrmArtifacts
 {
     public class ProgramSubject
     {
-        public long InternshipProgramId { get; set; }
-        public InternshipProgram Program { get; set; }
+        public long InternshipRegistrationId { get; set; }
+        public InternshipRegistration Registration { get; set; }
         public long InternshipSubjectId { get; set; }
         public InternshipSubject Subject { get; set; }
     }

src/InternshipSystem.Core/ValueObject/BranchAddress.cs

@@ -1,4 +1,7 @@
-namespace InternshipSystem.Core
+using FluentValidation;
+using FluentValidation.Validators;
+
+namespace InternshipSystem.Core
 {
     public class BranchAddress
     {
@@ -7,5 +10,22 @@
         public string City { get; set; }
         public string PostalCode { get; set; }
         public string Country { get; set; }
+
+        public class Validator : AbstractValidator<BranchAddress>
+        {
+            public Validator()
+            {
+                RuleFor(x => x.Country)
+                    .NotEmpty();
+                RuleFor(x => x.City)
+                    .NotEmpty();
+                RuleFor(x => x.PostalCode)
+                    .NotEmpty();
+                RuleFor(x => x.Street)
+                    .NotEmpty();
+                RuleFor(x => x.Building)
+                    .NotEmpty();
+            }
+        }
     }
 } 

src/InternshipSystem.Core/ValueObject/DocumentState.cs

@@ -2,7 +2,7 @@
 {
     public enum DocumentState
     {
-        NotSubmitted,
+        Draft,
         Submitted,
         Accepted,
         Rejected

src/InternshipSystem.Core/ValueObject/Mentor.cs

@@ -1,4 +1,6 @@
-namespace InternshipSystem.Core
+using FluentValidation;
+
+namespace InternshipSystem.Core
 {
     public class Mentor
     {
@@ -6,5 +8,29 @@
         public string LastName { get; set; }
         public string Email { get; set; }
         public string PhoneNumber { get; set; }
+
+        public void UpdateInformation(string firstName, string lastName, string email, string phoneNumber)
+        {
+            FirstName = firstName ?? FirstName;
+            LastName = lastName ?? LastName;
+            Email = email ?? Email;
+            PhoneNumber = phoneNumber ?? PhoneNumber;
+        }
+
+        public class Validate : AbstractValidator<Mentor>
+        {
+            public Validate()
+            {
+                RuleFor(x => x.FirstName)
+                    .NotEmpty();
+                RuleFor(x => x.LastName)
+                    .NotEmpty();
+                RuleFor(x => x.Email)
+                    .NotEmpty();
+                RuleFor(x => x.PhoneNumber)
+                    .NotEmpty();
+                
+            }
+        }
     }
 }

src/InternshipSystem.Repository/InternshipDbContext.cs

@@ -33,12 +33,12 @@ namespace InternshipSystem.Repository
             modelBuilder.Entity<ProgramSubject>(builder =>
             {
                 builder
-                    .HasKey(subject => new { subject.InternshipProgramId, subject.InternshipSubjectId });
+                    .HasKey(subject => new { InternshipProgramId = subject.InternshipRegistrationId, subject.InternshipSubjectId });
                 
                 builder
-                    .HasOne(k => k.Program)
-                    .WithMany(model => model.ChosenSubjects)
-                    .HasForeignKey(subject => subject.InternshipProgramId);
+                    .HasOne(k => k.Registration)
+                    .WithMany(model => model.Subjects)
+                    .HasForeignKey(subject => subject.InternshipRegistrationId);
                 
                 builder
                     .HasOne(k => k.Subject)