fix(api): fix api logic for exam screen

needs more work for the timercontext

context/TimerContext.tsx

@@ -1,31 +1,36 @@
 "use client";
 
-import React, { createContext, useContext, useState, useEffect } from "react";
+import React, {
+  createContext,
+  useContext,
+  useState,
+  useEffect,
+  useRef,
+} from "react";
 
-// Define the context type
 interface TimerContextType {
   timeRemaining: number;
   resetTimer: (duration: number) => void;
   stopTimer: () => void;
-  setInitialTime: (duration: number) => void; // New function to set the initial time
+  setInitialTime: (duration: number) => void;
 }
 
-// Create the context with a default value of `undefined`
 const TimerContext = createContext<TimerContextType | undefined>(undefined);
 
-// Provider Component
 export const TimerProvider: React.FC<{ children: React.ReactNode }> = ({
   children,
 }) => {
-  const [timeRemaining, setTimeRemaining] = useState<number>(0); // Default is 0
-  let timer: NodeJS.Timeout;
+  const [timeRemaining, setTimeRemaining] = useState<number>(0);
+  const timerRef = useRef<NodeJS.Timeout | null>(null);
 
+  // countdown effect
   useEffect(() => {
-    if (timeRemaining > 0) {
-      timer = setInterval(() => {
+    if (timeRemaining > 0 && !timerRef.current) {
+      timerRef.current = setInterval(() => {
         setTimeRemaining((prev) => {
           if (prev <= 1) {
-            clearInterval(timer);
+            clearInterval(timerRef.current!);
+            timerRef.current = null;
             return 0;
           }
           return prev - 1;
@@ -34,20 +39,29 @@ export const TimerProvider: React.FC<{ children: React.ReactNode }> = ({
     }
 
     return () => {
-      clearInterval(timer); // Cleanup timer on unmount
+      if (timerRef.current) {
+        clearInterval(timerRef.current);
+        timerRef.current = null;
+      }
     };
   }, [timeRemaining]);
 
   const resetTimer = (duration: number) => {
-    clearInterval(timer);
+    if (timerRef.current) clearInterval(timerRef.current);
+    timerRef.current = null;
     setTimeRemaining(duration);
   };
 
   const stopTimer = () => {
-    clearInterval(timer);
+    if (timerRef.current) {
+      clearInterval(timerRef.current);
+      timerRef.current = null;
+    }
   };
 
   const setInitialTime = (duration: number) => {
+    if (timerRef.current) clearInterval(timerRef.current);
+    timerRef.current = null;
     setTimeRemaining(duration);
   };
 
@@ -60,7 +74,6 @@ export const TimerProvider: React.FC<{ children: React.ReactNode }> = ({
   );
 };
 
-// Hook to use the TimerContext
 export const useTimer = (): TimerContextType => {
   const context = useContext(TimerContext);
   if (!context) {