Add the icon-by-value widget: first matching rule picks glyph, colour and label

frontend/src/components/Dashboard/IconWidget.tsx

@@ -1,6 +1,70 @@
+import type { WidgetDef } from "@/client"
+import { useLiveValue } from "@/components/Flow/liveStore"
+import { cn } from "@/lib/utils"
+import { ICON_COLORS, ICONS } from "./icons"
 import type { WidgetProps } from "./widgets"
 
-/** An icon — a stub until the icon widget is written. */
+/** One row of the mapping, as the document stores it. */
-export function IconWidget(_props: WidgetProps) {
+type Rule = { at?: unknown; icon?: string; color?: string; label?: string }
-  return <p className="text-sm text-muted-foreground">—</p>
+
+const config = (widget: WidgetDef) =>
+  (widget.config ?? {}) as Record<string, unknown>
+
+const text = (value: unknown, fallback = "") =>
+  value === null || value === undefined ? fallback : String(value)
+
+/** What a mapped value was meant to be: a bool, a number, or the text itself. */
+function coerce(raw: string): unknown {
+  const asNumber = Number(raw)
+  if (raw === "true" || raw === "false") return raw === "true"
+  return raw !== "" && Number.isFinite(asNumber) ? asNumber : raw
+}
+
+/**
+ * Whether a row claims this reading.
+ *
+ * Equality, plus `>=` when both sides are numbers: a ladder written from the
+ * top down then reads as thresholds, one field per row instead of a pair.
+ */
+const matches = (value: unknown, at: unknown) =>
+  value === at ||
+  (typeof value === "number" && typeof at === "number" && value >= at)
+
+/**
+ * A glyph picked by what a message says.
+ *
+ * Rows are checked top to bottom and the first match wins, so a weather
+ * condition, a boolean hint and a threshold ladder all fit the same widget.
+ */
+export function IconWidget({ widget }: WidgetProps) {
+  const cfg = config(widget)
+  const message = text(cfg.message)
+  const live = useLiveValue(message || undefined)
+
+  const value = live?.value
+  const rules = (cfg.rules ?? []) as Rule[]
+  const matched =
+    value === null || value === undefined
+      ? undefined
+      : rules.find((rule) => matches(value, coerce(text(rule.at))))
+  const Glyph = ICONS[matched?.icon ?? text(cfg.icon)] ?? null
+
+  // Unbound, unmatched, or pointed at a glyph that is not in the map.
+  if (!Glyph) return <p className="text-3xl text-muted-foreground">—</p>
+
+  return (
+    <div className="flex min-w-0 flex-col items-center justify-center gap-1">
+      <Glyph
+        className={cn("size-10", ICON_COLORS[matched?.color ?? "default"])}
+        // State is never carried by colour alone.
+        aria-label={matched?.label || text(value, "—")}
+        data-testid="icon-glyph"
+      />
+      {matched?.label ? (
+        <span className="w-full truncate text-center text-sm text-muted-foreground">
+          {matched.label}
+        </span>
+      ) : null}
+    </div>
+  )
 }