// Hook: AfterPowerPoint
// Stamp every slide with a small footer text frame showing report name and
// generation date.
//
// Presentations always carry provenance information even when downloaded or
// forwarded.
//
// Aspose.Slides positions and sizes are in POINTS (72 per inch), as floats -
// not EMU. Deriving the footer position from SlideSize keeps this correct on
// 4:3 and 16:9 alike. There is no IShapeCollection.AddTextFrame; add an
// auto-shape and give it a text frame.

using System.Drawing;

var stampText = $"{OutputName} - Generated {DateTime.Now:yyyy-MM-dd HH:mm}";

var slideWidth  = Presentation.SlideSize.Size.Width;
var slideHeight = Presentation.SlideSize.Size.Height;

const float Margin       = 20f;   // ~0.28 inch
const float FooterHeight = 18f;

foreach (var slide in Presentation.Slides)
{
    var shape = slide.Shapes.AddAutoShape(
        ShapeType.Rectangle,
        Margin,
        slideHeight - FooterHeight - Margin,
        slideWidth - (Margin * 2),
        FooterHeight);

    shape.FillFormat.FillType = FillType.NoFill;
    shape.LineFormat.FillFormat.FillType = FillType.NoFill;
    shape.AddTextFrame(stampText);

    var portion = shape.TextFrame.Paragraphs[0].Portions[0];
    portion.PortionFormat.FontHeight = 8;
    portion.PortionFormat.FillFormat.FillType = FillType.Solid;
    portion.PortionFormat.FillFormat.SolidFillColor.Color = Color.Gray;
}

Logger.LogInformation($"Stamped footer on {Presentation.Slides.Count} slide(s).");