Lau/listing view

backend/market/management/commands/seed_offers.py

@@ -0,0 +1,125 @@
+from decimal import Decimal
+
+from django.contrib.auth import get_user_model
+from django.core.management.base import BaseCommand
+from django.utils import timezone
+
+from market.models import Category, Item, Listing, Offer
+
+
+User = get_user_model()
+
+
+class Command(BaseCommand):
+    help = "Seed a listing with two pending offers for testing"
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--listing-id",
+            type=int,
+            default=None,
+            help="Add offers to an existing listing by ID",
+        )
+
+    def handle(self, *args, **options):
+        alice, _ = User.objects.get_or_create(
+            username="alice",
+            defaults={
+                "email": "alice@example.com",
+                "first_name": "Alice",
+                "last_name": "Johnson",
+                "phone_number": "+12155551234",
+                "phone_verified": True,
+            },
+        )
+        alice.set_password("testpassword123")
+        alice.save()
+
+        bob, _ = User.objects.get_or_create(
+            username="bob",
+            defaults={
+                "email": "bob@example.com",
+                "first_name": "Bob",
+                "last_name": "Williams",
+                "phone_number": "+12155555678",
+                "phone_verified": True,
+            },
+        )
+        bob.set_password("testpassword123")
+        bob.save()
+
+        self.stdout.write(
+            self.style.SUCCESS("Buyers ready: Alice Johnson, Bob Williams")
+        )
+
+        listing_id = options["listing_id"]
+        if listing_id:
+            try:
+                listing = Listing.objects.get(pk=listing_id)
+            except Listing.DoesNotExist:
+                self.stdout.write(
+                    self.style.ERROR(f"Listing with id={listing_id} not found")
+                )
+                return
+            self.stdout.write(
+                self.style.SUCCESS(
+                    f"Using existing listing: {listing.title} (id={listing.id})"
+                )
+            )
+        else:
+            seller, _ = User.objects.get_or_create(
+                username="lautaro",
+                defaults={
+                    "email": "lautaro@example.com",
+                    "first_name": "Lautaro",
+                    "last_name": "Beck",
+                },
+            )
+            seller.set_password("testpassword123")
+            seller.save()
+            self.stdout.write(
+                self.style.SUCCESS(f"Seller ready: {seller.get_full_name()}")
+            )
+
+            category, _ = Category.objects.get_or_create(name="Furniture")
+            listing = Item.objects.create(
+                seller=seller,
+                title="New offer",
+                description="ASDFASFAFS",
+                price=Decimal("12312.00"),
+                negotiable=True,
+                expires_at=timezone.now() + timezone.timedelta(days=60),
+                condition=Item.Condition.GOOD,
+                category=category,
+            )
+            self.stdout.write(self.style.SUCCESS(f"Created listing: {listing.title}"))
+
+        _, created_alice = Offer.objects.get_or_create(
+            user=alice,
+            listing=listing,
+            defaults={
+                "offered_price": Decimal("40.00"),
+                "message": "Would you take $40? I can pick up today.",
+            },
+        )
+
+        _, created_bob = Offer.objects.get_or_create(
+            user=bob,
+            listing=listing,
+            defaults={
+                "offered_price": Decimal("45.00"),
+                "message": "Interested! Is the price negotiable?",
+            },
+        )
+
+        new_count = sum([created_alice, created_bob])
+        skipped = 2 - new_count
+
+        self.stdout.write(
+            self.style.SUCCESS(
+                f"Created {new_count} offers, skipped {skipped} (already existed)"
+            )
+        )
+        self.stdout.write(
+            self.style.SUCCESS(f"\nDone! Offers added to listing id={listing.id}")
+        )

backend/market/migrations/0005_offer_status.py

@@ -0,0 +1,26 @@
+# Generated by Django 5.0.2 on 2026-03-27 21:34
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("market", "0004_rename_address_sublet_street_address_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="offer",
+            name="status",
+            field=models.CharField(
+                choices=[
+                    ("pending", "Pending"),
+                    ("accepted", "Accepted"),
+                    ("rejected", "Rejected"),
+                ],
+                default="pending",
+                max_length=10,
+            ),
+        ),
+    ]

backend/market/models.py

@@ -17,6 +17,11 @@ class User(AbstractUser):
 
 
 class Offer(models.Model):
+    class Status(models.TextChoices):
+        PENDING = "pending", "Pending"
+        ACCEPTED = "accepted", "Accepted"
+        REJECTED = "rejected", "Rejected"
+
     class Meta:
         constraints = [
             models.UniqueConstraint(
@@ -37,6 +42,9 @@ class Meta:
         max_digits=10, decimal_places=2, validators=[MinValueValidator(0)]
     )
     message = models.TextField(max_length=500, blank=True)
+    status = models.CharField(
+        max_length=10, choices=Status.choices, default=Status.PENDING
+    )
     created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):

backend/market/permissions.py

@@ -43,16 +43,22 @@ def has_object_permission(self, request, view, obj):
         )
 
 
-class OfferOwnerPermission(permissions.BasePermission):
+class ListingOwnerOffersPermission(permissions.BasePermission):
     """
-    Custom permission to allow owner of an offer to delete it.
+    Permission for listing-owner offer interactions:
+    - GET: listing seller can view offers on their listing
+    - PATCH/PUT: listing seller can update offer status
+    - DELETE: offer creator can delete/withdraw their own offer
     """
 
     def has_permission(self, request, view):
         return request.user.is_authenticated
 
     def has_object_permission(self, request, view, obj):
-        if request.method in permissions.SAFE_METHODS:  # GET
+        if request.method in permissions.SAFE_METHODS:
+            return obj.listing.seller == request.user
+
+        if request.method in ("PATCH", "PUT"):
             return obj.listing.seller == request.user
 
         return obj.user == request.user

backend/market/serializers.py

@@ -46,14 +46,49 @@ class OfferSerializer(ModelSerializer):
 
     class Meta:
         model = Offer
-        fields = ["id", "user", "listing", "offered_price", "message", "created_at"]
-        read_only_fields = ["id", "created_at", "user"]
+        fields = [
+            "id",
+            "user",
+            "listing",
+            "offered_price",
+            "message",
+            "status",
+            "created_at",
+        ]
+        read_only_fields = ["id", "created_at", "user", "status"]
 
     def create(self, validated_data):
         validated_data["user"] = self.context["request"].user
         return super().create(validated_data)
 
 
+class OfferStatusSerializer(ModelSerializer):
+    class Meta:
+        model = Offer
+        fields = ["id", "status"]
+        read_only_fields = ["id"]
+
+    def validate_status(self, value):
+        valid_statuses = [choice[0] for choice in Offer.Status.choices]
+        if value not in valid_statuses:
+            raise ValidationError(
+                f"Invalid status. Must be one of: {', '.join(valid_statuses)}"
+            )
+        return value
+
+
+class OfferDetailsSerializer(ModelSerializer):
+    """
+    Allows the offer owner to edit the offer's offered_price and message.
+    Status is intentionally read-only (managed by the listing owner).
+    """
+
+    class Meta:
+        model = Offer
+        fields = ["id", "offered_price", "message", "status"]
+        read_only_fields = ["id", "status"]
+
+
 # Create/Update Image Serializer
 class ListingImageSerializer(ModelSerializer):
     image = ImageField(write_only=True, required=False, allow_null=True)

backend/market/urls.py

@@ -11,7 +11,10 @@
     OffersReceived,
     Tags,
     UserFavorites,
+    change_offer_details,
+    change_offer_status,
     get_current_user,
+    get_my_offer_for_listing,
     get_phone_status,
     send_verification_code,
     verify_phone_code,
@@ -46,9 +49,24 @@
     # post: create an offer for an listing
     # delete: delete an offer for an listing
     path(
-        "listings/<listing_id>/offers/",
+        "listings/<int:listing_id>/offers/",
         Offers.as_view({"get": "list", "post": "create", "delete": "destroy"}),
     ),
+    # Current user's offer for an individual listing
+    # (Returns 404 when the user has no offer for that listing.)
+    path(
+        "listings/<int:listing_id>/offers/mine/",
+        get_my_offer_for_listing,
+        name="offers-mine",
+    ),
+    # Update offer status (PATCH)
+    path("offers/<int:offer_id>/", change_offer_status, name="offer-status"),
+    # Update offer offered_price + message (PATCH)
+    path(
+        "offers/<int:offer_id>/details/",
+        change_offer_details,
+        name="offer-details",
+    ),
     # Image Creation
     path("listings/<listing_id>/images/", CreateImages.as_view()),
     # Image Deletion