using Sunfish.Qr;

namespace Sunfish.WinForms;

/// <summary>Codigo QR de una direccion, para abrirla desde un movil. Pequena y sin redimensionar.</summary>
internal sealed class QrForm : Form
{
    public QrForm(string url)
    {
        SuspendLayout();
        AutoScaleDimensions = new SizeF(96F, 96F);
        AutoScaleMode = AutoScaleMode.Dpi;
        Text = Texts.QrTitle;
        FormBorderStyle = FormBorderStyle.FixedToolWindow;
        ShowInTaskbar = false;
        BackColor = Color.White;
        AutoSize = true;
        AutoSizeMode = AutoSizeMode.GrowAndShrink;
        Padding = new Padding(6);

        var qr = QrCode.Encode(url);
        int scale = Math.Max(3, UiImages.Px(5));
        var picture = new PictureBox
        {
            Image = Render(qr, scale), SizeMode = PictureBoxSizeMode.AutoSize,
            Location = new Point(Padding.Left, Padding.Top), Margin = new Padding(0),
        };
        var label = new Label
        {
            Text = url, AutoSize = true, MaximumSize = new Size(picture.Width, 0), ForeColor = Color.Black,
            Location = new Point(Padding.Left, picture.Bottom + 4), Margin = new Padding(0),
        };
        Controls.AddRange([picture, label]);
        ResumeLayout(false);
        PerformLayout();
        KeyPreview = true;
        KeyDown += (_, e) =>
        {
            if (e.KeyCode == Keys.Escape)
                Close();
        };
    }

    /// <summary>Modulos negros sobre blanco con el margen de la norma; pixeles exactos, sin suavizar.</summary>
    private static Bitmap Render(QrCode qr, int scale)
    {
        int size = (qr.Size + QrImage.QuietZone * 2) * scale;
        var bitmap = new Bitmap(size, size);
        using var g = Graphics.FromImage(bitmap);
        g.Clear(Color.White);
        for (int y = 0; y < qr.Size; y++)
            for (int x = 0; x < qr.Size; x++)
                if (qr[x, y])
                    g.FillRectangle(Brushes.Black, (x + QrImage.QuietZone) * scale, (y + QrImage.QuietZone) * scale, scale, scale);
        return bitmap;
    }
}