#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.IO;

using log4net.Core;

namespace log4net.Layout
{
  /// <summary>
  /// A very simple layout
  /// </summary>
  /// <remarks>
  /// <para>
  /// SimpleLayout consists of the level of the log statement,
  /// followed by " - " and then the log message itself. For example,
  /// <code>
  /// DEBUG - Hello world
  /// </code>
  /// </para>
  /// </remarks>
  /// <author>Nicko Cadell</author>
  /// <author>Gert Driesen</author>
  public class SimpleLayout : LayoutSkeleton
  {
    /// <summary>
    /// Constructs a SimpleLayout
    /// </summary>
    public SimpleLayout()
    {
      IgnoresException = true;
    }

    /// <summary>
    /// Initialize layout options
    /// </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 override void ActivateOptions()
    {
      // nothing to do.
    }

    /// <summary>
    /// Produces a simple formatted output.
    /// </summary>
    /// <param name="loggingEvent">the event being logged</param>
    /// <param name="writer">The TextWriter to write the formatted event to</param>
    /// <remarks>
    /// <para>
    /// Formats the event as the level of the event,
    /// followed by " - " and then the log message itself. The
    /// output is terminated by a newline.
    /// </para>
    /// </remarks>
    public override void Format(TextWriter writer, LoggingEvent loggingEvent)
    {
      if (loggingEvent is null)
      {
        throw new ArgumentNullException(nameof(loggingEvent));
      }

      if (loggingEvent.Level is not null)
      {
        writer.Write(loggingEvent.Level.DisplayName);
        writer.Write(" - ");
      }
      loggingEvent.WriteRenderedMessage(writer);
      writer.WriteLine();
    }
  }
}
