Improved profile and system prompt handling (#241)

app/MindWork AI Studio/Chat/ChatThread.cs

@@ -1,3 +1,5 @@
+using AIStudio.Settings;
+
 namespace AIStudio.Chat;
 
 /// <summary>
@@ -20,6 +22,11 @@ public sealed record ChatThread
     /// </summary>
     public string SelectedProvider { get; set; } = string.Empty;
 
+    /// <summary>
+    /// Specifies the profile selected for the chat thread.
+    /// </summary>
+    public string SelectedProfile { get; set; } = string.Empty;
+
     /// <summary>
     /// The name of the chat thread. Usually generated by an AI model or manually edited by the user.
     /// </summary>
@@ -39,4 +46,55 @@ public sealed record ChatThread
     /// The content blocks of the chat thread.
     /// </summary>
     public List<ContentBlock> Blocks { get; init; } = [];
+
+    /// <summary>
+    /// Prepares the system prompt for the chat thread.
+    /// </summary>
+    /// <remarks>
+    /// The actual system prompt depends on the selected profile. If no profile is selected,
+    /// the system prompt is returned as is. When a profile is selected, the system prompt
+    /// is extended with the profile chosen.
+    /// </remarks>
+    /// <param name="settingsManager">The settings manager instance to use.</param>
+    /// <param name="chatThread">The chat thread to prepare the system prompt for.</param>
+    /// <param name="logger">The logger instance to use.</param>
+    /// <returns>The prepared system prompt.</returns>
+    public string PrepareSystemPrompt(SettingsManager settingsManager, ChatThread chatThread, ILogger logger)
+    {
+        //
+        // Prepare the system prompt:
+        //
+        string systemPromptText;
+        var logMessage = $"Using no profile for chat thread '{chatThread.Name}'.";
+        if (string.IsNullOrWhiteSpace(chatThread.SelectedProfile))
+            systemPromptText = chatThread.SystemPrompt;
+        else
+        {
+            if(!Guid.TryParse(chatThread.SelectedProfile, out var profileId))
+                systemPromptText = chatThread.SystemPrompt;
+            else
+            {
+                if(chatThread.SelectedProfile == Profile.NO_PROFILE.Id || profileId == Guid.Empty)
+                    systemPromptText = chatThread.SystemPrompt;
+                else
+                {
+                    var profile = settingsManager.ConfigurationData.Profiles.FirstOrDefault(x => x.Id == chatThread.SelectedProfile);
+                    if(profile == default)
+                        systemPromptText = chatThread.SystemPrompt;
+                    else
+                    {
+                        logMessage = $"Using profile '{profile.Name}' for chat thread '{chatThread.Name}'.";
+                        systemPromptText = $"""
+                                            {chatThread.SystemPrompt}
+
+                                            {profile.ToSystemPrompt()}
+                                            """;
+                    }
+                }
+            }
+        }
+        
+        logger.LogInformation(logMessage);
+        return systemPromptText;
+    }
 }