Production hardening: kill switch, circuit breaker, trailing stops, log level, holiday calendar

src/NT8.Core/Logging/BasicLogger.cs

@@ -2,6 +2,18 @@ using System;
 
 namespace NT8.Core.Logging
 {
+    /// <summary>
+    /// Log severity levels.
+    /// </summary>
+    public enum LogLevel
+    {
+        Debug = 0,
+        Information = 1,
+        Warning = 2,
+        Error = 3,
+        Critical = 4
+    }
+
     /// <summary>
     /// Basic console logger implementation for .NET Framework 4.8
     /// </summary>
@@ -9,43 +21,53 @@ namespace NT8.Core.Logging
     {
         private readonly string _categoryName;
 
+        /// <summary>
+        /// Minimum log level to write. Messages below this level are suppressed.
+        /// Default is Information.
+        /// </summary>
+        public LogLevel MinimumLevel { get; set; }
+
         public BasicLogger(string categoryName = "")
         {
             _categoryName = categoryName;
+            MinimumLevel = LogLevel.Information;
         }
 
         public void LogDebug(string message, params object[] args)
         {
-            WriteLog("DEBUG", message, args);
+            WriteLog(LogLevel.Debug, "DEBUG", message, args);
         }
 
         public void LogInformation(string message, params object[] args)
         {
-            WriteLog("INFO", message, args);
+            WriteLog(LogLevel.Information, "INFO", message, args);
         }
 
         public void LogWarning(string message, params object[] args)
         {
-            WriteLog("WARN", message, args);
+            WriteLog(LogLevel.Warning, "WARN", message, args);
         }
 
         public void LogError(string message, params object[] args)
         {
-            WriteLog("ERROR", message, args);
+            WriteLog(LogLevel.Error, "ERROR", message, args);
         }
 
         public void LogCritical(string message, params object[] args)
         {
-            WriteLog("CRITICAL", message, args);
+            WriteLog(LogLevel.Critical, "CRITICAL", message, args);
         }
 
-        private void WriteLog(string level, string message, params object[] args)
+        private void WriteLog(LogLevel level, string levelLabel, string message, params object[] args)
         {
+            if (level < MinimumLevel)
+                return;
+
             var timestamp = DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss.fff");
             var formattedMessage = args.Length > 0 ? String.Format(message, args) : message;
             var category = !String.IsNullOrEmpty(_categoryName) ? String.Format("[{0}] ", _categoryName) : "";
-            
-            Console.WriteLine(String.Format("{0} [{1}] {2}{3}", timestamp, level, category, formattedMessage));
+
+            Console.WriteLine(String.Format("{0} [{1}] {2}{3}", timestamp, levelLabel, category, formattedMessage));
         }
     }
-}
+}