refactor: recompose and memoise (#522)

apps/client/src/features/cuesheet/cuesheet-table-header/CuesheetTableHeaderTimers.tsx

@@ -0,0 +1,31 @@
+import { formatDisplay } from 'ontime-utils';
+
+import { useTimer } from '../../../common/hooks/useSocket';
+import { formatTime } from '../../../common/utils/time';
+
+import style from './CuesheetTableHeader.module.scss';
+
+export default function CuesheetTableHeaderTimers() {
+  const timer = useTimer();
+
+  // prepare presentation variables
+  const isOvertime = (timer.current ?? 0) < 0;
+  const timerNow = timer.current == null ? '-' : `${isOvertime ? '-' : ''}${formatDisplay(timer.current)}`;
+  const timeNow = formatTime(timer.clock, {
+    showSeconds: true,
+    format: 'hh:mm:ss a',
+  });
+
+  return (
+    <>
+      <div className={style.timer}>
+        <div className={style.timerLabel}>Running Timer</div>
+        <div className={style.value}>{timerNow}</div>
+      </div>
+      <div className={style.clock}>
+        <div className={style.clockLabel}>Time Now</div>
+        <div className={style.value}>{timeNow}</div>
+      </div>
+    </>
+  );
+}