using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Drawing;


namespace firstCSharp
{
  class FirstForm : Form
  {
    
    public FirstForm()
    {
      BackColor = Color.Tomato;
      Text = "Hello world!";
      Height = 600;
      const double GOLDEN_RATIO = 1.618;
      Width = (int) (Height * GOLDEN_RATIO);

      MouseClick += FirstForm_MouseClick;
      MouseMove += FirstForm_MouseMove;
            Paint += FirstForm_Paint;

            Resize += resizeHandler;
            DoubleBuffered = true;
      // Opacity = .5;
    }

        private void resizeHandler(object sender, EventArgs e)
        {
            // When the windows resized, we want to generate a paint event
            // In Windows, we do this with the Invalidate function
            Invalidate();
        }

        private void setWorldCoordinates(Graphics graphics)
        {
            const int N_ROWS = 8;
            const int N_COLUMNS = 8;

            // ClientRectangle can provide the size of the client area
            int width = ClientRectangle.Width;
            int height = ClientRectangle.Height;

            // Find the smaller of the two dimensions 
            int squareSide = Math.Min(width, height);

            int totalMargin = width - squareSide;
            int leftMargin = totalMargin / 2;

            int topMargin = (height - squareSide) / 2;

            graphics.TranslateTransform(leftMargin, topMargin);

            // Specify the number of pixels/world coordinate
            graphics.ScaleTransform(squareSide / N_COLUMNS,
                squareSide / N_ROWS);

            // At this point we are using the scaled wcs
            // graphics.TranslateTransform(3, 1);
        }

        private void FirstForm_Paint(object sender, PaintEventArgs e)
        {
            // Draw a chessboard in the window.

            // Get the instance of class graphics that is associated 
            // with the client area of this window.
            Graphics graphics = e.Graphics;

            setWorldCoordinates(e.Graphics);

            /*
            // Draw a square showing where the board will be
            graphics.DrawRectangle(Pens.Green,
                new Rectangle(new Point(0, 0), 
                new Size(squareSide, squareSide)));

            graphics.FillRectangle(Brushes.Green,
                new Rectangle(new Point(0, 0),
                new Size(squareSide, squareSide)));


            */
            const int N_ROWS = 8;
            const int N_COLUMNS = 8;

            Brush lightSquareBrush = Brushes.Bisque;
            Brush darkSquareBrush = Brushes.DarkGreen;

            Brush nextSquare = lightSquareBrush;
            // int smallSquare = squareSide / N_ROWS;
            for(int row=0;row<N_ROWS;++row)
            {
                for(int column=0;column<N_COLUMNS;++column)
                {
                    //graphics.FillRectangle(nextSquare,
                    //   new Rectangle(column * smallSquare, row * smallSquare,
                    //  smallSquare, smallSquare));
                    graphics.FillRectangle(nextSquare,
                        new Rectangle(column, row, 1, 1));

                    nextSquare = (nextSquare == lightSquareBrush) ?
                        darkSquareBrush : lightSquareBrush;
                }
                    nextSquare = (nextSquare == lightSquareBrush) ?
                        darkSquareBrush : lightSquareBrush;
            }
        }

        // Messages are handled by a function called 
        // WndProc
        private const int WM_LBUTTONDOWN = 0x201;
        private const int MK_LBUTTON = 0x0001;
        private const int MK_RBUTTON = 0x0002;
        private const int MK_SHIFT = 0x0004;

        /*
    protected override void WndProc(ref Message m)
    {
       Console.WriteLine("Message Id is : {0}", m.Msg);
       Console.WriteLine("Message to string is: {0}",
                m.ToString());

       switch(m.Msg)
       {
           case WM_LBUTTONDOWN:
                    int iwparam = (int) m.WParam;
                    if ((iwparam & MK_LBUTTON) != 0)
                        Console.WriteLine("************LButton is up!");
                    if ((iwparam & MK_RBUTTON) != 0)
                        Console.WriteLine("************RButton is up!");
                    if ((iwparam & MK_SHIFT) != 0)
                        Console.WriteLine("************Shift is down!");

                    int iLParam = (int) m.LParam;
                    int x = iLParam & 0x0000ffff;
                    int y = (iLParam >> 16) & 0x0000ffff;

                    Console.WriteLine("xy coord is ({0}, {1})",
                        x, y);

                    break;
       }

       //if (m.Msg != WM_LBUTTONDOWN)
       {
           base.WndProc(ref m);
       }
    }
    */

    private void FirstForm_MouseMove(object sender, MouseEventArgs e)
    {
      // Text = String.Format("({0}, {1})", e.X, e.Y);

      // Get an instance of class Graphics
      Graphics graphics = CreateGraphics();
      setWorldCoordinates(graphics);

            // Create an array with points that you want to translate
            // from device coordinates to world coordinates.
            PointF[] mousePosition = new PointF[1];
            mousePosition[0] = new PointF(e.X, e.Y);
            graphics.TransformPoints(System.Drawing.Drawing2D.CoordinateSpace.World,
                System.Drawing.Drawing2D.CoordinateSpace.Device, mousePosition);
            //Text = mousePosition[0].ToString();
            Point truncatedPoint = new Point();
            truncatedPoint.X = (int) mousePosition[0].X;
            truncatedPoint.Y = (int) mousePosition[0].Y;
            Text = truncatedPoint.ToString();
    }

    private void FirstForm_MouseClick(object sender, 
      MouseEventArgs e)
    {
            // See if the left button was clicked
            if (e.Button == MouseButtons.Left)
            {
                // The want to change the color of the background
                // Let them pick a color.
                ColorDialog colorDialog = new ColorDialog();
                DialogResult result = colorDialog.ShowDialog();
                if (result != DialogResult.Cancel)
                {
                    BackColor = colorDialog.Color;
                }
            }
            else
            {
                OpenFileDialog fileDialog = new OpenFileDialog();
                DialogResult result = fileDialog.ShowDialog();
                if (result != DialogResult.Cancel)
                {
                    MessageBox.Show(fileDialog.FileName);
                }

            }

      /*
      if (BackColor == Color.Tomato)
      {
        BackColor = Color.Chartreuse;
      }
      else
      {
        BackColor = Color.Tomato;
      }
      */
    }
  }
}