const makeAnOrder = async (
  userId,
  shopId,
  items,
  notes,
  payment_method,
  address,
  name,
  phoneNumber,
  deliveryArea
) => {
  // VALIDATIONS

  if (!userId && !(name && phoneNumber))
    // If user id not sent AND name and phoneNumber not sent
    throw new AppError('Missing parameters in the request', 400);

  if (!shopId || !address || !deliveryArea)
    throw new AppError('Missing parameters in the request', 400);

  if (!payment_method || !['Visa', 'Cash'].includes(payment_method))
    throw new AppError('Missing payment method or invalid payment method');

  if (!items || !Array.isArray(items))
    throw new AppError('Missing items argument or it is not an array');

  // CHECK USER

  if (userId) {
    const user = await User.findById(userId);
    if (!user) throw new AppError('Invalid user id', 400);

    name = user.name;
    phoneNumber = user.phoneNumber;
  }

  // GET BRANCH ID

  const deliveryAreas = (
    await Shop.findById(shopId).select('delivery_areas')
  ).toObject().delivery_areas;

  let deliveryPrice = -1;

  for (let el of deliveryAreas) {
    if (el.area === deliveryArea) {
      if (deliveryPrice === -1 || el.price < deliveryPrice) {
        branchId = el.branch;
        deliveryPrice = el.price;
        break;
      }
    }
  }

  if (!branchId)
    throw new AppError('Delivery area not found in the given shop', 404);

  // HANDLE ITEMS

  const itemsIds = items.map((el) => mongoose.Types.ObjectId(el.id));

  let itemsObjects = (
    await Item.find({ _id: { $in: itemsIds }, active: true }).select(
      '_id addons price'
    )
  ).map((el) => el.toObject());

  if (!itemsObjects || itemsObjects.length === 0)
    throw new AppError('The requested items do not exist', 400);

  itemsObjects.forEach((item) => {
    item.addons.forEach((addon) => {
      addon.options = convertArrayToObject(addon.options, '_id');
    });
    item.addons = convertArrayToObject(item.addons, '_id');
  });

  itemsObjects = convertArrayToObject(itemsObjects, '_id');

  let totalPrice = 0;

  itemsToBeInserted = [];

  items.forEach((item) => {
    const itemToBeInserted = {
      item: item.id,
      addons: [],
      qty: item.qty,
    };

    totalPrice += itemsObjects[item.id].price * item.qty;

    if (item.addons && Array.isArray(item.addons)) {
      item.addons.forEach((addon) => {
        if (!itemsObjects[item.id])
          throw new AppError("The shop doesn't have this addon", 400);

        const originalAddon = itemsObjects[item.id].addons[addon.id];
        if (!originalAddon)
          throw new AppError('Addon not found for an item', 400);

        if (!addon.options || addon.options.length === 0)
          throw new AppError('A requested item does not have any addons', 400);

        addon.options.forEach((option) => {
          if (!originalAddon.options[option])
            throw new AppError(
              'A requested option does not belong to its addon',
              400
            );
        });

        if (originalAddon.multiple === false) {
          if (addon.options.length > 1)
            throw new AppError(
              'A requested addon can only contain one option but you requested more than one option'
            );
        }

        const addonToBeInserted = {
          name: originalAddon.name,
          multiple: originalAddon.multiple,
          options: [],
        };

        addon.options.forEach((option) => {
          const originalOption = originalAddon.options[option];

          totalPrice += originalOption.price * item.qty;

          addonToBeInserted.options.push({
            name: originalOption.name,
            price: originalOption.price,
          });
        });

        itemToBeInserted.addons.push(addonToBeInserted);
      });
    } else {
      throw new AppError('Invalid addons parameter in an item', 400);
    }

    itemsToBeInserted.push(itemToBeInserted);
  });

  totalPrice += deliveryPrice;

  const order = await Order.create({
    shop: shopId,
    ...(userId && { user: userId }),
    branch: branchId,
    items: itemsToBeInserted,
    notes: notes,
    payment_method: payment_method,
    user_address: address,
    total_price: totalPrice,
    name: name,
    phoneNumber: phoneNumber,
    delivery_area: deliveryArea,
  });

  order.__v = undefined;

  return order;
};