Added the informal address to the BeyondFacts Lab (#1176)

app/MindWork AI Studio/Tools/PluginSystem/ILangExtensions.cs

@@ -1,3 +1,5 @@
+using AIStudio.Settings.DataModel;
+
 using SharedTools;
 
 namespace AIStudio.Tools.PluginSystem;
@@ -5,30 +7,47 @@ namespace AIStudio.Tools.PluginSystem;
 public static class ILangExtensions
 {
     private static readonly ILogger<ILang> LOGGER = Program.LOGGER_FACTORY.CreateLogger<ILang>();
-    
+
     extension(ILang lang)
     {
-        public string GetText(ILanguagePlugin plugin, string fallbackEN, string? typeNamespace = null, string? typeName = null)
+        /// <summary>
+        /// Gets a text from a language plugin.
+        /// </summary>
+        /// <remarks>
+        /// A text of TA() asks for the form of address the person chose. Its informal variant counts only when the
+        /// language in use has it: the base language would answer with English, while the formal variant of the
+        /// language in use is the better fallback. Missing both, the text stays English.
+        /// </remarks>
+        /// <param name="plugin">The language plugin in use.</param>
+        /// <param name="fallbackEN">The text in English (US), which also makes its key.</param>
+        /// <param name="typeNamespace">The namespace of the type requesting the text, or null for the type of the receiver.</param>
+        /// <param name="typeName">The name of the type requesting the text, or null for the type of the receiver.</param>
+        /// <param name="addressForm">How the text addresses the reader; only texts of TA() have an informal variant.</param>
+        /// <returns>The text in the language of the plugin, or the English text.</returns>
+        public string GetText(ILanguagePlugin plugin, string fallbackEN, string? typeNamespace = null, string? typeName = null, AddressForm addressForm = AddressForm.FORMAL)
         {
             var type = lang.GetType();
             typeName ??= type.Name;
             typeNamespace ??= type.Namespace!;
-        
+
             // When the type's name ends with `1 or `2, etc. (i.e., generic classes), remove it:
             if(typeName.Contains('`'))
                 typeName = typeName[..typeName.IndexOf('`')];
-        
+
             var ns = $"{typeNamespace}::{typeName}".ToUpperInvariant().Replace(".", "::");
             var key = $"root::{ns}::T{I18NKeyHash.Of(fallbackEN)}";
-        
+
             if(plugin is NoPluginLanguage)
                 return fallbackEN;
-        
+
+            if(addressForm is AddressForm.INFORMAL && plugin.Content.TryGetValue(I18NAddressVariant.InformalKeyOf(key), out var informalText) && !string.IsNullOrWhiteSpace(informalText))
+                return informalText;
+
             if(plugin.TryGetText(key, out var text, logWarning: false))
             {
                 if(string.IsNullOrWhiteSpace(text))
                     return fallbackEN;
-            
+
                 return text;
             }