Delete customer functionality (#81)

* Initial draft

* Some more initial changes

* Delete user funnctionality

* Prepend comments to source files

* Fixed tests

* Removed hardcoded code for testing

---------

Co-authored-by: GitHub Action <[email protected]>

backend/core/src/Core.API/Core.API.csproj

@@ -22,8 +22,8 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.19.6" />
-    <PackageReference Include="Quantoz.Nexus.Sdk.Shared" Version="1.7.1" />
-    <PackageReference Include="Quantoz.Nexus.Sdk.Token" Version="1.7.1" />
+    <PackageReference Include="Quantoz.Nexus.Sdk.Shared" Version="1.9.0" />
+    <PackageReference Include="Quantoz.Nexus.Sdk.Token" Version="1.9.0" />
     <PackageReference Include="Quartz.Extensions.DependencyInjection" Version="3.8.1" />
     <PackageReference Include="Quartz.Extensions.Hosting" Version="3.8.1" />
     <PackageReference Include="ReHackt.Extensions.Options.Validation" Version="8.0.2" />

backend/core/src/Core.API/DependencyInjection/InfrastructureInjection.cs

@@ -4,6 +4,7 @@
 
 using Core.Domain.Abstractions;
 using Core.Domain.Repositories;
+using Core.Infrastructure.AzureB2CGraphService;
 using Core.Infrastructure.Compliance;
 using Core.Infrastructure.Compliance.IPLocator;
 using Core.Infrastructure.Compliance.Sanctionlist;
@@ -14,6 +15,7 @@
 using Core.Infrastructure.Nexus.Repositories;
 using Core.Infrastructure.Nexus.SigningService;
 using Microsoft.Extensions.Options;
+using Microsoft.Graph;
 using Nexus.Sdk.Shared.Http;
 using Nexus.Sdk.Token.Extensions;
 using Quartz;
@@ -25,6 +27,7 @@ public static class InfrastructureInjection
         public static IServiceCollection AddInfrastructure(this IServiceCollection services, IConfiguration configuration)
         {
             services
+                .AddB2CGraphService(configuration)
                 .AddNexus(configuration)
                 .AddIPLocator(configuration)
                 .AddSanctionlist(configuration)
@@ -83,6 +86,23 @@ private static IServiceCollection AddIPLocator(this IServiceCollection services,
             return services;
         }
 
+        public static IServiceCollection AddB2CGraphService(this IServiceCollection services, IConfiguration configuration)
+        {
+            services.AddOptions<B2CServiceOptions>()
+                .Bind(configuration.GetSection("B2CServiceOptions"))
+                .ValidateDataAnnotationsRecursively()
+                .ValidateOnStart();
+
+            services.AddSingleton(sp => sp.GetRequiredService<IOptions<B2CServiceOptions>>().Value);
+
+            services.AddHttpClient<IB2CGraphService, B2CGraphService>();
+
+            services.AddScoped<IB2CGraphService, B2CGraphService>();
+            services.AddScoped<GraphServiceClient>();
+
+            return services;
+        }
+
         private static IServiceCollection AddSanctionlist(this IServiceCollection services, IConfiguration configuration)
         {
             services.AddOptions<SanctionlistOptions>()

backend/core/src/Core.API/appsettings.json

@@ -12,6 +12,11 @@
       "Audience": ""
     }
   ],
+  "B2CServiceOptions": {
+    "ClientId": "",
+    "ClientSecret": "",
+    "Tenant": ""
+  },
   "NexusOptions": {
     "ApiUrl": "",
     "PaymentMethodOptions": {

backend/core/src/Core.Application/Commands/CustomerCommands/DeleteCustomerCommand.cs

@@ -0,0 +1,40 @@
+// Copyright 2023 Quantoz Technology B.V. and contributors. Licensed
+// under the Apache License, Version 2.0. See the NOTICE file at the root
+// of this distribution or at http://www.apache.org/licenses/LICENSE-2.0
+
+using Core.Domain.Repositories;
+using MediatR;
+
+namespace Core.Application.Commands.CustomerCommands
+{
+    public class DeleteCustomerCommand : IRequest
+    {
+        public string CustomerCode { get; set; }
+
+        public string IP { get; set; }
+
+        public DeleteCustomerCommand(string customerCode, string iP)
+        {
+            CustomerCode = customerCode;
+            IP = iP;
+        }
+    }
+
+    public class DeleteCustomerCommandHandler : IRequestHandler<DeleteCustomerCommand>
+    {
+        private readonly ICustomerRepository _customerRepository;
+
+        public DeleteCustomerCommandHandler(
+            ICustomerRepository customerRepository)
+        {
+            _customerRepository = customerRepository;
+        }
+
+        public async Task Handle(DeleteCustomerCommand request, CancellationToken cancellationToken)
+        {
+            var customer = await _customerRepository.GetAsync(request.CustomerCode, cancellationToken);
+
+            await _customerRepository.DeleteAsync(customer, request.IP);
+        }
+    }
+}

backend/core/src/Core.Application/Enums.cs

@@ -8,6 +8,7 @@ public enum ApplicationErrorCode
     {
         InvalidStatusError,
         InvalidPropertyError,
-        ExistingPropertyError
+        ExistingPropertyError,
+        NotFoundError
     }
 }

backend/core/src/Core.Domain/Repositories/ICustomerRepository.cs

@@ -15,5 +15,7 @@ public interface ICustomerRepository
         public Task<IEnumerable<CustomerLimit>> GetLimitsAsync(string customerCode, CancellationToken cancellationToken = default);
 
         public Task UpdateAsync(Customer customer, CancellationToken cancellationToken = default);
+
+        public Task DeleteAsync(Customer customer, string? ip = null, CancellationToken cancellationToken = default);
     }
 }

backend/core/src/Core.Infrastructure/AzureB2CGraphService/B2CGraphService.cs

@@ -0,0 +1,67 @@
+// Copyright 2023 Quantoz Technology B.V. and contributors. Licensed
+// under the Apache License, Version 2.0. See the NOTICE file at the root
+// of this distribution or at http://www.apache.org/licenses/LICENSE-2.0
+
+using Azure.Identity;
+using Core.Domain.Exceptions;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Microsoft.Graph;
+
+namespace Core.Infrastructure.AzureB2CGraphService
+{
+    public class B2CGraphService : IB2CGraphService
+    {
+        private readonly GraphServiceClient _graphServiceClient;
+        private readonly ILogger<B2CGraphService> _logger;
+
+        public B2CGraphService(
+            GraphServiceClient graphServiceClient,
+            IOptions<B2CServiceOptions> options,
+            ILogger<B2CGraphService> logger)
+        {
+            _graphServiceClient = graphServiceClient;
+            _logger = logger;
+
+            var clientId = options.Value.ClientId;
+            var clientSecret = options.Value.ClientSecret;
+            var tenant = options.Value.Tenant;
+
+            var clientSecretCredential = new ClientSecretCredential(tenant, clientId, clientSecret);
+
+            var scopes = new[] { "https://graph.microsoft.com/.default" };
+
+            _graphServiceClient = new GraphServiceClient(clientSecretCredential, scopes);
+        }
+
+        public async Task DeleteUserAsync(string customerCode)
+        {
+            _logger.LogInformation("Attempting to delete user {CustomerId} from B2C.", customerCode);
+
+            try
+            {
+                var user = await _graphServiceClient.Users[customerCode].GetAsync();
+
+                if (user != null)
+                {
+                    await _graphServiceClient.Users[customerCode].DeleteAsync();
+                    _logger.LogInformation("User {CustomerId} deleted successfully.", customerCode);
+                }
+                else
+                {
+                    _logger.LogInformation("User {CustomerId} not found.", customerCode);
+                }
+            }
+            catch (ServiceException ex) when (ex.IsMatch(GraphErrorCode.Request_ResourceNotFound.ToString()))
+            {
+                _logger.LogInformation("User {CustomerId} not found.", customerCode);
+                throw new CustomErrorsException("B2CGraphService", customerCode, "User not found.");
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "An unexpected error occurred while deleting user {CustomerId}.", customerCode);
+                throw new CustomErrorsException("B2CGraphService", customerCode, "An unexpected error occurred while deleting user.");
+            }
+        }
+    }
+}

backend/core/src/Core.Infrastructure/AzureB2CGraphService/B2CServiceOptions.cs

@@ -0,0 +1,20 @@
+// Copyright 2023 Quantoz Technology B.V. and contributors. Licensed
+// under the Apache License, Version 2.0. See the NOTICE file at the root
+// of this distribution or at http://www.apache.org/licenses/LICENSE-2.0
+
+using System.ComponentModel.DataAnnotations;
+
+namespace Core.Infrastructure.AzureB2CGraphService
+{
+    public class B2CServiceOptions
+    {
+        [Required]
+        public required string ClientId { get; set; }
+
+        [Required]
+        public required string ClientSecret { get; set; }
+
+        [Required]
+        public required string Tenant { get; set; }
+    }
+}

backend/core/src/Core.Infrastructure/AzureB2CGraphService/IB2CGraphService.cs

@@ -0,0 +1,13 @@
+// Copyright 2023 Quantoz Technology B.V. and contributors. Licensed
+// under the Apache License, Version 2.0. See the NOTICE file at the root
+// of this distribution or at http://www.apache.org/licenses/LICENSE-2.0
+
+using Core.Domain.Entities.CustomerAggregate;
+
+namespace Core.Infrastructure.AzureB2CGraphService
+{
+    public interface IB2CGraphService
+    {
+        public Task DeleteUserAsync(string customerCode);
+    }
+}

backend/core/src/Core.Infrastructure/Core.Infrastructure.csproj

@@ -7,9 +7,11 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Azure.Identity" Version="1.10.4" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.2" />
+    <PackageReference Include="Microsoft.Graph" Version="5.48.0" />
     <PackageReference Include="Otp.NET" Version="1.3.0" />
-    <PackageReference Include="Quantoz.Nexus.Sdk.Token" Version="1.7.1" />
+    <PackageReference Include="Quantoz.Nexus.Sdk.Token" Version="1.9.0" />
     <PackageReference Include="Quartz" Version="3.8.1" />
     <PackageReference Include="SendGrid" Version="9.29.2" />
     <PackageReference Include="WindowsAzure.Storage" Version="9.3.3" />

backend/core/src/Core.Infrastructure/Nexus/Enums.cs

@@ -24,7 +24,8 @@ public enum NexusErrorCodes
         TrustlevelNotFoundError = 4,
         InvalidStatus = 4,
         InvalidProperty = 5,
-        TransactionNotFoundError = 6
+        TransactionNotFoundError = 6,
+        NonZeroAccountBalance = 7,
     }
 
     public enum MailStatus

backend/core/src/Core.Infrastructure/Nexus/Repositories/NexusCustomerRepository.cs

@@ -5,21 +5,33 @@
 using Core.Domain.Entities.CustomerAggregate;
 using Core.Domain.Exceptions;
 using Core.Domain.Repositories;
+using Core.Infrastructure.AzureB2CGraphService;
+using Core.Infrastructure.Nexus.SigningService;
 using Nexus.Sdk.Shared.Requests;
 using Nexus.Sdk.Token;
+using Nexus.Sdk.Token.Requests;
 using Nexus.Sdk.Token.Responses;
+using Account = Core.Domain.Entities.AccountAggregate.Account;
 
 namespace Core.Infrastructure.Nexus.Repositories
 {
     public class NexusCustomerRepository : ICustomerRepository
     {
         private readonly ITokenServer _tokenServer;
         private readonly TokenOptions _tokenSettings;
-
-        public NexusCustomerRepository(ITokenServer tokenServer, TokenOptions tokenSettings)
+        private readonly ISigningService _signingService;
+        private readonly IB2CGraphService _b2cGraphService;
+
+        public NexusCustomerRepository(
+            ITokenServer tokenServer,
+            TokenOptions tokenSettings,
+            ISigningService signingService,
+            IB2CGraphService b2CGraphService)
         {
             _tokenServer = tokenServer;
             _tokenSettings = tokenSettings;
+            _signingService = signingService;
+            _b2cGraphService = b2CGraphService;
         }
 
         public async Task CreateAsync(Customer customer, string? ip = null, CancellationToken cancellationToken = default)
@@ -144,6 +156,104 @@ public async Task<IEnumerable<CustomerLimit>> GetLimitsAsync(string customerCode
             return limits;
         }
 
+        public async Task DeleteAsync(Customer customer, string? ip = null, CancellationToken cancellationToken = default)
+        {
+            var customerCodeExists = await _tokenServer.Customers.Exists(customer.CustomerCode);
+
+            if (!customerCodeExists)
+            {
+                throw new CustomErrorsException(NexusErrorCodes.CustomerNotFoundError.ToString(), customer.CustomerCode, Constants.NexusErrorMessages.CustomerNotFound);
+            }
+
+            // Check if the customer status is ACTIVE
+            if (customer.Status != CustomerStatus.ACTIVE.ToString())
+            {
+                throw new CustomErrorsException(NexusErrorCodes.InvalidStatus.ToString(), customer.Status.ToString(), "Invalid customer status");
+            }
+
+            // Get Customer accounts
+            var accounts = await _tokenServer.Accounts.Get(
+                new Dictionary<string, string>
+                {
+                    { "CustomerCode", customer.CustomerCode },
+                    { "Status", "ACTIVE" }
+                });
+
+            // Check if the customer has any accounts and balance
+            if (accounts.Records.Any())
+            {
+                foreach (var acc in accounts.Records)
+                {
+                    Account account = new()
+                    {
+                        AccountCode = acc.AccountCode,
+                        CustomerCode = acc.CustomerCode,
+                        PublicKey = acc.PublicKey
+                    };
+
+                    // Get the account balance
+                    var response = await _tokenServer.Accounts.GetBalances(account.AccountCode);
+
+                    var accountBalances = response.Balances;
+
+                    if (response.Balances.Any(balance => balance.Amount > 0))
+                    {
+                        throw new CustomErrorsException(NexusErrorCodes.NonZeroAccountBalance.ToString(), account.AccountCode, "Customer cannot be deleted due to non-zero balance");
+                    }
+
+                    if (accountBalances.Any())
+                    {
+                        // Get the token codes to be disabled
+                        var tokensToBeDisabled = accountBalances.Select(b => b.TokenCode).ToArray();
+
+                        await RemoveTrustlines(customer, account, tokensToBeDisabled);
+                    }
+                }
+            }
+
+            var deleteRequest = new DeleteCustomerRequest
+            {
+                CustomerCode = customer.CustomerCode
+            };
+
+            await _tokenServer.Customers.Delete(deleteRequest, ip);
+
+            // delete user from azure b2c
+            await _b2cGraphService.DeleteUserAsync(customer.CustomerCode);
+        }
+
+        private async Task RemoveTrustlines(Customer customer, Account account, string[]? tokensToBeDisabled = null)
+        {
+            var updateAccount = new UpdateTokenAccountRequest
+            {
+                Settings = new UpdateTokenAccountSettings
+                {
+                    AllowedTokens = new AllowedTokens
+                    {
+                        DisableTokens = tokensToBeDisabled
+                    }
+                }
+            };
+
+            var signableResponse = await _tokenServer.Accounts.Update(customer.CustomerCode, account.AccountCode, updateAccount);
+
+            switch (_tokenSettings.Blockchain)
+            {
+                case Blockchain.STELLAR:
+                    {
+                        var submitRequest = await _signingService.SignStellarTransactionEnvelopeAsync(account.PublicKey, signableResponse);
+                        await _tokenServer.Submit.OnStellarAsync(submitRequest);
+                        break;
+                    }
+                case Blockchain.ALGORAND:
+                    {
+                        var submitRequest = await _signingService.SignAlgorandTransactionAsync(account.PublicKey, signableResponse);
+                        await _tokenServer.Submit.OnAlgorandAsync(submitRequest);
+                        break;
+                    }
+            }
+        }
+
         public Task SaveChangesAsync(CancellationToken cancellationToken = default)
         {
             return Task.FromResult(true);