private static void ConfigureRepository()

in src/log4net/Core/DefaultRepositorySelector.cs [550:663]
91 lines of code
16 McCabe index (conditional complexity)

  private static void ConfigureRepository(Assembly assembly, ILoggerRepository repository)
  {
    repository.EnsureNotNull();

    // Look for the Configurator attributes (e.g. XmlConfiguratorAttribute) on the assembly
    ConfiguratorAttribute[] configAttributes = Attribute.GetCustomAttributes(assembly.EnsureNotNull(), typeof(ConfiguratorAttribute), false)
      .EnsureIs<ConfiguratorAttribute[]>();
    if (configAttributes.Length > 0)
    {
      // Sort the ConfiguratorAttributes in priority order
      Array.Sort(configAttributes);

      // Delegate to the attribute the job of configuring the repository
      foreach (ConfiguratorAttribute configAttr in configAttributes)
      {
        try
        {
          configAttr.Configure(assembly, repository);
        }
        catch (Exception e) when (!e.IsFatal())
        {
          LogLog.Error(_declaringType, $"Exception calling [{configAttr.GetType().FullName}] .Configure method.", e);
        }
      }
    }

    if (repository.Name == DefaultRepositoryName)
    {
      // Try to configure the default repository using an AppSettings specified config file
      // Do this even if the repository has been configured (or claims to be), this allows overriding
      // of the default config files etc., if that is required.

      string? repositoryConfigFile = SystemInfo.GetAppSetting("log4net.Config");
      if (repositoryConfigFile is not null && repositoryConfigFile.Length > 0)
      {
        string? applicationBaseDirectory = null;
        try
        {
          applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
        }
        catch (Exception e) when (!e.IsFatal())
        {
          LogLog.Warn(_declaringType, $"Exception getting ApplicationBaseDirectory. appSettings log4net.Config path [{repositoryConfigFile}] will be treated as an absolute URI", e);
        }

        string repositoryConfigFilePath = repositoryConfigFile;
        if (applicationBaseDirectory is not null)
        {
          repositoryConfigFilePath = Path.Combine(applicationBaseDirectory, repositoryConfigFile);
        }

        // Determine whether to watch the file or not based on an app setting value:
        bool.TryParse(SystemInfo.GetAppSetting("log4net.Config.Watch"), out bool watchRepositoryConfigFile);

        if (watchRepositoryConfigFile)
        {
          // As we are going to watch the config file it is required to resolve it as a 
          // physical file system path pass that in a FileInfo object to the Configurator
          FileInfo? repositoryConfigFileInfo = null;
          try
          {
            repositoryConfigFileInfo = new FileInfo(repositoryConfigFilePath);
          }
          catch (Exception e) when (!e.IsFatal())
          {
            LogLog.Error(_declaringType, $"DefaultRepositorySelector: Exception while parsing log4net.Config file physical path [{repositoryConfigFilePath}]", e);
          }

          if (repositoryConfigFileInfo is not null)
          {
            try
            {
              LogLog.Debug(_declaringType, $"Loading and watching configuration for default repository from AppSettings specified Config path [{repositoryConfigFilePath}]");

              XmlConfigurator.ConfigureAndWatch(repository, repositoryConfigFileInfo);
            }
            catch (Exception e) when (!e.IsFatal())
            {
              LogLog.Error(_declaringType, $"DefaultRepositorySelector: Exception calling XmlConfigurator.ConfigureAndWatch method with ConfigFilePath [{repositoryConfigFilePath}]", e);
            }
          }
        }
        else
        {
          // As we are not going to watch the config file it is easiest to just resolve it as a 
          // URI and pass that to the Configurator
          Uri? repositoryConfigUri = null;
          try
          {
            repositoryConfigUri = new Uri(repositoryConfigFilePath);
          }
          catch (Exception e) when (!e.IsFatal())
          {
            LogLog.Error(_declaringType, $"Exception while parsing log4net.Config file path [{repositoryConfigFile}]", e);
          }

          if (repositoryConfigUri is not null)
          {
            LogLog.Debug(_declaringType, $"Loading configuration for default repository from AppSettings specified Config URI [{repositoryConfigUri}]");

            try
            {
              // TODO: Support other types of configurator
              XmlConfigurator.Configure(repository, repositoryConfigUri);
            }
            catch (Exception e) when (!e.IsFatal())
            {
              LogLog.Error(_declaringType, $"Exception calling XmlConfigurator.Configure method with ConfigUri [{repositoryConfigUri}]", e);
            }
          }
        }
      }
    }
  }