using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Markup;

namespace sky
{
    /// <summary>
    /// Interaction logic for MapKnot.xaml
    /// </summary>
    [ContentProperty("ChildKnots")]
    public partial class MapKnot : StackPanel
    {
        List<FrameworkElementAdorner> connectionLines = new List<FrameworkElementAdorner>();
        int childCount = 0;

        public MapKnot()
        {
            InitializeComponent();
            LayoutUpdated += new EventHandler(MapKnot_LayoutUpdated);
            double fontSize = KnotTextContainer.FontSize;
            KnotTextContainer.Margin = new Thickness(0, fontSize/2, fontSize * 2, fontSize/2);
        }

        void MapKnot_LayoutUpdated(object sender, EventArgs e)
        {
            if (childCount != ChildKnotsContainer.Children.Count)
            {
                childCount = ChildKnotsContainer.Children.Count;

                Point rootBegin = KnotTextContainer.TranslatePoint(
                    new Point(0, KnotTextContainer.ActualHeight), this);
                Point rootEnd = KnotTextContainer.TranslatePoint(
                    new Point(KnotTextContainer.ActualWidth, KnotTextContainer.ActualHeight), this);
                AdornerLayer layer = AdornerLayer.GetAdornerLayer(this);
                foreach(FrameworkElementAdorner line in connectionLines)
                {
                    layer.Remove(line);
                }

                FrameworkElementAdorner line1 = CreateLine(rootBegin, rootEnd);
                layer.Add(line1);
                connectionLines.Add(line1);

                foreach (FrameworkElement childKnot in ChildKnots)
                {
                    TextBlock childKnotText = (childKnot as MapKnot).KnotTextContainer;
                    Point childBegin = childKnotText.TranslatePoint(
                        new Point(0, childKnotText.ActualHeight), this);
                    Point childEnd = childKnotText.TranslatePoint(
                        new Point(childKnotText.ActualWidth, childKnotText.ActualHeight), this);

                    FrameworkElementAdorner line2 = CreateLine(rootEnd, childBegin);
                    layer.Add(line2);
                    connectionLines.Add(line2);

                    FrameworkElementAdorner line3 = CreateLine(childBegin, childEnd);
                    layer.Add(line3);
                    connectionLines.Add(line3);
                }
            }
        }

        private FrameworkElementAdorner CreateLine(Point from, Point to)
        {
            Line line = new Line();
            line.X1 = from.X;
            line.X2 = to.X;
            line.Y1 = from.Y;
            line.Y2 = to.Y;
            line.Stroke = Brushes.Black;
            return new FrameworkElementAdorner(this, line);
        }

        public string KnotText
        {
            get { return KnotTextContainer.Text; }
            set { KnotTextContainer.Text = value; }
        }

        public UIElementCollection ChildKnots
        {
            get { return ChildKnotsContainer.Children; }
        }
    }
}