using System;
using System.Linq;
using System.Reactive.Linq;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Markup.Xaml;
using Avalonia.Media;
using Avalonia.Threading;
using Masuit.Tools;

namespace DispenserUI.Views.Controls;

public partial class CoordinateViewer : UserControl
{
    public static readonly StyledProperty<double[][]> CoordsProperty =
        AvaloniaProperty.Register<CoordinateViewer,
            double[][]>(nameof(Coords));

    public static readonly StyledProperty<double[][]> PathProperty =
        AvaloniaProperty.Register<CoordinateViewer,
            double[][]>(nameof(Path));

    public static readonly StyledProperty<bool> RotateProperty =
        AvaloniaProperty.Register<CoordinateViewer,
            bool>(nameof(Rotate));

    private readonly object _lock = new();

    public CoordinateViewer()
    {
        InitializeComponent();
        this.GetObservable(CoordsProperty).Throttle(TimeSpan.FromMilliseconds(1000))
            .Subscribe(val =>
            {
                if (val.IsNullOrEmpty()) return;
                Dispatcher.UIThread.InvokeAsync(InvalidateVisual);
            });
        this.GetObservable(PathProperty).Throttle(TimeSpan.FromSeconds(1))
            .Subscribe(val =>
            {
                if (val.IsNullOrEmpty()) return;
                Dispatcher.UIThread.InvokeAsync(InvalidateVisual);
            });
    }

    private void InitializeComponent()
    {
        AvaloniaXamlLoader.Load(this);
    }

    public double[][] Coords
    {
        get => GetValue(CoordsProperty);
        set => SetValue(CoordsProperty, value);
    }

    public double[][] Path
    {
        get => GetValue(PathProperty);
        set => SetValue(PathProperty, value);
    }

    public bool Rotate
    {
        get => GetValue(RotateProperty);
        set => SetValue(RotateProperty, value);
    }

    public override void Render(DrawingContext context)
    {
        lock (_lock)
        {
            base.Render(context);

            if (Coords.IsNullOrEmpty())
            {
                return;
            }

            var coords = CloneCoords(Coords);

            var boundsWidth = DesiredSize.Width;
            var boundsHeight = DesiredSize.Height;

            if (Rotate)
            {
                // 将坐标进行旋转90°
                Rotate90Degrees(coords);
            }

            // 将坐标进行Y轴翻转
            var points = coords.Select(point => new Point(-point[0], point[1])).ToList();

            // 找到坐标中最小的X、Y坐标
            var minX = points.Min(point => point.X);
            // 查找最小的Y
            var minY = points.Min(point => point.Y);
            // 找到最大的X
            var maxX = points.Max(point => point.X);
            // 找到最大的Y
            var maxY = points.Max(point => point.Y);

            var aspectRatio = (maxY - minY) / (maxX - minX);

            // 更改缩放比例，使得容器的宽高比尽量接近坐标的宽高比
            var scaleBoundsWidth = boundsHeight / aspectRatio;

            var scaleX = scaleBoundsWidth / (maxX - minX);
            var scaleY = boundsHeight / (maxY - minY);

            var offsetX = (boundsWidth - (maxX - minX) * scaleX) / 2;


            foreach (var point in points)
            {
                // 将X 进行居中对齐
                var x = (point.X - minX) * scaleX + offsetX;
                var y = (point.Y - minY) * scaleY;


                var rect = new Rect(x, y, 2, 5);

                var pen = new Pen(Brushes.Black, 0.5);
                context.DrawRectangle(pen, rect);
            }


            // 如果路径不为空的话，绘制路径
            if (Path.IsNullOrEmpty()) return;

            // 计算出路径的坐标点
            var paths = Path
                .Select(point => new Point((-point[0] - minX) * scaleX + offsetX, (point[1] - minY) * scaleY)).ToList();

            var geometry = new StreamGeometry();

            using (var ctx = geometry.Open())
            {
                ctx.BeginFigure(paths[0], false);
                foreach (var point in paths.Skip(1))
                {
                    ctx.LineTo(point);
                }

                ctx.EndFigure(false);
            }

            // 绘制路径
            context.DrawGeometry(null, new Pen(Brushes.Red, 1), geometry);

            // 在开始的第一个点标注为绿色
            var startPoint = paths[0];
            context.DrawEllipse(new SolidColorBrush(Colors.Green), new Pen(Brushes.Green, 1),
                new Rect(new Point(startPoint.X - 2, startPoint.Y - 2), new Size(5, 5)));

            // 最后一个点标注为黄色
            var endPoint = paths[^1];
            context.DrawEllipse(new SolidColorBrush(Colors.Yellow), new Pen(Brushes.Yellow, 1),
                new Rect(new Point(endPoint.X - 2, endPoint.Y - 2), new Size(5, 5)));
        }
    }

    private static void Rotate90Degrees(double[][] coords)
    {
        foreach (var coord in coords)
        {
            var tempX = coord[0];
            var tempY = coord[1];
            coord[0] = -tempY;
            coord[1] = tempX;
        }
    }

    private static double[][] CloneCoords(double[][] original)
    {
        var copy = new double[original.Length][];

        // 逐行复制
        for (var i = 0; i < original.Length; i++)
        {
            copy[i] = new double[original[i].Length];
            Array.Copy(original[i], copy[i], original[i].Length);
        }

        return copy;
    }
}