using DrawFigureLibrary;
using DrawFigureLibrary.Figures;
using System.Windows;
using System.Windows.Controls;
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 int                       CanvasW => _renderTarget?.PixelWidth ?? 800;
        private int                       CanvasH => _renderTarget?.PixelHeight ?? 400;

        private void ClickAddRectangle(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(RectName, out string name)) return;

                if (!TryReadInt(RectX.Text, "X", 0, CanvasW - 1, out int x)) return;
                if (!TryReadInt(RectY.Text, "Y", 0, CanvasH - 1, out int y)) return;
                if (!TryReadInt(RectW.Text, "W", 1, CanvasW, out int w)) return;
                if (!TryReadInt(RectH.Text, "H", 1, CanvasH, out int h)) return;

                if (x + w > CanvasW || y + h > CanvasH)
                {
                    MessageBox.Show("Фигура не помещается в область рисования.");
                    return;
                }

                ShapeContainer.AddFigure(new RectangleFigure(name, x, y, w, h));
                Upd();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddSquare(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(SquareName, out string name)) return;

                if (!TryReadInt(SquareX.Text, "X", 0, CanvasW - 1, out int x)) return;
                if (!TryReadInt(SquareY.Text, "Y", 0, CanvasH - 1, out int y)) return;

                int maxSide = Math.Min(CanvasW, CanvasH);
                if (!TryReadInt(SquareSide.Text, "Side", 1, maxSide, out int side)) return;

                if (x + side > CanvasW || y + side > CanvasH)
                {
                    MessageBox.Show("Фигура не помещается в область рисования.");
                    return;
                }

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

        private void ClickAddEllipse(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(EllipseName, out string name)) return;

                if (!TryReadInt(EllipseX.Text, "X", 0, CanvasW - 1, out int x)) return;
                if (!TryReadInt(EllipseY.Text, "Y", 0, CanvasH - 1, out int y)) return;
                if (!TryReadInt(EllipseW.Text, "W", 1, CanvasW, out int w)) return;
                if (!TryReadInt(EllipseH.Text, "H", 1, CanvasH, out int h)) return;

                if (x + w > CanvasW || y + h > CanvasH)
                {
                    MessageBox.Show("Фигура не помещается в область рисования.");
                    return;
                }

                ShapeContainer.AddFigure(new EllipseFigure(name, x, y, w, h));
                Upd();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddCircle(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(CircleName, out string name)) return;

                if (!TryReadInt(CircleX.Text, "X", 0, CanvasW - 1, out int x)) return;
                if (!TryReadInt(CircleY.Text, "Y", 0, CanvasH - 1, out int y)) return;

                int maxD = Math.Min(CanvasW, CanvasH);
                if (!TryReadInt(CircleD.Text, "Диаметр", 1, maxD, out int d)) return;

                if (x + d > CanvasW || y + d > CanvasH)
                {
                    MessageBox.Show("Фигура не помещается в область рисования.");
                    return;
                }

                ShapeContainer.AddFigure(new CircleFigure(name, x, y, d));
                Upd();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickPolyStart(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(PolyName, out string name)) return;

                if (!TryReadInt(PolyCount.Text, "Кол-во вершин", 3, 50, out _polyExpected)) return;

                _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 (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickPolyAddPoint(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadInt(PolyX.Text, "X точки", 0, CanvasW - 1, out int x)) return;
                if (!TryReadInt(PolyY.Text, "Y точки", 0, CanvasH - 1, out int y)) return;

                if (_polyPoints.Count >= _polyExpected)
                {
                    MessageBox.Show("Все точки уже введены.");
                    return;
                }

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

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

        private void ClickPolyFinish(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(PolyName, out string name)) return;

                if (_polyPoints.Count != _polyExpected)
                {
                    MessageBox.Show("Не все точки введены.");
                    return;
                }

                if (_polyPoints.Count < 3)
                {
                    MessageBox.Show("Минимум 3 точки.");
                    return;
                }

                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
            {
                if (!TryReadName(TriName, out string name)) return;

                if (!TryReadInt(Ax.Text, "Ax", 0, CanvasW - 1, out int ax)) return;
                if (!TryReadInt(Ay.Text, "Ay", 0, CanvasH - 1, out int ay)) return;

                if (!TryReadInt(Bx.Text, "Bx", 0, CanvasW - 1, out int bx)) return;
                if (!TryReadInt(By.Text, "By", 0, CanvasH - 1, out int by)) return;

                if (!TryReadInt(Cx.Text, "Cx", 0, CanvasW - 1, out int cx)) return;
                if (!TryReadInt(Cy.Text, "Cy", 0, CanvasH - 1, out int cy)) return;

                var a = new Point(ax, ay);
                var b = new Point(bx, by);
                var c = new Point(cx, cy);

                ShapeContainer.AddFigure(new Triangle(name, a, b, c));
                Upd();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickAddTerrainPointSunPointHumanPointText(object sender, RoutedEventArgs e)
        {
            try
            {
                if (!TryReadName(SceneName, out string name)) return;

                if (!TryReadInt(SceneX.Text, "X", 0, CanvasW - 1, out int x)) return;
                if (!TryReadInt(SceneY.Text, "Y", 0, CanvasH - 1, out int y)) return;

                if (!TryReadInt(SceneW.Text, "W", 1, CanvasW, out int sceneW)) return;
                if (!TryReadInt(SceneH.Text, "H", 1, CanvasH, out int sceneH)) return;

                if (x + sceneW > CanvasW || y + sceneH > CanvasH)
                {
                    MessageBox.Show("Сцена не помещается в область рисования.");
                    return;
                }

                ShapeContainer.AddFigure(new TerrainPointSunPointHumanPointText(name, x, y, sceneW, sceneH));
                Upd();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ClickMoveSelected(object sender, RoutedEventArgs e)
        {
            try
            {
                var fig = GetSelectedFigureOrThrow();

                if (!TryReadInt(MoveDx.Text, "dX", -CanvasW, CanvasW, out int dx)) return;
                if (!TryReadInt(MoveDy.Text, "dY", -CanvasH, CanvasH, out int dy)) return;

                if (fig.MoveByChecked(dx, dy))
                    Redraw();
            }
            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 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;
        }
        private bool TryReadInt(string raw, string field, int min, int max, out int value)
        {
            if (!int.TryParse(raw?.Trim(), out value))
            {
                MessageBox.Show($"Поле \"{field}\": нужно целое число.");
                return false;
            }

            if (value < min || value > max)
            {
                MessageBox.Show($"Поле \"{field}\": допустимо [{min}..{max}].");
                return false;
            }

            return true;
        }


        private bool TryReadName(TextBox tb, out string name)
        {
            name = (tb.Text ?? "").Trim();

            if (string.IsNullOrWhiteSpace(name))
            {
                MessageBox.Show("Имя фигуры не должно быть пустым.");
                return false;
            }

            if (name.Length > 40)
            {
                MessageBox.Show("Имя фигуры слишком длинное (максимум 40 символов).");
                return false;
            }

            string kostil = name;

            if (ShapeContainer.FigureList.Any(f => string.Equals(f.Name, kostil, StringComparison.OrdinalIgnoreCase)))
            {
                MessageBox.Show("Фигура с таким именем уже существует.");
                return false;
            }

            return true;
        }
    }
}