using DrawFigureLibrary;
using DrawFigureLibrary.Figures;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;


namespace Main
{
    public partial class MainWindow : Window
    {
        private RenderTargetBitmap?       _renderTarget                   ;

        private int                       _polyExpected                   ;
        private List<Point>               _polyPoints = new List<Point>() ;

        private DrawFigureLibrary.Figure? _mouseSelected                  ;
        private bool                      _isDragging                     ;
        private Point                     _lastMouse                      ;

        private void ClickAddRectangle(object sender, RoutedEventArgs e) 
        {
            try
            {
                string name = RectName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                int x = int.Parse(RectX.Text);
                int y = int.Parse(RectY.Text);
                int w = int.Parse(RectW.Text);
                int h = int.Parse(RectH.Text);

                ShapeContainer.AddFigure(new RectangleFigure(name, x, y, w, h));

                Upd();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddSquare(object sender, RoutedEventArgs e)
        {
            try
            {
                string name = SquareName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                int x    = int.Parse(SquareX.Text)    ;
                int y    = int.Parse(SquareY.Text)    ;
                int side = int.Parse(SquareSide.Text) ;

                ShapeContainer.AddFigure(new SquareFigure(name, x, y, side));
                
                Upd();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddEllipse(object sender, RoutedEventArgs e) 
        {
            try
            {
                string name = EllipseName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                int x = int.Parse(EllipseX.Text);
                int y = int.Parse(EllipseY.Text);
                int w = int.Parse(EllipseW.Text);
                int h = int.Parse(EllipseH.Text);

                ShapeContainer.AddFigure(new EllipseFigure(name, x, y, w, h));

                Upd();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddCircle(object sender, RoutedEventArgs e)
        {
            try
            {
                string name = CircleName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                int x = int.Parse(CircleX.Text);
                int y = int.Parse(CircleY.Text);
                int d = int.Parse(CircleD.Text);

                ShapeContainer.AddFigure(new CircleFigure(name, x, y, d));

                Upd();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickPolyStart(object sender, RoutedEventArgs e)
        {
            try
            {
                string name = PolyName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                _polyExpected = int.Parse(PolyCount.Text);
                if (_polyExpected < 3) throw new Exception("Минимум 3 вершины.");

                _polyPoints = new List<Point>();
                PolyCount.IsEnabled = false;
                PolyX.IsEnabled = true;
                PolyY.IsEnabled = true;
                PolyAddPointBtn.IsEnabled = true;
                PolyFinishBtn.IsEnabled = false;

                PolyStatus.Text = $"Точек: 0 / {_polyExpected}";
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex) {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickPolyAddPoint(object sender, RoutedEventArgs e)
        {
            try
            {
                int x = int.Parse(PolyX.Text);
                int y = int.Parse(PolyY.Text);

                if (_polyPoints.Count >= _polyExpected) throw new Exception("Все точки уже введены.");

                _polyPoints.Add(new Point(x, y));
                PolyStatus.Text = $"Точек: {_polyPoints.Count} / {_polyExpected}";

                if (_polyPoints.Count == _polyExpected)
                {
                    PolyAddPointBtn.IsEnabled = false;
                    PolyFinishBtn.IsEnabled = true;
                }
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex) {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickPolyFinish(object sender, RoutedEventArgs e)
        {
            try
            {
                string name = PolyName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");
                if (_polyPoints.Count != _polyExpected) throw new Exception("Не все точки введены.");

                ShapeContainer.AddFigure(new PolygonFigure(name, _polyPoints.ToArray()));
                Upd();

                PolyCount.IsEnabled = true;
                PolyX.IsEnabled = false;
                PolyY.IsEnabled = false;
                PolyAddPointBtn.IsEnabled = false;
                PolyFinishBtn.IsEnabled = false;
                PolyStatus.Text = "";
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddTriangle(object sender, RoutedEventArgs e)
        {
            try
            {
                string name = TriName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                var a = new Point(int.Parse(Ax.Text), int.Parse(Ay.Text));
                var b = new Point(int.Parse(Bx.Text), int.Parse(By.Text));
                var c = new Point(int.Parse(Cx.Text), int.Parse(Cy.Text));

                ShapeContainer.AddFigure(new Triangle(name, a, b, c));

                Upd();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddTerrainPointSunPointHumanPointText(object sender, RoutedEventArgs e)
        {
            try
            {
                string name = SceneName.Text.Trim();
                if (!NameIsValid(name)) throw new Exception("Имя пустое или уже занято.");

                int x = int.Parse(SceneX.Text);
                int y = int.Parse(SceneY.Text);
                int sceneW = int.Parse(SceneW.Text);
                int sceneH = int.Parse(SceneH.Text);

                ShapeContainer.AddFigure(new TerrainPointSunPointHumanPointText(name, x, y, sceneW, sceneH));

                Upd();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickMoveSelected(object sender, RoutedEventArgs e)
        {
            try
            {
                var fig = GetSelectedFigureOrThrow();
                int dx = int.Parse(MoveDx.Text);
                int dy = int.Parse(MoveDy.Text);

                fig.MoveBy(dx, dy);
                Redraw();
            }
            catch (FormatException)
            {
                MessageBox.Show("Некорректный формат числа");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void ClickDeleteSelected(object sender, RoutedEventArgs e)
        {
            try
            {
                var fig = GetSelectedFigureOrThrow();

                bool ok = ShapeContainer.RemoveFigure(fig);
                if (!ok) throw new Exception("Фигура для удаления не найдена.");

                Upd();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            Init.DrawingImage = DrawingImage;

            int width = (int)DrawingImage.Width;
            int height = (int)DrawingImage.Height;

            if (width <= 0) width = 800;
            if (height <= 0) height = 400;

            _renderTarget = new RenderTargetBitmap(width, height, 96, 96, PixelFormats.Pbgra32);
            DrawingImage.Source = _renderTarget;

            ImgBorder.Width = width;
            ImgBorder.Height = height;

            Upd();
        }

        private void Redraw() 
        {
            if (_renderTarget == null) return;

            DrawingVisual drawVis = new DrawingVisual();

            using (var ctx = drawVis.RenderOpen())
            {
                foreach (var fig in ShapeContainer.FigureList)
                {
                    fig.Draw(ctx);
                }
            }

            _renderTarget.Clear();
            _renderTarget.Render(drawVis);
            DrawingImage.Source = _renderTarget;
        }
        private void RefreshCombo() 
        {
            FigureCombo.ItemsSource = null;
            FigureCombo.ItemsSource = ShapeContainer.FigureList.Select(f => f.Name);
            if (FigureCombo.Items.Count > 0 && FigureCombo.SelectedIndex < 0)
            {
                FigureCombo.SelectedIndex = 0;
            }
        }

        private void Upd()
        {
            Redraw();
            RefreshCombo();
        }

        private bool NameIsValid(string? name)
        {
            if (string.IsNullOrWhiteSpace(name)) return false;
            if (ShapeContainer.FigureList.Any(f => f.Name == name)) return false;
            return true;
        }
        private Figure GetSelectedFigureOrThrow()
        {
            if (FigureCombo.SelectedItem == null) throw new Exception("Фигура не выбрана.");

            string name = FigureCombo.SelectedItem.ToString()!;
            var fig = ShapeContainer.FindByName(name);
            if (fig == null) throw new Exception("Фигура для операции не найдена.");

            return fig;
        }

        private void MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            var p = e.GetPosition(DrawingImage);

            _mouseSelected =
                ShapeContainer.FigureList
                    .AsEnumerable()
                    .Reverse()
                    .FirstOrDefault(f => f.HitTest(p));

            if (_mouseSelected != null)
            {
                FigureCombo.SelectedItem = _mouseSelected.Name;

                _isDragging = true;
                _lastMouse = p;

                DrawingImage.CaptureMouse();
                e.Handled = true;
            }
        }

        private void MouseMove(object sender, MouseEventArgs e)
        {
            if (!_isDragging || _mouseSelected == null) return;
            if (e.LeftButton != MouseButtonState.Pressed) return;

            var p = e.GetPosition(DrawingImage);

            int dx = (int)Math.Round(p.X - _lastMouse.X);
            int dy = (int)Math.Round(p.Y - _lastMouse.Y);

            if (dx == 0 && dy == 0) return;

            if (_mouseSelected.MoveByChecked(dx, dy))
            {
                _lastMouse = p;
                Redraw();
            }

            e.Handled = true;
        }

        private void MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            if (!_isDragging) return;

            _isDragging = false;
            _mouseSelected = null;

            DrawingImage.ReleaseMouseCapture();
            e.Handled = true;
        }
    }
}