Added PowerPoint templates to the Slide Assistant (#1055)

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

app/Tests/Tools/PowerPoint/PresentationFileTests.cs

@@ -0,0 +1,126 @@
+using AIStudio.Tools.PowerPoint;
+
+using DocumentFormat.OpenXml.Packaging;
+
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace AIStudio.Tests.Tools.PowerPoint;
+
+/// <summary>
+/// Checks that a presentation file comes about without anything next to the file the user chose.
+/// </summary>
+/// <remarks>
+/// Inside the Flatpak, the save dialog grants access to exactly the chosen file. A temporary file next
+/// to it, or a file moved there, fails, which no test on another system would notice otherwise. The
+/// test template reads as L1 "Title" and L2 "Content".
+/// </remarks>
+[TestFixture]
+public sealed class PresentationFileTests
+{
+    private static readonly SlideDeckSpec DECK = new("Mars",
+    [
+        new SlideSpec("L1", false, "Mars", "A plan", [], [], [], null),
+        new SlideSpec("L2", false, "Why Mars", string.Empty, [new SlideTextBlock([new SlideParagraph("Close to Earth", 0)])], [], [], null),
+    ]);
+
+    private static readonly PresentationWriteOptions OPTIONS = new(null, string.Empty, false);
+
+    private static readonly byte[] PREVIOUS_CONTENT = [1, 2, 3];
+
+    private string templateFolder = string.Empty;
+    private string targetFolder = string.Empty;
+
+    [SetUp]
+    public void CreateFolders()
+    {
+        var testFolder = Path.Join(Path.GetTempPath(), "mindwork-ai-studio-tests", Guid.NewGuid().ToString("N"));
+        this.templateFolder = Directory.CreateDirectory(Path.Join(testFolder, "templates")).FullName;
+        this.targetFolder = Directory.CreateDirectory(Path.Join(testFolder, "presentations")).FullName;
+    }
+
+    [TearDown]
+    public void RemoveFolders() => Directory.Delete(Path.GetDirectoryName(this.templateFolder)!, true);
+
+    [Test]
+    public async Task ThePresentationGoesIntoTheChosenFileOnly()
+    {
+        var templatePath = await this.CreateTemplateAsync();
+        var targetPath = Path.Join(this.targetFolder, "Mars.pptx");
+        await File.WriteAllBytesAsync(targetPath, PREVIOUS_CONTENT);
+        var temporaryFiles = TemporaryFiles();
+
+        var result = await PresentationFile.CreateAsync(templatePath, targetPath, DECK, BasisOf(templatePath), OPTIONS, new NoPictures(), NullLogger.Instance, CancellationToken.None);
+
+        using var document = PresentationDocument.Open(targetPath, false);
+        Assert.Multiple(() =>
+        {
+            Assert.That(result.IsWritten, Is.True);
+            Assert.That(Directory.GetFileSystemEntries(this.targetFolder), Is.EqualTo(new[] { targetPath }), "Nothing else came about next to the chosen file.");
+            Assert.That(document.PresentationPart!.SlideParts.Count(), Is.EqualTo(2), "The chosen file holds the presentation instead of what it held before.");
+            Assert.That(TemporaryFiles(), Is.EquivalentTo(temporaryFiles), "The copy of the template is gone.");
+        });
+    }
+
+    [Test]
+    public async Task AChangedTemplateLeavesTheChosenFileAlone()
+    {
+        var templatePath = await this.CreateTemplateAsync();
+        var targetPath = Path.Join(this.targetFolder, "Mars.pptx");
+        await File.WriteAllBytesAsync(targetPath, PREVIOUS_CONTENT);
+        var temporaryFiles = TemporaryFiles();
+
+        // Without a basis, nothing is known to fit, as after a change of the template:
+        var result = await PresentationFile.CreateAsync(templatePath, targetPath, DECK, new Dictionary<string, string>(), OPTIONS, new NoPictures(), NullLogger.Instance, CancellationToken.None);
+
+        var targetContent = await File.ReadAllBytesAsync(targetPath);
+        Assert.Multiple(() =>
+        {
+            Assert.That(result.IsWritten, Is.False);
+            Assert.That(targetContent, Is.EqualTo(PREVIOUS_CONTENT));
+            Assert.That(TemporaryFiles(), Is.EquivalentTo(temporaryFiles), "The copy of the template is gone.");
+        });
+    }
+
+    [Test]
+    public async Task TheTemplateItselfMayBeTheChosenFile()
+    {
+        var templatePath = await this.CreateTemplateAsync();
+        var basis = BasisOf(templatePath);
+
+        var result = await PresentationFile.CreateAsync(templatePath, templatePath, DECK, basis, OPTIONS, new NoPictures(), NullLogger.Instance, CancellationToken.None);
+
+        using var document = PresentationDocument.Open(templatePath, false);
+        Assert.Multiple(() =>
+        {
+            Assert.That(result.IsWritten, Is.True);
+            Assert.That(document.PresentationPart!.SlideParts.Count(), Is.EqualTo(2), "The template was copied before it was written over.");
+        });
+    }
+
+    private async Task<string> CreateTemplateAsync()
+    {
+        var templatePath = Path.Join(this.templateFolder, "template.pptx");
+        using var template = TestTemplate.Create(
+            new TestLayout("Title", TestPlaceholder.Title(), TestPlaceholder.Subtitle(new SlotBounds(1_524_000, 3_602_038, 9_144_000, 1_655_762))),
+            new TestLayout("Content", TestPlaceholder.Title(), TestPlaceholder.Text(1, TestTemplate.MASTER_BODY_BOUNDS)));
+
+        await File.WriteAllBytesAsync(templatePath, template.ToArray());
+        return templatePath;
+    }
+
+    private static IReadOnlyDictionary<string, string> BasisOf(string templatePath) => PresentationTemplate.ReadFile(templatePath).DescribeBasisOf(DECK);
+
+    /// <summary>
+    /// The files in the folder where the presentations come about; others may have left some there.
+    /// </summary>
+    private static string[] TemporaryFiles()
+    {
+        var folder = Path.Join(Path.GetTempPath(), "mindwork-ai-studio-presentations");
+        return Directory.Exists(folder) ? Directory.GetFiles(folder) : [];
+    }
+
+    private sealed class NoPictures : IPictureSource
+    {
+        public Task<SlidePicture?> LoadAsync(int number, CancellationToken token) => Task.FromResult<SlidePicture?>(null);
+    }
+}