Part 3: Pseudo code demonstrating the final phase of how to isolate logging components through decoration.

IAuthenticationStep.cs

public interface IAuthenticationStep
{
    bool IsAuthentic(HttpRequest request);
}

LoggingAuthenticationStep.cs

public class LoggingAuthenticationStep : IAuthenticationStep
{
    private readonly ILogger logger;
    private readonly IAuthenticationStep inner;
    
    public LoggingAuthenticationStep(ILogger logger, IAuthenticationStep inner)
    {
        this.logger = logger;
        this.inner = inner;
    }
    
    public bool IsAuthentic(HttpRequest request)
    {
        this.logger.Trace($"Beginning authentication step: {typeof(this.inner).FullName}");
        var result = this.inner.IsAuthentic(request);
        this.logger.Trace($"Step found request to be authentic: {result}");
        return result;
    }
}

SignatureAuthenticationProcedure.cs

public class SignatureAuthenticationProcedure : IAuthenticationProcedure
{
    private readonly IEnumerable<IAuthenticationSteps> authenticationSteps;
    
    public SignatureAuthenticationProcedure(IEnumerable<IAuthenticationStep> authenticationSteps)
    {
        this.authenticationSteps = authenticationSteps;
    }
    
    public AuthenticationResult Authenticate(HttpRequest request)
    {   
        return this.authenticationSteps.All(step => step.IsAuthentic(request));
    }
}

SignatureAuthenticationStep.cs

public class SignatureVerificationStep : IAuthenticationStep
{
    public bool IsAuthentic(HttpRequest request)
    {
        // ...
    }
}

TimestampAuthenticationStep.cs

public class TimestampAuthenticationStep : IAuthenticationStep
{
    public bool IsAuthentic(HttpRequest request)
    {
        // ...
    }
}