refactor: clarify frontend module ownership

src/shared/lib/index.ts

@@ -8,3 +8,4 @@ export {
 	formatSnapshotTime,
 	instrumentLogoUrl,
 } from "./display";
+export { useUrlPeriod } from "./useUrlPeriod";

src/shared/lib/useUrlPeriod.ts

@@ -0,0 +1,27 @@
+import { useEffect } from "react";
+import { useSearchParams } from "react-router";
+
+import { isValidPeriod } from "./calendar";
+
+function useUrlPeriod() {
+	const [parameters, setParameters] = useSearchParams();
+	const from = parameters.get("from");
+	const to = parameters.get("to");
+	const isValid = isValidPeriod(from, to);
+	useEffect(() => {
+		if (isValid || (!parameters.has("from") && !parameters.has("to"))) return;
+		const normalized = new URLSearchParams(parameters);
+		normalized.delete("from");
+		normalized.delete("to");
+		setParameters(normalized, { replace: true });
+	}, [isValid, parameters, setParameters]);
+
+	return {
+		from: isValid ? from : null,
+		parameters,
+		setParameters,
+		to: isValid ? to : null,
+	};
+}
+
+export { useUrlPeriod };