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AspClassic.Scripting/Runtime/LanguageConfiguration.cs

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+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Threading;
+using AspClassic.Scripting.Utils;
+
+namespace AspClassic.Scripting.Runtime;
+
+internal sealed class LanguageConfiguration
+{
+	private readonly AssemblyQualifiedTypeName _providerName;
+
+	private readonly string _displayName;
+
+	private readonly IDictionary<string, object> _options;
+
+	private LanguageContext _context;
+
+	public LanguageContext LanguageContext => _context;
+
+	public AssemblyQualifiedTypeName ProviderName => _providerName;
+
+	public string DisplayName => _displayName;
+
+	public LanguageConfiguration(AssemblyQualifiedTypeName providerName, string displayName, IDictionary<string, object> options)
+	{
+		_providerName = providerName;
+		_displayName = displayName;
+		_options = options;
+	}
+
+	internal LanguageContext LoadLanguageContext(ScriptDomainManager domainManager, out bool alreadyLoaded)
+	{
+		if (_context == null)
+		{
+			Assembly assembly = domainManager.Platform.LoadAssembly(_providerName.AssemblyName.FullName);
+			Type type = assembly.GetType(_providerName.TypeName);
+			if (type == null)
+			{
+				throw new InvalidOperationException($"Failed to load language '{_displayName}': assembly '{assembly.Location}' does not contain type '{_providerName.TypeName}'");
+			}
+			if (!type.IsSubclassOf(typeof(LanguageContext)))
+			{
+				throw new InvalidOperationException($"Failed to load language '{_displayName}': type '{type}' is not a valid language provider because it does not inherit from LanguageContext");
+			}
+			LanguageContext value;
+			try
+			{
+				value = (LanguageContext)Activator.CreateInstance(type, domainManager, _options);
+			}
+			catch (TargetInvocationException ex)
+			{
+				throw new TargetInvocationException($"Failed to load language '{_displayName}': {ex.InnerException.Message}", ex.InnerException);
+			}
+			catch (Exception ex2)
+			{
+				throw new InvalidImplementationException(Strings.InvalidCtorImplementation(type, ex2.Message), ex2);
+			}
+			alreadyLoaded = Interlocked.CompareExchange(ref _context, value, null) != null;
+		}
+		else
+		{
+			alreadyLoaded = true;
+		}
+		return _context;
+	}
+}