using DevExpress.Pdf;
using DevExpress.Drawing;
using DevExpress.Data.Utils.Security;
using System.Drawing;

Stream DrawPageText(Stream documentStream, string textToDraw) {
    using var processor = new PdfDocumentProcessor();
    processor.LoadDocument(documentStream);

    using var g = processor.CreateGraphicsPageSystem();
    var page = processor.Document.Pages[0];

    using var brush = new DXSolidBrush(Color.Black);
    var font = new DXFont("Arial", 25);

    var stringSize = g.MeasureString(textToDraw, font);
    var x = (page.CropBox.Width - stringSize.Width) / 2;
    var y = (page.CropBox.Height - stringSize.Height) / 2;

    g.DrawString(textToDraw, font, brush, (float)x, (float)y);
    g.AddToPageForeground(page);

    var outputStream = new MemoryStream();
    processor.SaveDocument(outputStream);
    outputStream.Position = 0;

    return outputStream;
}

Stream DrawPageImage(Stream documentStream, Stream imageStream) {
    using var processor = new PdfDocumentProcessor();
    processor.LoadDocument(documentStream);

    using var g = processor.CreateGraphicsPageSystem();
    var page = processor.Document.Pages[0];

    var image = DXImage.FromStream(imageStream);
    var rect = new RectangleF((float)page.CropBox.Left + 150, (float)page.CropBox.Height / 2 - 40, (float)page.CropBox.Width - 300, 40);

    g.DrawImage(image, rect);
    g.AddToPageForeground(page);

    var outputStream = new MemoryStream();
    processor.SaveDocument(outputStream);
    outputStream.Position = 0;

    return outputStream;
}

Stream DrawPageShapes(Stream documentStream, bool drawRectangle, bool drawEllipse, bool drawPolygon, bool drawLines, bool drawBeziers, bool drawPath) {
    using var processor = new PdfDocumentProcessor();
    processor.LoadDocument(documentStream);

    using var g = processor.CreateGraphicsPageSystem();
    var page = processor.Document.Pages[0];

    using var brush = new DXSolidBrush(Color.Black);
    using var pen = new DXPen(brush);

    var pageCropBox = new RectangleF(0, 0, (float)page.CropBox.Width, (float)page.CropBox.Height);
    var cell = new RectangleF(0, 0, pageCropBox.Width / 2, pageCropBox.Height / 3);

    if (drawRectangle)
        DrawRectangle(g, pen, pageCropBox, cell);
    if (drawEllipse)
        DrawEllipse(g, pen, pageCropBox, cell);
    if (drawPolygon)
        DrawPolygon(g, pen, pageCropBox, cell);
    if (drawLines)
        DrawLines(g, pen, pageCropBox, cell);
    if (drawBeziers)
        DrawBeziers(g, pen, pageCropBox, cell);
    if (drawPath)
        DrawPath(g, pen, pageCropBox, cell);

    g.AddToPageForeground(page);

    var outputStream = new MemoryStream();
    processor.SaveDocument(outputStream);
    outputStream.Position = 0;

    return outputStream;
}

void DrawRectangle(PdfGraphics g, DXPen pen, RectangleF pageCropBox, RectangleF cell) {
    var rectCell = new RectangleF(pageCropBox.Left + 10, pageCropBox.Height - cell.Height + 10, cell.Width - 20, cell.Height - 20);
    g.DrawRectangle(pen, rectCell);
}

void DrawEllipse(PdfGraphics g, DXPen pen, RectangleF pageCropBox, RectangleF cell) {
    var ellipseCell = new RectangleF(pageCropBox.Left + 10, pageCropBox.Height - cell.Height * 2 + 10, cell.Width - 20, cell.Height - 20);
    g.DrawEllipse(pen, ellipseCell);
}

void DrawPolygon(PdfGraphics g, DXPen pen, RectangleF pageCropBox, RectangleF cell) {
    var starCell = new RectangleF(pageCropBox.Left + 10, pageCropBox.Height - cell.Height * 3 + 10, cell.Width - 20, cell.Height - 20);
    g.DrawPolygon(pen, Enumerable.Range(0, 10).Select(x => {
        var angle = Math.PI / 2 + x * Math.PI / 5;
        var R = starCell.Height / 2;
        var r = x % 2 == 0 ? R : R * ((3 - Math.Sqrt(5)) / 2);
        return new PointF((float)(starCell.Left + starCell.Width / 2 + r * Math.Cos(angle)),
            (float)(starCell.Top + starCell.Height / 2 + r * Math.Sin(angle)));
    }).ToArray());
}

void DrawLines(PdfGraphics g, DXPen pen, RectangleF pageCropBox, RectangleF cell) {
    var linesCell = new RectangleF(pageCropBox.Left + cell.Width + 10, pageCropBox.Height - cell.Height + 10, cell.Width - 20, cell.Height - 20);
    g.DrawLines(pen, Enumerable.Range(0, 10).Select(x => new PointF(linesCell.Left + linesCell.Width / 10 * x,
        StrongRandom.Next((int)linesCell.Top, (int)linesCell.Bottom))).ToArray());
}

void DrawBeziers(PdfGraphics g, DXPen pen, RectangleF pageCropBox, RectangleF cell) {
    var bezierCell = new RectangleF(pageCropBox.Left + cell.Width + 10, pageCropBox.Height - cell.Height * 2 + 10, cell.Width - 20, cell.Height - 20);
    g.DrawBeziers(pen, Enumerable.Range(0, 10).Select(x => new PointF(bezierCell.Left + bezierCell.Width / 10 * x,
        StrongRandom.Next((int)bezierCell.Top, (int)bezierCell.Bottom))).ToArray());
}

void DrawPath(PdfGraphics g, DXPen pen, RectangleF pageCropBox, RectangleF cell) {
    var pathCell = new RectangleF(pageCropBox.Left + cell.Width + 10, pageCropBox.Height - cell.Height * 3 + 10, cell.Width - 20, cell.Height - 20);
    using var path = new DXGraphicsPath();
    path.AddEllipse(new(pathCell.Left, pathCell.Top, pathCell.Height, pathCell.Height));
    path.AddEllipse(new(pathCell.Left + pathCell.Height / 5, pathCell.Top + pathCell.Height * 2 / 3, pathCell.Height / 5, pathCell.Height / 5));
    path.AddEllipse(new(pathCell.Left + pathCell.Height * 3 / 5, pathCell.Top + pathCell.Height * 2 / 3, pathCell.Height / 5, pathCell.Height / 5));
    path.AddCurve([
        new(pathCell.Left + pathCell.Height / 6, pathCell.Top + pathCell.Height / 3),
        new(pathCell.Left + pathCell.Height / 2, pathCell.Top + pathCell.Height / 6),
        new(pathCell.Left + pathCell.Height * 5 / 6, pathCell.Top + pathCell.Height / 3)
    ], 0.7f);
    g.DrawPath(pen, path);
}