{
  "id": "promotionId",
  "userMessage": "User message defined in the promotion",
  "suggestion": "If you add one more X product, you will receive a discount of Y TL",
}

{
     "suggestionPromotions": [
            {
                "id": "ORNS8M1ROXCXY988",
                "userMessage": "",
                "suggestion": "Get 1 more and have 20% discount!",
                "additionalData": {
                    "addToCart": [
                        1, // productID
                        2,
                        3
                    ]
                }
            }
        ]
}

function calculatePromotion(
    body: { subOrders: Array<{ id: string }> },
    params: { amoutOff: number; buyProductIds: string[] },
    context:{ promotionId: string, userTransactions?: any[], couponGiftAmount?: number },
) {
    // We are checking if there is any product from the "buyProductIds" parameter within the "subOrders."
    return body.subOrders.some((s) => params.buyProductIds.includes(s.id))
        ? params.amoutOff
        : 0;
}

const body = {
    subOrders: [
        {
            id: '1',
        },
        {
            id: '2',
        },
    ]
};

const params = {
    buyProductIds: ["1", "2", "3", "5"], // Apply a discount if any of these products are purchased
    amoutOff: 50, // The total amount eligible for the discount
};

// Result: A discount of 50 TL has been calculated based on the purchase of the X product with the existing parameters and returned.
console.log(calculatePromotion(body, params));

function calculatePromotion(
 body: { subOrders: Array<{ id: string; price: number }> },
 params: {
  purchasedProductIds: string[]; // An array containing the IDs of products eligible for discounts upon purchase.
  discountProductsToBeAppliedIds: string[]; // An array containing the IDs of the products on which the discount will be applied.
  discountedProductPrice: number; // The discounted price to be applied for each product.
 },
context:{ promotionId: string,  // The ID of the promotion that you do not want to be applied again when recalculated from a previous calculation.
 userTransactions?: any[],     //  Data such as user's past transactions and the number of times the promotion has been used can be found.
couponGiftAmount?: number  // The entered gift amount on the coupon, if available, is checked for applicability and applied.
 },
) {
  const purchasedProducts = body.subOrders.filter((s) =>
    params.purchasedProductIds.includes(s.id) // Filtering the 'subOrders' array to include only the purchased products based on their IDs.
  );

  let totalDiscountAmount = 0; // Initialize the variable to hold the total discount amount.

  const discountProductsToBeApplied = body.subOrders.filter((s) =>
    params.discountProductsToBeAppliedIds.includes(s.id) // Filtering the 'subOrders' array to include only the discounted products based on their IDs.
  );

  const countOfDiscountProduct = discountProductsToBeApplied.length <= purchasedProducts.length ? discountProductsToBeApplied.length : purchasedProducts.length; // Determine the number of discounted products based on the minimum of either the existing discounted products or the purchased products.

  for (let i = 0; i < countOfDiscountProduct; i++) { // Enter a loop for the number of discounted products.
    totalDiscountAmount = countOfDiscountProduct * (discountProductsToBeApplied[i].price - params.discountedProductPrice); //Calculate the total discount amount by multiplying the number of discounted products by the difference between the product price and the discounted price.
  }

  return totalDiscountAmount; // Return the total discount amount.
}

// The 'body' object represents the 'subOrders' data, which contains many products with 'id' and 'price' properties.
const body = {
  subOrders: [
    {
      id: '1',
      price: 100,
    },
    {
      id: '2',
      price: 150,
    },
    {
      id: '3',
      price: 150,
    },
    {
      id: '4',
      price: 150,
    },
  ]
};

const params = {
  purchasedProductIds: ['1', '2'], // An array containing the IDs of the purchased products.
  discountedProductPrice: 50, // The discounted price applied to each product.
  discountProductsToBeAppliedIds: ['3', '4'] // An array containing the IDs of the products where the discount will be applied.
};

// Result: With the existing parameters, a total discount of 200 TL is returned based on the purchase of two X products, where, if available, the price of two Y products is set to Z TL each.
console.log(calculatePromotion(body, params));