Added backups of all data, restorable on another computer (#1008)

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

app/Tests/Tools/DataBackup/DataRestoreFollowUpTests.cs

@@ -0,0 +1,155 @@
+using System.Text.Json;
+
+using AIStudio.Tools.DataBackup;
+
+using SettingsVersion = AIStudio.Settings.Version;
+
+namespace AIStudio.Tests.Tools.DataBackup;
+
+/// <summary>
+/// Checks what the first start after a restore, a crashed backup, or a crashed preparation removes,
+/// and what it must keep.
+/// </summary>
+/// <remarks>
+/// While the runtime has not finished a restore, its journal and the data it replaced are the only way
+/// back. Removing them would lose the data of the user for good.
+/// </remarks>
+[TestFixture]
+public sealed class DataRestoreFollowUpTests
+{
+    private string testDirectory = string.Empty;
+
+    private string DataDirectory => Path.Combine(this.testDirectory, "data");
+
+    private string ConfigDirectory => Path.Combine(this.testDirectory, "config");
+
+    [SetUp]
+    public void CreateFolders() => this.testDirectory = Path.Combine(Path.GetTempPath(), $"ai-studio-restore-follow-up-{Guid.NewGuid():N}");
+
+    [TearDown]
+    public void RemoveFolders()
+    {
+        if (Directory.Exists(this.testDirectory))
+            Directory.Delete(this.testDirectory, true);
+    }
+
+    [Test]
+    public void WhatABackupOrAPreparationLeftHalfwayIsRemoved()
+    {
+        WriteFile(Path.Combine(this.DataDirectory, ".backup-staging", "0123456789abcdef", "store"), "copy");
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-pending", "workspaces", "chat", "thread.json"), "{}");
+        WriteFile(Path.Combine(this.ConfigDirectory, ".restore-pending", "settings.json"), "{}");
+
+        DataRestoreFollowUp.RemoveLeftovers(this.DataDirectory, this.ConfigDirectory);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(Directory.Exists(Path.Combine(this.DataDirectory, ".backup-staging")), Is.False);
+            Assert.That(Directory.Exists(Path.Combine(this.DataDirectory, ".restore-pending")), Is.False);
+            Assert.That(Directory.Exists(Path.Combine(this.ConfigDirectory, ".restore-pending")), Is.False);
+        });
+    }
+
+    [Test]
+    public void ARestoreWhichWaitsForTheRestartIsKept()
+    {
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-pending", "workspaces", "chat", "thread.json"), "{}");
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-pending", DataRestoreFormat.READY_FILE_NAME), "now");
+
+        DataRestoreFollowUp.RemoveLeftovers(this.DataDirectory, this.ConfigDirectory);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(DataRestoreFollowUp.IsRestorePending(this.DataDirectory), Is.True);
+            Assert.That(DataRestoreFollowUp.IsRestoreUnfinished(this.DataDirectory), Is.False);
+            Assert.That(File.Exists(Path.Combine(this.DataDirectory, ".restore-pending", "workspaces", "chat", "thread.json")), Is.True);
+        });
+    }
+
+    [Test]
+    public void ARestoreWhichTheRuntimeHasNotFinishedKeepsEverything()
+    {
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-pending", DataRestoreFormat.READY_FILE_NAME), "now");
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-pending", DataRestoreFormat.JOURNAL_FILE_NAME), """{ "moves": [], "started": 0 }""");
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-previous", "workspaces", "chat", "thread.json"), "{}");
+        var target = new DataRestoreTarget(this.DataDirectory, this.ConfigDirectory, "26.10.1", SettingsVersion.V6, []);
+
+        DataRestoreFollowUp.RemoveLeftovers(this.DataDirectory, this.ConfigDirectory);
+        var removedReplacedData = DataRestoreFollowUp.RemoveReplacedData(this.DataDirectory, this.ConfigDirectory);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(DataRestoreFollowUp.IsRestoreUnfinished(this.DataDirectory), Is.True);
+            Assert.That(DataRestoreFollowUp.IsRestorePending(this.DataDirectory), Is.False, "The runtime moves it back rather than applying it.");
+            Assert.That(removedReplacedData, Is.False);
+            Assert.That(File.Exists(Path.Combine(this.DataDirectory, ".restore-previous", "workspaces", "chat", "thread.json")), Is.True, "These are the data of the user.");
+            Assert.That(() => DataRestorePreparer.Discard(target), Throws.InvalidOperationException);
+            Assert.That(File.Exists(Path.Combine(this.DataDirectory, ".restore-pending", DataRestoreFormat.JOURNAL_FILE_NAME)), Is.True);
+        });
+    }
+
+    [Test]
+    public void TheReplacedDataAreRemovedOnceNoRestoreWaits()
+    {
+        WriteFile(Path.Combine(this.DataDirectory, ".restore-previous", "workspaces", "chat", "thread.json"), "{}");
+        WriteFile(Path.Combine(this.ConfigDirectory, ".restore-previous", "settings.json"), "{}");
+
+        var removedReplacedData = DataRestoreFollowUp.RemoveReplacedData(this.DataDirectory, this.ConfigDirectory);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(removedReplacedData, Is.True);
+            Assert.That(Directory.Exists(Path.Combine(this.DataDirectory, ".restore-previous")), Is.False);
+            Assert.That(Directory.Exists(Path.Combine(this.ConfigDirectory, ".restore-previous")), Is.False);
+        });
+    }
+
+    [Test]
+    public async Task TheReportOfTheRuntimeIsRead()
+    {
+        WriteFile(Path.Combine(this.DataDirectory, DataRestoreFormat.RESULT_FILE_NAME), """
+            {
+              "outcome": "ROLLED_BACK",
+              "detail": "Could not move '.restore-pending/plugins' to 'plugins': access denied",
+              "prepared_at_utc": "2026-10-15T08:00:00.0000000+00:00",
+              "backup_created_at_utc": "2026-10-01T17:30:00.0000000+00:00",
+              "backup_app_version": "26.10.1",
+              "finished_at_utc": "2026-10-15T08:01:00.123456+00:00"
+            }
+            """);
+
+        var report = await DataRestoreFollowUp.ReadReportAsync(this.DataDirectory, CancellationToken.None);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(report, Is.Not.Null);
+            Assert.That(report!.Outcome, Is.EqualTo(DataRestoreOutcome.ROLLED_BACK));
+            Assert.That(report.BackupAppVersion, Is.EqualTo("26.10.1"));
+            Assert.That(report.Detail, Does.Contain("access denied"));
+        });
+    }
+
+    [Test]
+    public async Task WithoutARestoreThereIsNoReport()
+    {
+        Directory.CreateDirectory(this.DataDirectory);
+
+        var report = await DataRestoreFollowUp.ReadReportAsync(this.DataDirectory, CancellationToken.None);
+
+        Assert.That(report, Is.Null);
+    }
+
+    [Test]
+    public void AReportWithAnUnknownOutcomeCannotBeRead()
+    {
+        WriteFile(Path.Combine(this.DataDirectory, DataRestoreFormat.RESULT_FILE_NAME), """{ "outcome": "SOMETHING_NEW", "detail": "", "prepared_at_utc": "", "backup_created_at_utc": "", "backup_app_version": "", "finished_at_utc": "" }""");
+
+        Assert.That(async () => await DataRestoreFollowUp.ReadReportAsync(this.DataDirectory, CancellationToken.None), Throws.InstanceOf<JsonException>());
+    }
+
+    private static void WriteFile(string path, string content)
+    {
+        Directory.CreateDirectory(Path.GetDirectoryName(path)!);
+        File.WriteAllText(path, content);
+    }
+}