Moved the chats of the BeyondFacts Lab to the embedded chat of assistants (#1203)

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

@@ -0,0 +1,38 @@
+using AIStudio.Chat;
+using AIStudio.Chat.Embedded;
+
+namespace AIStudio.Assistants.BeyondFactsLab;
+
+/// <summary>
+/// Lets the embedded chat of a place of the BeyondFacts Lab live where the lab keeps it, e.g., in the folder of a step
+/// of a preparation.
+/// </summary>
+/// <remarks>
+/// The ID of a chat of the lab follows from its place, see BflThreadId, so the store serves the one chat of its place
+/// and refuses any other. Files, paths, and locks stay those of BeyondFactsLabStore, so chats stored before keep
+/// working, and the cleanup of the provenance store still finds every chat, see
+/// BeyondFactsLabStore.ReadAllThreadLocations.
+/// </remarks>
+/// <param name="store">The store of the lab.</param>
+/// <param name="location">The place of the chat.</param>
+public sealed class BflChatStore(BeyondFactsLabStore store, BflThreadLocation location) : IEmbeddedChatStore
+{
+    /// <inheritdoc />
+    public Task<ChatThread?> LoadThreadAsync(Guid chatId, CancellationToken token = default) => store.LoadThreadAsync(this.LocationOf(chatId), token);
+
+    /// <inheritdoc />
+    public Task SaveThreadAsync(ChatThread thread, CancellationToken token = default) => store.SaveThreadAsync(this.LocationOf(thread.ChatId), thread, token);
+
+    /// <inheritdoc />
+    public Task DeleteThreadAsync(Guid chatId, CancellationToken token = default) => store.DeleteThreadAsync(this.LocationOf(chatId), token);
+
+    /// <summary>
+    /// Gets the place of a chat, which must be the place of this store.
+    /// </summary>
+    /// <param name="chatId">The ID of the chat.</param>
+    /// <returns>The place of the store.</returns>
+    /// <exception cref="ArgumentException">The chat belongs to another place.</exception>
+    private BflThreadLocation LocationOf(Guid chatId) => chatId == location.ChatId
+        ? location
+        : throw new ArgumentException("The chat belongs to another place of the lab.", nameof(chatId));
+}