feat: implement automated sentiment analysis for product reviews

backend/controller/reviewController.js

@@ -4,6 +4,10 @@ import Product from "../model/productModel.js";
 import User from "../model/userModel.js";
 import { sendNotification } from "../services/notificationService.js";
 
+// 1. Import and initialize the sentiment library
+import Sentiment from 'sentiment';
+const sentiment = new Sentiment();
+
 async function recalculateProductRating(productId) {
   const result = await Review.aggregate([
     { $match: { productId: new mongoose.Types.ObjectId(productId) } },
@@ -45,6 +49,19 @@ export const addReview = async (req, res) => {
       return res.status(404).json({ message: "Product not found" });
     }
 
+    // 2. Perform the sentiment analysis on the comment text
+    let sentimentScore = 0;
+    let sentimentLabel = 'Neutral';
+
+    if (comment && comment.trim().length > 0) {
+      const result = sentiment.analyze(comment);
+      sentimentScore = result.score;
+
+      // Assign labels based on the score threshold
+      if (sentimentScore >= 2) sentimentLabel = 'Positive';
+      else if (sentimentScore <= -2) sentimentLabel = 'Negative';
+    }
+
     const existingReview = await Review.findOne({
       userId: req.userId,
       productId,
@@ -53,6 +70,10 @@ export const addReview = async (req, res) => {
     if (existingReview) {
       existingReview.rating = rating;
       existingReview.comment = comment;
+      // 3. Update existing review with new sentiment data
+      existingReview.sentimentScore = sentimentScore;
+      existingReview.sentimentLabel = sentimentLabel;
+
       await existingReview.save();
 
       const { avgRating, reviewCount } = await recalculateProductRating(productId);
@@ -65,12 +86,15 @@ export const addReview = async (req, res) => {
       });
     }
 
+    // 4. Create new review with sentiment data attached
     const newReview = new Review({
       userId: req.userId,
       productId,
       name: user.name,
       rating,
       comment,
+      sentimentScore,
+      sentimentLabel
     });
 
     await newReview.save();
@@ -115,4 +139,4 @@ export const getProductReviews = async (req, res) => {
     console.log(error);
     res.status(500).json({ message: "Server error" });
   }
-};
+};

backend/model/reviewModel.js

@@ -30,6 +30,18 @@ const reviewSchema = new mongoose.Schema(
       type: String,
       required: true,
     },
+    // Add this inside the reviewSchema definition
+sentimentScore: {
+    type: Number,
+    required: false,
+    default: 0 // Scores usually range from negative to positive numbers
+},
+sentimentLabel: {
+    type: String,
+    enum: ['Positive', 'Neutral', 'Negative'],
+    default: 'Neutral'
+}
+
   },
   {
     timestamps: true,

frontend/src/pages/ProductDetail.jsx

@@ -8,7 +8,6 @@ import 'react-toastify/dist/ReactToastify.css';
 import { FaChevronLeft, FaChevronRight, FaHeart, FaShare, FaShoppingCart, FaStar } from 'react-icons/fa';
 import RelatedProduct from '../components/RelatedProduct';
 
-
 function ProductDetail() {
   const { userData } = useContext(userDataContext);
   const { productId } = useParams();
@@ -120,16 +119,17 @@ function ProductDetail() {
   };
 
   const handleAddToWishlist = () => {
-  if (!productData?._id) return;
-
-  if (isWishlisted) {
-    removeFromWishlist(productData._id);
-    toast.info('Removed from wishlist');
-  } else {
-    addToWishlist(productData._id);
-    toast.success('Added to wishlist 💖');
-  }
-};
+    if (!productData?._id) return;
+
+    if (isWishlisted) {
+      removeFromWishlist(productData._id);
+      toast.info('Removed from wishlist');
+    } else {
+      addToWishlist(productData._id);
+      toast.success('Added to wishlist 💖');
+    }
+  };
+
   // share
   const handleShare = async () => {
     if (navigator.share) {
@@ -460,16 +460,16 @@ function ProductDetail() {
 
             <div className="flex gap-3">
               <button
-  onClick={handleAddToWishlist}
-  className={`flex-1 py-3 rounded-lg flex items-center justify-center gap-2 transition-all duration-200
-    ${isWishlisted
-      ? 'bg-rose-600 text-white'
-      : 'bg-gray-800 text-white hover:bg-gray-700'
-    }`}
->
-  <FaHeart className={isWishlisted ? 'text-white' : ''} />
-  {isWishlisted ? 'Wishlisted' : 'Wishlist'}
-</button>
+                onClick={handleAddToWishlist}
+                className={`flex-1 py-3 rounded-lg flex items-center justify-center gap-2 transition-all duration-200
+                  ${isWishlisted
+                    ? 'bg-rose-600 text-white'
+                    : 'bg-gray-800 text-white hover:bg-gray-700'
+                  }`}
+              >
+                <FaHeart className={isWishlisted ? 'text-white' : ''} />
+                {isWishlisted ? 'Wishlisted' : 'Wishlist'}
+              </button>
               <button
                 type="button"
                 onClick={handleShare}
@@ -559,10 +559,23 @@ function ProductDetail() {
                         Edit Review
                       </button>
                     </div>
-                    <div className="flex gap-1 mb-2" aria-hidden="true">
+                    <div className="flex items-center gap-1 mb-2" aria-hidden="true">
                       {[...Array(userReview.rating)].map((_, i) => (
                         <FaStar key={i} className="text-yellow-400" />
                       ))}
+
+                      {/* Integrated Sentiment Badge for Current User's Review */}
+                      {userReview.sentimentLabel === 'Positive' && (
+                        <span className="ml-3 px-2 py-0.5 rounded text-xs font-medium bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-400 border border-green-200 dark:border-green-800">
+                          Helpful Positive
+                        </span>
+                      )}
+                      {userReview.sentimentLabel === 'Negative' && (
+                        <span className="ml-3 px-2 py-0.5 rounded text-xs font-medium bg-red-100 text-red-800 dark:bg-red-900/30 dark:text-red-400 border border-red-200 dark:border-red-800">
+                          Critical Review
+                        </span>
+                      )}
+
                     </div>
                     <p className="text-slate-700 dark:text-gray-300">
                       {userReview.comment}
@@ -651,9 +664,24 @@ function ProductDetail() {
                             <FaStar key={i} className="text-yellow-400" />
                           ))}
                         </div>
-                        <span className="text-cyan-400 font-semibold">
-                          {review.name}
-                        </span>
+                        <div className="flex items-center gap-3">
+                          <span className="text-cyan-400 font-semibold">
+                            {review.name}
+                          </span>
+
+                          {/* Integrated Sentiment Badge for the General Review List */}
+                          {review.sentimentLabel === 'Positive' && (
+                            <span className="px-2 py-0.5 rounded text-xs font-medium bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-400 border border-green-200 dark:border-green-800">
+                              Helpful Positive
+                            </span>
+                          )}
+                          {review.sentimentLabel === 'Negative' && (
+                            <span className="px-2 py-0.5 rounded text-xs font-medium bg-red-100 text-red-800 dark:bg-red-900/30 dark:text-red-400 border border-red-200 dark:border-red-800">
+                              Critical Review
+                            </span>
+                          )}
+
+                        </div>
                       </div>
                       <p className="text-slate-700 dark:text-gray-300">
                         {review.comment}
@@ -697,4 +725,4 @@ function ProductDetail() {
   );
 }
 
-export default ProductDetail;
+export default ProductDetail;