using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

namespace SGU.CredentialProvider;

internal static class ProviderTileIcon
{
    // LogonUI enlarges the dedicated-tile artwork. Supply a dense source image
    // so the mascot remains crisp at the large sign-in surface.
    public const int Size = 256;
    private const string MascotResourceName = "SGU.CredentialProvider.Branding.LaSalleMascot.png";

    public static Bitmap Create()
    {
        Bitmap bitmap = new(Size, Size, PixelFormat.Format32bppArgb);
        using Graphics graphics = Graphics.FromImage(bitmap);
        graphics.CompositingQuality = CompositingQuality.HighQuality;
        graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
        graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
        graphics.Clear(Color.Transparent);

        using Stream sourceStream = typeof(ProviderTileIcon).Assembly.GetManifestResourceStream(MascotResourceName)
            ?? throw new InvalidOperationException($"The branded Credential Provider logo '{MascotResourceName}' is unavailable.");
        using Bitmap mascot = new(sourceStream);
        using GraphicsPath circularMask = new();
        circularMask.AddEllipse(0, 0, Size, Size);
        graphics.SetClip(circularMask);
        graphics.DrawImage(mascot, new Rectangle(0, 0, Size, Size));

        return bitmap;
    }
}