bitforum-backend/Web.Api/Common/CustomResults.cs

using SharedKernel.Results;

namespace Web.Api.Common;

public static class CustomResults
{
    public static IResult Problem(Result result)
    {
        if (result.IsSuccess)
        {
            throw new InvalidOperationException();
        }

        return Results.Problem(
            title: GetTitle(result.Error),
            detail: result.Error.Description,
            type: GetType(result.Error.Type),
            statusCode: GetStatusCode(result.Error.Type),
            extensions: GetErrors(result)
        );

        static string GetTitle(Error error) => error.Type switch
        {
            ErrorType.Validation => error.Code,
            ErrorType.Problem => error.Code,
            ErrorType.Unauthorized => error.Code,
            ErrorType.NotFound => error.Code,
            ErrorType.Forbidden => error.Code,
            ErrorType.Conflict => error.Code,
            ErrorType.MethodNotAllowed => error.Code,
            _ => "Server failure"
        };

        static string GetType(ErrorType errorType) => errorType switch
        {
            ErrorType.Validation => "https://tools.ietf.org/html/rfc7231#section-6.5.1",
            ErrorType.Problem => "https://tools.ietf.org/html/rfc7231#section-6.5.1",
            ErrorType.Unauthorized => "https://tools.ietf.org/html/rfc7235#section-3.1",
            ErrorType.NotFound => "https://tools.ietf.org/html/rfc7231#section-6.5.4",
            ErrorType.Forbidden => "https://tools.ietf.org/html/rfc7231#section-6.5.3",
            ErrorType.Conflict => "https://tools.ietf.org/html/rfc7231#section-6.5.8",
            ErrorType.MethodNotAllowed => "https://tools.ietf.org/html/rfc7231#section-6.5.5",
            _ => "https://tools.ietf.org/html/rfc7231#section-6.6.1"
        };

        static int GetStatusCode(ErrorType errorType) => errorType switch
        {
            ErrorType.Validation or ErrorType.Problem => StatusCodes.Status400BadRequest,
            ErrorType.Unauthorized => StatusCodes.Status401Unauthorized,
            ErrorType.NotFound => StatusCodes.Status404NotFound,
            ErrorType.Forbidden => StatusCodes.Status403Forbidden,
            ErrorType.Conflict => StatusCodes.Status409Conflict,
            ErrorType.MethodNotAllowed => StatusCodes.Status405MethodNotAllowed,
            _ => StatusCodes.Status500InternalServerError
        };

        static Dictionary<string, object?>? GetErrors(Result result)
        {
            if (result.Error is not ValidationError validationError)
            {
                return null;
            }

            return new Dictionary<string, object?>
            {
                { "errors", validationError.Errors }
            };
        }
    }
}