using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;
using System.Windows.Media.Imaging;

namespace SilverlightApplication1
{
    public partial class MainPage : UserControl
    {
        private bool PolygonStarted = false;
        private Line Line1, Line2;
        private int LineSwich;
        private Point pt, pt2, first;
        private Point[] Points = new Point[1000];
        int PointCounter = 0;
        public MainPage()
        {
            InitializeComponent();
            Loaded += new RoutedEventHandler(Page_Loaded);
        }

        void Page_Loaded(object sender, RoutedEventArgs e)
        {
            LayoutRoot.MouseMove += new MouseEventHandler(LayoutRoot_MouseMove);
            LayoutRoot.MouseLeftButtonDown += new MouseButtonEventHandler(LayoutRoot_MouseLeftButtonDown);
        }


        void LayoutRoot_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            pt = e.GetPosition(LayoutRoot);
            PolygonStarted = !PolygonFinished(first, pt);

            if (!PolygonStarted)
            {
                if (LineSwich == 2)
                {
                    LayoutRoot.Children.Remove(Line2);
                    Line2.X2 = first.X;
                    Line2.Y2 = first.Y;
                    LayoutRoot.Children.Add(Line2);
                }
                else
                {
                    LayoutRoot.Children.Remove(Line1);
                    Line1.X2 = first.X;
                    Line1.Y2 = first.Y;
                    LayoutRoot.Children.Add(Line1);
                }
                first.X = 0;
                first.Y = 0;
            }
            if ((first.X == 0 & first.Y == 0) | PointIsValid(pt))
            {
                SavePoint(pt);
                Line1 = new Line();
                Line2 = new Line();
                LineSwich = 1;
            }
            else
                pt = Points[PointCounter - 1];

        }

        bool PointIsValid(Point p)
        {
            if (first.X == 0 & first.Y == 0)
            {
                return(true);
            }


            for (int i = 0; i < PointCounter + 1; i++)
            {
                if (((Math.Sqrt((p.X - Points[i].X) * (p.X - Points[i].X) + (p.Y - Points[i].Y) * (p.Y - Points[i].Y)) < 10) &
                    Points[i] != first))
                {
                    return (false);
                }
            }
            return (true);
        }

        void SavePoint(Point p)
        {
            Points[PointCounter] = p;
            PointCounter++;
        }

        bool PolygonFinished(Point pt1, Point pt2)
        {
            if ((pt1.X == 0) & (pt1.Y == 0))
                return(false);

            double d = Math.Sqrt((pt1.X-pt2.X) * (pt1.X-pt2.X) + (pt1.Y-pt2.Y) * (pt1.Y-pt2.Y));
            if (d < 6)
                return (true);
            else
                return (false);
        }

        void LayoutRoot_MouseMove(object sender, MouseEventArgs e)
        {
            if (PolygonStarted)
            {
                if ((first.X == 0) & (first.Y == 0))
                    first = pt;
                pt2 = e.GetPosition(LayoutRoot);
                if (LineSwich == 1)
                {
                    LineSwich = 2;
                    LayoutRoot.Children.Remove(Line1);
                    Line2.X1 = pt.X;
                    Line2.Y1 = pt.Y;
                    Line2.X2 = pt2.X;
                    Line2.Y2 = pt2.Y;
                    Line2.Stroke = new SolidColorBrush(Colors.Black);
                    Line2.StrokeStartLineCap = PenLineCap.Round;
                    Line2.StrokeEndLineCap = PenLineCap.Round;
                    Line2.StrokeThickness = 1;
                    LayoutRoot.Children.Add(Line2);
                }
                else
                {
                    LineSwich = 1;
                    LayoutRoot.Children.Remove(Line2);
                    Line1.X1 = pt.X;
                    Line1.Y1 = pt.Y;
                    Line1.X2 = pt2.X;
                    Line1.Y2 = pt2.Y;
                    Line1.Stroke = new SolidColorBrush(Colors.Black);
                    Line1.StrokeStartLineCap = PenLineCap.Round;
                    Line1.StrokeEndLineCap = PenLineCap.Round;
                    Line1.StrokeThickness = 1;
                    LayoutRoot.Children.Add(Line1);
                }
            }
        }

        private void UserControl_Loaded(object sender, RoutedEventArgs e)
        {

        }

        public class SearchEngine
        {
            public bool SearchIsDone = false;
            public Point GlobalTrailPoint = new Point(0, 0);
            WriteableBitmap wb;
            int width, height;

            public void CreateBitmap(Canvas Can)
            {
                wb = new WriteableBitmap(Can, null);
                width = wb.PixelWidth;
                height = wb.PixelHeight;
            }

            public void IncGlobalTrailPoint()
            {
                if (GlobalTrailPoint.X < width - 1)
                    GlobalTrailPoint.X += 1;
                else
                {
                    if (GlobalTrailPoint.Y < height - 1)
                    {
                        GlobalTrailPoint.Y += 1;
                        GlobalTrailPoint.X = 1;
                    }
                    else
                        SearchIsDone = true;
                }
            }

            public bool PointIsWhite(Point p)
            {
                if (wb.Pixels[(int)GlobalTrailPoint.Y * wb.PixelWidth + (int)GlobalTrailPoint.X] != -1)
                    return (false);
                else
                    return (true);
            }

        }

        public void LookupVertex()
        {
            SearchEngine SE = new SearchEngine();
            SE.CreateBitmap(LayoutRoot);
            while (SE.PointIsWhite(SE.GlobalTrailPoint) & !SE.SearchIsDone)
            {
                SE.IncGlobalTrailPoint();
            }



            if (!SE.SearchIsDone)
            {
                MessageBox.Show("X" + SE.GlobalTrailPoint.X.ToString() + " Y" + SE.GlobalTrailPoint.Y.ToString());
            }


        }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            LookupVertex();
        }


    }
}