#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 log4net.Core;

namespace log4net.Util.PatternStringConverters
{
  /// <summary>
  /// Writes a newline to the output
  /// </summary>
  /// <remarks>
  /// <para>
  /// Writes the system dependent line terminator to the output.
  /// This behavior can be overridden by setting the <see cref="PatternConverter.Option"/>:
  /// </para>
  /// <list type="definition">
  ///   <listheader>
  ///     <term>Option Value</term>
  ///     <description>Output</description>
  ///   </listheader>
  ///   <item>
  ///     <term>DOS</term>
  ///     <description>DOS or Windows line terminator <c>"\r\n"</c></description>
  ///   </item>
  ///   <item>
  ///     <term>UNIX</term>
  ///     <description>UNIX line terminator <c>"\n"</c></description>
  ///   </item>
  /// </list>
  /// </remarks>
  /// <author>Nicko Cadell</author>
  internal sealed class NewLinePatternConverter : LiteralPatternConverter, IOptionHandler
  {
    #region Implementation of IOptionHandler

    /// <summary>
    /// Initialize the converter
    /// </summary>
    /// <remarks>
    /// <para>
    /// This is part of the <see cref="IOptionHandler"/> delayed object
    /// activation scheme. The <see cref="ActivateOptions"/> method must 
    /// be called on this object after the configuration properties have
    /// been set. Until <see cref="ActivateOptions"/> is called this
    /// object is in an undefined state and must not be used. 
    /// </para>
    /// <para>
    /// If any of the configuration properties are modified then 
    /// <see cref="ActivateOptions"/> must be called again.
    /// </para>
    /// </remarks>
    public void ActivateOptions()
    {
      if (SystemInfo.EqualsIgnoringCase(Option, "DOS"))
      {
        Option = "\r\n";
      }
      else if (SystemInfo.EqualsIgnoringCase(Option, "UNIX"))
      {
        Option = "\n";
      }
      else
      {
        Option = SystemInfo.NewLine;
      }
    }

    #endregion
  }
}