clean-node-1-excerpt-11.js

// API route to create an order
app.post("/orders", async (req, res) => {
  // HTTP request payload validation
  // abortEarly is false in order to retrieve all the errors at once
  const { error } = Joi.validate(req.body, orderSchema, {
    abortEarly: false
  });

  if (error) {
    const errorMessage = error.details.map(({ message, context }) =>
      Object.assign({ message, context })
    );
    return res.status(400).send({ data: errorMessage });
  }

  // Fetch the list of products based on the products provided in the order
  const productList = await Product.findAll({
    where: {
      id: { [Op.in]: req.body.product_list.map(id => parseInt(id, 0)) }
    }
  });

  if (productList.length === 0) {
    return res.status(400).send({
      data: [
        { message: "Unknown products", context: { key: "product_list" } }
      ]
    });
  }

  const productListData = productList.map(product => product.toJSON());

  // Compute the total weight order
  const orderTotalWeight = productListData
    .map(p => p.weight)
    .reduce((prev, cur) => prev + cur, 0);

  // Compute the total price amount
  const orderProductListPrice = productListData
    .map(p => p.price)
    .reduce((prev, cur) => prev + cur, 0);

  // Compute the shipment price amount
  const SHIPMENT_PRICE_STEP = 25;
  const SHIPMENT_WEIGHT_STEP = 10;
  const orderShipmentPrice =
    SHIPMENT_PRICE_STEP * Math.round(orderTotalWeight / SHIPMENT_WEIGHT_STEP);

  // Compute the order price
  let totalAmount = orderProductListPrice + orderShipmentPrice;

  // Compute the discount
  const DISCOUNT_THRESHOLD = 1000;
  const DISCOUNT_RATIO = 0.95;
  if (totalAmount > DISCOUNT_THRESHOLD) {
    totalAmount = totalAmount * DISCOUNT_RATIO;
  }

  const orderData = Object.assign(
    {
      total_amount: totalAmount,
      shipment_amount: orderShipmentPrice,
      total_weight: orderTotalWeight
    },
    { product_list: req.body.product_list }
  );

  const order = await Order.create(orderData);
  res.set("Location", `/orders/${order.id}`);
  res.status(201).send();
});