First piece of minimal logging configuration

Author: JustinGrote

src/PowerShellEditorServices/Logging/LanguageServerLogger.cs

@@ -0,0 +1,44 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Microsoft.PowerShell.EditorServices.Logging;
+internal class DynamicLogLevelOptions(
+    LogLevel initialLevel,
+    IOptionsMonitor<LoggerFilterOptions> optionsMonitor) : IConfigureOptions<LoggerFilterOptions>
+{
+    private LogLevel _currentLevel = initialLevel;
+    private readonly IOptionsMonitor<LoggerFilterOptions> _optionsMonitor = optionsMonitor;
+
+    public void Configure(LoggerFilterOptions options) => options.MinLevel = _currentLevel;
+
+    public void SetLogLevel(LogLevel level)
+    {
+        _currentLevel = level;
+        // Trigger reload of options to apply new log level
+        _optionsMonitor.CurrentValue.MinLevel = level;
+    }
+}
+
+public static class LoggingBuilderExtensions
+{
+    public static ILoggingBuilder AddLspClientConfigurableMinimumLevel(
+        this ILoggingBuilder builder,
+        LogLevel initialLevel = LogLevel.Trace
+    )
+    {
+        builder.Services.AddOptions<LoggerFilterOptions>();
+        builder.Services.AddSingleton<DynamicLogLevelOptions>(sp =>
+        {
+            IOptionsMonitor<LoggerFilterOptions> optionsMonitor = sp.GetRequiredService<IOptionsMonitor<LoggerFilterOptions>>();
+            return new(initialLevel, optionsMonitor);
+        });
+        builder.Services.AddSingleton<IConfigureOptions<LoggerFilterOptions>>(sp =>
+            sp.GetRequiredService<DynamicLogLevelOptions>());
+        return builder;
+    }
+}
+