Add admin panel, cart, checkout, and digital key delivery

Co-authored-by: Cursor <cursoragent@cursor.com>

app/cart.py

@@ -0,0 +1,82 @@
+from __future__ import annotations
+
+from decimal import Decimal
+
+from fastapi import Request
+from sqlalchemy import func, select
+from sqlalchemy.orm import Session
+
+from app.models import Product, ProductKey
+
+
+def get_cart_map(request: Request) -> dict[str, int]:
+    raw = request.session.get("cart") or {}
+    cart: dict[str, int] = {}
+    for key, value in raw.items():
+        try:
+            qty = int(value)
+        except (TypeError, ValueError):
+            continue
+        if qty > 0:
+            cart[str(key)] = qty
+    return cart
+
+
+def save_cart(request: Request, cart: dict[str, int]) -> None:
+    request.session["cart"] = {str(k): int(v) for k, v in cart.items() if int(v) > 0}
+
+
+def cart_count(request: Request) -> int:
+    return sum(get_cart_map(request).values())
+
+
+def available_stock(db: Session, product_id: int) -> int:
+    return int(
+        db.scalar(
+            select(func.count())
+            .select_from(ProductKey)
+            .where(ProductKey.product_id == product_id, ProductKey.is_sold.is_(False))
+        )
+        or 0
+    )
+
+
+def build_cart_items(db: Session, request: Request) -> tuple[list[dict], Decimal]:
+    cart = get_cart_map(request)
+    items: list[dict] = []
+    total = Decimal("0.00")
+    if not cart:
+        return items, total
+
+    product_ids = [int(pid) for pid in cart.keys()]
+    products = {
+        p.id: p
+        for p in db.scalars(select(Product).where(Product.id.in_(product_ids))).all()
+    }
+
+    clean_cart = dict(cart)
+    for pid_str, qty in cart.items():
+        product = products.get(int(pid_str))
+        if not product or not product.is_active:
+            clean_cart.pop(pid_str, None)
+            continue
+        stock = available_stock(db, product.id)
+        qty = min(qty, max(stock, 0))
+        if qty <= 0:
+            clean_cart.pop(pid_str, None)
+            continue
+        clean_cart[pid_str] = qty
+        line_total = product.price * qty
+        total += line_total
+        items.append(
+            {
+                "product": product,
+                "quantity": qty,
+                "stock": stock,
+                "line_total": line_total,
+            }
+        )
+
+    if clean_cart != cart:
+        save_cart(request, clean_cart)
+    return items, total