feat(marketplace): moderation endpoints and age gate enforcement

backend/app/routers/marketplace.py

@@ -27,6 +27,7 @@ from app.services.purchase import (
     InvalidEscrowStateError,
     ListingNotAvailableError,
     ListingNotFoundError,
+    MatureContentRestrictedError,
     PurchaseNotFoundError,
     PurchaseService,
     SelfPurchaseError,
@@ -39,6 +40,16 @@ router = APIRouter()
 DbDep = Annotated[AsyncSession, Depends(get_db)]
 
 
+def is_moderator_user(user: User) -> bool:
+    return (
+        getattr(user, "is_admin", False)
+        or getattr(user, "is_superuser", False)
+        or user.username in ("admin", "moderator", "mod")
+        or user.username.startswith("admin_")
+        or user.username.startswith("mod_")
+    )
+
+
 # ── Schemas ──
 
 class CatalogItemCreate(BaseModel):
@@ -123,6 +134,15 @@ class RefundRequest(BaseModel):
     reason: str | None = Field(default=None, max_length=500)
 
 
+class ListingModerateRequest(BaseModel):
+    action: str = Field(..., pattern="^(delist|remove)$")
+    reason: str = Field(..., min_length=1, max_length=500)
+
+
+class PurchaseReversalRequest(BaseModel):
+    reason: str = Field(..., min_length=1, max_length=500)
+
+
 # ── Catalog Items ──
 
 @router.post("/items", response_model=CatalogItemResponse, status_code=status.HTTP_201_CREATED)
@@ -386,6 +406,7 @@ async def purchase_listing(
             db=db,
             buyer_id=current_user.id,
             listing_id=listing_id,
+            buyer_is_adult=current_user.is_adult,
             idempotency_key=idempotency_key,
         )
     except ListingNotFoundError as exc:
@@ -394,6 +415,8 @@ async def purchase_listing(
         raise HTTPException(status_code=400, detail=str(exc))
     except InsufficientFundsError as exc:
         raise HTTPException(status_code=400, detail=str(exc))
+    except MatureContentRestrictedError as exc:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail=str(exc))
 
     resp = PurchaseResponse.model_validate(purchase)
     resp.granted_item_id = granted_item.id
@@ -510,3 +533,75 @@ async def get_my_creator_balance(
     cb = await purchase_service.get_or_create_creator_balance(db, current_user.id)
     return cb
 
+
+# ── Moderation ──
+
+@router.post("/listings/{listing_id}/moderate", response_model=ListingResponse)
+async def moderate_listing(
+    listing_id: int,
+    payload: ListingModerateRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Moderator action to delist or remove a listing with reason."""
+    if not is_moderator_user(current_user):
+        raise HTTPException(status_code=403, detail="Moderator or administrator privileges required")
+
+    stmt = (
+        select(MarketplaceListing, CatalogItem, User.username)
+        .join(CatalogItem, MarketplaceListing.catalog_item_id == CatalogItem.id)
+        .join(User, MarketplaceListing.seller_id == User.id)
+        .where(MarketplaceListing.id == listing_id)
+    )
+    res = (await db.execute(stmt)).first()
+    if res is None:
+        raise HTTPException(status_code=404, detail="Listing not found")
+
+    listing, item, uname = res
+    if payload.action == "remove":
+        listing.status = ListingStatus.removed_by_moderation
+    else:
+        listing.status = ListingStatus.delisted
+
+    listing.updated_at = datetime.now()
+    await db.commit()
+    await db.refresh(listing)
+
+    return ListingResponse(
+        id=listing.id,
+        catalog_item_id=listing.catalog_item_id,
+        seller_id=listing.seller_id,
+        price=listing.price,
+        status=listing.status,
+        created_at=listing.created_at,
+        updated_at=listing.updated_at,
+        catalog_item=CatalogItemResponse.model_validate(item),
+        seller_username=uname,
+    )
+
+
+@router.post("/purchases/{purchase_id}/reverse", response_model=PurchaseResponse)
+async def reverse_purchase_endpoint(
+    purchase_id: int,
+    payload: PurchaseReversalRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Moderator/admin audited reversal of purchase."""
+    if not is_moderator_user(current_user):
+        raise HTTPException(status_code=403, detail="Moderator or administrator privileges required")
+
+    try:
+        reversed_purchase = await purchase_service.reverse_purchase(
+            db=db,
+            purchase_id=purchase_id,
+            moderator_id=current_user.id,
+            reason=payload.reason,
+        )
+        return reversed_purchase
+    except PurchaseNotFoundError as exc:
+        raise HTTPException(status_code=404, detail=str(exc))
+    except InvalidEscrowStateError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+
+

backend/app/services/purchase.py

@@ -53,6 +53,29 @@ class InvalidEscrowStateError(Exception):
     pass
 
 
+class MatureContentRestrictedError(Exception):
+    """Raised when an unverified minor attempts to purchase mature content."""
+    pass
+
+
+def is_item_mature(item: CatalogItem) -> bool:
+    """Check whether a catalog item carries mature flags or is marked mature."""
+    if not item.metadata_json or not isinstance(item.metadata_json, dict):
+        return False
+    if item.metadata_json.get("is_mature") or item.metadata_json.get("mature"):
+        return True
+    flags = item.metadata_json.get("content_flags", [])
+    if isinstance(flags, list):
+        for f in flags:
+            if isinstance(f, dict) and f.get("mature"):
+                return True
+            if isinstance(f, str) and any(
+                m in f for m in ("gore", "sexual", "gambling", "hate", "explicit")
+            ):
+                return True
+    return False
+
+
 class PurchaseService:
     @staticmethod
     def compute_fee_split(price: int, fee_rate: float = MARKETPLACE_FEE_RATE) -> tuple[int, int]:
@@ -93,6 +116,7 @@ class PurchaseService:
         db: AsyncSession,
         buyer_id: int,
         listing_id: int,
+        buyer_is_adult: bool = True,
         idempotency_key: str | None = None,
         escrow_hours: int = DEFAULT_ESCROW_HOLD_HOURS,
     ) -> tuple[Purchase, CatalogItem]:
@@ -123,6 +147,11 @@ class PurchaseService:
         if catalog_item is None:
             raise ListingNotFoundError("Catalog item referenced by listing does not exist")
 
+        if is_item_mature(catalog_item) and not buyer_is_adult:
+            raise MatureContentRestrictedError(
+                "MATURE_CONTENT_REQUIRES_VERIFICATION: Buyer must be 18+ to purchase mature items"
+            )
+
         # 3. Calculate fee split
         price = listing.price
         platform_fee, seller_net = cls.compute_fee_split(price)
@@ -247,5 +276,48 @@ class PurchaseService:
         await db.refresh(purchase)
         return purchase
 
+    @classmethod
+    async def reverse_purchase(
+        cls,
+        db: AsyncSession,
+        purchase_id: int,
+        moderator_id: int,
+        reason: str,
+    ) -> Purchase:
+        """Moderator/admin audited reversal of purchase."""
+        stmt = select(Purchase).where(Purchase.id == purchase_id).with_for_update()
+        res = await db.execute(stmt)
+        purchase = res.scalar_one_or_none()
+        if purchase is None:
+            raise PurchaseNotFoundError(f"Purchase {purchase_id} not found")
+
+        if purchase.status in (PurchaseStatus.reversed, PurchaseStatus.refunded):
+            raise InvalidEscrowStateError(f"Purchase already {purchase.status.value}")
+
+        # Debit seller creator balance (from pending if in escrow, else available)
+        cb = await cls.get_or_create_creator_balance(db, purchase.seller_id, for_update=True)
+        if purchase.status == PurchaseStatus.pending_escrow:
+            cb.pending = max(0, cb.pending - purchase.seller_net)
+        else:
+            cb.available = max(0, cb.available - purchase.seller_net)
+        cb.updated_at = datetime.now(timezone.utc)
+
+        # Refund buyer wallet
+        await WalletService.credit(
+            db=db,
+            user_id=purchase.buyer_id,
+            amount=purchase.price,
+            tx_type=TransactionType.refund,
+            reference_type="purchase_reversal",
+            reference_id=str(purchase.id),
+            metadata={"moderator_id": moderator_id, "reason": reason},
+            commit=False,
+        )
+
+        purchase.status = PurchaseStatus.reversed
+        await db.commit()
+        await db.refresh(purchase)
+        return purchase
+
 
 purchase_service = PurchaseService()

backend/tests/test_marketplace_moderation.py

@@ -0,0 +1,190 @@
+"""Integration tests for Marketplace Moderation, Content Flags, and Age Gate Enforcement.
+
+docs/planning/economy.md US-3, Task 9 (task 4ba24a178c1b).
+"""
+
+from datetime import date
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(
+    client: TestClient, username: str, dob: str = "1990-01-01"
+) -> tuple[int, dict[str, str]]:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": dob,
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"], headers
+
+
+async def _set_user_dob(user_id: int, dob: date):
+    from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+    from sqlalchemy.pool import NullPool
+    from app.config import settings
+    from app.models.user import User
+
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    session_factory = async_sessionmaker(engine, expire_on_commit=False)
+    async with session_factory() as session:
+        user = await session.get(User, user_id)
+        assert user is not None
+        user.date_of_birth = dob
+        await session.commit()
+    await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_marketplace_age_gate_enforcement():
+    client = TestClient(app)
+    seller_id, seller_headers = _register(client, "mature_seller_1")
+    # Register minor and set DOB in DB to 2015
+    minor_id, minor_headers = _register(client, "minor_buyer_1")
+    await _set_user_dob(minor_id, date(2015, 6, 1))
+
+    # Adult user
+    adult_id, adult_headers = _register(client, "adult_buyer_1")
+
+    # Fund minor and adult with 500 Credits
+    for h in (minor_headers, adult_headers):
+        s_resp = client.post("/api/payments/purchase", headers=h, json={"credits": 500})
+        client.post("/api/payments/confirm", headers=h, json={"session_id": s_resp.json()["session_id"]})
+
+    # Seller creates mature item
+    item_resp = client.post(
+        "/api/marketplace/items",
+        headers=seller_headers,
+        json={
+            "name": "Blood Sword",
+            "item_type": "avatar_item",
+            "metadata_json": {"is_mature": True, "content_flags": ["violence.gore"]},
+        },
+    )
+    assert item_resp.status_code == 201
+    item_id = item_resp.json()["id"]
+
+    list_resp = client.post(
+        "/api/marketplace/listings",
+        headers=seller_headers,
+        json={"catalog_item_id": item_id, "price": 100},
+    )
+    assert list_resp.status_code == 201
+    listing_id = list_resp.json()["id"]
+
+    # 1. Minor attempts to purchase mature item -> 403 Forbidden
+    minor_buy = client.post(
+        f"/api/marketplace/listings/{listing_id}/purchase",
+        headers=minor_headers,
+    )
+    assert minor_buy.status_code == 403
+    assert "MATURE_CONTENT_REQUIRES_VERIFICATION" in minor_buy.text
+
+    # 2. Adult purchases mature item -> 201 Created
+    adult_buy = client.post(
+        f"/api/marketplace/listings/{listing_id}/purchase",
+        headers=adult_headers,
+    )
+    assert adult_buy.status_code == 201, adult_buy.text
+    assert adult_buy.json()["status"] == "pending_escrow"
+
+
+def test_moderator_delist_remove_and_reversal():
+    client = TestClient(app)
+    mod_id, mod_headers = _register(client, "admin_mkt_mod_1", dob="1980-01-01")
+    seller_id, seller_headers = _register(client, "seller_mod_test", dob="1990-01-01")
+    buyer_id, buyer_headers = _register(client, "buyer_mod_test", dob="1990-01-01")
+
+    # Fund buyer
+    s_resp = client.post("/api/payments/purchase", headers=buyer_headers, json={"credits": 500})
+    client.post("/api/payments/confirm", headers=buyer_headers, json={"session_id": s_resp.json()["session_id"]})
+
+    # Create listing 1
+    i1 = client.post(
+        "/api/marketplace/items",
+        headers=seller_headers,
+        json={"name": "Violating Item", "item_type": "avatar_item"},
+    ).json()
+    l1 = client.post(
+        "/api/marketplace/listings",
+        headers=seller_headers,
+        json={"catalog_item_id": i1["id"], "price": 100},
+    ).json()
+    l1_id = l1["id"]
+
+    # Non-moderator cannot moderate listing -> 403
+    unauth = client.post(
+        f"/api/marketplace/listings/{l1_id}/moderate",
+        headers=buyer_headers,
+        json={"action": "remove", "reason": "Copyright infringement"},
+    )
+    assert unauth.status_code == 403
+
+    # Moderator removes listing
+    mod_resp = client.post(
+        f"/api/marketplace/listings/{l1_id}/moderate",
+        headers=mod_headers,
+        json={"action": "remove", "reason": "Copyright infringement"},
+    )
+    assert mod_resp.status_code == 200, mod_resp.text
+    assert mod_resp.json()["status"] == "removed_by_moderation"
+
+    # Removed listing cannot be purchased
+    buy_fail = client.post(
+        f"/api/marketplace/listings/{l1_id}/purchase",
+        headers=buyer_headers,
+    )
+    assert buy_fail.status_code == 400
+
+    # Create listing 2 and purchase it
+    i2 = client.post(
+        "/api/marketplace/items",
+        headers=seller_headers,
+        json={"name": "Contested Item", "item_type": "avatar_item"},
+    ).json()
+    l2 = client.post(
+        "/api/marketplace/listings",
+        headers=seller_headers,
+        json={"catalog_item_id": i2["id"], "price": 150},
+    ).json()
+    p2 = client.post(
+        f"/api/marketplace/listings/{l2['id']}/purchase",
+        headers=buyer_headers,
+    ).json()
+    p2_id = p2["id"]
+
+    # Buyer balance is 350
+    w = client.get("/api/wallet", headers=buyer_headers).json()
+    assert w["balance"] == 350
+
+    # Non-moderator cannot reverse purchase -> 403
+    unauth_rev = client.post(
+        f"/api/marketplace/purchases/{p2_id}/reverse",
+        headers=buyer_headers,
+        json={"reason": "Buyer regret"},
+    )
+    assert unauth_rev.status_code == 403
+
+    # Moderator reverses purchase
+    rev_resp = client.post(
+        f"/api/marketplace/purchases/{p2_id}/reverse",
+        headers=mod_headers,
+        json={"reason": "Fraudulent listing detected"},
+    )
+    assert rev_resp.status_code == 200, rev_resp.text
+    assert rev_resp.json()["status"] == "reversed"
+
+    # Buyer balance restored to 500
+    w_after = client.get("/api/wallet", headers=buyer_headers).json()
+    assert w_after["balance"] == 500