Allow assistants to run in the background (#828)

app/MindWork AI Studio/Tools/AssistantSessions/AssistantSessionStateWriter.cs

@@ -0,0 +1,78 @@
+using System.Text;
+
+namespace AIStudio.Tools.AssistantSessions;
+
+/// <summary>
+/// Collects typed assistant session state values for a snapshot.
+/// </summary>
+public sealed class AssistantSessionStateWriter
+{
+    /// <summary>
+    /// Stores captured fields by their stable dictionary names.
+    /// </summary>
+    private readonly Dictionary<string, IAssistantSessionSnapshotField> fields = new(StringComparer.Ordinal);
+
+    /// <summary>
+    /// Stores a typed state value.
+    /// </summary>
+    /// <typeparam name="T">The value type.</typeparam>
+    /// <param name="key">The typed state key.</param>
+    /// <param name="value">The captured value.</param>
+    public void Set<T>(AssistantSessionStateKey<T> key, T value)
+    {
+        this.fields[key.Name] = new AssistantSessionSnapshotField<T>(value);
+    }
+
+    /// <summary>
+    /// Stores a list copy.
+    /// </summary>
+    /// <typeparam name="T">The list item type.</typeparam>
+    /// <param name="key">The typed state key.</param>
+    /// <param name="values">The values to copy.</param>
+    public void SetList<T>(AssistantSessionStateKey<List<T>> key, IEnumerable<T> values)
+    {
+        this.Set(key, values.ToList());
+    }
+
+    /// <summary>
+    /// Stores a hash set copy.
+    /// </summary>
+    /// <typeparam name="T">The set item type.</typeparam>
+    /// <param name="key">The typed state key.</param>
+    /// <param name="values">The values to copy.</param>
+    public void SetHashSet<T>(AssistantSessionStateKey<HashSet<T>> key, IEnumerable<T> values)
+    {
+        this.Set(key, values.ToHashSet());
+    }
+
+    /// <summary>
+    /// Stores a dictionary copy.
+    /// </summary>
+    /// <typeparam name="TKey">The dictionary key type.</typeparam>
+    /// <typeparam name="TValue">The dictionary value type.</typeparam>
+    /// <param name="key">The typed state key.</param>
+    /// <param name="values">The values to copy.</param>
+    public void SetDictionary<TKey, TValue>(AssistantSessionStateKey<Dictionary<TKey, TValue>> key, IDictionary<TKey, TValue> values) where TKey : notnull
+    {
+        this.Set(key, new Dictionary<TKey, TValue>(values));
+    }
+
+    /// <summary>
+    /// Stores the current text from a string builder.
+    /// </summary>
+    /// <param name="key">The typed state key.</param>
+    /// <param name="value">The string builder to read.</param>
+    public void SetStringBuilder(AssistantSessionStateKey<string> key, StringBuilder value)
+    {
+        this.Set(key, value.ToString());
+    }
+
+    /// <summary>
+    /// Returns the captured fields as a dictionary.
+    /// </summary>
+    /// <returns>A copied dictionary containing the captured fields.</returns>
+    public Dictionary<string, IAssistantSessionSnapshotField> ToDictionary()
+    {
+        return new(this.fields, StringComparer.Ordinal);
+    }
+}