#region Apache License

//

// Licensed to the Apache Software Foundation (ASF) under one or more 

// contributor license agreements. See the NOTICE file distributed with

// this work for additional information regarding copyright ownership. 

// The ASF licenses this file to you under the Apache License, Version 2.0

// (the "License"); you may not use this file except in compliance with 

// the License. You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//

#endregion



using System;

using System.Text;

using System.IO;



using log4net.Util;



namespace log4net.Util.PatternStringConverters

{

	/// <summary>

	/// Write the current threads username to the output

	/// </summary>

	/// <remarks>

	/// <para>

	/// Write the current threads username to the output writer

	/// </para>

	/// </remarks>

	/// <author>Nicko Cadell</author>

	internal sealed class UserNamePatternConverter : PatternConverter 

	{

		/// <summary>

		/// Write the current threads username to the output

		/// </summary>

		/// <param name="writer">the writer to write to</param>

		/// <param name="state">null, state is not set</param>

		/// <remarks>

		/// <para>

		/// Write the current threads username to the output <paramref name="writer"/>.

		/// </para>

		/// </remarks>

		override protected void Convert(TextWriter writer, object state) 

		{

#if (NETCF || SSCLI)

			// On compact framework there's no notion of current Windows user

			writer.Write( SystemInfo.NotAvailableText );

#else

			try

			{

				System.Security.Principal.WindowsIdentity windowsIdentity = null;

				windowsIdentity = System.Security.Principal.WindowsIdentity.GetCurrent();

				if (windowsIdentity != null && windowsIdentity.Name != null)

				{

					writer.Write( windowsIdentity.Name );

				}

			}

			catch(System.Security.SecurityException)

			{

				// This security exception will occur if the caller does not have 

				// some undefined set of SecurityPermission flags.

				LogLog.Debug(declaringType, "Security exception while trying to get current windows identity. Error Ignored.");



				writer.Write( SystemInfo.NotAvailableText );

			}

#endif

		}



	    #region Private Static Fields



	    /// <summary>

	    /// The fully qualified type of the UserNamePatternConverter class.

	    /// </summary>

	    /// <remarks>

	    /// Used by the internal logger to record the Type of the

	    /// log message.

	    /// </remarks>

	    private readonly static Type declaringType = typeof(UserNamePatternConverter);



	    #endregion Private Static Fields

	}

}