Route legacy logging through file logger provider

Connects existing exception logging to the new file logger and adds an ILoggerProvider bridge for Microsoft logging.

Services/Logger.cs

@@ -1,53 +1,52 @@
-using System;
 using System.IO;
-using System.Text;
+using UtopiaCanteenSystem.Services.Logging;
 
 namespace UtopiaCanteenSystem.Services;
 
 public static class Logger
 {
-    private static readonly object _lock = new();
-
     public static void Log(Exception ex, string context = "")
     {
         try
         {
-            if (ex == null) return;
+            if (ex == null)
+                return;
 
-            var localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+            if (FileLogger.IsConfigured)
-            var appRoot = Path.Combine(localAppData, "UtopiaCanteenSystem");
-            var logsDir = Path.Combine(appRoot, "Logs");
-            var logFile = Path.Combine(logsDir, "error.log");
-
-            try
-            {
-                if (!Directory.Exists(logsDir))
-                    Directory.CreateDirectory(logsDir);
-            }
-            catch
             {
+                FileLogger.Error(context, ex.Message, ex);
                 return;
             }
 
-            var sb = new StringBuilder();
+            WriteLegacyErrorLog(ex, context);
-            sb.AppendLine($"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}]");
-            if (!string.IsNullOrWhiteSpace(context))
-                sb.AppendLine($"Context: {context}");
-            sb.AppendLine($"Message: {ex.Message}");
-            sb.AppendLine($"StackTrace: {ex.StackTrace}");
-            if (ex.InnerException != null)
-                sb.AppendLine($"InnerException: {ex.InnerException.Message}");
-            sb.AppendLine("----------------------------------------------------");
-
-            lock (_lock)
-            {
-                File.AppendAllText(logFile, sb.ToString());
-            }
         }
         catch
         {
             // never throw from logger
         }
     }
+
+    private static void WriteLegacyErrorLog(Exception ex, string context)
+    {
+        var localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        var logsDir = Path.Combine(localAppData, "UtopiaCanteenSystem", "Logs");
+        var logFile = Path.Combine(logsDir, "error.log");
+
+        if (!Directory.Exists(logsDir))
+            Directory.CreateDirectory(logsDir);
+
+        var lines = new List<string>
+        {
+            $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}]",
+            string.IsNullOrWhiteSpace(context) ? string.Empty : $"Context: {context}",
+            $"Message: {ex.Message}",
+            $"StackTrace: {ex.StackTrace}"
+        };
+        if (ex.InnerException != null)
+            lines.Add($"InnerException: {ex.InnerException.Message}");
+        lines.Add("----------------------------------------------------");
+
+        File.AppendAllText(logFile, string.Join(Environment.NewLine, lines.Where(l => !string.IsNullOrEmpty(l))) + Environment.NewLine);
+    }
 }
 

Services/Logging/FileLoggerProvider.cs

@@ -0,0 +1,60 @@
+using Microsoft.Extensions.Logging;
+
+namespace UtopiaCanteenSystem.Services.Logging;
+
+public sealed class FileLoggerProvider : ILoggerProvider
+{
+    public ILogger CreateLogger(string categoryName) => new FileLoggerAdapter(categoryName);
+
+    public void Dispose()
+    {
+    }
+
+    private sealed class FileLoggerAdapter : ILogger
+    {
+        private readonly string _category;
+
+        public FileLoggerAdapter(string category) => _category = category;
+
+        public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+
+        public bool IsEnabled(LogLevel logLevel) => logLevel >= LogLevel.Information;
+
+        public void Log<TState>(
+            LogLevel logLevel,
+            EventId eventId,
+            TState state,
+            Exception? exception,
+            Func<TState, Exception?, string> formatter)
+        {
+            if (!IsEnabled(logLevel))
+                return;
+
+            var message = formatter(state, exception);
+            var component = ShortCategory(_category);
+            switch (logLevel)
+            {
+                case LogLevel.Critical:
+                case LogLevel.Error:
+                    FileLogger.Error(component, message, exception);
+                    break;
+                case LogLevel.Warning:
+                    FileLogger.Warn(component, message, exception);
+                    break;
+                case LogLevel.Debug:
+                case LogLevel.Trace:
+                    FileLogger.Debug(component, message);
+                    break;
+                default:
+                    FileLogger.Info(component, message);
+                    break;
+            }
+        }
+
+        private static string ShortCategory(string category)
+        {
+            var idx = category.LastIndexOf('.');
+            return idx >= 0 ? category[(idx + 1)..] : category;
+        }
+    }
+}