#region Setup
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using ChartForgeX.Core;
using ChartForgeX.Primitives;
using ChartForgeX.Rendering;
using ChartForgeX.Themes;
using ChartForgeX.Topology;
using ChartForgeX.Typography;
using ChartForgeX.VisualArtifacts;
using ChartForgeX.VisualBlocks;

var mode = VisualThemeMode.Dark;
var theme = VisualTheme.Graphite();
var model = SankeyOptionsRecipe.Create("quantitative-colors", mode);
var context = new VisualRenderContext(
    new VisualLayoutOptions(new VisualSize(800, 440)), theme, mode,
    new VisualFrame("Requests across processing stages", "Request counts size ribbons; independent latency measurements color them", showLegend: null, showSurface: false));
var prepared = model.Prepare(context);
File.WriteAllText("visual.svg", prepared.ToSvg());
File.WriteAllBytes("visual.png", prepared.ToPng());
File.WriteAllText("visual.html", prepared.ToArtifact("example", VisualArtifactKind.Chart).ToHtmlPage());
#endregion

/// <summary>Aligned and ordered flows retain parallel-link identities and independent link paint.</summary>
public static class SankeyOptionsRecipe {
    public static Chart Create(string variant = "options", VisualThemeMode mode = VisualThemeMode.Light) {
        var requests = ChartSeries.CreateSankey(new ChartSeriesId("request-flows"), "Requests", new[] {
            new ChartNode("received", "Received"), new ChartNode("north", "North"), new ChartNode("south", "South"),
            new ChartNode("north-support", "Support"), new ChartNode("south-support", "Support"), new ChartNode("completed", "Completed"),
            new ChartNode("review", "Review"), new ChartNode("imported", "Imported")
        }, new[] {
            new ChartFlowLink("received-north", "received", "north", 72), new ChartFlowLink("received-south", "received", "south", 28),
            new ChartFlowLink("north-standard", "north", "north-support", 52), new ChartFlowLink("north-priority", "north", "north-support", 20),
            new ChartFlowLink("south-standard", "south", "south-support", 28),
            new ChartFlowLink("north-completed", "north-support", "completed", 72), new ChartFlowLink("south-completed", "south-support", "completed", 28),
            new ChartFlowLink("received-review", "received", "review", 5), new ChartFlowLink("imported-completed", "imported", "completed", 10)
        });
        var quantitative = variant.EndsWith("quantitative-colors", StringComparison.Ordinal);
        if (quantitative) {
            // Illustrative latency is an independent color fact; request weights and flow identities remain unchanged.
            var latency = new double?[] { 180, 95, 125, 40, 0, null, 65, 110, 210 };
            requests.ReplaceFlowData(requests.Nodes, requests.FlowLinks.Select((link, index) =>
                new ChartFlowLink(link.Id, link.SourceId, link.TargetId, link.Value, latency[index])));
        }
        requests.WithNodeState("north-support", ChartSeriesState.Warning).WithPointColor(0, ChartColor.FromHex("#7356BD"))
            .WithFlowStyle("north-priority", new ChartFlowStyle(fill: ChartColor.FromHex("#AF6B24"), fillOpacity: .7,
                fillPattern: ChartFillPattern.DiagonalForward, stroke: ChartColor.FromHex("#764415"), strokeWidth: 1))
            .WithFlowState("north-priority", ChartSeriesState.Warning);
        var chart = Chart.Create().AddSeries(requests).ConfigureSankey(options => {
            options.Alignment = ChartSankeyAlignment.Center;
            options.VerticalAlignment = ChartSankeyVerticalAlignment.Top;
            options.NodeOrder = ChartSankeyNodeOrder.LabelAscending;
            options.LabelPlacement = ChartSankeyLabelPlacement.Center;
            options.EdgeLabelPlacement = ChartSankeyEdgeLabelPlacement.Outside;
            options.NodeWidth = 16; options.NodeGap = 12; options.NodeCornerRadius = 1;
            options.RibbonFill = ChartColor.FromHex("#607DAA"); options.RibbonOpacity = .45;
        });
        if (variant.EndsWith("source-colors", StringComparison.Ordinal) || variant.EndsWith("target-colors", StringComparison.Ordinal) || quantitative) {
            chart.ConfigureSankey(options => {
                options.RibbonFill = null; // Let the selected endpoint or measurement policy supply ribbon paint.
                options.FlowColorMode = quantitative ? ChartSankeyFlowColorMode.Quantitative
                    : variant.EndsWith("target-colors", StringComparison.Ordinal) ? ChartSankeyFlowColorMode.Target : ChartSankeyFlowColorMode.Source;
                if (quantitative) {
                    options.ColorScale = ChartColorScale.Sequential(ChartColor.FromHex("#2166AC"), ChartColor.FromHex("#B2182B"))
                        .WithValueRange(0, 240).WithNoDataColor(ChartColor.FromHex("#9CA3AF"));
                    options.ColorDimension.Name = "Illustrative latency";
                    options.ColorDimension.ValueFormat = ChartValueFormat.Number("0 'ms'", CultureInfo.InvariantCulture);
                    options.ColorDimension.LegendStyle = ChartColorLegendStyle.Gradient;
                }
            });
            if (quantitative) chart.WithLegend(true).ConfigureLabels(labels => labels.NoData = "Not sampled");
        }
        return chart;
    }
}