feat(scoreboard): unit 3 — edge coupling and line fitting, both pure

ResolveEdges: the strip and the social bar are a coupled pair that own opposite edges whenever both are visible; the social bar keeps its choice and the scoreboard is pushed to the other edge. Hide either and the survivor keeps its own preference — so hiding the scoreboard frees the social bar, which is what 'resolved at render time' has to mean. FitLine: takes MEASURED tile widths (the renderer measures with FormattedText; a guessed character width would make the fit lie for a long handle), keeps full size when it fits, shrinks above the 14px legibility floor, and only then wraps — never scrolls, because a reader cannot wait for the fact to come round.
2026-10-30 14:36:56 -07:00
parent 6b6ccd7b0a
commit 359e58a4c2
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+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace ytLive.Models;
+
+/// <summary>Which edge a full-width bar occupies.</summary>
+public enum BarEdge
+{
+    Top,
+    Bottom,
+}
+
+/// <summary>The scoreboard's placement and line-fitting arithmetic, kept pure so both are testable
+/// without a renderer.
+///
+/// <para>Two rules from the creator (2026-10-30):
+/// the strip and the social bar are a COUPLED pair that own opposite edges, resolved at render time
+/// from what is actually visible; and a strip that does not fit SHRINKS to a floor and then wraps to
+/// a second line — it never scrolls, because a creator reading the screen cannot wait for the fact
+/// to come round.</para></summary>
+public static class ScoreboardLayout
+{
+    public const double FloorFontSize = 14;
+    public const double MaxFontSize = 24;
+
+    /// <summary>Result of fitting the enabled tiles into one strip.</summary>
+    public readonly record struct Fit(double FontSize, int LineCount, bool Shrunk)
+    {
+        public bool Wrapped => LineCount > 1;
+    }
+
+    /// <summary>Resolves the edge pair. When both bars are visible they take opposite edges; the
+    /// social bar keeps its own choice and the scoreboard is pushed to the other one. When either is
+    /// hidden the survivor keeps its preferred edge — so hiding the scoreboard frees the social bar
+    /// to sit anywhere, exactly as the creator asked.</summary>
+    public static (BarEdge Social, BarEdge Scoreboard) ResolveEdges(
+        bool socialVisible, BarEdge socialPreferred,
+        bool scoreboardVisible, BarEdge scoreboardPreferred)
+    {
+        if (socialVisible && scoreboardVisible)
+            return (socialPreferred, Opposite(socialPreferred));
+
+        return (socialPreferred, scoreboardPreferred);
+    }
+
+    public static BarEdge Opposite(BarEdge edge) => edge == BarEdge.Top ? BarEdge.Bottom : BarEdge.Top;
+
+    /// <summary>Fits measured tile widths (at <paramref name="requestedSize"/>) into the available
+    /// width: full size if they fit, otherwise shrink, and only if the shrink would drop below the
+    /// legibility floor does it wrap. Widths are passed in because the renderer MEASURES them —
+    /// guessing a character width would make the fit lie for a wide glyph or a long handle.</summary>
+    public static Fit FitLine(IReadOnlyList<double> tileWidths, double separatorWidth,
+        double availableWidth, double requestedSize = MaxFontSize, double floorSize = FloorFontSize)
+    {
+        var count = tileWidths?.Count ?? 0;
+        if (count == 0 || availableWidth <= 0)
+            return new Fit(requestedSize, 1, false);
+
+        var total = tileWidths!.Sum() + separatorWidth * (count - 1);
+        if (total <= availableWidth)
+            return new Fit(requestedSize, 1, false);
+
+        var scaled = requestedSize * (availableWidth / total);
+        if (scaled >= floorSize)
+            return new Fit(scaled, 1, true);
+
+        // Below the floor: keep the floor and wrap. Greedy packing, measured widths scaled to the
+        // floor size so the line breaks match what is actually drawn.
+        var factor = floorSize / requestedSize;
+        var lines = 1;
+        var lineWidth = 0.0;
+        foreach (var width in tileWidths)
+        {
+            var w = width * factor;
+            var needed = lineWidth == 0 ? w : lineWidth + separatorWidth + w;
+            if (needed > availableWidth && lineWidth > 0)
+            {
+                lines++;
+                lineWidth = w;
+            }
+            else
+            {
+                lineWidth = needed;
+            }
+        }
+        return new Fit(floorSize, lines, true);
+    }
+}