#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 = ComparisonRecipe.Create("compact", mode);
var context = new VisualRenderContext(
    new VisualLayoutOptions(new VisualSize(360, 360)), theme, mode,
    new VisualFrame("Checks over the reporting period", "Observed checks against the forecast and available capacity", 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>Bars, a forecast area and an observed line share daily categories, including explicit missing and empty states.</summary>
public static class ComparisonRecipe {
    public static Chart Create(string variant = "wide", VisualThemeMode mode = VisualThemeMode.Light) {
        var count = variant == "empty" ? 0 : variant == "dense" ? 24 : 12;
        var names = variant == "wrapped-legend"
            ? new[] { "Observed checks across all locations", "Expected coverage of monitored services", "Capacity available for the next assessment" }
            : new[] { "Observed", "Expected", "Capacity" };
        // Bars sit behind the forecast area and the observed line, so the series are added back to front.
        var capacity = ChartSeries.CreateBar(new ChartSeriesId("capacity"), names[2], Points(count, variant, 2, false));
        var expected = ChartSeries.CreateArea(new ChartSeriesId("expected"), names[1], Points(count, variant, 1));
        var observed = ChartSeries.CreateLine(new ChartSeriesId("observed"), names[0], Points(count, variant, 0));
        if (variant is "explicit-status" or "explicit-series") {
            var colors = VisualTheme.Graphite().Resolve(mode);
            var selected = variant == "explicit-status"
                ? new[] { colors.Status.Pass.Fill, colors.Status.Medium.Fill, colors.Status.Critical.Fill }
                : colors.Palette.Take(3).ToArray();
            observed.WithColor(selected[0]); expected.WithColor(selected[1]); capacity.WithColor(selected[2]);
        }
        return Chart.Create().WithXLabels(Enumerable.Range(1, count).Select(index => "Day " + index).ToArray())
            .AddSeries(capacity).AddSeries(expected).AddSeries(observed);
    }

    private static IEnumerable<ChartPoint> Points(int count, string variant, int series, bool allowBreaks = true) {
        for (var index = 0; index < count; index++) {
            if (variant == "missing" && (index == 2 || index == 3)) continue;
            // Capacity grows in steps, the forecast follows it and observed checks swing around the forecast.
            var value = variant == "zero" ? 0.0 : series switch {
                2 => 64 + index / 3 * 5 + index % 3,
                1 => 46 + index * 1.6,
                _ => 44 + index * 1.7 + Math.Round(Math.Sin(index * 1.3) * 7)
            };
            yield return new ChartPoint(index + 1, Math.Round(value), allowBreaks && variant == "missing" && index == 4);
        }
    }
}