using System;
using Microsoft.Maui.Graphics;
using Microsoft.Maui.Graphics.Skia.Views;
using PointStateType = Tizen.NUI.PointStateType;
 
namespace Microsoft.Maui.Platform
{
	public class PlatformTouchGraphicsView : SkiaGraphicsView
	{
		IGraphicsView? _graphicsView;
		RectF _bounds;
		bool _dragStarted;
		PointF[] _lastMovedViewPoints = Array.Empty<PointF>();
		bool _pressedContained;
 
		public PlatformTouchGraphicsView(IDrawable? drawable = null) : base(drawable)
		{
			HoverEvent += OnHoverEvent;
			TouchEvent += OnTouchEvent;
		}
 
		protected override void OnResized()
		{
			base.OnResized();
			_bounds = new RectF(0, 0, SizeWidth.ToScaledDP(), SizeHeight.ToScaledDP());
		}
 
		public void Connect(IGraphicsView graphicsView) => _graphicsView = graphicsView;
 
		public void Disconnect() => _graphicsView = null;
 
		bool OnTouchEvent(object source, TouchEventArgs e)
		{
			int touchCount = (int)e.Touch.GetPointCount();
			var touchPoints = new PointF[touchCount];
			for (uint i = 0; i < touchCount; i++)
				touchPoints[i] = new PointF(e.Touch.GetLocalPosition(i).X.ToScaledDP(), e.Touch.GetLocalPosition(i).Y.ToScaledDP());
 
			switch (e.Touch.GetState(0))
			{
				case PointStateType.Motion:
					TouchesMoved(touchPoints);
					break;
				case PointStateType.Down:
					TouchesBegan(touchPoints);
					break;
				case PointStateType.Up:
					TouchesEnded(touchPoints);
					break;
				case PointStateType.Interrupted:
					TouchesCanceled();
					break;
			}
 
			return false;
		}
 
		bool OnHoverEvent(object source, HoverEventArgs e)
		{
			int touchCount = (int)e.Hover.GetPointCount();
			var touchPoints = new PointF[touchCount];
			for (uint i = 0; i < touchCount; i++)
				touchPoints[i] = new PointF(e.Hover.GetLocalPosition(i).X.ToScaledDP(), e.Hover.GetLocalPosition(i).Y.ToScaledDP());
 
			switch (e.Hover.GetState(0))
			{
				case PointStateType.Motion:
					_graphicsView?.MoveHoverInteraction(touchPoints);
					break;
				case PointStateType.Started:
					_graphicsView?.StartHoverInteraction(touchPoints);
					break;
				case PointStateType.Finished:
					_graphicsView?.EndHoverInteraction();
					break;
			}
 
			return false;
		}
 
		void TouchesBegan(PointF[] points)
		{
			_dragStarted = false;
			_lastMovedViewPoints = points;
			_graphicsView?.StartInteraction(points);
			_pressedContained = true;
		}
 
		void TouchesMoved(PointF[] points)
		{
			if (!_dragStarted)
			{
				if (points.Length == 1)
				{
					float deltaX = _lastMovedViewPoints[0].X - points[0].X;
					float deltaY = _lastMovedViewPoints[0].Y - points[0].Y;
 
					if (MathF.Abs(deltaX) <= 3 && MathF.Abs(deltaY) <= 3)
						return;
				}
			}
 
			_lastMovedViewPoints = points;
			_dragStarted = true;
			_pressedContained = _bounds.ContainsAny(points);
			_graphicsView?.DragInteraction(points);
		}
 
		void TouchesEnded(PointF[] points)
		{
			_graphicsView?.EndInteraction(points, _pressedContained);
		}
 
		void TouchesCanceled()
		{
			_pressedContained = false;
			_graphicsView?.CancelInteraction();
		}
	}
}