fix(ui): fix results screen

context/ExamContext.tsx

@@ -7,6 +7,7 @@ import React, {
   useEffect,
   ReactNode,
 } from "react";
+import { useRouter } from "next/navigation";
 
 import { Exam, ExamAnswer, ExamAttempt, ExamContextType } from "@/types/exam";
 import { getFromStorage, removeFromStorage, setToStorage } from "@/lib/utils";
@@ -21,6 +22,7 @@ const STORAGE_KEYS = {
 export const ExamProvider: React.FC<{ children: ReactNode }> = ({
   children,
 }) => {
+  const router = useRouter();
   const [currentExam, setCurrentExamState] = useState<Exam | null>(null);
   const [currentAttempt, setCurrentAttemptState] = useState<ExamAttempt | null>(
     null
@@ -81,13 +83,14 @@ export const ExamProvider: React.FC<{ children: ReactNode }> = ({
 
   const setCurrentExam = (exam: Exam) => {
     setCurrentExamState(exam);
-
     setCurrentAttemptState(null);
   };
 
   const startExam = () => {
     if (!currentExam) {
-      throw new Error("No exam selected");
+      console.warn("No exam selected, redirecting to /unit");
+      router.push("/unit");
+      return;
     }
 
     const attempt: ExamAttempt = {
@@ -103,7 +106,9 @@ export const ExamProvider: React.FC<{ children: ReactNode }> = ({
 
   const setAnswer = (questionId: string, answer: any) => {
     if (!currentAttempt) {
-      throw new Error("No exam attempt started");
+      console.warn("No exam attempt started, redirecting to /unit");
+      router.push("/unit");
+      return;
     }
 
     setCurrentAttemptState((prev) => {
@@ -138,7 +143,9 @@ export const ExamProvider: React.FC<{ children: ReactNode }> = ({
 
   const setApiResponse = (response: any) => {
     if (!currentAttempt) {
-      throw new Error("No exam attempt started");
+      console.warn("No exam attempt started, redirecting to /unit");
+      router.push("/unit");
+      return;
     }
 
     setCurrentAttemptState((prev) => {
@@ -150,9 +157,11 @@ export const ExamProvider: React.FC<{ children: ReactNode }> = ({
     });
   };
 
-  const submitExam = (): ExamAttempt => {
+  const submitExam = (): ExamAttempt | null => {
     if (!currentAttempt) {
-      throw new Error("No exam attempt to submit");
+      console.warn("No exam attempt to submit, redirecting to /unit");
+      router.push("/unit");
+      return null;
     }
 
     // Calculate score (simple example - you can customize this)
@@ -209,7 +218,7 @@ export const ExamProvider: React.FC<{ children: ReactNode }> = ({
   const isExamStarted = () => !!currentExam && !!currentAttempt;
 
   const isExamCompleted = (): boolean => {
-    if (!isHydrated) return false; // ⛔ wait for hydration
+    if (!isHydrated) return false; // wait for hydration
     return currentAttempt !== null && currentAttempt.endTime !== undefined;
   };
 
@@ -246,12 +255,18 @@ export const useExam = (): ExamContextType => {
   return context;
 };
 
-// Hook for exam results (only when exam is completed)
-export const useExamResults = (): ExamAttempt => {
-  const { currentAttempt, isExamCompleted } = useExam();
+// Hook for exam results (only when exam is completed) - now returns null instead of throwing
+export const useExamResults = (): ExamAttempt | null => {
+  const { currentAttempt, isExamCompleted, isHydrated } = useExam();
 
+  // Wait for hydration before making decisions
+  if (!isHydrated) {
+    return null;
+  }
+
+  // If no completed exam is found, return null (let component handle redirect)
   if (!isExamCompleted() || !currentAttempt) {
-    throw new Error("No completed exam attempt found");
+    return null;
   }
 
   return currentAttempt;