Added the guided chat to the BeyondFacts Lab (#1177)

app/MindWork AI Studio/Assistants/BeyondFactsLab/BflPromptTemplate.cs

@@ -0,0 +1,60 @@
+using System.Text.RegularExpressions;
+
+namespace AIStudio.Assistants.BeyondFactsLab;
+
+/// <summary>
+/// Fills the placeholders of a prompt of the BeyondFacts Lab, written as {{NAME}} in upper case.
+/// </summary>
+/// <remarks>
+/// A prompt with a placeholder nobody fills is an error, not a prompt with a gap: the model would read the
+/// placeholder as text. The values are inserted in one pass, so a value which contains a placeholder itself, such
+/// as a detail the person entered, stays as it is.
+/// </remarks>
+public static partial class BflPromptTemplate
+{
+    /// <summary>
+    /// The language the model answers in.
+    /// </summary>
+    public const string RESPONSE_LANGUAGE = "RESPONSE_LANGUAGE";
+
+    /// <summary>
+    /// How the model addresses the person.
+    /// </summary>
+    public const string ADDRESS_FORM = "ADDRESS_FORM";
+
+    /// <summary>
+    /// The guide of the lab.
+    /// </summary>
+    public const string KNOWLEDGE = "KNOWLEDGE";
+
+    /// <summary>
+    /// The prompt of the step the chat belongs to.
+    /// </summary>
+    public const string STEP = "STEP";
+
+    /// <summary>
+    /// What the person entered into the forms.
+    /// </summary>
+    public const string DETAILS = "DETAILS";
+
+    /// <summary>
+    /// The key details the forms still lack.
+    /// </summary>
+    public const string MISSING_DETAILS = "MISSING_DETAILS";
+
+    /// <summary>
+    /// Fills every placeholder of a template.
+    /// </summary>
+    /// <param name="template">The template.</param>
+    /// <param name="values">The value of each placeholder, by its name.</param>
+    /// <returns>The prompt.</returns>
+    /// <exception cref="FormatException">The template has a placeholder without a value.</exception>
+    public static string Fill(string template, IReadOnlyDictionary<string, string> values) => PlaceholderPattern().Replace(template, match =>
+    {
+        var name = match.Groups["name"].Value;
+        return values.TryGetValue(name, out var value) ? value : throw new FormatException($"The prompt has the placeholder '{name}', which has no value.");
+    });
+
+    [GeneratedRegex(@"\{\{\s*(?<name>[^{}]*?)\s*\}\}")]
+    private static partial Regex PlaceholderPattern();
+}