Connected.Components/Components/Chart/Charts/Bar.razor.cs

using Microsoft.AspNetCore.Components;

namespace Connected.Components;

partial class Bar : Chart
{
	[CascadingParameter] public Chart ChartParent { get; set; }

	private List<SvgPath> _horizontalLines = new();
	private List<SvgText> _horizontalValues = new();

	private List<SvgPath> _verticalLines = new();
	private List<SvgText> _verticalValues = new();

	private List<SvgLegend> _legends = new();
	private List<ChartSeries> _series = new();

	private List<SvgPath> _bars = new();

	protected override void OnParametersSet()
	{
		base.OnParametersSet();
		_horizontalLines.Clear();
		_verticalLines.Clear();
		_horizontalValues.Clear();
		_verticalValues.Clear();
		_legends.Clear();
		_bars.Clear();

		if (ChartParent != null)
			_series = ChartParent.ChartSeries;

		var maxY = 0.0;
		var numValues = 0;
		var numXLabels = XAxisLabels.Length;
		foreach (var item in _series)
		{
			if (numValues < item.Data.Length)
			{
				numValues = item.Data.Length;
			}
			foreach (int i in item.Data)
			{
				if (maxY < i)
				{
					maxY = i;
				}
			}
		}

		var boundHeight = 350.0;
		var boundWidth = 650.0;

		double gridYUnits = ChartParent?.ChartOptions.YAxisTicks ?? 20;
		double gridXUnits = 30;

		var numVerticalLines = numValues - 1;

		var numHorizontalLines = ((int)(maxY / gridYUnits)) + 1;

		var verticalStartSpace = 25.0;
		var horizontalStartSpace = 30.0;
		var verticalEndSpace = 25.0;
		var horizontalEndSpace = 30.0;

		var verticalSpace = (boundHeight - verticalStartSpace - verticalEndSpace) / (numHorizontalLines);
		var horizontalSpace = (boundWidth - horizontalStartSpace - horizontalEndSpace) / (numVerticalLines);

		//Horizontal Grid Lines
		var y = verticalStartSpace;
		double startGridY = 0;
		for (var counter = 0; counter <= numHorizontalLines; counter++)
		{
			var line = new SvgPath()
			{
				Index = counter,
				Data = $"M {ToS(horizontalStartSpace)} {ToS((boundHeight - y))} L {ToS((boundWidth - horizontalEndSpace))} {ToS((boundHeight - y))}"
			};
			_horizontalLines.Add(line);

			var lineValue = new SvgText() { X = (horizontalStartSpace - 10), Y = (boundHeight - y + 5), Value = ToS(startGridY, ChartParent?.ChartOptions.YAxisFormat) };
			_horizontalValues.Add(lineValue);

			startGridY += gridYUnits;
			y += verticalSpace;
		}

		//Vertical Grid Lines
		var x = horizontalStartSpace;
		double startGridX = 0;
		for (var counter = 0; counter <= numVerticalLines; counter++)
		{

			var line = new SvgPath()
			{
				Index = counter,
				Data = $"M {ToS(x)} {ToS((boundHeight - verticalStartSpace))} L {ToS(x)} {ToS(verticalEndSpace)}"
			};
			_verticalLines.Add(line);

			var xLabels = "";
			if (counter < numXLabels)
			{
				xLabels = XAxisLabels[counter];
			}

			var lineValue = new SvgText() { X = x, Y = boundHeight - 2, Value = xLabels };
			_verticalValues.Add(lineValue);

			startGridX += gridXUnits;
			x += horizontalSpace;
		}


		//Bars
		var colorcounter = 0;
		double barsPerSeries = 0;
		foreach (var item in _series)
		{
			double gridValueX = horizontalStartSpace + barsPerSeries;
			double gridValueY = boundHeight - verticalStartSpace;

			foreach (var dataLine in item.Data)
			{
				var dataValue = dataLine * verticalSpace / gridYUnits;
				var gridValue = gridValueY - dataValue;
				var bar = $"M {ToS(gridValueX)} {ToS(gridValueY)} L {ToS(gridValueX)} {ToS(gridValue)}";

				gridValueX += horizontalSpace;

				var line = new SvgPath()
				{
					Index = colorcounter,
					Data = bar
				};
				_bars.Add(line);
			}

			barsPerSeries += 10;

			var legend = new SvgLegend()
			{
				Index = colorcounter,
				Labels = item.Name
			};
			colorcounter++;
			_legends.Add(legend);
		}
	}
}