Add more logging and trace parameters

src/Vegasco.Server.Api/Cars/CreateCar.cs

@@ -39,19 +39,41 @@ public static class CreateCar
 		IEnumerable<IValidator<Request>> validators,
 		ApplicationDbContext dbContext,
 		UserAccessor userAccessor,
+		ILoggerFactory loggerFactory,
 		CancellationToken cancellationToken)
 	{
+		ILogger logger = loggerFactory.CreateLogger(nameof(CreateCar));
+		
 		List<ValidationResult> failedValidations = await validators.ValidateAllAsync(request, cancellationToken: cancellationToken);
 		if (failedValidations.Count > 0)
 		{
+			logger.LogDebug(
+				"Validation failed for request {@Request} with errors {@Errors}",
+				request,
+				failedValidations
+					.Where(x => !x.IsValid)
+					.SelectMany(x => x.Errors)
+					.Select(x => x.ErrorMessage));
+
 			return TypedResults.BadRequest(new HttpValidationProblemDetails(failedValidations.ToCombinedDictionary()));
 		}
 
+		bool isDuplicate = await dbContext.Cars
+			.AnyAsync(x => x.Name.ToUpper() == request.Name.ToUpper(), cancellationToken);
+
+		if (isDuplicate)
+		{
+			logger.LogDebug("Car with name '{CarName}' (case insensitive) already exists", request.Name);
+			return TypedResults.Conflict();
+		}
+
 		string userId = userAccessor.GetUserId();
 
 		User? user = await dbContext.Users.FindAsync([userId], cancellationToken: cancellationToken);
 		if (user is null)
 		{
+			logger.LogDebug("User with ID '{UserId}' not found, creating new user", userId);
+
 			user = new User
 			{
 				Id = userId
@@ -65,17 +87,11 @@ public static class CreateCar
 			UserId = userId
 		};
 
-		bool isDuplicate = await dbContext.Cars
-			.AnyAsync(x => x.Name.ToUpper() == request.Name.ToUpper(), cancellationToken);
-
-		if (isDuplicate)
-		{
-			return TypedResults.Conflict();
-		}
-
 		await dbContext.Cars.AddAsync(car, cancellationToken);
 		await dbContext.SaveChangesAsync(cancellationToken);
 
+		logger.LogTrace("Created new car: {@Car}", car);
+
 		Response response = new(car.Id.Value, car.Name);
 		return TypedResults.Created($"/v1/cars/{car.Id}", response);
 	}