From 49592ac660ab788dcdc0211d467fa8220f7e0af1 Mon Sep 17 00:00:00 2001
From: Jacob Sommer <js0mmer@users.noreply.github.com>
Date: Wed, 13 Nov 2024 15:22:26 -0800
Subject: [PATCH] Do duplicate review check on frontend (#501)

* frontend check for duplicate review in form

* remove explicit dup check on backend
---
 api/src/controllers/reviews.ts               | 12 ----------
 site/src/component/ReviewForm/ReviewForm.tsx | 25 +++++++++++++++++---
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/api/src/controllers/reviews.ts b/api/src/controllers/reviews.ts
index 66b4a54d..61b16217 100644
--- a/api/src/controllers/reviews.ts
+++ b/api/src/controllers/reviews.ts
@@ -125,18 +125,6 @@ const reviewsRouter = router({
       verified: verifiedCount >= 3, // auto-verify if use has 3+ verified reviews
     };
 
-    /** @todo: do a check for existing review on the frontend, remove this for the sake of speed since constraints will already prevent duplicate reviews on insertion */
-    //check if review already exists for same professor, course, and user (do this before verifying captcha)
-    const existingReview = await db
-      .select({ count: count() })
-      .from(review)
-      .where(
-        and(eq(review.userId, userId), eq(review.courseId, input.courseId), eq(review.professorId, input.professorId)),
-      );
-    if (existingReview[0].count > 0) {
-      throw new TRPCError({ code: 'BAD_REQUEST', message: 'You have already reviewed this professor and course!' });
-    }
-
     // Verify the captcha
     const verifyResponse = await verifyCaptcha(reviewToAdd);
     if (!verifyResponse?.success) throw new TRPCError({ code: 'BAD_REQUEST', message: 'ReCAPTCHA token is invalid' });
diff --git a/site/src/component/ReviewForm/ReviewForm.tsx b/site/src/component/ReviewForm/ReviewForm.tsx
index cb844bd5..715ad624 100644
--- a/site/src/component/ReviewForm/ReviewForm.tsx
+++ b/site/src/component/ReviewForm/ReviewForm.tsx
@@ -10,7 +10,7 @@ import RangeSlider from 'react-bootstrap-range-slider';
 import Modal from 'react-bootstrap/Modal';
 import ReCAPTCHA from 'react-google-recaptcha';
 import { addReview, editReview } from '../../store/slices/reviewSlice';
-import { useAppDispatch } from '../../store/hooks';
+import { useAppDispatch, useAppSelector } from '../../store/hooks';
 import { ReviewProps } from '../Review/Review';
 import ThemeContext from '../../style/theme-context';
 import { quarters } from '@peterportal/types';
@@ -63,6 +63,7 @@ const ReviewForm: FC<ReviewFormProps> = ({
   const [anonymous, setAnonymous] = useState(reviewToEdit?.userDisplay === anonymousName);
   const [validated, setValidated] = useState(false);
   const { darkMode } = useContext(ThemeContext);
+  const reviews = useAppSelector((state) => state.review.reviews);
   useEffect(() => {
     if (show) {
       // form opened
@@ -158,6 +159,12 @@ const ReviewForm: FC<ReviewFormProps> = ({
     }
   };
 
+  const alreadyReviewedCourseProf = (courseId: string, professorId: string) => {
+    return reviews.some(
+      (review) => review.courseId === courseId && review.professorId === professorId && review.authored,
+    );
+  };
+
   // select instructor if in course context
   const instructorSelect = courseProp && (
     <Form.Group>
@@ -176,8 +183,14 @@ const ReviewForm: FC<ReviewFormProps> = ({
         </option>
         {Object.keys(courseProp?.instructors).map((ucinetid) => {
           const name = courseProp?.instructors[ucinetid].name;
+          const alreadyReviewed = alreadyReviewedCourseProf(courseProp?.id, ucinetid);
           return (
-            <option key={ucinetid} value={ucinetid}>
+            <option
+              key={ucinetid}
+              value={ucinetid}
+              title={alreadyReviewed ? 'You have already reviewed this professor' : undefined}
+              disabled={alreadyReviewed}
+            >
               {name}
             </option>
           );
@@ -210,8 +223,14 @@ const ReviewForm: FC<ReviewFormProps> = ({
         {Object.keys(professorProp?.courses).map((courseID) => {
           const name =
             professorProp?.courses[courseID].department + ' ' + professorProp?.courses[courseID].courseNumber;
+          const alreadyReviewed = alreadyReviewedCourseProf(courseID, professorProp?.ucinetid);
           return (
-            <option key={courseID} value={courseID}>
+            <option
+              key={courseID}
+              value={courseID}
+              title={alreadyReviewed ? 'You have already reviewed this course' : undefined}
+              disabled={alreadyReviewed}
+            >
               {name}
             </option>
           );