#region Copyright 2008-2014 by Roger Knapp, Licensed under the Apache License, Version 2.0
/* Licensed 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.Security.Permissions;
using System.Diagnostics;

using CSharpTest.Net.Logging;
using CSharpTest.Net.Logging.Implementation;
using System.Runtime.CompilerServices;

/// <summary>
/// Provides an abstraction api for logging to various outputs.  This class in the global namespace for a reason.
/// Since you may want to change log infrastructure at any time, it's important that no 'Using' statements are
/// required to access the log infrastructure.  Secondly, a static class api can provide improved performance
/// over other possible types.  We will be forcing the default configuration of log4net rather than requiring
/// each component to independently configure itself.
/// </summary>
[System.Reflection.Obfuscation(Exclude = true)]
[System.Diagnostics.DebuggerNonUserCode()]
public static partial class Log
{
	static Log()
	{
		Configuration.Configure();
	}
	#region Config Options
	/// <summary>
	/// Provides configuration options for the Log subsystem
	/// </summary>
	[System.Diagnostics.DebuggerNonUserCode()]
	public static class Config
	{
		static Config()
		{
			//force the static c'tor on Log()
			Log.IsVerboseEnabled.ToString();
		}

		/// <summary> Gets or sets the current log LogLevel </summary>
		public static LogLevels Level
		{
			get { return Configuration.LogLevel; }
			[MethodImpl(MethodImplOptions.NoInlining)]
			set
			{
				if ((Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose) MessageQueue.Push(1, LogLevels.Verbose, null, String.Format("Log Level changed from {0} to {1}.", Configuration.LogLevel, value), null);
				Configuration.LogLevel = value;
			}
		}
		/// <summary> Gets or sets the current log LogLevel </summary>
		public static LogOutputs Output
		{
			get { return Configuration.LogOutput; }
			[MethodImpl(MethodImplOptions.NoInlining)]
			set
			{
				if ((Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose) MessageQueue.Push(1, LogLevels.Verbose, null, String.Format("Log Output changed from {0} to {1}.", Configuration.LogOutput, value), null);
				Configuration.LogOutput = value;
			}
		}
		/// <summary> 
		/// Gets or sets the availability of stack info etc.  The following performance characterists were taken with a 
		/// simple example app running 10 threads each writing 1000 log statements in a tight-loop.  The times below reflect
		/// threading enabled (someone having called Log.AppStart()).  The following hardware was used:
		/// AMD Turion 64x2 TL-62  2.10 GHz, 3 GB RAM running Vista 32-bit SP1  (HP Notebook).  The time indicated below
		/// was estimated by taking the total number of milliseconds until all threads completed and dividing by the 10,000
		/// messages that were written.
		/// <list>
		///		<item>Cost per call 0.005 ms with no context   (None)</item>
		///		<item>Cost per call 0.035 ms with calling method   (LogImmediateCaller)</item>
		///		<item>Cost per call 0.060 ms with calling method &amp; assembly info   (LogImmediateCaller | LogAddAssemblyInfo)</item>
		///		<item>Cost per call 0.160 ms with calling method &amp; file info   (LogImmediateCaller | LogAddFileInfo)</item>
		///		<item>Cost per call 0.190 ms with calling method &amp; assembly info &amp; file info   (LogImmediateCaller | LogAddAssemblyInfo | LogAddFileInfo)</item>
		/// </list>
		/// </summary>
		public static LogOptions Options
		{
			get { return Configuration.LogOption; }
			[MethodImpl(MethodImplOptions.NoInlining)]
			set
			{
				if ((Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose) MessageQueue.Push(1, LogLevels.Verbose, null, String.Format("Log Options changed from {0} to {1}.", Configuration.LogOption, value), null);
				Configuration.LogOption = value;
			}
		}

		/// <summary> Gets or sets the format provider to use when formatting strings </summary>
		public static IFormatProvider FormatProvider { set { if( value != null ) Configuration.InnerFormatter = value; } }

		/// <summary> Changes the log level required to write to a specific output device. </summary>
		[MethodImpl(MethodImplOptions.NoInlining)]
		public static LogLevels SetOutputLevel(LogOutputs outputToConfigure, LogLevels newLevel)
		{
			LogLevels old = LogLevels.None;
			switch(outputToConfigure)
			{
				case LogOutputs.AspNetTrace: { old = Configuration.LEVEL_ASPNET; Configuration.LEVEL_ASPNET = newLevel; break; }
				case LogOutputs.Console: { old = Configuration.LEVEL_CONSOLE; Configuration.LEVEL_CONSOLE = newLevel; break; }
				case LogOutputs.EventLog: { old = Configuration.LEVEL_EVENTLOG; Configuration.LEVEL_EVENTLOG = newLevel; break; }
				case LogOutputs.LogFile: { old = Configuration.LEVEL_LOGFILE; Configuration.LEVEL_LOGFILE = newLevel; break; }
				case LogOutputs.TraceWrite: { old = Configuration.LEVEL_TRACE; Configuration.LEVEL_TRACE = newLevel; break; }
				case LogOutputs.All:
					{
						Configuration.LEVEL_ASPNET = newLevel;
						Configuration.LEVEL_CONSOLE = newLevel;
						Configuration.LEVEL_EVENTLOG = newLevel;
						Configuration.LEVEL_LOGFILE = newLevel;
						Configuration.LEVEL_TRACE = newLevel;
						break;
					}
			}
			MessageQueue.Push(1, LogLevels.Verbose, null, String.Format("Log level for {0} changed from {1} to {2}.", outputToConfigure, old, newLevel), null);
			return old;
		}

		/// <summary> 
		/// Changes the output format used to write to a specific output device. The format of this string behaves just like
		/// EventData.ToString().  The string can contain any public field or property available for the CSharpTest.Net.Logging.EventData 
		/// class surrounded by braces {} and yes, properties/fields are case sensative.  The input string should look something
		/// like the following examples: 
		/// "[{ManagedThreadId:D2}] {Level,8} - {Message}{Location}{Exception}" -- this is the default format of ToString()
		/// "{EventTime:o} [{ProcessId:D4},{ManagedThreadId:D2}] {Level,8} - {Message}{Location}{Exception}"  -- This is the default log file format.
		/// </summary>
		[MethodImpl(MethodImplOptions.NoInlining)]
		public static void SetOutputFormat(LogOutputs outputToConfigure, string newFormat)
		{
			newFormat = LogUtils.PrepareFormatString(newFormat);
			switch(outputToConfigure)
			{
				case LogOutputs.AspNetTrace: { Configuration.FORMAT_ASPNET = newFormat; break; }
				case LogOutputs.Console: { Configuration.FORMAT_CONSOLE = newFormat; break; }
				case LogOutputs.EventLog: { Configuration.FORMAT_EVENTLOG = newFormat; break; }
				case LogOutputs.LogFile: { Configuration.FORMAT_LOGFILE = newFormat; break; }
				case LogOutputs.TraceWrite: { Configuration.FORMAT_TRACE = newFormat; break; }
				case LogOutputs.All:
					{ 
						Configuration.FORMAT_ASPNET = newFormat;
						Configuration.FORMAT_CONSOLE = newFormat; 
						Configuration.FORMAT_EVENTLOG = newFormat; 
						Configuration.FORMAT_LOGFILE = newFormat; 
						Configuration.FORMAT_TRACE = newFormat;
						break;
					}
			}
			MessageQueue.Push(1, LogLevels.Verbose, null, String.Format("Log output for {0} changed to: '{1}'.", outputToConfigure, newFormat), null);
		}

		/// <summary>
		/// Gets or sets the current log file name, insert '{0}' in the file's name to allow log rolling
		/// </summary>
		public static string LogFile
		{
			get { return Configuration.CurrentLogFile; }
			[MethodImpl(MethodImplOptions.NoInlining)]
			set
			{
				string newname = value;
				try
				{
					if (!System.IO.Path.IsPathRooted(newname))
						newname = System.IO.Path.GetFullPath(newname);
					Configuration.CurrentLogFile = new System.IO.FileInfo(newname).FullName;
					MessageQueue.LogFileChanged();
				}
				catch (ArgumentException ae)
				{
					MessageQueue.Push(1, LogLevels.Error, ae, String.Format("Unable to set log path to: {0}", value), null);
				}
			}
		}

		/// <summary> Gets or sets the maximum size in bytes the log file is allowed to be before rolling to history </summary>
		public static int LogFileMaxSize { get { return Configuration.FILE_SIZE_THREASHOLD; } set { Configuration.FILE_SIZE_THREASHOLD = Math.Max(8192, value); } }
		/// <summary> Gets or sets the maximum number of history log files to keep on the system </summary>
		public static int LogFileMaxHistory { get { return Configuration.FILE_MAX_HISTORY_SIZE; } set { Configuration.FILE_MAX_HISTORY_SIZE = Math.Max(1, value); } }

		/// <summary> Sets the event log name we will write events to. </summary>
		public static string EventLogName { get { return Configuration.EventLogName; } set { Configuration.EventLogName = value; } }
		/// <summary> Sets the event log source we will write events with, It's up to you to register this value. </summary>
		public static string EventLogSource { get { return Configuration.EventLogSource; } set { Configuration.EventLogSource = value; } }
	}
	
	#endregion

	/// <summary> Returns true if 'Info' messages are being recorded. </summary>
	public static bool IsInfoEnabled { get { return (Configuration.LogLevel & LogLevels.Info) == LogLevels.Info; } }
	/// <summary> Returns true if 'Verbose' messages are being recorded. </summary>
	public static bool IsVerboseEnabled { get { return (Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose; } }

	// FYI, these are only for the benifit of the following methods...
	private static readonly Exception e = null;
	private static readonly string format = String.Empty;
	private static readonly object[] args = new object[0];

	/// <summary> 
	/// Enables calls to Log.xxx() to be processed on another thread to improve throughput... 
	/// Place this in a using() statement within Main:  using( new Log.AppStart("Some Name") )
	/// This call (and Disponse) IS Thread safe and can be called multiple times either 
	/// concurrently, sequentially, nested, or overlapping calls are all permitted and handled.
	/// </summary>
	public static IDisposable AppStart(string format, params object[] args) { return new MessageQueue.ThreadingControl(LogUtils.Format(format, args)); }

	/// <summary>
	/// Pushes a string into the trace stack so that log messages appear with the 'context'
	/// set to the information provided.  The operation named should be performed by the
	/// current thread and the IDisposable object returned should be disposed when the
	/// operation completes.
	/// </summary>
	/// <example>
	/// using( Log.Start("Reading File") )
	/// {
	///		... do something ...
	/// }
	/// </example>
	/// <param name="format"></param>
	/// <param name="args"></param>
	/// <returns>An IDisposable object that should be destroyed by calling the Dispose() 
	/// method when the activity is complete.</returns>
	public static IDisposable Start(string format, params object[] args) { return new TraceStack(LogUtils.Format(format, args)); }

	/// <summary>
	/// Forces any left-behind calls to Start() to be closed.
	/// </summary>
	public static void ClearStack() { TraceStack.Clear(); }

	/// <summary>
	/// Write directly to the log reguardless of the currently configured log-LogLevel
	/// </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Write(string format, params object[] args) { MessageQueue.Push(1, LogLevels.None, e, format, args); }

	/// <summary> Logs a Critical error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Critical(Exception e) { if ((Configuration.LogLevel & LogLevels.Critical) == LogLevels.Critical) MessageQueue.Push(1, LogLevels.Critical, e, format, args); }
	/// <summary> Logs a Critical error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Critical(Exception e, string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Critical) == LogLevels.Critical) MessageQueue.Push(1, LogLevels.Critical, e, format, args); }
	/// <summary> Logs a Critical error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Critical(string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Critical) == LogLevels.Critical) MessageQueue.Push(1, LogLevels.Critical, e, format, args); }

	/// <summary> Logs an Error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Error(Exception e) { if ((Configuration.LogLevel & LogLevels.Error) == LogLevels.Error) MessageQueue.Push(1, LogLevels.Error, e, format, args); }
	/// <summary> Logs an Error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Error(Exception e, string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Error) == LogLevels.Error)  MessageQueue.Push(1, LogLevels.Error, e, format, args); }
	/// <summary> Logs an Error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Error(string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Error) == LogLevels.Error) MessageQueue.Push(1, LogLevels.Error, e, format, args); }

	/// <summary> Logs a Warning </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Warning(Exception e) { if ((Configuration.LogLevel & LogLevels.Warning) == LogLevels.Warning) MessageQueue.Push(1, LogLevels.Warning, e, format, args); }
	/// <summary> Logs a Warning </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Warning(Exception e, string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Warning) == LogLevels.Warning) MessageQueue.Push(1, LogLevels.Warning, e, format, args); }
	/// <summary> Logs a Warning </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Warning(string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Warning) == LogLevels.Warning) MessageQueue.Push(1, LogLevels.Warning, e, format, args); }

	/// <summary> Logs a Info error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Info(Exception e) { if ((Configuration.LogLevel & LogLevels.Info) == LogLevels.Info) MessageQueue.Push(1, LogLevels.Info, e, format, args); }
	/// <summary> Logs a Info error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Info(Exception e, string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Info) == LogLevels.Info) MessageQueue.Push(1, LogLevels.Info, e, format, args); }
	/// <summary> Logs an Informational message </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Info(string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Info) == LogLevels.Info) MessageQueue.Push(1, LogLevels.Info, e, format, args); }

	/// <summary> Logs a Verbose error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Verbose(Exception e) { if ((Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose) MessageQueue.Push(1, LogLevels.Verbose, e, format, args); }
	/// <summary> Logs a Verbose error </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Verbose(Exception e, string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose) MessageQueue.Push(1, LogLevels.Verbose, e, format, args); }
	/// <summary> Logs a Verbose message </summary>
	[MethodImpl(MethodImplOptions.NoInlining)]
	public static void Verbose(string format, params object[] args) { if ((Configuration.LogLevel & LogLevels.Verbose) == LogLevels.Verbose) MessageQueue.Push(1, LogLevels.Verbose, e, format, args); }
}