SQLVision/SQLVision.Visualizers/Visualizers/ChartVisualizer.cs

using SQLVision.Core.Enums;
using SQLVision.Core.Models;
using SQLVision.Visualizers.Interfaces;
using System.Data;

namespace SQLVision.Visualizers.Visualizers;

public class ChartVisualizer : IVisualizer
{
    public FrameworkElement Visualize(DataTable data, OutputDefinition definition)
    {
        if (data.Rows.Count == 0)
        {
            return CreateEmptyChartMessage("Нет данных для построения графика");
        }

        try
        {
            var chartType = definition.ChartType;
            var cartesianChart = new CartesianChart
            {
                Series = CreateSeries(data, definition),
                XAxes = CreateXAxes(data, definition),
                YAxes = CreateYAxes(definition),
                LegendPosition = LegendPosition.Right,
                TooltipPosition = LiveChartsCore.Measure.TooltipPosition.Hidden
            };

            return cartesianChart;
        }
        catch (Exception)
        {
            return CreateEmptyChartMessage("Ошибка при построении графика");
        }
    }

    private ISeries[] CreateSeries(DataTable data, OutputDefinition definition)
    {
        var series = new List<ISeries>();

        if (!string.IsNullOrEmpty(definition.SeriesColumn))
        {
            // Разделение по сериям
            var seriesGroups = data.AsEnumerable()
                .GroupBy(row => row[definition.SeriesColumn])
                .ToList();

            foreach (var group in seriesGroups)
            {
                var seriesName = group.Key.ToString();
                var values = group.Select(row =>
                {
                    if (string.IsNullOrEmpty(definition.YAxisColumn))
                        return Convert.ToDouble(row[1]);
                    return Convert.ToDouble(row[definition.YAxisColumn]);
                }).ToArray();

                series.Add(CreateSeriesByType(definition.ChartType, values, seriesName));
            }
        }
        else
        {
            // Одна серия
            var values = data.AsEnumerable()
                .Select(row =>
                {
                    if (string.IsNullOrEmpty(definition.YAxisColumn))
                        return Convert.ToDouble(row[1]);
                    return Convert.ToDouble(row[definition.YAxisColumn]);
                }).ToArray();

            series.Add(CreateSeriesByType(definition.ChartType, values, definition.Description));
        }

        return series.ToArray();
    }

    private ISeries CreateSeriesByType(ChartType chartType, double[] values, string name)
    {
        return chartType switch
        {
            ChartType.Line => new LineSeries<double>
            {
                Values = values,
                Name = name,
                Fill = null,
                GeometrySize = 8,
                LineSmoothness = 0
            },
            ChartType.Bar => new ColumnSeries<double>
            {
                Values = values,
                Name = name
            },
            ChartType.Area => new LineSeries<double>
            {
                Values = values,
                Name = name,
                Fill = new SolidColorPaint(SKColors.Blue.WithAlpha(50))
            },
            ChartType.Scatter => new ScatterSeries<ObservablePoint>
            {
                Values = values.Select((v, i) => new ObservablePoint(i, v)),
                Name = name,
                GeometrySize = 10
            },
            _ => new LineSeries<double>
            {
                Values = values,
                Name = name
            }
        };
    }

    private Axis[] CreateXAxes(DataTable data, OutputDefinition definition)
    {
        var labels = new List<string>();

        if (!string.IsNullOrEmpty(definition.XAxisColumn))
        {
            labels = data.AsEnumerable()
                .Select(row => row[definition.XAxisColumn].ToString())
                .ToList();
        }
        else if (data.Columns.Count > 0)
        {
            // Берем первый столбец для оси X
            labels = data.AsEnumerable()
                .Select(row => row[0].ToString())
                .ToList();
        }
        else
        {
            labels = Enumerable.Range(0, data.Rows.Count)
                .Select(i => i.ToString())
                .ToList();
        }

        return new[]
        {
            new Axis
            {
                Labels = labels.ToArray(),
                LabelsRotation = labels.Count > 10 ? 45 : 0,
                TextSize = 12
            }
        };
    }

    private Axis[] CreateYAxes(OutputDefinition definition)
    {
        return new[]
        {
            new Axis
            {
                Name = string.IsNullOrEmpty(definition.YAxisColumn) ? "Значения" : definition.YAxisColumn,
                TextSize = 12
            }
        };
    }

    private FrameworkElement CreateEmptyChartMessage(string message)
    {
        var textBlock = new TextBlock
        {
            Text = message,
            HorizontalAlignment = HorizontalAlignment.Center,
            VerticalAlignment = VerticalAlignment.Center,
            FontSize = 16,
            Foreground = new Microsoft.UI.Xaml.Media.SolidColorBrush(Microsoft.UI.Colors.Gray)
        };

        var border = new Border
        {
            Child = textBlock,
            Background = new Microsoft.UI.Xaml.Media.SolidColorBrush(Microsoft.UI.Colors.Transparent),
            Padding = new Thickness(20)
        };

        return border;
    }

    public bool CanVisualize(OutputType type) => type == OutputType.Chart;
}