Common-VS2019/SacsStandardBase/Base/App/SaLogger.cs

using System;
using System.IO;
using Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.IO;
using Sarand.Net.Standard.Base.Utils;

namespace Sarand.Net.Standard.Base.App
{
	//=======================================================================
	public static class SaLogger
	{
		//-------------------------------------------------------------------
		// Data members.
		private static String logDirectoryPath   = String.Empty;
		private static String logFilenamePrefix  = String.Empty;

		//-------------------------------------------------------------------
		// Construction.

		//-------------------------------------------------------------------
		// Properties.
		public static SaMessageLevel ConsoleLevel { get; set; } = SaMessageLevel.Debug;
		public static SaMessageLevel LogFileLevel { get; set; } = SaMessageLevel.Info;
		public static String LogFolder
		{
			get { return logDirectoryPath; }
			set
			{
				logDirectoryPath = "";
				if (FileUtil.ValidateDirectory(value, true))
					logDirectoryPath = value;
			}
		}
		public static bool LoggingToFile
		{
			get { return !StringUtil.IsEmpty(logDirectoryPath); }
		}
		public static String LogFilenamePrefix
		{
			get { return StringUtil.EmptyOnNull(logFilenamePrefix); }
			set { logFilenamePrefix = value; }
		}
		public static bool IncludeHostInFileMessage { get; set; } = true;
		public static bool IncludeUserInFileMessage { get; set; } = true;

		//-------------------------------------------------------------------
		// Logging.
		// TODO - Enhanced logging:
		//   Include: System.Runtime.CompilerServices
		//   public static void Error (String message,
		//     [System.Runtime.CompilerServices.CallerFilePath] string file = "",
		//     [System.Runtime.CompilerServices.CallerMemberName] string member = "",
		//     [System.Runtime.CompilerServices.CallerLineNumber] int line = 0)
		//     {
		//        Debug.WriteLine("{0}_{1}({2}): {3}", Path.GetFileName(file), member, line, message);
		//     }
		public static bool Error (String message, bool logToFile = false)
		{
			Log(message, SaMessageLevel.Error, logToFile);
			return false;
		}
		public static bool Warn (String message, bool logToFile = false)
		{
			Log(message, SaMessageLevel.Warning, logToFile);
			return false;
		}
		public static void Info (String message, bool logToFile = false)
		{
			Log(message, SaMessageLevel.Info, logToFile);
		}
		public static void Debug (String message, bool logToFile = false)
		{
			Log(message, SaMessageLevel.Debug, logToFile);
		}
		public static void Trace (String message, bool logToFile = false)
		{
			Log(message, SaMessageLevel.Trace, logToFile);
		}

		//-------------------------------------------------------------------
		/// <summary>
		/// Log message.
		/// <para></para>
		/// <para>Error and warning messages are forced to file unless logToFile is explicitly false</para>
		/// </summary>
		public static void Log (String message, SaMessageLevel level = SaMessageLevel.Info, bool? logToFile = null)
		{
			if (level == SaMessageLevel.None) return;
			message = message.Trim();
			WriteToConsole(FormatMessage(message, level), level);
			if (LogToFile(level, logToFile))
				WriteToLogFile(FormatMessage(message, level, true), level);
		}
		private static bool LogToFile (SaMessageLevel level, bool? logToFile)
		{
			switch (level)
			{
				case SaMessageLevel.Fatal:
				case SaMessageLevel.Exception:
				case SaMessageLevel.Error:
				case SaMessageLevel.Warning:
					return true;
			}
			return (logToFile != null && logToFile == true);
		}
		private static String FormatMessage (String message, SaMessageLevel level, bool forFile = false)
		{
			DateTime now = DateTime.Now;
			if (forFile)
				return
					now.ToString("yyyyMMdd:HHmmss ") + GetLevelAbbrFile(level) + " " +
					(IncludeHostInFileMessage ? SacsSystem.ComputerName.PadRight(12) + " " : "") +
					(IncludeUserInFileMessage ? SacsSystem.UserName.PadRight(16) + " " : "") +
					message;
			return now.ToString("yyyyMMdd:HHmmss ") + GetLevelAbbrFile(level) + " " + message;
		}

		//-------------------------------------------------------------------
		/// <summary>Message level abbreviation.</summary>
		public static String GetLevelAbbr (SaMessageLevel level)
		{
			String abbr = SacsSystem.GetMessageLevelCode(level);
			return (!StringUtil.IsEmpty(abbr) ? abbr : "UNK");
		}
		private static String GetLevelAbbrFile (SaMessageLevel level)
		{
			return GetLevelAbbr(level).PadRight(3, ' ').Substring(0, 3).ToUpper();
		}
		private static String GetLevelAbbrConsole (SaMessageLevel level)
		{
			// Visual Studio Output window colour coded snippets.
			if (level == SaMessageLevel.Fatal) return "Error [Fatal]";
			if (level == SaMessageLevel.Exception) return "Error [Exception]";
			if (level == SaMessageLevel.Error) return "Error";
			if (level == SaMessageLevel.Warning) return "Warning";
			return GetLevelAbbr(level).PadRight(3, ' ').Substring(0, 3).ToUpper();
		}

		//-------------------------------------------------------------------
		public static void WriteBlankLine (bool logToFile = false)
		{
			WriteToConsole("", SaMessageLevel.Error);
			if (logToFile)
				WriteToLogFile("", SaMessageLevel.Error);
		}
		public static void WriteBlankLines(int lineCount, bool logToFile = false)
		{
			for (int i = 0; i < Math.Min(10, lineCount); i++)
			{
				WriteToConsole("", SaMessageLevel.Error);
				if (logToFile)
					WriteToLogFile("", SaMessageLevel.Error);
			}
		}

		//-------------------------------------------------------------------
		private static void WriteToConsole (String message, SaMessageLevel level = SaMessageLevel.Info)
		{
#if DEBUG
			// NB There should be a way to colour error/warning messages.
			// Ref. https://stackoverflow.com/questions/2426609/how-do-i-write-color-text-to-the-visual-studio-output-window-from-c
			// Console output.
			if (level.CompareTo(ConsoleLevel) <= 0)
			{
				// Use Debug.Write rather than Console.Write.
				System.Diagnostics.Debug.WriteLine(message);
				//System.Console.WriteLine(message));
			}
#endif
		}
		// Ref. https://stackoverflow.com/questions/6195084/thread-safe-logging-class-implementation
		private static readonly object _syncObject = new object();
		private static void WriteToLogFile (String message, SaMessageLevel level = SaMessageLevel.Info)
		{
			// File output - skip if not logging to file or message level is higher than that for logging to file.
			if (!LoggingToFile || level.CompareTo(LogFileLevel) > 0) return;
			// Only one thread can own the lock, so other threads entering
			// this method will wait here until lock is available.
			lock (_syncObject)
			{
				String logFolder = GetLogFolder();
				if (FileUtil.ValidateDirectory(logFolder, true))
				{
					String logPath = logFolder + Path.DirectorySeparatorChar + GetLogFilename();
					if (!StringUtil.IsEmpty(message) || File.Exists(logPath))
					{
						using (StreamWriter file = File.AppendText(logPath))
							file.WriteLine(message);
					}
				}
			}
		}

		//-------------------------------------------------------------------
		private static String GetLogFolder ()
		{
			return logDirectoryPath + Path.DirectorySeparatorChar + DateTime.Today.Format("yyyy") + Path.DirectorySeparatorChar + DateTime.Today.Format("yyyyMM");
		}
		private static String GetLogFilename ()
		{
			return FileUtil.FormatFilename(LogFilenamePrefix + (!StringUtil.IsEmpty(LogFilenamePrefix) ? "-" : "") + DateTime.Today.Format("yyyyMMdd") + ".log");
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}