Added a way to read what the AI received from your sources (#1100)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/Tests/Tools/Databases/TemporaryProvenanceStore.cs

@@ -0,0 +1,62 @@
+using System.Reflection;
+
+using AIStudio.Tools.Databases;
+using AIStudio.Tools.Databases.ProvenanceStore;
+
+using Microsoft.Data.Sqlite;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace AIStudio.Tests.Tools.Databases;
+
+/// <summary>
+/// A provenance store in a directory of its own, migrated the way the app migrates its own, and
+/// deleted again afterward.
+/// </summary>
+/// <param name="directory">The directory the database lives in.</param>
+/// <param name="databasePath">The path of the database file.</param>
+internal sealed class TemporaryProvenanceStore(string directory, string databasePath) : IAsyncDisposable
+{
+    public SqliteProvenanceStoreClientImplementation Client { get; } = new("SQLite", databasePath, directory, string.Empty);
+
+    /// <summary>
+    /// The file of the database, to check what it holds on the disk.
+    /// </summary>
+    public string DatabasePath => databasePath;
+
+    public static async Task<TemporaryProvenanceStore> CreateAsync()
+    {
+        SQLitePCL.Batteries_V2.Init();
+
+        var directory = Path.Combine(Path.GetTempPath(), $"ai-studio-provenance-store-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(directory);
+
+        var store = new TemporaryProvenanceStore(directory, Path.Combine(directory, "provenance.sqlite3"));
+        await using var context = store.CreateContext();
+        await ProvenanceStoreSchemaMigrator.MigrateAsync(context, CancellationToken.None);
+        return store;
+    }
+
+    /// <summary>
+    /// Makes a provider of the database clients which hands out this store, and nothing else.
+    /// </summary>
+    public DatabaseClientProvider CreateClientProvider()
+    {
+        var databases = new DatabaseClientProvider(null!, NullLoggerFactory.Instance);
+        var clients = (Dictionary<DatabaseRole, DatabaseClient>)typeof(DatabaseClientProvider).GetField("clients", BindingFlags.Instance | BindingFlags.NonPublic)!.GetValue(databases)!;
+        clients.Add(DatabaseRole.PROVENANCE_STORE, this.Client);
+        return databases;
+    }
+
+    /// <summary>
+    /// Opens the database directly, to check what the client does not show.
+    /// </summary>
+    public ProvenanceStoreDbContext CreateContext() => new(ProvenanceStoreDbContext.CreateOptions(databasePath));
+
+    public ValueTask DisposeAsync()
+    {
+        // The pooled connections hold the file open, which would keep it from being deleted on Windows:
+        SqliteConnection.ClearAllPools();
+        Directory.Delete(directory, true);
+        return ValueTask.CompletedTask;
+    }
+}