using Microsoft.AspNetCore.Mvc.Filters;
using PostSharp.Patterns.Diagnostics;
using System;
using System.Collections.Generic;
using System.Net;
using System.Threading.Tasks;
using static PostSharp.Patterns.Diagnostics.SemanticMessageBuilder;
 
namespace MicroserviceExample
{
  [Log(AttributeExclude = true)]
  public class LoggingActionFilter : IAsyncActionFilter
  {
    private static readonly LogSource logger = LogSource.Get();
 
    public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
    {
      // Read the Request-Id header so we can assign it to the activity.
      string parentOperationId = context.HttpContext.Request.Headers["Request-Id"];
 
 
      OpenActivityOptions options = default;
 
      // Set the parent id.
      if (!string.IsNullOrEmpty(parentOperationId))
      {
        options.SyntheticParentId = parentOperationId;
      }
      else
      {
        options.IsSyntheticRootId = true;
      }
 
      // Process cross-context properties (aka baggage).
      string correlationContext = context.HttpContext.Request.Headers["Correlation-Context"];
      if (!string.IsNullOrEmpty(correlationContext))
      {
        options.Properties = ParseCorrelationContext(correlationContext)?.ToArray();
      }
 
      var request = context.HttpContext.Request;
      using (var activity = logger.Default.OpenActivity(Semantic("Request", ("Path", request.Path),
          ("Query", request.QueryString), ("Method", request.Method)), options))
      {
        try
        {
          await next();
 
          var response = context.HttpContext.Response;
 
          if (response.StatusCode >= (int) HttpStatusCode.OK && response.StatusCode <= 299)
          {
            // Success.
            activity.SetOutcome(LogLevel.Info, Semantic("Success", ("StatusCode", response.StatusCode)));
          }
          else
          {
            // Failure.
            activity.SetOutcome(LogLevel.Warning, Semantic("Failure", ("StatusCode", response.StatusCode)));
          }
        }
        catch (Exception e)
        {
          activity.SetException(e);
        }
      }
    }
 
    private static List<LoggingProperty> ParseCorrelationContext(string correlationContext)
    {
      var properties = new List<LoggingProperty>();
      foreach (var pair in correlationContext.Split(',', StringSplitOptions.RemoveEmptyEntries))
      {
        var posOfEqual = pair.IndexOf('=');
        if (posOfEqual <= 0)
        {
          continue;
        }
 
        var propertyName = pair.Substring(0, posOfEqual);
        var propertyValue = pair.Substring(posOfEqual + 1);
        properties.Add(new LoggingProperty(propertyName, propertyValue) { IsBaggage = true });
      }
 
      return properties;
    }
  }
}