Implemented New Sustainability Score Calculation and Fixed Bugs When Renting Items

application/backend/secondchance_backend/item/api.py

@@ -10,7 +10,7 @@
 from .serializers import ItemListSerializer, ItemDetailSerializer, RentalListSerializer
 from django.shortcuts import get_object_or_404
 from useraccount.models import User
-
+from datetime import date, datetime
 
 @api_view(["GET"])
 @authentication_classes([])
@@ -161,11 +161,21 @@ def rent_item(request, pk):
     try:
         start_date = request.POST.get("start_date", "")
         end_date = request.POST.get("end_date", "")
-        number_of_days = request.POST.get("number_of_days", "")
-        total_price = request.POST.get("total_price", "")
-
-        item = Item.objects.get(pk=pk)
-
+        number_of_days = int(request.POST.get("number_of_days", 0))
+        total_price = float(request.POST.get("total_price", 0))
+
+        try:
+            start_date = datetime.strptime(start_date, "%Y-%m-%d").date()
+            end_date = datetime.strptime(end_date, "%Y-%m-%d").date()
+        except ValueError as e:
+            return JsonResponse({"success": False, "error": "Error parsing dates."}, status=404)
+
+
+        try:
+            item = Item.objects.get(pk=pk)
+        except Item.DoesNotExist:
+            return JsonResponse({"success": False, "error": "Item not found."}, status=404)
+
         Rental.objects.create(
             item=item,
             start_date=start_date,
@@ -174,8 +184,10 @@ def rent_item(request, pk):
             total_price=total_price,
             created_by=request.user,
         )
-
+
+
         request.user.increment_items_rented()
+
 
         return JsonResponse({"success": True})
     except Exception as e:

application/backend/secondchance_backend/item/utils/categories.py

@@ -0,0 +1,62 @@
+def get_user_rented_categories(user):
+    """
+    Get the categories of items that a user has rented from
+
+    args: 
+    user instance
+    used to get items rented by user
+
+
+    return: list of categories
+    rtype: list?
+    """
+    from item.models import Rental
+    # convert QuerySet to list before returning
+    return list(
+        Rental.objects.filter(created_by=user)
+        .values_list('item__category', flat=True) # returns desired field 
+    )
+
+
+
+def get_user_listed_categories(user):
+    """
+    Get the categories of items that a user has listed
+
+    args: 
+    user instance
+    used to get items listed by user
+
+
+    return: list of categories
+    rtype: list?
+    """
+    from item.models import Item
+
+    return list(
+        Item.objects.filter(seller=user)
+        .values_list('category', flat=True)
+    )
+
+def count_items_rented_from_user(user):
+    """
+    Get the number of items that are currently being rented from the given user
+    Find the rentals that have an item that belongs to the user instance passed in
+
+    args:
+    user instance
+
+    return: number of items being rented from the user
+    rtype: int
+    """
+    from datetime import date
+    from item.models import Rental, Item
+
+    today = date.today()
+
+    # count the number of listings belonging to the user that are being rented out
+    return Rental.objects.filter(
+        item__seller = user, # listings put up by user
+        start_date__lte = today, # listed items rented today or sooner
+        end_date__gte = today # listed items rented today or after
+    ).count()

application/backend/secondchance_backend/useraccount/models.py

@@ -3,7 +3,12 @@
 from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin, UserManager
 from django.db import models
 from django.utils import timezone
+from enum import Enum 
+# from item.utils.categories import get_user_listed_categories, get_user_rented_categories
 
+# this breaks the code 
+# from item.models import Item
+# from item.models import Rental
 
 class CustomUserManager(UserManager):
     """
@@ -177,6 +182,8 @@ def increment_items_rented(self):
         self.items_rented += 1
         self.calculate_sustainability_score()
         self.save(update_fields=["items_rented", "sustainability_score"])
+
+
 
     def calculate_sustainability_score(self):
         """
@@ -190,19 +197,75 @@ def calculate_sustainability_score(self):
         :return: None
         :rtype: None
         """
+        # 30% of total score = days since join date
+        # 25% items rented by user
+        # 30% items listed by user
+        # 15% popularity (items listed by the user currently being rented by other users) 
+
+        max_normalized_score = 100
+
+        # compute how many days out of 2 years the user has been on the platform
+        # then normalize it
         if self.date_joined:
-            days_on_platform = (timezone.now() - self.date_joined).days
+            days_on_platform = (timezone.now() - self.date_joined).days 
         else:
             days_on_platform = 0
 
-        score = (
-            (self.items_rented_out * 2.5)
-            + (self.items_rented * 1.5)
-            + (days_on_platform * 0.1)
+        max_points_date_joined = 730 # 2 years in days since the user joined the platform
+        time_score = min((days_on_platform / max_points_date_joined) * 100, 100)
+
+        # get the items rented by the user
+
+        if self.items_rented or self.items_rented != 0:
+            from item.utils.categories import get_user_rented_categories
+
+            rented_categories = get_user_rented_categories(self)        
+            rented_items_weighted = 0 
+
+            # sum weights
+            for category in rented_categories:
+                rented_items_weighted += CATEGORY_WEIGHTS[category.lower()]
+
+        else:
+            rented_items_weighted = 0
+
+        max_rented_score = 40
+        rented_items_score = min(max((rented_items_weighted / max_rented_score) * 100, 0), max_normalized_score) # compute here
+
+        # compute score for items listed by user and how many of them are being rented
+        if self.items_rented_out:
+            from item.utils.categories import get_user_listed_categories
+            from item.utils.categories import count_items_rented_from_user
+
+            raw_popularity_score = count_items_rented_from_user(self) 
+
+            listed_categories = get_user_listed_categories(self)
+
+            listed_items_weighted = 0
+            for category in listed_categories:
+                listed_items_weighted += CATEGORY_WEIGHTS[category.lower()]
+
+        else:
+            raw_popularity_score = 0
+            listed_items_weighted = 0
+
+        max_listed_score = 50
+        max_raw_popularity_score = 80
+
+        listed_items_score = min(max((listed_items_weighted / max_listed_score) * 100, 0), max_normalized_score) # compute here
+
+        popularity_score = min(max(raw_popularity_score / max_raw_popularity_score * 100, 0), max_normalized_score)
+
+        total_sustainability_score = (
+            time_score * 0.3
+            + rented_items_score * 0.25
+            + listed_items_score * 0.3
+            + popularity_score * 0.15
         )
-
         max_score = 100
-        normalized_score = min(max(round(score), 1), max_score)
+        normalized_score = min(max(round(total_sustainability_score), 0), max_score)
+
+        # update user's score in DB
         self.sustainability_score = normalized_score
 
     def save(self, *args, **kwargs):
@@ -215,3 +278,21 @@ def save(self, *args, **kwargs):
         """
         self.calculate_sustainability_score()
         super().save(*args, **kwargs)
+
+CATEGORY_WEIGHTS = {
+    "electronics": 2,
+    "furniture": 1.5,
+    "clothing": 3,
+    "books": 3,
+    "appliances": 2,
+    "sports": 2.5,
+    "toys": 2.5,
+    "tools": 2,
+    "vehicles": 2,
+    "party": 2,
+    "music": 1,
+    "photography": 1,
+    "gardening": 1.5,
+    "office": 1,
+    "other": 1,
+}

application/secondchance/app/components/items/RentalSidebar.tsx

@@ -39,14 +39,16 @@ const RentalSidebar: React.FC<RentalSidebarProps> = ({ item, userId }) => {
   const [dateRange, setDateRange] = useState<Range>(initialDateRange);
   const [minDate, setMinDate] = useState<Date>(new Date());
   const [reservedDates, setReservedDates] = useState<Date[]>([]);
+  const [sustainabilityScore, setSustainabilityScore] = useState<number>(0);
 
   const processRental = async () => {
     if (userId) {
       if (dateRange.startDate && dateRange.endDate) {
         const formData = new FormData();
-        formData.append('location', item.location);
-        formData.append('condition', item.condition);
-        formData.append('category', item.category);
+        // removed fields not present in Rental Model
+        // formData.append('location', item.location); 
+        // formData.append('condition', item.condition);
+        // formData.append('category', item.category);
         formData.append('start_date', format(dateRange.startDate, 'yyyy-MM-dd'));
         formData.append('end_date', format(dateRange.endDate, 'yyyy-MM-dd'));
         formData.append('number_of_days', days.toString());
@@ -97,17 +99,39 @@ const RentalSidebar: React.FC<RentalSidebarProps> = ({ item, userId }) => {
     setReservedDates(dates);
   };
 
+  const fetchSustainabilityScore = async () => {
+    if (userId) {
+      try {
+        const userData = await apiService.get(`/api/auth/users/${userId}/`);
+        setSustainabilityScore(userData.sustainability_score || 0);
+      } catch (error) {
+        console.error('Error fetching sustainability score:', error);
+      }
+    }
+  };
+
+  // bug fix: made the second useEffect wait for the sustainabilityScore to change
+  // instead of executing before it
   useEffect(() => {
     getRentals();
+    fetchSustainabilityScore();
+  }, [userId]);
+
+  useEffect(() => {
 
     if (dateRange.startDate && dateRange.endDate) {
       const dayCount = differenceInDays(dateRange.endDate, dateRange.startDate);
 
       if (dayCount && item.price_per_day) {
         const _fee = ((dayCount * item.price_per_day) / 100) * 5;
 
+        const discountModifier = 0.03;
+        let sustainabilityDiscount = sustainabilityScore * discountModifier;
+
+        console.log("SUSTAINABILITY DISCOUNT:", sustainabilityDiscount);
+
         setFee(_fee);
-        setTotalPrice(dayCount * item.price_per_day + _fee);
+        setTotalPrice((dayCount * item.price_per_day + _fee) - sustainabilityDiscount);
         setDays(dayCount);
       } else {
         const _fee = (item.price_per_day / 100) * 5;
@@ -117,7 +141,7 @@ const RentalSidebar: React.FC<RentalSidebarProps> = ({ item, userId }) => {
         setDays(1);
       }
     }
-  }, [dateRange]);
+  }, [dateRange, sustainabilityScore], ); 
 
   return (
     <aside className="col-span-2 mt-6 rounded-xl border border-gray-200 bg-white p-6 shadow-xl">
@@ -149,14 +173,19 @@ const RentalSidebar: React.FC<RentalSidebarProps> = ({ item, userId }) => {
 
       <div className="mb-4 flex items-center justify-between text-gray-700">
         <p className="text-md">Service Fee</p>
-        <p className="text-md">${fee}</p>
+        <p className="text-md">${fee.toFixed(2)}</p>
+      </div>
+
+      <div className="mb-4 flex items-center justify-between text-gray-700">
+        <p className="text-md">Sustainability Score Discount</p>
+        <p className="text-md">${(sustainabilityScore * 0.03).toFixed(2)}</p>
       </div>
 
       <hr className="my-4" />
 
       <div className="mt-4 flex items-center justify-between text-lg font-bold text-gray-900">
         <p>Total Amount</p>
-        <p>${totalPrice}</p>
+        <p>${totalPrice.toFixed(2)}</p>
       </div>
     </aside>
   );