BITKit/Src/Unity/Scripts/UX/Chart/SkiaChart.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using UnityEngine;
using UnityEngine.UIElements;


namespace BITKit.UX
{
	public class LineChart : VisualElement
	{
		public new class UxmlTraits : VisualElement.UxmlTraits
		{
			private readonly UxmlStringAttributeDescription m_JsonAttribute = new()
			{
				name = "Json"
			};

			private readonly UxmlBoolAttributeDescription m_allowWarningsAttribute = new()
			{
				name = "allowWarnings",
				defaultValue = false
			};

			public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc)
			{
				base.Init(ve, bag, cc);
				var x = (LineChart)ve;
				x.Json = m_JsonAttribute.GetValueFromBag(bag, cc);
				x.AllowWarning = m_allowWarningsAttribute.GetValueFromBag(bag, cc);

			}
		}

		public new class UxmlFactory : UxmlFactory<LineChart, UxmlTraits>
		{
		}

		public LineChart()
		{
			RegisterCallback<CustomStyleResolvedEvent>(OnCustomStyleResolved);
	

			style.flexDirection = FlexDirection.Row;
			_dataContainer = this.Create<VisualElement>();
			_chartContainer = this.Create<VisualElement>();
			_chartContainer.style.flexGrow = 1;

			_dataContainer.style.justifyContent = Justify.SpaceBetween;

			_dataContainer.name = "Data";
			_chartContainer.name = "Chart";
			
			_chartContainer.generateVisualContent+= GenerateVisualContent;
			
			 _chartContainer.style.marginBottom = 0;
			 _chartContainer.style.marginLeft = 8;
			 _chartContainer.style.marginRight = 8;
			 _chartContainer.style.marginTop = 0 ;

			 pickingMode = PickingMode.Ignore;
			 _dataContainer.pickingMode = PickingMode.Ignore;
			 
			 _chartContainer.style.flexDirection = FlexDirection.RowReverse;
			_dataContainer.style.flexDirection = FlexDirection.ColumnReverse;
			
			_chartContainer.RegisterCallback<PointerMoveEvent>(OnPointerMove);
		}

		private void OnPointerMove(PointerMoveEvent evt)
		{
			//_chartContainer.tooltip = evt.localPosition.ToString();
		}

		private void OnCustomStyleResolved(CustomStyleResolvedEvent evt)
		{
			if (evt.customStyle.TryGetValue(new CustomStyleProperty<Color>("--chart-secondary-color"),
				    out var helpLineColor))
			{
				_secondaryColor = helpLineColor;
			}

			for (int i = 0; i < 8; i++)
			{
				if (evt.customStyle.TryGetValue(new CustomStyleProperty<Color>($"--chart-line-color--{i}"),
					    out var lineColor))
				{
					_lineColors[i] = lineColor;
				}
			}
			
			MarkDirtyRepaint();
		}

		public string Json
		{
			get => _json;
			set
			{
				_json = value;
				GenerateLayout();
			}
		}

		private string _json;
		public bool AllowWarning { get; set; }

		public Color SecondaryColor
		{
			get => _secondaryColor;
			set
			{
				_secondaryColor = value;
				GenerateLayout();
			}
		}

		private Color _secondaryColor;

		private readonly VisualElement _dataContainer;
		private readonly VisualElement _chartContainer;

		private readonly Color[] _lineColors = new[]
		{
			Color.red,
			Color.red,
			Color.red,
			Color.red,
			Color.red,
			Color.red,
			Color.red,
			Color.red,
		};

		private void GenerateLayout()
		{
			JArray[] array;
			float[] data;
			try
			{
				array = JsonConvert.DeserializeObject<JArray[]>(Json);
				data = array.SelectMany(x => x.ToObject<float[]>()).ToArray();
			}
			catch (Exception e)
			{
				if (AllowWarning)
					Debug.LogException(e);
				return;
			}

			if (data is null or { Length: 0 })
			{
				if (AllowWarning)
					BIT4Log.Log<LineChart>("Data is null or empty");
				return;
			}

			
			//假如min是x,max是y,将中间的差用data.Length划分
			var max = data.Max();
			var min = data.Min();

			var difference = max - min;

			var maxLength = array.Select(x => x.Count).Max();

			max += difference / maxLength;
			min -= difference / maxLength;

			//Debug.Log($"min:{min} max:{max} difference:{difference} max:{max}");

			_dataContainer.Clear();
			for (var i = 0; i <= maxLength; i++)
			{
				var label = _dataContainer.Create<Label>();
			
				//var value = (max - min) / (data.Length - 1) * i + min;
			
				var t = (float)i / maxLength;
				var value = Mathf.Lerp(min, max, t);
				label.text = Math.Round(value, 2).ToString();
			}
			MarkDirtyRepaint();
		}

		private void GenerateVisualContent(MeshGenerationContext context)
		{

			if (float.IsNaN(layout.width) || float.IsNaN(layout.height))
			{
				if (AllowWarning)
					BIT4Log.Log<LineChart>("Width or height is NaN");
				return;
			}

			JArray[] array;
			float[] data;
			try
			{
				array = JsonConvert.DeserializeObject<JArray[]>(Json);
				data = array.SelectMany(x => x.ToObject<float[]>()).ToArray();
			}
			catch (Exception e)
			{
				if (AllowWarning)
					Debug.LogException(e);
				return;
			}

			if (data is null or { Length: 0 })
			{
				if (AllowWarning)
					BIT4Log.Log<LineChart>("Data is null or empty");
				return;
			}

			//假如min是x,max是y,将中间的差用data.Length划分
			var max = data.Max();
			var min = data.Min();

			var difference = max - min;

			var maxLength = array.Select(x => x.Count).Max();

			max += difference / maxLength;
			min -= difference / maxLength;
			difference = max - min;
		
			if (_chartContainer.layout.width is float.NaN or < 10 || _chartContainer.layout.height is float.NaN or < 10)
			{
				if (AllowWarning)
					BIT4Log.Log<LineChart>("Width or height is NaN or less than 10");
				return;
			}
	

			var linePaint = context.painter2D;
			linePaint.lineWidth = resolvedStyle.unityTextOutlineWidth;
			var width = contentRect.width;
			var height = contentRect.height;
			
		
			for (var index = 0; index < array.Length; index++)
			{
				var row = array[index];
				DoubleBuffer<Vector2> buffer = new();
				
				data = row.ToObject<float[]>();

				var lastWidth = 0f;

				linePaint.strokeColor = _lineColors[index];
				var tempColor = _lineColors[index];
				tempColor.a *= 0.2f;
				linePaint.fillColor = tempColor;

				linePaint.BeginPath();
	
				linePaint.MoveTo(new(0,height));
				linePaint.lineJoin = LineJoin.Round;
				
				for (var i = 0; i < data.Length; i++)
				{
					var value = data[i];
					var posX = width / data.Length * i;
					var p = (value - min) / difference;
					var poxY = height-height * p;

					var currentPoint = new Vector2(posX, poxY);
					if (buffer.TryGetRelease(out var previousPoint))
					{
						linePaint.LineTo(previousPoint);
					}

					linePaint.LineTo(currentPoint);
			
					buffer.Release(currentPoint);
					
					if(i == data.Length-1)
					{
						lastWidth = posX;
					}
				}
				linePaint.LineTo(new (lastWidth,height));
				linePaint.ClosePath();
				linePaint.Stroke();
				linePaint.Fill();
			}
		}
	}
}