using System;
using System.Drawing;
using System.Windows.Forms;

namespace ShapeDrawingApp
{
    public partial class Form1 : Form
    {
        private enum ShapeType
        {
            Ellipse,
            RoundedRectangle,
            Rectangle
        }

        private ShapeType currentShapeType = ShapeType.Ellipse;
        private bool isDrawing = false;
        private Point startPoint;

        public Form1()
        {
            InitializeComponent();
        }

        private void btnDrawShape_Click(object sender, EventArgs e)
        {
            isDrawing = true;
            startPoint = new Point(0, 0);
        }

        private void drawingPanel_MouseDown(object sender, MouseEventArgs e)
        {
            if (isDrawing)
            {
                startPoint = e.Location;
            }
        }

        private void drawingPanel_MouseUp(object sender, MouseEventArgs e)
        {
            if (isDrawing)
            {
                isDrawing = false;
                Point endPoint = e.Location;

                int width = Math.Abs(endPoint.X - startPoint.X);
                int height = Math.Abs(endPoint.Y - startPoint.Y);

                Graphics graphics = drawingPanel.CreateGraphics();
                Pen pen = new Pen(Color.Black, 2);

                switch (currentShapeType)
                {
                    case ShapeType.Ellipse:
                        graphics.DrawEllipse(pen, startPoint.X, startPoint.Y, width, height);
                        break;

                    case ShapeType.RoundedRectangle:
                        int cornerRadius = 20; // You can adjust this value
                        Rectangle rect = new Rectangle(startPoint.X, startPoint.Y, width, height);
                        graphics.DrawRoundedRectangle(pen, rect, cornerRadius);
                        break;

                    case ShapeType.Rectangle:
                        graphics.DrawRectangle(pen, startPoint.X, startPoint.Y, width, height);
                        break;
                }

                graphics.Dispose();
            }
        }

        private void radioEllipse_CheckedChanged(object sender, EventArgs e)
        {
            currentShapeType = ShapeType.Ellipse;
        }

        private void radioRoundedRectangle_CheckedChanged(object sender, EventArgs e)
        {
            currentShapeType = ShapeType.RoundedRectangle;
        }

        private void radioRectangle_CheckedChanged(object sender, EventArgs e)
        {
            currentShapeType = ShapeType.Rectangle;
        }
    }

    // Extension method for drawing rounded rectangles
    public static class GraphicsExtensions
    {
        public static void DrawRoundedRectangle(this Graphics graphics, Pen pen, Rectangle rectangle, int cornerRadius)
        {
            int diameter = cornerRadius * 2;
            Size size = new Size(diameter, diameter);
            Rectangle arc = new Rectangle(rectangle.Location, size);
            graphics.DrawArc(pen, arc, 180, 90);
            arc.X = rectangle.Right - diameter;
            graphics.DrawArc(pen, arc, 270, 90);
            arc.Y = rectangle.Bottom - diameter;
            graphics.DrawArc(pen, arc, 0, 90);
            arc.X = rectangle.Left;
            graphics.DrawArc(pen, arc, 90, 90);
            graphics.DrawLine(pen, arc.X + cornerRadius, rectangle.Top, arc.X + rectangle.Width - cornerRadius, rectangle.Top);
            graphics.DrawLine(pen, arc.X + cornerRadius, rectangle.Bottom, arc.X + rectangle.Width - cornerRadius, rectangle.Bottom);
            graphics.DrawLine(pen, rectangle.Left, arc.Y + cornerRadius, rectangle.Left, arc.Y + rectangle.Height - cornerRadius);
            graphics.DrawLine(pen, rectangle.Right, arc.Y + cornerRadius, rectangle.Right, arc.Y + rectangle.Height - cornerRadius);
        }
    }
}