Refactor exception handling middleware

Updated DependencyInjection to use GlobalExceptionHandler.
Removed ExceptionHandlingMiddleware and added
GlobalExceptionHandlerMiddleware for unified exception
handling across the application.

DigitalData.Core.API/BasicCRUDControllerBase.cs

@@ -1,15 +1,15 @@
-using DigitalData.Core.Abstractions;
-using DigitalData.Core.Abstractions.Application;
+using DigitalData.Core.Application.Interfaces;
 using Microsoft.AspNetCore.Mvc;
 
 namespace DigitalData.Core.API
 {
     [ApiController]
     [Route("api/[controller]")]
+    [Obsolete("Use MediatR")]
     public class BasicCRUDControllerBase<TCRUDService, TDto, TEntity, TId> : CRUDControllerBase<TCRUDService, TDto, TDto, TDto, TEntity, TId>
         where TCRUDService : ICRUDService<TDto, TDto, TEntity, TId>
-        where TDto : class, IUnique<TId>
-        where TEntity : class, IUnique<TId>
+        where TDto : class
+        where TEntity : class
     {
         public BasicCRUDControllerBase(ILogger logger, TCRUDService service) : base(logger, service)
         {

DigitalData.Core.API/CRUDControllerBase.cs

@@ -1,7 +1,6 @@
-using DigitalData.Core.Abstractions;
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.Interfaces;
 using Microsoft.AspNetCore.Mvc;
+using DigitalData.Core.Application.DTO;
 
 namespace DigitalData.Core.API
 {
@@ -15,12 +14,13 @@ namespace DigitalData.Core.API
     /// <typeparam name="TId">The type of the entity's identifier.</typeparam>
     [ApiController]
     [Route("api/[controller]")]
+    [Obsolete("Use MediatR")]
     public class CRUDControllerBase<TCRUDService, TCreateDto, TReadDto, TUpdateDto, TEntity, TId> : ControllerBase
         where TCRUDService : ICRUDService<TCreateDto, TReadDto, TEntity, TId>
         where TCreateDto : class
         where TReadDto : class
-        where TUpdateDto : class, IUnique<TId>
-        where TEntity : class, IUnique<TId>
+        where TUpdateDto : class
+        where TEntity : class
     {
         protected readonly ILogger _logger;
         protected readonly TCRUDService _service;

DigitalData.Core.API/CRUDControllerBaseWithErrorHandling.cs

@@ -1,7 +1,6 @@
-using DigitalData.Core.Abstractions;
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.Interfaces;
 using Microsoft.AspNetCore.Mvc;
+using DigitalData.Core.Application.DTO;
 
 namespace DigitalData.Core.API
 {
@@ -16,12 +15,13 @@ namespace DigitalData.Core.API
     /// <typeparam name="TId">The type of the entity's identifier.</typeparam>
     [ApiController]
     [Route("api/[controller]")]
+    [Obsolete("Use MediatR")]
     public class CRUDControllerBaseWithErrorHandling<TCRUDService, TCreateDto, TReadDto, TUpdateDto, TEntity, TId> : ControllerBase
         where TCRUDService : ICRUDService<TCreateDto, TReadDto, TEntity, TId>
         where TCreateDto : class
         where TReadDto : class
-        where TUpdateDto : class, IUnique<TId>
-        where TEntity : class, IUnique<TId>
+        where TUpdateDto : class
+        where TEntity : class
     {
         protected readonly ILogger _logger;
         protected readonly TCRUDService _service;

DigitalData.Core.API/CSPMiddleware.cs

@@ -1,47 +1,46 @@
-namespace DigitalData.Core.API
+namespace DigitalData.Core.API;
+
+/// <summary>
+/// Middleware to add Content Security Policy (CSP) headers to the HTTP response.
+/// </summary>
+public class CSPMiddleware
 {
+    private readonly RequestDelegate _next;
+    private readonly string _policy;
+
     /// <summary>
-    /// Middleware to add Content Security Policy (CSP) headers to the HTTP response.
+    /// Initializes a new instance of the <see cref="CSPMiddleware"/> class.
     /// </summary>
-    public class CSPMiddleware
+    /// <param name="next">The next middleware in the request pipeline.</param>
+    /// <param name="policy">The CSP policy string with placeholders for nonces.</param>
+    public CSPMiddleware(RequestDelegate next, string policy)
     {
-        private readonly RequestDelegate _next;
-        private readonly string _policy;
+        _next = next;
+        _policy = policy;
+    }
 
-        /// <summary>
-        /// Initializes a new instance of the <see cref="CSPMiddleware"/> class.
-        /// </summary>
-        /// <param name="next">The next middleware in the request pipeline.</param>
-        /// <param name="policy">The CSP policy string with placeholders for nonces.</param>
-        public CSPMiddleware(RequestDelegate next, string policy)
+    /// <summary>
+    /// Invokes the middleware to add the CSP header to the response.
+    /// </summary>
+    /// <param name="context">The HTTP context.</param>
+    /// <returns>A task that represents the completion of request processing.</returns>
+    public async Task Invoke(HttpContext context)
+    {
+        // Generate a nonce (number used once) for inline scripts and styles
+        var nonce = Convert.ToBase64String(Guid.NewGuid().ToByteArray());
+
+        // Store the nonce in the context items for later use
+        context.Items["csp-nonce"] = nonce;
+
+        // Add the CSP header to the response
+        context.Response.OnStarting(() =>
         {
-            _next = next;
-            _policy = policy;
-        }
+            context.Response.Headers.Append("Content-Security-Policy",
+                string.Format(_policy, nonce));
+            return Task.CompletedTask;
+        });
 
-        /// <summary>
-        /// Invokes the middleware to add the CSP header to the response.
-        /// </summary>
-        /// <param name="context">The HTTP context.</param>
-        /// <returns>A task that represents the completion of request processing.</returns>
-        public async Task Invoke(HttpContext context)
-        {
-            // Generate a nonce (number used once) for inline scripts and styles
-            var nonce = Convert.ToBase64String(Guid.NewGuid().ToByteArray());
-
-            // Store the nonce in the context items for later use
-            context.Items["csp-nonce"] = nonce;
-
-            // Add the CSP header to the response
-            context.Response.OnStarting(() =>
-            {
-                context.Response.Headers.Add("Content-Security-Policy",
-                    string.Format(_policy, nonce));
-                return Task.CompletedTask;
-            });
-
-            // Call the next middleware in the pipeline
-            await _next(context);
-        }
+        // Call the next middleware in the pipeline
+        await _next(context);
     }
 }

DigitalData.Core.API/ControllerExtensions.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.DTO;
 using Microsoft.AspNetCore.Mvc;
 using System.Text;
 

DigitalData.Core.API/DIExtensions.cs

@@ -1,53 +1,50 @@
-using Microsoft.AspNetCore.Builder;
-using System.Configuration;
+namespace DigitalData.Core.API;
 
-namespace DigitalData.Core.API
+/// <summary>
+/// Provides extension methods for adding middleware to the application's request pipeline.
+/// </summary>
+public static class DIExtensions
 {
     /// <summary>
-    /// Provides extension methods for adding middleware to the application's request pipeline.
+    /// Adds the <see cref="CSPMiddleware"/> to the application's request pipeline to include 
+    /// Content Security Policy (CSP) headers in the HTTP response.
     /// </summary>
-    public static class DIExtensions
-    {
-        /// <summary>
-        /// Adds the <see cref="CSPMiddleware"/> to the application's request pipeline to include 
-        /// Content Security Policy (CSP) headers in the HTTP response.
-        /// </summary>
-        /// <param name="app">The application builder.</param>
-        /// <param name="policy">
-        /// The CSP policy string with placeholders. The first format parameter {0} will be replaced 
-        /// by the nonce value.
-        /// </param>
-        /// <returns>The application builder with the CSP middleware added.</returns>
-        public static IApplicationBuilder UseCSPMiddleware(this IApplicationBuilder app, string policy)
-            => app.UseMiddleware<CSPMiddleware>(policy);
+    /// <param name="app">The application builder.</param>
+    /// <param name="policy">
+    /// The CSP policy string with placeholders. The first format parameter {0} will be replaced 
+    /// by the nonce value.
+    /// </param>
+    /// <returns>The application builder with the CSP middleware added.</returns>
+    public static IApplicationBuilder UseCSPMiddleware(this IApplicationBuilder app, string policy)
+        => app.UseMiddleware<CSPMiddleware>(policy);
 
-        /// <summary>
-        /// Checks if the DiP (Development in Production) mode is enabled for the WebApplicationBuilder.
-        /// </summary>
-        /// <param name="builder">The WebApplicationBuilder instance.</param>
-        /// <returns>True if DiP mode is enabled; otherwise, false.</returns>
-        public static bool IsDiP(this WebApplicationBuilder builder) => builder.Configuration.GetValue<bool>("DiPMode");
+    /// <summary>
+    /// Checks if the DiP (Development in Production) mode is enabled for the WebApplicationBuilder.
+    /// </summary>
+    /// <param name="builder">The WebApplicationBuilder instance.</param>
+    /// <returns>True if DiP mode is enabled; otherwise, false.</returns>
+    public static bool IsDiP(this WebApplicationBuilder builder) => builder.Configuration.GetValue<bool>("DiPMode");
 
-        /// <summary>
-        /// Checks if the DiP (Development in Production) mode is enabled for the WebApplication.
-        /// </summary>
-        /// <param name="app">The WebApplication instance.</param>
-        /// <returns>True if DiP mode is enabled; otherwise, false.</returns>
-        public static bool IsDiP(this WebApplication app) => app.Configuration.GetValue<bool>("DiPMode");
+    /// <summary>
+    /// Checks if the DiP (Development in Production) mode is enabled for the WebApplication.
+    /// </summary>
+    /// <param name="app">The WebApplication instance.</param>
+    /// <returns>True if DiP mode is enabled; otherwise, false.</returns>
+    public static bool IsDiP(this WebApplication app) => app.Configuration.GetValue<bool>("DiPMode");
 
-        /// <summary>
-        /// Checks if the environment is Development or DiP (Development in Production) mode is enabled for the WebApplicationBuilder.
-        /// </summary>
-        /// <param name="builder">The WebApplicationBuilder instance.</param>
-        /// <returns>True if the environment is Development or DiP mode is enabled; otherwise, false.</returns>
-        public static bool IsDevOrDiP(this WebApplicationBuilder builder) => builder.Environment.IsDevelopment() || builder.IsDiP();
+    /// <summary>
+    /// Checks if the environment is Development or DiP (Development in Production) mode is enabled for the WebApplicationBuilder.
+    /// </summary>
+    /// <param name="builder">The WebApplicationBuilder instance.</param>
+    /// <returns>True if the environment is Development or DiP mode is enabled; otherwise, false.</returns>
+    public static bool IsDevOrDiP(this WebApplicationBuilder builder) => builder.Environment.IsDevelopment() || builder.IsDiP();
 
-        /// <summary>
-        /// Checks if the environment is Development or DiP (Development in Production) mode is enabled for the WebApplication.
-        /// </summary>
-        /// <param name="app">The WebApplication instance.</param>
-        /// <returns>True if the environment is Development or DiP mode is enabled; otherwise, false.</returns>
-        public static bool IsDevOrDiP(this WebApplication app) => app.Environment.IsDevelopment() || app.IsDiP();
+    /// <summary>
+    /// Checks if the environment is Development or DiP (Development in Production) mode is enabled for the WebApplication.
+    /// </summary>
+    /// <param name="app">The WebApplication instance.</param>
+    /// <returns>True if the environment is Development or DiP mode is enabled; otherwise, false.</returns>
+    public static bool IsDevOrDiP(this WebApplication app) => app.Environment.IsDevelopment() || app.IsDiP();
 
 		/// <summary>
 		/// Configures the services with options from the specified section of the appsettings.json file.
@@ -65,5 +62,4 @@ namespace DigitalData.Core.API
 			builder.Services.Configure<T>(section);
 			return builder;
 		}
-	}
-}
+	}

DigitalData.Core.API/DigitalData.Core.API.csproj

@@ -32,8 +32,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\DigitalData.Core.Abstractions\DigitalData.Core.Abstractions.csproj" />
-    <ProjectReference Include="..\DigitalData.Core.DTO\DigitalData.Core.DTO.csproj" />
+    <ProjectReference Include="..\DigitalData.Core.Application\DigitalData.Core.Application.csproj" />
+    <ProjectReference Include="..\DigitalData.Core.Exceptions\DigitalData.Core.Exceptions.csproj" />
   </ItemGroup>
 
   <ItemGroup>

DigitalData.Core.API/ReadControllerBase.cs

@@ -1,6 +1,6 @@
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.Interfaces;
 using Microsoft.AspNetCore.Mvc;
+using DigitalData.Core.Application.DTO;
 
 namespace DigitalData.Core.API
 {
@@ -12,6 +12,7 @@ namespace DigitalData.Core.API
     /// <typeparam name="TId">The type of the entity's identifier.</typeparam>
     [ApiController]
     [Route("api/[controller]")]
+    [Obsolete("Use MediatR")]
     public class ReadControllerBase<TReadService, TReadDto, TEntity, TId> : ControllerBase
         where TReadService : IReadService<TReadDto, TEntity, TId>
         where TReadDto : class

DigitalData.Core.API/ReadControllerBaseWithErrorHandling.cs

@@ -1,5 +1,5 @@
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.DTO;
+using DigitalData.Core.Application.Interfaces;
 using Microsoft.AspNetCore.Mvc;
 
 namespace DigitalData.Core.API
@@ -13,6 +13,7 @@ namespace DigitalData.Core.API
     /// <typeparam name="TId">The type of the entity's identifier.</typeparam>
     [ApiController]
     [Route("api/[controller]")]
+    [Obsolete("Use MediatR")]
     public class ReadControllerBaseWithErrorHandling<TReadService, TReadDto, TEntity, TId> : ControllerBase
         where TReadService : IReadService<TReadDto, TEntity, TId>
         where TReadDto : class

DigitalData.Core.Abstractions/DigitalData.Core.Abstractions.csproj

@@ -37,8 +37,4 @@
 		<PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="7.5.1" />
 	</ItemGroup>
 
-	<ItemGroup>
-	  <ProjectReference Include="..\DigitalData.Core.DTO\DigitalData.Core.DTO.csproj" />
-	</ItemGroup>
-
 </Project>

DigitalData.Core.Abstractions/IUnique.cs

@@ -1,7 +0,0 @@
-namespace DigitalData.Core.Abstractions
-{
-    public interface IUnique<T>
-    {
-        public T Id { get; }
-    }
-}

DigitalData.Core.Abstractions/ServiceResultExtensions.cs

@@ -1,13 +0,0 @@
-namespace DigitalData.Core.Abstractions
-{
-    public static class ServiceResultExtensions
-    {
-        public static bool Try<T>(this T? nullableResult, out T result)
-        {
-#pragma warning disable CS8601 // Possible null reference assignment.
-            result = nullableResult;
-#pragma warning restore CS8601 // Possible null reference assignment.
-            return nullableResult is not null;
-        }
-    }
-}

DigitalData.Core.Application/BasicCRUDService.cs

@@ -1,7 +1,6 @@
 using AutoMapper;
-using DigitalData.Core.Abstractions;
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.Abstractions.Infrastructure;
+using DigitalData.Core.Application.Interfaces;
+using DigitalData.Core.Application.Interfaces.Repository;
 
 namespace DigitalData.Core.Application
 {
@@ -18,9 +17,10 @@ namespace DigitalData.Core.Application
     /// reducing the need for multiple DTOs and simplifying the data mapping process. It leverages AutoMapper for object mapping
     /// and a culture-specific translation service for any necessary text translations, ensuring a versatile and internationalized approach to CRUD operations.
     /// </remarks>
+    [Obsolete("Use MediatR")]
     public class BasicCRUDService<TCRUDRepository, TDto, TEntity, TId> :
         CRUDService<TCRUDRepository, TDto, TDto, TEntity, TId>, IBasicCRUDService<TDto, TEntity, TId>
-         where TCRUDRepository : ICRUDRepository<TEntity, TId> where TDto : class, IUnique<TId> where TEntity : class, IUnique<TId>
+         where TCRUDRepository : ICRUDRepository<TEntity, TId> where TDto : class where TEntity : class
     {
         /// <summary>
         /// Initializes a new instance of the BasicCRUDService with the specified repository, translation service, and AutoMapper configuration.

DigitalData.Core.Application/CRUDService.cs

@@ -1,9 +1,8 @@
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.Abstractions.Infrastructure;
-using AutoMapper;
-using DigitalData.Core.DTO;
-using DigitalData.Core.Abstractions;
+using AutoMapper;
 using Microsoft.Extensions.Logging;
+using DigitalData.Core.Application.Interfaces.Repository;
+using DigitalData.Core.Application.Interfaces;
+using DigitalData.Core.Application.DTO;
 
 namespace DigitalData.Core.Application
 {
@@ -14,8 +13,10 @@ namespace DigitalData.Core.Application
     /// <typeparam name="TReadDto">The DTO type for read operations.</typeparam>
     /// <typeparam name="TEntity">The entity type.</typeparam>
     /// <typeparam name="TId">The type of the identifier for the entity.</typeparam>
+    /// 
+    [Obsolete("Use MediatR")]
     public class CRUDService<TCRUDRepository, TCreateDto, TReadDto, TEntity, TId> : ReadService<TCRUDRepository, TReadDto, TEntity, TId>, ICRUDService<TCreateDto, TReadDto, TEntity, TId>
-        where TCRUDRepository : ICRUDRepository<TEntity, TId> where TCreateDto : class where TReadDto : class where TEntity : class, IUnique<TId>
+        where TCRUDRepository : ICRUDRepository<TEntity, TId> where TCreateDto : class where TReadDto : class where TEntity : class
     {
 
         /// <summary>
@@ -36,7 +37,7 @@ namespace DigitalData.Core.Application
         {
             var entity = _mapper.Map<TEntity>(createDto);
             var createdEntity = await _repository.CreateAsync(entity);
-            return createdEntity is null ? Result.Fail<TId>() : Result.Success(createdEntity.Id);
+            return createdEntity is null ? Result.Fail<TId>() : Result.Success(createdEntity.GetIdOrDefault<TId>());
         }
 
         /// <summary>
@@ -44,12 +45,12 @@ namespace DigitalData.Core.Application
         /// </summary>
         /// <param name="updateDto">The DTO to update an entity from.</param>
         /// <returns>A service message indicating success or failure.</returns>
-        public virtual async Task<Result> UpdateAsync<TUpdateDto>(TUpdateDto updateDto) where TUpdateDto : IUnique<TId>
+        public virtual async Task<Result> UpdateAsync<TUpdateDto>(TUpdateDto updateDto)
         {
-            var currentEntitiy = await _repository.ReadByIdAsync(updateDto.Id);
+            var currentEntitiy = await _repository.ReadByIdAsync(updateDto.GetIdOrDefault<TId>());
 
             if (currentEntitiy is null)
-                return Result.Fail().Notice(LogLevel.Warning, Flag.NotFound, $"{updateDto.Id} is not found in update process of {GetType()} entity.");
+                return Result.Fail().Notice(LogLevel.Warning, Flag.NotFound, $"{updateDto.GetIdOrDefault<TId>()} is not found in update process of {GetType()} entity.");
     
             var entity = _mapper.Map(updateDto, currentEntitiy);
 

DigitalData.Core.Application/DIExtensions.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Application;
+using DigitalData.Core.Application.Interfaces;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;

DigitalData.Core.Application/DTO/BaseDto.cs

@@ -0,0 +1,17 @@
+namespace DigitalData.Core.Application.DTO
+{
+	/// <summary>
+	/// Represents a base Data Transfer Object (DTO) with an identifier.
+	/// </summary>
+	/// <typeparam name="TId">The type of the identifier.</typeparam>
+	/// <param name="Id">The identifier of the DTO.</param>
+	public record BaseDTO<TId>(TId Id) where TId : notnull
+	{
+		/// <summary>
+		/// Returns the hash code for this instance, based on the identifier.
+		/// This override ensures that the hash code is derived consistently from the identifier.
+		/// </summary>
+		/// <returns>A hash code for the current object, derived from the identifier.</returns>
+		public override int GetHashCode() => Id.GetHashCode();
+	}
+}

DigitalData.Core.Application/DTO/CookieConsentSettings.cs

@@ -0,0 +1,74 @@
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Represents settings related to user cookie consent dialogs. Designed to be serialized into JSON format for use with JavaScript frontend libraries,
+    /// such as the bootstrap-cookie-consent-settings at the GitHub repository: https://github.com/shaack/bootstrap-cookie-consent-settings
+    /// </summary>
+    public class CookieConsentSettings
+    {
+        /// <summary>
+        /// URL to the privacy policy page.
+        /// </summary>
+        public string? PrivacyPolicyUrl { get; set; }
+
+        /// <summary>
+        /// URL to the legal notice page.
+        /// </summary>
+        public string? LegalNoticeUrl { get; set; }
+
+        /// <summary>
+        /// URL to the content of the dialog box.
+        /// </summary>
+        public string? ContentURL { get; set; }
+
+        /// <summary>
+        /// CSS class for the 'Agree' button.
+        /// </summary>
+        public string? ButtonAgreeClass { get; set; }
+
+        /// <summary>
+        /// CSS class for the 'Don't Agree' button.
+        /// </summary>
+        public string? ButtonDontAgreeClass { get; set; }
+
+        /// <summary>
+        /// CSS class for the 'Save' button.
+        /// </summary>
+        public string? ButtonSaveClass { get; set; }
+
+        /// <summary>
+        /// Language in which the modal is displayed.
+        /// </summary>
+        public string? Lang { get; set; }
+
+        /// <summary>
+        /// Default language for the modal if the user's browser language is not supported.
+        /// </summary>
+        public string? DefaultLang { get; set; }
+
+        /// <summary>
+        /// Name of the cookie used to store the consent status.
+        /// </summary>
+        public string? CookieName { get; set; }
+
+        /// <summary>
+        /// Number of days the cookie will be stored.
+        /// </summary>
+        public int CookieStorageDays { get; set; }
+
+        /// <summary>
+        /// Identifier for the modal dialog element.
+        /// </summary>
+        public string? ModalId { get; set; }
+
+        /// <summary>
+        /// Indicates whether to also store the settings in the browser's localStorage.
+        /// </summary>
+        public bool AlsoUseLocalStorage { get; set; }
+
+        /// <summary>
+        /// List of categories for cookie consent.
+        /// </summary>
+        public List<string>? Categories { get; set; }
+    }
+}

DigitalData.Core.Application/DTO/DIExtensions.cs

@@ -0,0 +1,33 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using System.Configuration;
+
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Provides extension methods for dependency injection.
+    /// </summary>
+    public static class DIExtensions
+    {
+        /// <summary>
+        /// Adds the <see cref="CookieConsentSettings"/> to the service collection.
+        /// </summary>
+        /// <param name="services">The service collection to add the settings to.</param>
+        /// <returns>The updated service collection.</returns>
+        /// <exception cref="ConfigurationErrorsException">
+        /// Thrown if the 'CookieConsentSettings' section is missing or improperly configured in appsettings.json.
+        /// </exception>
+        public static IServiceCollection AddCookieConsentSettings(this IServiceCollection services)
+        {
+            services.AddSingleton(sp =>
+            {
+                var configuration = sp.GetRequiredService<IConfiguration>();
+                var settings = configuration.GetSection("CookieConsentSettings").Get<CookieConsentSettings>();
+                return settings is null
+                    ? throw new ConfigurationErrorsException("The 'CookieConsentSettings' section is missing or improperly configured in appsettings.json.")
+                    : settings;
+            });
+            return services;
+        }
+    }
+}

DigitalData.Core.Application/DTO/DTOExtensions.cs

@@ -0,0 +1,367 @@
+using Microsoft.Extensions.Logging;
+using System.Text;
+
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Provides extension methods for data transfer objects (DTOs).
+    /// </summary>
+    public static class DTOExtensions
+    {
+        /// <summary>
+        /// Adds a single message to the result, if not null.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the message to.</param>
+        /// <param name="message">The message to add.</param>
+        /// <returns>The updated result.</returns>
+        public static T Message<T>(this T result, string? message) where T : Result
+        {
+            if(message is not null)
+                result.Messages.Add(message);
+            return result;
+        }
+
+        internal static IEnumerable<T> FilterNull<T>(this IEnumerable<T?> list)
+        {
+            foreach (var item in list)
+                if(item is not null)
+                    yield return item;
+        }
+
+        /// <summary>
+        /// Adds multiple messages to the result, after removing nulls.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the messages to.</param>
+        /// <param name="messages">The messages to add.</param>
+        /// <returns>The updated result.</returns>
+        public static T Message<T>(this T result, params string?[] messages) where T : Result
+        {
+            result.Messages.AddRange(messages.FilterNull());
+            return result;
+        }
+
+        /// <summary>
+        /// Adds a collection of messages to the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the messages to.</param>
+        /// <param name="messages">The collection of messages to add.</param>
+        /// <returns>The updated result.</returns>
+        public static T Message<T>(this T result, IEnumerable<string?> messages) where T : Result
+        {
+            result.Messages.AddRange(messages.FilterNull());
+            return result;
+        }
+
+        /// <summary>
+        /// Adds a notice to the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the notice to.</param>
+        /// <param name="notice">The notice to add.</param>
+        /// <returns>The updated result.</returns>
+        public static T Notice<T>(this T result, Notice notice) where T : Result
+        {
+            result.Notices.Add(notice);
+            return result;
+        }
+
+        /// <summary>
+        /// Adds a collection of notices to the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the notices to.</param>
+        /// <param name="notices">The collection of notices to add.</param>
+        /// <returns>The updated result.</returns>
+        public static T Notice<T>(this T result, IEnumerable<Notice> notices) where T : Result
+        {
+            result.Notices.AddRange(notices);
+            return result;
+        }
+
+        /// <summary>
+        /// Adds notices with a specific log level and flags to the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the notices to.</param>
+        /// <param name="level">The log level of the notices.</param>
+        /// <param name="flags">The flags associated with the notices.</param>
+        /// <returns>The updated result.</returns>
+        public static T Notice<T>(this T result, LogLevel level, params Enum[] flags) where T : Result
+        {
+            var notices = flags.Select(flag => new Notice()
+            {
+                Flag = flag,
+                Level = level
+            });
+            result.Notices.AddRange(notices);
+            return result;
+        }
+
+        /// <summary>
+        /// Adds a notice with a specific log level, flag, and messages to the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the notice to.</param>
+        /// <param name="level">The log level of the notice.</param>
+        /// <param name="flag">The flag associated with the notice.</param>
+        /// <param name="messages">The messages to add to the notice.</param>
+        /// <returns>The updated result.</returns>
+        public static T Notice<T>(this T result, LogLevel level, Enum flag, params string?[] messages) where T : Result
+        {
+            result.Notices.Add(new Notice()
+            {
+                Flag = flag,
+                Level = level,
+                Messages = messages.FilterNull().ToList()
+            });
+            return result;
+        }
+
+        /// <summary>
+        /// Adds a notice with a specific log level and messages to the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the result.</typeparam>
+        /// <param name="result">The result to add the notice to.</param>
+        /// <param name="level">The log level of the notice.</param>
+        /// <param name="messages">The messages to add to the notice.</param>
+        /// <returns>The updated result.</returns>
+        public static T Notice<T>(this T result, LogLevel level, params string[] messages) where T : Result
+        {
+            result.Notices.Add(new Notice()
+            {
+                Flag = null,
+                Level = level,
+                Messages = messages.FilterNull().ToList()
+            });
+            return result;
+        }
+
+        /// <summary>
+        /// Checks if any notice has the specified flag.
+        /// </summary>
+        /// <param name="notices">The collection of notices to check.</param>
+        /// <param name="flag">The flag to check for.</param>
+        /// <returns>True if any notice has the specified flag; otherwise, false.</returns>
+        public static bool HasFlag(this IEnumerable<Notice> notices, Enum flag) => notices.Any(n => n.Flag?.ToString() == flag.ToString());
+
+        /// <summary>
+        /// Checks if any notice has any of the specified flags.
+        /// </summary>
+        /// <param name="notices">The collection of notices to check.</param>
+        /// <param name="flags">The flags to check for.</param>
+        /// <returns>True if any notice has any of the specified flags; otherwise, false.</returns>
+        public static bool HasAnyFlag(this IEnumerable<Notice> notices, params Enum[] flags) => flags.Any(f => notices.HasFlag(f));
+
+        /// <summary>
+        /// Executes a function based on the success or failure of the task result, 
+        /// without using result data.
+        /// </summary>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="tResult">The task returning a result to evaluate.</param>
+        /// <param name="Success">The function to execute if the result is successful.</param>
+        /// <param name="Fail">The function to execute if the result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static I? Then<I>(this Result result, Func<I> Success)
+        {
+            return result.IsSuccess ? Success() : default;
+        }
+
+        /// <summary>
+        /// Executes a function based on the success or failure of the task result,
+        /// using the data in the result.
+        /// </summary>
+        /// <typeparam name="T">The type of the data in the result.</typeparam>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="tResult">The task returning a data result to evaluate.</param>
+        /// <param name="Success">The function to execute if the data result is successful.</param>
+        /// <param name="Fail">The function to execute if the data result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I?> ThenAsync<I>(this Result result, Func<Task<I>> SuccessAsync)
+        {
+            return result.IsSuccess ? await SuccessAsync() : default;
+        }
+
+        /// <summary>
+        /// Executes a function based on the success or failure of the result.
+        /// </summary>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="result">The result to evaluate.</param>
+        /// <param name="Success">The function to execute if the result is successful.</param>
+        /// <param name="Fail">The function to execute if the result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static I Then<I>(this Result result, Func<I> Success, Func<List<string>, List<Notice>, I> Fail)
+        {
+            return result.IsSuccess ? Success() : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Asynchronously executes a function based on the success or failure of the result.
+        /// </summary>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="result">The result to evaluate.</param>
+        /// <param name="SuccessAsync">The asynchronous function to execute if the result is successful.</param>
+        /// <param name="Fail">The function to execute if the result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I> ThenAsync<I>(this Result result, Func<Task<I>> SuccessAsync, Func<List<string>, List<Notice>, I> Fail)
+        {
+            return result.IsSuccess ? await SuccessAsync() : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Executes a function based on the success or failure of the data result.
+        /// </summary>
+        /// <typeparam name="T">The type of the data in the result.</typeparam>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="result">The data result to evaluate.</param>
+        /// <param name="Success">The function to execute if the data result is successful.</param>
+        /// <param name="Fail">The function to execute if the data result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static I Then<T, I>(this DataResult<T> result, Func<T, I> Success, Func<List<string>, List<Notice>, I> Fail)
+        {
+            return result.IsSuccess ? Success(result.Data) : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Asynchronously executes a function based on the success or failure of the data result.
+        /// </summary>
+        /// <typeparam name="T">The type of the data in the result.</typeparam>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="result">The data result to evaluate.</param>
+        /// <param name="SuccessAsync">The asynchronous function to execute if the data result is successful.</param>
+        /// <param name="Fail">The function to execute if the data result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I> ThenAsync<T, I>(this DataResult<T> result, Func<T, Task<I>> SuccessAsync, Func<List<string>, List<Notice>, I> Fail)
+        {
+            return result.IsSuccess ? await SuccessAsync(result.Data) : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Asynchronously executes a function based on the success or failure of a task returning a result.
+        /// </summary>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="tResult">The task returning a result to evaluate.</param>
+        /// <param name="Success">The function to execute if the result is successful.</param>
+        /// <param name="Fail">The function to execute if the result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I> ThenAsync<I>(this Task<Result> tResult, Func<I> Success, Func<List<string>, List<Notice>, I> Fail)
+        {
+            Result result = await tResult;
+            return result.IsSuccess ? Success() : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Asynchronously executes a function based on the success or failure of a task returning a result.
+        /// </summary>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="tResult">The task returning a result to evaluate.</param>
+        /// <param name="SuccessAsync">The asynchronous function to execute if the result is successful.</param>
+        /// <param name="Fail">The function to execute if the result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I> ThenAsync<I>(this Task<Result> tResult, Func<Task<I>> SuccessAsync, Func<List<string>, List<Notice>, I> Fail)
+        {
+            Result result = await tResult;
+            return result.IsSuccess ? await SuccessAsync() : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Asynchronously executes a function based on the success or failure of a task returning a data result.
+        /// </summary>
+        /// <typeparam name="T">The type of the data in the result.</typeparam>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="tResult">The task returning a data result to evaluate.</param>
+        /// <param name="Success">The function to execute if the data result is successful.</param>
+        /// <param name="Fail">The function to execute if the data result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I> ThenAsync<T, I>(this Task<DataResult<T>> tResult, Func<T, I> Success, Func<List<string>, List<Notice>, I> Fail)
+        {
+            DataResult<T> result = await tResult;
+            return result.IsSuccess ? Success(result.Data) : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Asynchronously executes a function based on the success or failure of a task returning a data result.
+        /// </summary>
+        /// <typeparam name="T">The type of the data in the result.</typeparam>
+        /// <typeparam name="I">The type of the return value.</typeparam>
+        /// <param name="tResult">The task returning a data result to evaluate.</param>
+        /// <param name="SuccessAsync">The asynchronous function to execute if the data result is successful.</param>
+        /// <param name="Fail">The function to execute if the data result is a failure.</param>
+        /// <returns>The result of the executed function.</returns>
+        public static async Task<I> ThenAsync<T, I>(this Task<DataResult<T>> tResult, Func<T, Task<I>> SuccessAsync, Func<List<string>, List<Notice>, I> Fail)
+        {
+            DataResult<T> result = await tResult;
+            return result.IsSuccess ? await SuccessAsync(result.Data) : Fail(result.Messages, result.Notices);
+        }
+
+        /// <summary>
+        /// Joins the values into a single string with optional start, separator, and end strings.
+        /// </summary>
+        /// <typeparam name="T">The type of the values.</typeparam>
+        /// <param name="values">The values to join.</param>
+        /// <param name="start">The starting string.</param>
+        /// <param name="separator">The separator string.</param>
+        /// <param name="end">The ending string.</param>
+        /// <returns>The joined string.</returns>
+        public static string Join<T>(this IEnumerable<T> values, string start = "", string seperator = ". ", string end = ".") 
+            => new StringBuilder(start).Append(string.Join(seperator, values)).Append(end).ToString();
+
+        /// <summary>
+        /// Logs the notices using the specified logger.
+        /// </summary>
+        /// <param name="logger">The logger to use.</param>
+        /// <param name="notices">The collection of notices to log.</param>
+        /// <param name="start">The starting string for each notice.</param>
+        /// <param name="separator">The separator string for messages in each notice.</param>
+        /// <param name="end">The ending string for each notice.</param>
+        public static void LogNotice(this ILogger logger, IEnumerable<Notice> notices, string start = ": ", string seperator = ". ", string end = ".\n")
+        {
+            foreach(LogLevel level in Enum.GetValues(typeof(LogLevel)))
+            {
+                var logNotices = notices.Where(n => n.Level == level);
+
+                if (!logNotices.Any())
+                    continue;
+
+                var sb = new StringBuilder();
+                foreach(Notice notice in logNotices)
+                {
+                    if (notice.Flag is not null)
+                        sb.Append(notice.Flag);
+
+                    if (notice.Messages.Any())
+                        sb.Append(start).Append(string.Join(seperator, notice.Messages)).AppendLine(end);
+                    else sb.Append(end);
+                }
+                logger.Log(level, sb.ToString());
+            }
+        }
+
+        /// <summary>
+        /// Logs the notices from a result using the specified logger.
+        /// </summary>
+        /// <param name="logger">The logger to use.</param>
+        /// <param name="result">The result containing the notices to log.</param>
+        /// <param name="start">The starting string for each notice.</param>
+        /// <param name="separator">The separator string for messages in each notice.</param>
+        /// <param name="end">The ending string for each notice.</param>
+        public static void LogNotice(this ILogger logger, Result result, string start = ": ", string seperator = ". ", string end = ".\n")
+            => logger.LogNotice(notices: result.Notices, start: start, seperator: seperator, end: end);
+
+        /// <summary>
+        /// Determines if the data result is right (true).
+        /// </summary>
+        /// <param name="bResult">The data result to evaluate.</param>
+        /// <returns>True if the data result is true; otherwise, false.</returns>
+        public static bool IsRight(this DataResult<bool> bResult) => bResult.Data;
+
+        /// <summary>
+        /// Determines if the data result is wrong (false).
+        /// </summary>
+        /// <param name="bResult">The data result to evaluate.</param>
+        /// <returns>True if the data result is false; otherwise, false.</returns>
+        public static bool IsWrong(this DataResult<bool> bResult) => !bResult.Data;
+    }
+}

DigitalData.Core.Application/DTO/DataResult.cs

@@ -0,0 +1,26 @@
+using System.Text.Json.Serialization;
+
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Represents a result of an operation that includes data, inheriting from <see cref="Result"/>.
+    /// </summary>
+    /// <typeparam name="T">The type of the data included in the result.</typeparam>
+    public class DataResult<T> : Result
+    {
+        /// <summary>
+        /// Gets or sets the data included in the result. This property is required.
+        /// It will be ignored during JSON serialization if the value is null.
+        /// </summary>
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+        public required T Data { get; set; }
+
+        /// <summary>
+        /// Converts the current <see cref="DataResult{T}"/> to a failed <see cref="DataResult{I}"/>,
+        /// preserving the messages and notices.
+        /// </summary>
+        /// <typeparam name="I">The type of the data in the new failed result.</typeparam>
+        /// <returns>A failed <see cref="DataResult{I}"/> with the current messages and notices.</returns>
+        public DataResult<I> ToFail<I>() => Fail<I>().Message(Messages).Notice(Notices);
+    }
+}

DigitalData.Core.Application/DTO/Flag.cs

@@ -0,0 +1,50 @@
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Defines flags that indicate specific types of status or conditions in a service operation.
+    /// These flags help in categorizing and identifying specific circumstances or issues that may arise during execution.
+    /// </summary>
+    public enum Flag
+    {
+        /// <summary>
+        /// Indicates a security breach or vulnerability has been detected during the service operation.
+        /// </summary>
+        SecurityBreach,
+
+        /// <summary>
+        /// Indicates a potential issue with data integrity during the service operation.
+        /// This flag is used when data may have been altered, corrupted, or is otherwise unreliable,
+        /// which could impact the accuracy or trustworthiness of the operation's results.
+        /// </summary>
+        DataIntegrityIssue,
+
+        /// <summary>
+        /// Indicates that either a security breach, a data integrity issue, or both have been detected during the service operation.
+        /// This flag is used when it is not sure whether the problem is security or data integrity. In this case, data integrity should be checked first.
+        /// </summary>
+        SecurityBreachOrDataIntegrity,
+
+        /// <summary>
+        /// Indicates a possible security breach during the service operation.
+        /// </summary>
+        PossibleSecurityBreach,
+
+        /// <summary>
+        /// Indicates a possible issue with data integrity during the service operation.
+        /// This flag is used when there is a suspicion of data alteration, corruption, or unreliability.
+        /// </summary>
+        PossibleDataIntegrityIssue,
+
+        /// <summary>
+        /// Indicates that either a possible security breach, a possible data integrity issue, or both have been detected during the service operation.
+        /// This flag is used when it is uncertain whether the issue is related to security, data integrity, or both.
+        /// </summary>
+        PossibleSecurityBreachOrDataIntegrity,
+
+        /// <summary>
+        /// Indicates that the requested resource or operation could not be found.
+        /// This flag is used when the specified item or condition does not exist or is unavailable.
+        /// </summary>
+        NotFound
+    }
+}

DigitalData.Core.Application/DTO/Notice.cs

@@ -0,0 +1,25 @@
+using Microsoft.Extensions.Logging;
+
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Represents a notice for logging purposes, containing a flag, log level, and associated messages.
+    /// </summary>
+    public class Notice
+    {
+        /// <summary>
+        /// Gets or sets an optional flag associated with the notice.
+        /// </summary>
+        public Enum? Flag { get; init; } = null;
+
+        /// <summary>
+        /// Gets or sets the log level for the notice.
+        /// </summary>
+        public LogLevel Level { get; init; } = LogLevel.None;
+
+        /// <summary>
+        /// Gets a list of messages associated with the notice.
+        /// </summary>
+        public List<string> Messages { get; init; } = new();
+    }
+}

DigitalData.Core.Application/DTO/Result.cs

@@ -0,0 +1,97 @@
+using System.Text.Json.Serialization;
+
+namespace DigitalData.Core.Application.DTO
+{
+    /// <summary>
+    /// Represents the result of an operation, containing information about its success or failure,
+    /// messages for the client, and notices for logging.
+    /// </summary>
+    public class Result
+    {
+        /// <summary>
+        /// Gets or sets a value indicating whether the operation was successful.
+        /// </summary>
+        public bool IsSuccess { get; set; } = false;
+
+        /// <summary>
+        /// Gets a value indicating whether the operation failed.
+        /// </summary>
+        public bool IsFailed => !IsSuccess;
+
+        /// <summary>
+        /// Gets a list of messages intended for the client.
+        /// </summary>
+        public List<string> Messages { get; init; } = new();
+
+        /// <summary>
+        /// Gets a list of notices intended for logging purposes. This property is ignored during JSON serialization.
+        /// </summary>
+        [JsonIgnore]
+        public List<Notice> Notices = new();
+
+        /// <summary>
+        /// Creates a <see cref="DataResult{T}"/> with the specified data.
+        /// </summary>
+        /// <typeparam name="T">The type of the data.</typeparam>
+        /// <param name="data">The data to include in the result.</param>
+        /// <returns>A new <see cref="DataResult{T}"/> instance.</returns>
+        public DataResult<T> Data<T>(T data) => new()
+        {
+            IsSuccess = IsSuccess,
+            Messages = Messages,
+            Notices = Notices,
+            Data = data
+        };
+
+        /// <summary>
+        /// Checks if any notice has the specified flag.
+        /// </summary>
+        /// <param name="flag">The flag to check.</param>
+        /// <returns>True if any notice has the specified flag; otherwise, false.</returns>
+        public bool HasFlag(Enum flag) => Notices.Any(n => n.Flag?.ToString() == flag.ToString());
+
+        /// <summary>
+        /// Checks if any notice has any of the specified flags.
+        /// </summary>
+        /// <param name="flags">The flags to check.</param>
+        /// <returns>True if any notice has any of the specified flags; otherwise, false.</returns>
+        public bool HasAnyFlag(params Enum[] flags) => flags.Any(HasFlag);
+
+        /// <summary>
+        /// Creates a new successful <see cref="Result"/>.
+        /// </summary>
+        /// <returns>A new successful <see cref="Result"/>.</returns>
+        public static Result Success() => new() { IsSuccess = true };
+
+        /// <summary>
+        /// Creates a new failed <see cref="Result"/>.
+        /// </summary>
+        /// <returns>A new failed <see cref="Result"/>.</returns>
+        public static Result Fail() => new() { IsSuccess = false };
+
+        /// <summary>
+        /// Creates a new successful <see cref="DataResult{T}"/> with the specified data.
+        /// </summary>
+        /// <typeparam name="T">The type of the data.</typeparam>
+        /// <param name="data">The data to include in the result.</param>
+        /// <returns>A new successful <see cref="DataResult{T}"/> with the specified data.</returns>
+        public static DataResult<T> Success<T>(T data) => new()
+        {
+            IsSuccess = true,
+            Data = data
+        };
+
+        /// <summary>
+        /// Creates a new failed <see cref="DataResult{T}"/> with no data.
+        /// </summary>
+        /// <typeparam name="T">The type of the data.</typeparam>
+        /// <returns>A new failed <see cref="DataResult{T}"/> with no data.</returns>
+#pragma warning disable CS8601 // Possible null reference assignment.
+        public static DataResult<T> Fail<T>() => new()
+        {
+            IsSuccess = false,
+            Data = default
+        };
+#pragma warning restore CS8601 // Possible null reference assignment.
+    }
+}

DigitalData.Core.Application/DigitalData.Core.Application.csproj

@@ -27,7 +27,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="7.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration" Version="7.0.0" />
     <PackageReference Include="Microsoft.Extensions.Localization.Abstractions" Version="7.0.16" />
     <PackageReference Include="Microsoft.Extensions.Logging" Version="7.0.0" />
@@ -37,20 +36,22 @@
     <PackageReference Include="System.Security.Cryptography.Cng" Version="5.0.0" />
   </ItemGroup>
 
-	<ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
-		<PackageReference Include="AutoMapper" Version="13.0.1" />
-	</ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
+	<PackageReference Include="AutoMapper" Version="13.0.1" />
+	<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="7.0.0" />
+	<PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="7.0.0" />
+  </ItemGroup>
 
-	<ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
-		<PackageReference Include="AutoMapper" Version="14.0.0" />
-	</ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+	<PackageReference Include="AutoMapper" Version="14.0.0" />
+	<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="8.0.1" />
+	<PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="8.0.0" />
+  </ItemGroup>
 
-	<ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
-		<PackageReference Include="AutoMapper" Version="14.0.0" />
-	</ItemGroup>
-
-  <ItemGroup>
-    <ProjectReference Include="..\DigitalData.Core.Abstractions\DigitalData.Core.Abstractions.csproj" />
+  <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
+	<PackageReference Include="AutoMapper" Version="14.0.0" />
+	<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="9.0.5" />
+	<PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="9.0.5" />
   </ItemGroup>
 
 </Project>

DigitalData.Core.Application/DirectorySearchService.cs

@@ -1,10 +1,10 @@
-using DigitalData.Core.Abstractions.Application;
-using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.CodeAnalysis;
 using System.DirectoryServices;
 using Microsoft.Extensions.Caching.Memory;
 using System.DirectoryServices.AccountManagement;
-using DigitalData.Core.DTO;
 using Microsoft.Extensions.Options;
+using DigitalData.Core.Application.Interfaces;
+using DigitalData.Core.Application.DTO;
 
 namespace DigitalData.Core.Application
 {

DigitalData.Core.Application/EntityExtensions.cs

@@ -0,0 +1,94 @@
+namespace DigitalData.Core.Application;
+
+/// <summary>
+/// Provides extension methods for retrieving the value of an 'Id' property from objects.
+/// </summary>
+public static class EntityExtensions
+{
+    /// <summary>
+    /// Attempts to retrieve the value of the 'Id' property from the specified object.
+    /// </summary>
+    /// <typeparam name="TId">The expected type of the 'Id' property.</typeparam>
+    /// <param name="obj">The object from which to retrieve the 'Id' property.</param>
+    /// <returns>
+    /// The value of the 'Id' property if it exists and is of type <typeparamref name="TId"/>; otherwise, <c>default</c>.
+    /// </returns>
+    public static TId? GetIdOrDefault<TId>(this object? obj)
+    {
+        var prop = obj?.GetType().GetProperty("Id");
+        return prop is not null && prop.GetValue(obj) is TId id ? id : default;
+    }
+
+    /// <summary>
+    /// Retrieves the value of the 'Id' property from the specified object, or throws an exception if not found or of the wrong type.
+    /// </summary>
+    /// <typeparam name="TId">The expected type of the 'Id' property.</typeparam>
+    /// <param name="obj">The object from which to retrieve the 'Id' property.</param>
+    /// <returns>The value of the 'Id' property.</returns>
+    /// <exception cref="InvalidOperationException">
+    /// Thrown if the object does not have a readable 'Id' property of type <typeparamref name="TId"/>.
+    /// </exception>
+    public static TId? GetId<TId>(this object? obj)
+        => obj.GetIdOrDefault<TId>()
+        ?? throw new InvalidOperationException($"The object of type '{obj?.GetType().FullName ?? "null"}' does not have a readable 'Id' property of type '{typeof(TId).FullName}'.");
+
+    /// <summary>
+    /// Tries to retrieve the value of the 'Id' property from the specified object.
+    /// </summary>
+    /// <typeparam name="TId">The expected type of the 'Id' property.</typeparam>
+    /// <param name="obj">The object from which to retrieve the 'Id' property.</param>
+    /// <param name="id">When this method returns, contains the value of the 'Id' property if found; otherwise, the default value for the type.</param>
+    /// <returns>
+    /// <c>true</c> if the 'Id' property was found and is of type <typeparamref name="TId"/>; otherwise, <c>false</c>.
+    /// </returns>
+    public static bool TryGetId<TId>(object? obj, out TId id)
+    {
+#pragma warning disable CS8601
+        id = obj.GetIdOrDefault<TId>();
+#pragma warning restore CS8601
+        return id is not null;
+    }
+
+    /// <summary>
+    /// Attempts to retrieve the value of the 'Id' property from the specified object.
+    /// </summary>
+    /// <param name="obj">The object from which to retrieve the 'Id' property.</param>
+    /// <returns>
+    /// The value of the 'Id' property if it exists; otherwise, <c>null</c>.
+    /// </returns>
+    public static object? GetIdOrDefault(this object? obj)
+    {
+        var prop = obj?.GetType().GetProperty("Id");
+        return prop?.GetValue(obj);
+    }
+
+    /// <summary>
+    /// Retrieves the value of the 'Id' property from the specified object, or throws an exception if not found.
+    /// </summary>
+    /// <param name="obj">The object from which to retrieve the 'Id' property.</param>
+    /// <returns>The value of the 'Id' property.</returns>
+    /// <exception cref="InvalidOperationException">
+    /// Thrown if the object does not have a readable 'Id' property.
+    /// </exception>
+    public static object GetId(this object? obj)
+        => obj.GetIdOrDefault()
+        ?? throw new InvalidOperationException($"The object of type '{obj?.GetType().FullName ?? "null"}' does not have a readable 'Id' property.");
+
+    /// <summary>
+    /// Tries to retrieve the value of the 'Id' property from the specified object.
+    /// </summary>
+    /// <param name="obj">The object from which to retrieve the 'Id' property.</param>
+    /// <param name="id">
+    /// When this method returns, contains the value of the 'Id' property if found; otherwise, <c>null</c>.
+    /// </param>
+    /// <returns>
+    /// <c>true</c> if the 'Id' property was found; otherwise, <c>false</c>.
+    /// </returns>
+    public static bool TryGetId(object? obj, out object id)
+    {
+#pragma warning disable CS8601
+        id = obj.GetIdOrDefault();
+#pragma warning restore CS8601
+        return id is not null;
+    }
+}

DigitalData.Core.Application/Interfaces/IBasicCRUDService.cs

@@ -1,6 +1,4 @@
-using DigitalData.Core.Abstractions.Infrastructure;
-
-namespace DigitalData.Core.Abstractions.Application
+namespace DigitalData.Core.Application.Interfaces
 {
     /// <summary>
     /// Implements a simplified CRUD service interface that uses a single Data Transfer Object (DTO) type for all CRUD operations,
@@ -15,8 +13,9 @@ namespace DigitalData.Core.Abstractions.Application
     /// This interface is useful for entities that do not require different DTOs for different operations,
     /// allowing for a more concise and maintainable codebase when implementing services for such entities.
     /// </remarks>
+    [Obsolete("Use MediatR")]
     public interface IBasicCRUDService<TDto, TEntity, TId> : ICRUDService<TDto, TDto, TEntity, TId>
-        where TDto : class, IUnique<TId> where TEntity : class, IUnique<TId>
+        where TDto : class where TEntity : class
     {
     }
 }

DigitalData.Core.Application/Interfaces/ICRUDService.cs

@@ -1,9 +1,10 @@
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.DTO;
 
-namespace DigitalData.Core.Abstractions.Application
+namespace DigitalData.Core.Application.Interfaces
 {
+    [Obsolete("Use MediatR")]
     public interface ICRUDService<TCreateDto, TReadDto, TEntity, TId> : IReadService<TReadDto, TEntity, TId>
-        where TCreateDto : class where TReadDto : class where TEntity : class, IUnique<TId>
+        where TCreateDto : class where TReadDto : class where TEntity : class
     {
         /// <summary>
         /// Asynchronously creates a new entity based on the provided <paramref name="createDto"/> and returns the identifier of the created entity wrapped in a <see cref="DataResult{TId}"/>.
@@ -20,6 +21,6 @@ namespace DigitalData.Core.Abstractions.Application
         /// </summary>
         /// <param name="updateDto">The updateDTO with updated values for the entity.</param>
         /// <returns>An Result indicating the outcome of the update operation, with an appropriate message.</returns>
-        Task<Result> UpdateAsync<TUpdateDto>(TUpdateDto updateDto) where TUpdateDto : IUnique<TId>;
+        Task<Result> UpdateAsync<TUpdateDto>(TUpdateDto updateDto);
     }
 }

DigitalData.Core.Application/Interfaces/IDirectorySearchService.cs

@@ -1,7 +1,7 @@
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.DTO;
 using System.DirectoryServices;
 
-namespace DigitalData.Core.Abstractions.Application
+namespace DigitalData.Core.Application.Interfaces
 {
     public interface IDirectorySearchService
     {

DigitalData.Core.Application/Interfaces/IJWTService.cs

@@ -2,7 +2,7 @@
 using System.IdentityModel.Tokens.Jwt;
 using System.Security.Cryptography;
 
-namespace DigitalData.Core.Application
+namespace DigitalData.Core.Application.Interfaces
 {
     /// <summary>
     /// Defines the operations for JWT service handling claims of type <typeparamref name="TClaimValue"/>.

DigitalData.Core.Application/Interfaces/IReadService.cs

@@ -1,7 +1,8 @@
-using DigitalData.Core.DTO;
+using DigitalData.Core.Application.DTO;
 
-namespace DigitalData.Core.Abstractions.Application
+namespace DigitalData.Core.Application.Interfaces
 {
+    [Obsolete("Use MediatR")]
     public interface IReadService<TReadDto, TEntity, TId>
         where TReadDto : class where TEntity : class
     {

DigitalData.Core.Application/Interfaces/Repository/Extensions.cs

@@ -1,6 +1,6 @@
 using System.Linq.Expressions;
 
-namespace DigitalData.Core.Abstractions.Infrastructure;
+namespace DigitalData.Core.Application.Interfaces.Repository;
 
 public static class Extensions
 {

DigitalData.Core.Application/Interfaces/Repository/ICRUDRepository.cs

@@ -1,11 +1,11 @@
-namespace DigitalData.Core.Abstractions.Infrastructure
+namespace DigitalData.Core.Application.Interfaces.Repository
 {
     /// <summary>
     /// Defines the contract for CRUD operations on a repository for entities of type TEntity.
     /// </summary>
     /// <typeparam name="TEntity">The type of the entity this repository works with.</typeparam>
     /// <typeparam name="TId">The type of the identifier for the entity.</typeparam>
-    public interface ICRUDRepository<TEntity, TId> where TEntity : class, IUnique<TId>
+    public interface ICRUDRepository<TEntity, TId> where TEntity : class
     {
         /// <summary>
         /// Adds a new entity to the repository.

DigitalData.Core.Application/Interfaces/Repository/IEntityMapper.cs

@@ -1,4 +1,4 @@
-namespace DigitalData.Core.Abstractions.Infrastructure
+namespace DigitalData.Core.Application.Interfaces.Repository
 {
     /// <summary>
     /// Defines methods for mapping between entities and Data Transfer Objects (DTOs).

DigitalData.Core.Application/Interfaces/Repository/IRepository.cs

@@ -1,6 +1,6 @@
 using System.Linq.Expressions;
 
-namespace DigitalData.Core.Abstractions.Infrastructure;
+namespace DigitalData.Core.Application.Interfaces.Repository;
 
 public interface IRepository<TEntity>
 {

DigitalData.Core.Application/JWTService.cs

@@ -1,63 +1,63 @@
-using Microsoft.IdentityModel.Tokens;
+using DigitalData.Core.Application.Interfaces;
+using Microsoft.IdentityModel.Tokens;
 using System.IdentityModel.Tokens.Jwt;
 using System.Security.Cryptography;
 
-namespace DigitalData.Core.Application
+namespace DigitalData.Core.Application;
+
+/// <summary>
+/// Implements the <see cref="IJWTService{TClaimValue}"/> interface to manage JWT operations for claims of type <typeparamref name="TClaimValue"/>.
+/// </summary>
+public class JWTService<TClaimValue> : IJWTService<TClaimValue>
 {
+    private readonly Func<TClaimValue, SecurityTokenDescriptor> _factory;
+
     /// <summary>
-    /// Implements the <see cref="IJWTService{TClaimValue}"/> interface to manage JWT operations for claims of type <typeparamref name="TClaimValue"/>.
+    /// Initializes a new instance of the <see cref="JWTService{TClaimValue}"/> class.
     /// </summary>
-    public class JWTService<TClaimValue> : IJWTService<TClaimValue>
+    /// <param name="tokenDescriptorFactory">A factory function to produce <see cref="SecurityTokenDescriptor"/> based on the claim value.</param>
+    public JWTService(Func<TClaimValue, SecurityTokenDescriptor> tokenDescriptorFactory)
     {
-        private readonly Func<TClaimValue, SecurityTokenDescriptor> _factory;
+        _factory = tokenDescriptorFactory;
+    }
 
-        /// <summary>
-        /// Initializes a new instance of the <see cref="JWTService{TClaimValue}"/> class.
-        /// </summary>
-        /// <param name="tokenDescriptorFactory">A factory function to produce <see cref="SecurityTokenDescriptor"/> based on the claim value.</param>
-        public JWTService(Func<TClaimValue, SecurityTokenDescriptor> tokenDescriptorFactory)
-        {
-            _factory = tokenDescriptorFactory;
-        }
+    /// <summary>
+    /// Generates a symmetric security key with the specified byte size.
+    /// </summary>
+    /// <param name="byteSize">The size of the security key in bytes. Default is 32 bytes.</param>
+    /// <returns>A new instance of <see cref="SymmetricSecurityKey"/>.</returns>
+    public static SymmetricSecurityKey GenerateSecurityKey(int byteSize = 32)
+    {
+        using var rng = RandomNumberGenerator.Create();
+        var randomBytes = new byte[byteSize];
+        rng.GetBytes(randomBytes);
+        var securityKey = new SymmetricSecurityKey(randomBytes);
 
-        /// <summary>
-        /// Generates a symmetric security key with the specified byte size.
-        /// </summary>
-        /// <param name="byteSize">The size of the security key in bytes. Default is 32 bytes.</param>
-        /// <returns>A new instance of <see cref="SymmetricSecurityKey"/>.</returns>
-        public static SymmetricSecurityKey GenerateSecurityKey(int byteSize = 32)
-        {
-            using var rng = RandomNumberGenerator.Create();
-            var randomBytes = new byte[byteSize];
-            rng.GetBytes(randomBytes);
-            var securityKey = new SymmetricSecurityKey(randomBytes);
+        return securityKey;
+    }
 
-            return securityKey;
-        }
+    /// <summary>
+    /// Generates a JWT for the specified claim value.
+    /// </summary>
+    /// <param name="claimValue">The claim value to encode in the JWT.</param>
+    /// <returns>A JWT as a string.</returns>
+    public string GenerateToken(TClaimValue claimValue)
+    {
+        var tokenDescriptor = _factory(claimValue);
 
-        /// <summary>
-        /// Generates a JWT for the specified claim value.
-        /// </summary>
-        /// <param name="claimValue">The claim value to encode in the JWT.</param>
-        /// <returns>A JWT as a string.</returns>
-        public string GenerateToken(TClaimValue claimValue)
-        {
-            var tokenDescriptor = _factory(claimValue);
+        var tokenHandler = new JwtSecurityTokenHandler();
+        var token = tokenHandler.CreateToken(tokenDescriptor);
+        return tokenHandler.WriteToken(token);
+    }
 
-            var tokenHandler = new JwtSecurityTokenHandler();
-            var token = tokenHandler.CreateToken(tokenDescriptor);
-            return tokenHandler.WriteToken(token);
-        }
-
-        /// <summary>
-        /// Reads and validates a security token from a string representation.
-        /// </summary>
-        /// <param name="token">The JWT to read.</param>
-        /// <returns>A <see cref="JwtSecurityToken"/> if the token is valid; otherwise, null.</returns>
-        public JwtSecurityToken? ReadSecurityToken(string token)
-        {
-            var tokenHandler = new JwtSecurityTokenHandler();
-            return tokenHandler.CanReadToken(token) ? tokenHandler.ReadToken(token) as JwtSecurityToken : null;
-        }
+    /// <summary>
+    /// Reads and validates a security token from a string representation.
+    /// </summary>
+    /// <param name="token">The JWT to read.</param>
+    /// <returns>A <see cref="JwtSecurityToken"/> if the token is valid; otherwise, null.</returns>
+    public JwtSecurityToken? ReadSecurityToken(string token)
+    {
+        var tokenHandler = new JwtSecurityTokenHandler();
+        return tokenHandler.CanReadToken(token) ? tokenHandler.ReadToken(token) as JwtSecurityToken : null;
     }
 }

DigitalData.Core.Application/Key.cs

@@ -1,11 +1,11 @@
-namespace DigitalData.Core.Application
+namespace DigitalData.Core.Application;
+
+[Obsolete("Use MediatR")]
+public static class Key
 {
-    public static class Key
-    {
-        public static readonly string EntityDoesNotExist = "EntityDoesNotExist";
-        public static readonly string ReadFailed = "ReadFailed";
-        public static readonly string UpdateFailed = "UpdateFailed";
-        public static readonly string DeletionFailed = "DeletionFailed";
-        public static readonly string DirSearcherDisconnected = "DirSearcherDisconnected";
-    }
+    public static readonly string EntityDoesNotExist = "EntityDoesNotExist";
+    public static readonly string ReadFailed = "ReadFailed";
+    public static readonly string UpdateFailed = "UpdateFailed";
+    public static readonly string DeletionFailed = "DeletionFailed";
+    public static readonly string DirSearcherDisconnected = "DirSearcherDisconnected";
 }

DigitalData.Core.Application/ReadService.cs

@@ -1,79 +1,78 @@
-using DigitalData.Core.Abstractions.Application;
-using DigitalData.Core.Abstractions.Infrastructure;
-using AutoMapper;
-using DigitalData.Core.DTO;
-using DigitalData.Core.Abstractions;
+using AutoMapper;
+using DigitalData.Core.Application.DTO;
+using DigitalData.Core.Application.Interfaces;
+using DigitalData.Core.Application.Interfaces.Repository;
 
-namespace DigitalData.Core.Application
+namespace DigitalData.Core.Application;
+
+/// <summary>
+/// Provides generic Read (Read and Delete) operations for a specified type of entity.
+/// </summary>
+/// <typeparam name="TReadDto">The DTO type for read operations.</typeparam>
+/// <typeparam name="TEntity">The entity type.</typeparam>
+/// <typeparam name="TId">The type of the identifier for the entity.</typeparam>
+[Obsolete("Use MediatR")]
+public class ReadService<TCRUDRepository, TReadDto, TEntity, TId> : IReadService<TReadDto, TEntity, TId>
+    where TCRUDRepository : ICRUDRepository<TEntity, TId> where TReadDto : class where TEntity : class
 {
+    protected readonly TCRUDRepository _repository;
+    protected readonly IMapper _mapper;
+
     /// <summary>
-    /// Provides generic Read (Read and Delete) operations for a specified type of entity.
+    /// Initializes a new instance of the CRUDService class with the specified repository, translation service, and mapper.
     /// </summary>
-    /// <typeparam name="TReadDto">The DTO type for read operations.</typeparam>
-    /// <typeparam name="TEntity">The entity type.</typeparam>
-    /// <typeparam name="TId">The type of the identifier for the entity.</typeparam>
-    public class ReadService<TCRUDRepository, TReadDto, TEntity, TId> : IReadService<TReadDto, TEntity, TId>
-        where TCRUDRepository : ICRUDRepository<TEntity, TId> where TReadDto : class where TEntity : class, IUnique<TId>
+    /// <param name="repository">The CRUD repository for accessing the database.</param>
+    /// <param name="mapper">The AutoMapper instance for mapping between DTOs and entity objects.</param>
+    public ReadService(TCRUDRepository repository, IMapper mapper)
     {
-        protected readonly TCRUDRepository _repository;
-        protected readonly IMapper _mapper;
-
-        /// <summary>
-        /// Initializes a new instance of the CRUDService class with the specified repository, translation service, and mapper.
-        /// </summary>
-        /// <param name="repository">The CRUD repository for accessing the database.</param>
-        /// <param name="mapper">The AutoMapper instance for mapping between DTOs and entity objects.</param>
-        public ReadService(TCRUDRepository repository, IMapper mapper)
-        {
-            _repository = repository;
-            _mapper = mapper;
-        }
-
-        /// <summary>
-        /// Asynchronously reads an entity by its identifier and maps it to a read DTO.
-        /// </summary>
-        /// <param name="id">The identifier of the entity to read.</param>
-        /// <returns>A service result indicating success or failure, including the read DTO if successful.</returns>
-        public virtual async Task<DataResult<TReadDto>> ReadByIdAsync(TId id)
-        {
-            var entity = await _repository.ReadByIdAsync(id);
-            return entity is null
-                ? Result.Fail<TReadDto>()
-                : Result.Success(_mapper.Map<TReadDto>(entity));
-        }
-
-        /// <summary>
-        /// Asynchronously reads all entities and maps them to read DTOs.
-        /// </summary>
-        /// <returns>A service result including a collection of read DTOs.</returns>
-        public virtual async Task<DataResult<IEnumerable<TReadDto>>> ReadAllAsync()
-        {
-            var entities = await _repository.ReadAllAsync();
-            var readDto = _mapper.Map<IEnumerable<TReadDto>>(entities);
-            return Result.Success(readDto);
-        }
-
-        /// <summary>
-        /// Asynchronously deletes an entity by its identifier.
-        /// </summary>
-        /// <param name="id">The identifier of the entity to delete.</param>
-        /// <returns>A service message indicating success or failure.</returns>
-        public virtual async Task<Result> DeleteAsyncById(TId id)
-        {
-            TEntity? entity = await _repository.ReadByIdAsync(id);
-
-            if (entity is null)
-                return Result.Fail();
-
-            bool isDeleted = await _repository.DeleteAsync(entity);
-            return isDeleted ? Result.Success() : Result.Fail();
-        }
-
-        /// <summary>
-        /// Asynchronously checks if an entity with the specified identifier exists.
-        /// </summary>
-        /// <param name="id">The identifier of the entity to check.</param>
-        /// <returns>A Task that represents the asynchronous operation. The task result contains a boolean value indicating whether the entity exists.</returns>
-        public virtual async Task<bool> HasEntity(TId id) => await _repository.CountAsync(id) > 0;
+        _repository = repository;
+        _mapper = mapper;
     }
+
+    /// <summary>
+    /// Asynchronously reads an entity by its identifier and maps it to a read DTO.
+    /// </summary>
+    /// <param name="id">The identifier of the entity to read.</param>
+    /// <returns>A service result indicating success or failure, including the read DTO if successful.</returns>
+    public virtual async Task<DataResult<TReadDto>> ReadByIdAsync(TId id)
+    {
+        var entity = await _repository.ReadByIdAsync(id);
+        return entity is null
+            ? Result.Fail<TReadDto>()
+            : Result.Success(_mapper.Map<TReadDto>(entity));
+    }
+
+    /// <summary>
+    /// Asynchronously reads all entities and maps them to read DTOs.
+    /// </summary>
+    /// <returns>A service result including a collection of read DTOs.</returns>
+    public virtual async Task<DataResult<IEnumerable<TReadDto>>> ReadAllAsync()
+    {
+        var entities = await _repository.ReadAllAsync();
+        var readDto = _mapper.Map<IEnumerable<TReadDto>>(entities);
+        return Result.Success(readDto);
+    }
+
+    /// <summary>
+    /// Asynchronously deletes an entity by its identifier.
+    /// </summary>
+    /// <param name="id">The identifier of the entity to delete.</param>
+    /// <returns>A service message indicating success or failure.</returns>
+    public virtual async Task<Result> DeleteAsyncById(TId id)
+    {
+        TEntity? entity = await _repository.ReadByIdAsync(id);
+
+        if (entity is null)
+            return Result.Fail();
+
+        bool isDeleted = await _repository.DeleteAsync(entity);
+        return isDeleted ? Result.Success() : Result.Fail();
+    }
+
+    /// <summary>
+    /// Asynchronously checks if an entity with the specified identifier exists.
+    /// </summary>
+    /// <param name="id">The identifier of the entity to check.</param>
+    /// <returns>A Task that represents the asynchronous operation. The task result contains a boolean value indicating whether the entity exists.</returns>
+    public virtual async Task<bool> HasEntity(TId id) => await _repository.CountAsync(id) > 0;
 }

DigitalData.Core.Client/BaseHttpClientService.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Client;
+using DigitalData.Core.Client.Interface;
 using System.Diagnostics.CodeAnalysis;
 using System.Net;
 using System.Web;

DigitalData.Core.Client/DIExtensions.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Client;
+using DigitalData.Core.Client.Interface;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;

DigitalData.Core.Client/HttpClientService.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Client;
+using DigitalData.Core.Client.Interface;
 using Microsoft.Extensions.Options;
 using System.Net;
 

DigitalData.Core.Client/Interface/IBaseHttpClientService.cs

@@ -1,6 +1,6 @@
 using System.Net;
 
-namespace DigitalData.Core.Abstractions.Client
+namespace DigitalData.Core.Client.Interface
 {
     public interface IBaseHttpClientService
     {

DigitalData.Core.Client/Interface/IHttpClientOptions.cs

@@ -1,4 +1,4 @@
-namespace DigitalData.Core.Abstractions.Client
+namespace DigitalData.Core.Client.Interface
 {
     public interface IHttpClientOptions
     {

DigitalData.Core.Client/Interface/IHttpClientService.cs

@@ -1,4 +1,4 @@
-namespace DigitalData.Core.Abstractions.Client
+namespace DigitalData.Core.Client.Interface
 {
     public interface IHttpClientService<TClientOptions> : IBaseHttpClientService where TClientOptions : IHttpClientOptions
     {

DigitalData.Core.Client/ServiceFactory.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Client;
+using DigitalData.Core.Client.Interface;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace DigitalData.Core.Client

DigitalData.Core.Exceptions/BadRequestException.cs

@@ -0,0 +1,22 @@
+namespace DigitalData.Core.Exceptions;
+
+/// <summary>
+/// Represents an exception that is thrown when a bad request is encountered.
+/// </summary>
+public class BadRequestException : Exception
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="BadRequestException"/> class.
+    /// </summary>
+    public BadRequestException()
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="BadRequestException"/> class with a specified error message.
+    /// </summary>
+    /// <param name="message">The message that describes the error.</param>
+    public BadRequestException(string? message) : base(message)
+    {
+    }
+}

DigitalData.Core.Exceptions/DependencyInjection.cs

@@ -0,0 +1,12 @@
+using Microsoft.AspNetCore.Builder;
+
+namespace DigitalData.Core.Exceptions;
+
+public static class DependencyInjection
+{
+    public static IApplicationBuilder UseGlobalExceptionHandler(this IApplicationBuilder app)
+    {
+        app.UseMiddleware<GlobalExceptionHandlerMiddleware>();
+        return app;
+    }
+}

DigitalData.Core.Exceptions/DigitalData.Core.Exceptions.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>net7.0;net8.0;net9.0</TargetFrameworks>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.3.0" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.5" />
+  </ItemGroup>
+
+</Project>

DigitalData.Core.Exceptions/GlobalExceptionHandlerMiddleware.cs

@@ -0,0 +1,83 @@
+namespace DigitalData.Core.Exceptions;
+
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+using System.Net;
+using System.Text.Json;
+
+/// <summary>
+/// Middleware for handling exceptions globally in the application.
+/// Captures exceptions thrown during the request pipeline execution,
+/// logs them, and returns an appropriate HTTP response with a JSON error message.
+/// </summary>
+public class GlobalExceptionHandlerMiddleware
+{
+    private readonly RequestDelegate _next;
+    private readonly ILogger<GlobalExceptionHandlerMiddleware>? _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="GlobalExceptionHandlerMiddleware"/> class.
+    /// </summary>
+    /// <param name="next">The next middleware in the request pipeline.</param>
+    /// <param name="logger">The logger instance for logging exceptions.</param>
+    public GlobalExceptionHandlerMiddleware(RequestDelegate next, ILogger<GlobalExceptionHandlerMiddleware>? logger = null)
+    {
+        _next = next;
+        _logger = logger;
+    }
+
+    /// <summary>
+    /// Invokes the middleware to handle the HTTP request.
+    /// </summary>
+    /// <param name="context">The HTTP context of the current request.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
+    public async Task InvokeAsync(HttpContext context)
+    {
+        try
+        {
+            await _next(context); // Continue down the pipeline
+        }
+        catch (Exception ex)
+        {
+            await HandleExceptionAsync(context, ex, _logger);
+        }
+    }
+
+    /// <summary>
+    /// Handles exceptions by logging them and writing an appropriate JSON response.
+    /// </summary>
+    /// <param name="context">The HTTP context of the current request.</param>
+    /// <param name="exception">The exception that occurred.</param>
+    /// <param name="logger">The logger instance for logging the exception.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
+    private static async Task HandleExceptionAsync(HttpContext context, Exception exception, ILogger? logger = null)
+    {
+        context.Response.ContentType = "application/json";
+
+        string message;
+
+        switch (exception)
+        {
+            case BadRequestException badRequestEx:
+                context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
+                message = badRequestEx.Message;
+                break;
+
+            case NotFoundException notFoundEx:
+                context.Response.StatusCode = (int)HttpStatusCode.NotFound;
+                message = notFoundEx.Message;
+                break;
+
+            default:
+                logger?.LogError(exception, "Unhandled exception occurred.");
+                context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
+                message = "An unexpected error occurred.";
+                break;
+        }
+
+        await context.Response.WriteAsync(JsonSerializer.Serialize(new
+        {
+            message
+        }));
+    }
+}

DigitalData.Core.Exceptions/NotFoundException.cs

@@ -0,0 +1,22 @@
+namespace DigitalData.Core.Exceptions;
+
+/// <summary>
+/// Represents an exception that is thrown when a requested resource is not found.
+/// </summary>
+public class NotFoundException : Exception
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="NotFoundException"/> class.
+    /// </summary>
+    public NotFoundException()
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="NotFoundException"/> class with a specified error message.
+    /// </summary>
+    /// <param name="message">The message that describes the error.</param>
+    public NotFoundException(string? message) : base(message)
+    {
+    }
+}

DigitalData.Core.Infrastructure.AutoMapper/EntityAutoMapper.cs

@@ -1,5 +1,5 @@
 using AutoMapper;
-using DigitalData.Core.Abstractions.Infrastructure;
+using DigitalData.Core.Application.Interfaces.Repository;
 
 namespace DigitalData.Core.Infrastructure.AutoMapper;
 

DigitalData.Core.Infrastructure/CRUDRepository.cs

@@ -1,5 +1,5 @@
 using DigitalData.Core.Abstractions;
-using DigitalData.Core.Abstractions.Infrastructure;
+using DigitalData.Core.Application.Interfaces.Repository;
 using Microsoft.EntityFrameworkCore;
 
 namespace DigitalData.Core.Infrastructure

DigitalData.Core.Infrastructure/DbRepository.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Infrastructure;
+using DigitalData.Core.Application.Interfaces.Repository;
 using Microsoft.EntityFrameworkCore;
 using System.Linq.Expressions;
 

DigitalData.Core.Infrastructure/DependencyInjection.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Infrastructure;
+using DigitalData.Core.Application.Interfaces.Repository;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 

DigitalData.Core.Infrastructure/DigitalData.Core.Infrastructure.csproj

@@ -41,6 +41,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\DigitalData.Core.Abstractions\DigitalData.Core.Abstractions.csproj" />
+    <ProjectReference Include="..\DigitalData.Core.Application\DigitalData.Core.Application.csproj" />
   </ItemGroup>
 
   <ItemGroup>

DigitalData.Core.Infrastructure/EntityConfigurationOptions.cs

@@ -1,4 +1,4 @@
-using DigitalData.Core.Abstractions.Infrastructure;
+using DigitalData.Core.Application.Interfaces.Repository;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace DigitalData.Core.Infrastructure;

DigitalData.Core.Tests/Client/BaseHttpClientServiceTest.cs

@@ -1,5 +1,5 @@
-using DigitalData.Core.Abstractions.Client;
-using DigitalData.Core.Client;
+using DigitalData.Core.Client;
+using DigitalData.Core.Client.Interface;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace DigitalData.Core.Tests.Client

DigitalData.Core.Tests/Infrastructure/DbRepositoryTests.cs

@@ -6,8 +6,8 @@ using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using System.Reflection;
-using DigitalData.Core.Abstractions.Infrastructure;
 using DigitalData.Core.Infrastructure.AutoMapper;
+using DigitalData.Core.Application.Interfaces.Repository;
 
 public class DbRepositoryTests
 {

DigitalData.Core.sln

@@ -39,6 +39,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DigitalData.Core.Infrastruc
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Infrastructure", "Infrastructure", "{41795B74-A757-4E93-B907-83BFF04EEE5C}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DigitalData.Core.Exceptions", "DigitalData.Core.Exceptions\DigitalData.Core.Exceptions.csproj", "{BAEF6CC9-4FE2-4E3F-9D32-911C9E8CCFB4}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -100,6 +102,10 @@ Global
 		{CE00E1F7-2771-4D9C-88FB-E564894E539E}.Debug|Any CPU.Build.0 = Release|Any CPU
 		{CE00E1F7-2771-4D9C-88FB-E564894E539E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{CE00E1F7-2771-4D9C-88FB-E564894E539E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BAEF6CC9-4FE2-4E3F-9D32-911C9E8CCFB4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BAEF6CC9-4FE2-4E3F-9D32-911C9E8CCFB4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BAEF6CC9-4FE2-4E3F-9D32-911C9E8CCFB4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BAEF6CC9-4FE2-4E3F-9D32-911C9E8CCFB4}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -121,6 +127,7 @@ Global
 		{C9266749-9504-4EA9-938F-F083357B60B7} = {72CBAFBA-55CC-49C9-A484-F8F4550054CB}
 		{CE00E1F7-2771-4D9C-88FB-E564894E539E} = {41795B74-A757-4E93-B907-83BFF04EEE5C}
 		{41795B74-A757-4E93-B907-83BFF04EEE5C} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
+		{BAEF6CC9-4FE2-4E3F-9D32-911C9E8CCFB4} = {02EA681E-C7D8-13C7-8484-4AC65E1B71E8}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {8E2C3187-F848-493A-9E79-56D20DDCAC94}