using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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 Tango.Core.Helpers;
using Tango.SharedUI.Shapes;

namespace Tango.SharedUI.Controls
{
    /// <summary>
    /// Interaction logic for HiveControl.xaml
    /// </summary>
    public partial class HiveControl : UserControl
    {
        public event EventHandler<HexagonControl> HexagonSelected;

        public event EventHandler HiveGenerated;

        public ObservableCollection<HexagonControl> Hexagons
        {
            get { return (ObservableCollection<HexagonControl>)GetValue(HexagonsProperty); }
            set { SetValue(HexagonsProperty, value); }
        }
        public static readonly DependencyProperty HexagonsProperty =
            DependencyProperty.Register("Hexagons", typeof(ObservableCollection<HexagonControl>), typeof(HiveControl), new PropertyMetadata(null));

        public ObservableCollection<HexagonControl> SelectedHexagons
        {
            get { return (ObservableCollection<HexagonControl>)GetValue(SelectedHexagonsProperty); }
            set { SetValue(SelectedHexagonsProperty, value); }
        }
        public static readonly DependencyProperty SelectedHexagonsProperty =
            DependencyProperty.Register("SelectedHexagons", typeof(ObservableCollection<HexagonControl>), typeof(HiveControl), new PropertyMetadata(null));

        public int MaxSelections
        {
            get { return (int)GetValue(MaxSelectionsProperty); }
            set { SetValue(MaxSelectionsProperty, value); }
        }
        public static readonly DependencyProperty MaxSelectionsProperty =
            DependencyProperty.Register("MaxSelections", typeof(int), typeof(HiveControl), new PropertyMetadata(3));

        public bool DisplayGridPosition
        {
            get { return (bool)GetValue(DisplayGridPositionProperty); }
            set { SetValue(DisplayGridPositionProperty, value); }
        }
        public static readonly DependencyProperty DisplayGridPositionProperty =
            DependencyProperty.Register("DisplayGridPosition", typeof(bool), typeof(HiveControl), new PropertyMetadata(false));

        public HexagonControl CenterHexagon
        {
            get { return (HexagonControl)GetValue(CenterHexagonProperty); }
            set { SetValue(CenterHexagonProperty, value); }
        }
        public static readonly DependencyProperty CenterHexagonProperty =
            DependencyProperty.Register("CenterHexagon", typeof(HexagonControl), typeof(HiveControl), new PropertyMetadata(null));

        public int HiveWidth
        {
            get { return (int)GetValue(HiveWidthProperty); }
            set { SetValue(HiveWidthProperty, value); }
        }
        public static readonly DependencyProperty HiveWidthProperty =
            DependencyProperty.Register("HiveWidth", typeof(int), typeof(HiveControl), new PropertyMetadata(5));

        public int HiveHeight
        {
            get { return (int)GetValue(HiveHeightProperty); }
            set { SetValue(HiveHeightProperty, value); }
        }
        public static readonly DependencyProperty HiveHeightProperty =
            DependencyProperty.Register("HiveHeight", typeof(int), typeof(HiveControl), new PropertyMetadata(5));

        public HiveControl()
        {
            Hexagons = new ObservableCollection<HexagonControl>();
            SelectedHexagons = new ObservableCollection<HexagonControl>();

            InitializeComponent();

            HiveHeight = 5;
            HiveWidth = 5;
            this.Loaded += HiveControl_Loaded;
        }

        private void HiveControl_Loaded(object sender, RoutedEventArgs e)
        {
            GenerateHive();
            HiveGenerated?.Invoke(this,new EventArgs());
        }

        private void GenerateHive()
        {
            Hexagons.Clear();
            SelectedHexagons.Clear();
            canvas.Children.Clear();

            double width = ActualWidth;
            double height = ActualHeight;
            double hexHeight = height / (double)HiveHeight;

            int gap = (int)((Math.Round(HiveHeight / 2d, MidpointRounding.AwayFromZero)) / 2d);

            for (int column = 0; column < HiveWidth / 2; column++)
            {
                for (int row = gap; row < HiveHeight - (gap % 2 != 0 ? gap : gap + 1); row++)
                {
                    AddHexagon(hexHeight, row, column);
                }

                gap--;
            }

            int centerColumn = (int)Math.Round(HiveHeight / 2d, MidpointRounding.ToEven);

            for (int row = 0; row < HiveHeight; row++)
            {
                AddHexagon(hexHeight, row, centerColumn);
            }

            gap = 0;

            for (int column = centerColumn + 1; column < HiveWidth; column++)
            {
                for (int row = gap; row < HiveHeight - (gap % 2 != 0 ? gap : gap + 1); row++)
                {
                    AddHexagon(hexHeight, row, column);
                }

                gap++;
            }

            Width = Hexagons.Max(x => x.Points.Max(y => y.X));

            CenterHexagon = GetHexagon((int)Math.Round(HiveWidth / 2d, MidpointRounding.ToEven), (int)Math.Round(HiveHeight / 2d, MidpointRounding.ToEven));
        }

        private void AddHexagon(double hexHeight, int row, int col)
        {
            Point[] points = HexToPoints(hexHeight, row, col);
            HexagonControl hexagon = new HexagonControl(points, row, col);
            hexagon.HorizontalAlignment = HorizontalAlignment.Center;
            hexagon.VerticalAlignment = VerticalAlignment.Center;
            hexagon.Stroke = Brushes.Black;
            hexagon.StrokeThickness = 1;
            hexagon.Fill = new SolidColorBrush(ColorHelper.GetRandomGrayscaleColor());

            canvas.Children.Add(hexagon);
            Hexagons.Add(hexagon);

            hexagon.Bind(HexagonControl.DisplayGridPositionProperty, this, DisplayGridPositionProperty, BindingMode.OneWay);

            hexagon.MouseEnter += Hexagon_MouseEnter;
            hexagon.MouseUp += Hexagon_MouseUp;
        }

        private void Hexagon_MouseUp(object sender, MouseButtonEventArgs e)
        {
            HexagonControl hexagon = sender as HexagonControl;
            ToggleHexagonSelection(hexagon);
        }

        public void SelectHexagon(HexagonControl hexagon)
        {
            SelectedHexagons.Clear();
            SelectedHexagons.Add(hexagon);
            Hexagons.ToList().ForEach(x => x.IsSelected = false);
            hexagon.IsSelected = true;
            HexagonSelected?.Invoke(this, hexagon);
        }

        private void ToggleHexagonSelection(HexagonControl hexagon)
        {
            bool selected = !hexagon.IsSelected;

            if (MaxSelections > Hexagons.Where(x => x.IsSelected).Count())
            {
                hexagon.IsSelected = selected;
            }
            else
            {
                if (selected)
                {
                    SelectedHexagons.First().IsSelected = false;
                    SelectedHexagons.Remove(SelectedHexagons.First());
                    hexagon.IsSelected = true;
                }
                else
                {
                    hexagon.IsSelected = false;
                }
            }

            if (selected)
            {
                SelectedHexagons.Add(hexagon);
                HexagonSelected?.Invoke(this, hexagon);
            }
            else
            {
                SelectedHexagons.Remove(hexagon);
            }
        }

        private void Hexagon_MouseEnter(object sender, MouseEventArgs e)
        {
            Canvas.SetZIndex(sender as FrameworkElement, canvas.Children.OfType<HexagonControl>().Where(x => !x.IsSelected).Max(x => Canvas.GetZIndex(x)) + 1);

            foreach (var item in canvas.Children.OfType<HexagonControl>().Where(x => x.IsSelected))
            {
                Canvas.SetZIndex(item, canvas.Children.OfType<HexagonControl>().Max(x => Canvas.GetZIndex(x)) + 1);
            }
        }

        private Point[] HexToPoints(double height, float row, float col)
        {
            // Start with the leftmost corner of the upper left hexagon.
            double width = HexWidth(height);
            double y = height / 2;
            double x = 0;

            // Move down the required number of rows.
            y += row * height;

            // If the column is odd, move down half a hex more.
            if (col % 2 == 1) y += height / 2;

            // Move over for the column number.
            x += col * (width * 0.75f);

            // Generate the points.
            return new Point[]
                {
            new Point(x, y),
            new Point(x + width * 0.25f, y - height / 2),
            new Point(x + width * 0.75f, y - height / 2),
            new Point(x + width, y),
            new Point(x + width * 0.75f, y + height / 2),
            new Point(x + width * 0.25f, y + height / 2),
                };
        }

        private double HexWidth(double height)
        {
            return (double)(4 * (height / 2 / Math.Sqrt(3)));
        }

        public HexagonControl GetHexagon(int row, int column)
        {
            return Hexagons.Where(x => x.Row == row && x.Column == column).FirstOrDefault();
        }
    }
}