feat: complete pragativeer v2 frontend and backend, docker setup, and cbt engine

src/hooks/useExamTimer.ts

@@ -0,0 +1,49 @@
+import { useEffect, useState, useRef } from 'react';
+import { useCBTStore } from '@/store/cbtStore';
+
+export function useExamTimer() {
+  const { startTime, totalDuration, status, submitExam } = useCBTStore();
+  const [timeRemaining, setTimeRemaining] = useState<number>(totalDuration);
+  const frameRef = useRef<number | null>(null);
+
+  useEffect(() => {
+    if (status !== 'IN_PROGRESS' || !startTime) {
+      return;
+    }
+
+    const calculateTime = () => {
+      const now = Date.now();
+      const elapsedSeconds = Math.floor((now - startTime) / 1000);
+      const remaining = Math.max(0, totalDuration - elapsedSeconds);
+
+      setTimeRemaining(remaining);
+
+      if (remaining === 0) {
+        submitExam('TIMED_OUT');
+      } else {
+        // Use requestAnimationFrame for a high-performance loop instead of setInterval
+        // We throttle updates to when the second actually changes
+        frameRef.current = requestAnimationFrame(calculateTime);
+      }
+    };
+
+    frameRef.current = requestAnimationFrame(calculateTime);
+
+    return () => {
+      if (frameRef.current) cancelAnimationFrame(frameRef.current);
+    };
+  }, [startTime, totalDuration, status, submitExam]);
+
+  // Format HH:MM:SS
+  const hours = Math.floor(timeRemaining / 3600);
+  const minutes = Math.floor((timeRemaining % 3600) / 60);
+  const seconds = timeRemaining % 60;
+
+  const formattedTime = [
+    hours.toString().padStart(2, '0'),
+    minutes.toString().padStart(2, '0'),
+    seconds.toString().padStart(2, '0'),
+  ].join(':');
+
+  return { timeRemaining, formattedTime, isTimedOut: timeRemaining === 0 };
+}