Merge pull request #7 from databases-CSCI3354/add-to-cart

Add to cart

app/__init__.py

@@ -1,4 +1,5 @@
 import os
+import secrets
 
 from flask import Flask
 
@@ -9,6 +10,8 @@
 def create_app(test_config=None):
     # create and configure the app
     app = Flask(__name__, instance_relative_config=True)
+    secret_key = secrets.token_hex(32)
+    app.secret_key = secret_key
     app.config["DATABASE"] = os.path.join(app.root_path, "northwind.db")
     app.teardown_appcontext(close_db)
     init_app(app=app)

app/models/product.py

@@ -14,3 +14,14 @@ class Product(BaseModel):
     UnitsOnOrder: int
     ReorderLevel: int
     Discontinued: str
+
+
+class CartItem(BaseModel):
+    ProductID: int
+    Quantity: int
+    ProductName: str
+    TotalPrice: float
+
+
+class Cart(BaseModel):
+    items: dict[int, CartItem]

app/routes/main.py

@@ -1,7 +1,7 @@
 from flask import Blueprint, render_template
 
 from app.models.product import Product
-from app.services.products import ProductService
+from app.services.product import ProductService
 
 main_bp = Blueprint("main", __name__)
 

app/routes/product.py

@@ -1,22 +1,61 @@
 from typing import Optional
 
-from flask import Blueprint, render_template
+from flask import Blueprint, jsonify, render_template, request
 
 from app.models.category import Category
-from app.models.product import Product
+from app.models.product import CartItem, Product
 from app.models.supplier import Supplier
+from app.services.cart import save_item_to_cart
 from app.services.category import CategoryService
-from app.services.products import ProductService
+from app.services.product import ProductService
 from app.services.supplier import SupplierService
+from app.utils.logger import setup_logger
 
 product_bp = Blueprint("product", __name__)
 
 
+log = setup_logger(__name__)
+
+
 @product_bp.route("/<int:product_id>")
 def index(product_id: int):
-    product: Product = ProductService().get_product_by_id(product_id)
+    product: Optional[Product] = ProductService().get_product_by_id(product_id)
+    if not product:
+        raise ValueError(f"Error rendering product page: product not found with id {product_id}")
     category: Optional[Category] = CategoryService().get_category_by_id(product.CategoryID)
     supplier: Optional[Supplier] = SupplierService().get_supplier_by_id(product.SupplierID)
     return render_template(
         "product/index.html", product=product, category=category, supplier=supplier
     )
+
+
+@product_bp.route("/<int:product_id>", methods=["POST"])
+def add_to_cart(product_id):
+    product: Optional[Product] = ProductService().get_product_by_id(product_id)
+    if not product:
+        raise ValueError(f"Error adding product to cart: product not found with id {product_id}")
+
+    quantity = int(request.form.get("quantity", 1))
+
+    if quantity > product.UnitsInStock:
+        raise ValueError(
+            f"Error adding product to cart: requested quantity exceeds available stock"
+        )
+
+    cart_item = CartItem(
+        ProductID=product_id,
+        Quantity=quantity,
+        ProductName=product.ProductName,
+        TotalPrice=product.UnitPrice * quantity,
+    )
+
+    save_item_to_cart(cart_item=cart_item)
+    log.info(f"Added the following item to cart: {cart_item}")
+
+    # category: Optional[Category] = CategoryService().get_category_by_id(product.CategoryID)
+    # supplier: Optional[Supplier] = SupplierService().get_supplier_by_id(product.SupplierID)
+    # return render_template(
+    #     "product/index.html", product=product, category=category, supplier=supplier
+    # )
+
+    return jsonify({"message": f"Added {product.ProductName} to cart"})

app/services/cart.py

@@ -0,0 +1,15 @@
+from flask import session
+
+from app.models.product import Cart, CartItem
+
+
+def get_cart() -> Cart:
+    if "cart" not in session:
+        session["cart"] = Cart(items={})
+    return Cart.model_validate(session["cart"])
+
+
+def save_item_to_cart(cart_item: CartItem) -> None:
+    cart = get_cart()
+    cart.items[cart_item.ProductID] = cart_item
+    session["cart"] = cart.model_dump()

app/services/product.py

@@ -0,0 +1,39 @@
+from typing import Optional
+
+from app.models.product import Product
+from app.utils.database import get_db
+from app.utils.logger import setup_logger
+
+log = setup_logger(__name__)
+
+
+class ProductService:
+
+    def __init__(self):
+        self.cursor = get_db().cursor()
+        self.columns = list(Product.model_fields.keys())
+
+    def get_all_products(self) -> list[Product]:
+        self.cursor.execute("SELECT * FROM Products")
+        products: list[Product] = [
+            Product.model_validate(dict(zip(self.columns, row))) for row in self.cursor.fetchall()
+        ]
+        return products
+
+    def get_product_by_id(self, product_id: Optional[int]) -> Optional[Product]:
+        if not product_id:
+            return None
+        self.cursor.execute(f"SELECT * FROM Products WHERE ProductID = {product_id}")
+        rows: list = self.cursor.fetchall()
+        match len(rows):
+            case 0:
+                log.info(f"No product found with id {product_id}")
+                return None
+            case 1:
+                product: Product = Product.model_validate(dict(zip(self.columns, rows[0])))
+                return product
+            case _:
+                log.error(
+                    f"Invalid number of rows returned for product with id {product_id}: {len(rows)}"
+                )
+                raise ValueError("Multiple rows returned")

app/templates/base.html

@@ -1,8 +1,8 @@
 <!doctype html>
-<title>{% block title %}{% endblock %} - Online Commerce Site</title>
+<title>{% block title %}{% endblock %} - Walmart</title>
 <link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
 <nav>
-  <h1>Online Commerce Site</h1>
+  <h1>Walmart</h1>
   <ul>
 
   </ul>
@@ -15,4 +15,4 @@ <h1>Online Commerce Site</h1>
     <div class="flash">{{ message }}</div>
   {% endfor %}
   {% block content %}{% endblock %}
-</section>
+</section>

app/templates/product/index.html

@@ -17,8 +17,56 @@ <h2 class="card-title">{{ product.ProductName }}</h2>
                     <p>{{ product.QuantityPerUnit }}</p>
                 </div>
             </div>
+
+            <form action="{{ url_for('product.add_to_cart', product_id=product.ProductID) }}" method="POST">
+                <div class="d-flex align-items-center mt-3">
+
+                    <button type="button" class="btn btn-outline-secondary" id="decrease-qty">-</button>
+                    <input type="number" name="quantity" id="quantity" class="form-control mx-2 text-center" min="1"
+                        max="{{ product.UnitsInStock }}" value="1" style="width: 80px;" readonly>
+                    <button type="button" class="btn btn-outline-secondary" id="increase-qty">+</button>
+
+                    <button type="submit" class="btn btn-primary ml-3" id="add-to-cart">
+                        Add to Cart
+                    </button>
+                </div>
+
+            </form>
+
             <a href="{{ url_for('main.index') }}" class="btn btn-secondary mt-3">Back to Products</a>
         </div>
     </div>
 </div>
+
+<style>
+    /* Hide the spinners (up/down arrows) in the number input */
+    input[type="number"]::-webkit-outer-spin-button,
+    input[type="number"]::-webkit-inner-spin-button {
+        -webkit-appearance: none;
+        margin: 0;
+    }
+</style>
+
+<script>
+    document.addEventListener('DOMContentLoaded', function () {
+        const quantityInput = document.getElementById('quantity');
+        const decreaseButton = document.getElementById('decrease-qty');
+        const increaseButton = document.getElementById('increase-qty');
+
+        decreaseButton.addEventListener('click', function () {
+            let currentValue = parseInt(quantityInput.value);
+            if (currentValue > 1) {
+                quantityInput.value = currentValue - 1;
+            }
+        });
+
+        increaseButton.addEventListener('click', function () {
+            let currentValue = parseInt(quantityInput.value);
+            if (currentValue < parseInt(quantityInput.max)) {
+                quantityInput.value = currentValue + 1;
+            }
+        });
+    });
+</script>
+
 {% endblock %}

app/utils/logger.py

@@ -0,0 +1,13 @@
+import logging
+
+
+def setup_logger(name: str) -> logging.Logger:
+    """Setup a logger with basic formatting."""
+    logger = logging.getLogger(name)
+    logger.setLevel(logging.INFO)
+    handler = logging.StreamHandler()
+    formatter = logging.Formatter("%(levelname)-8s [%(name)s] %(message)s")
+    handler.setFormatter(formatter)
+    logger.addHandler(handler)
+    logger.propagate = False
+    return logger