feat: Add necessary middlewares for tax inclusive pricing (#7827)

We are adding tax inclusive pricing calculation when listing products.

Two things to keep in mind:
- `region_id` will be required if you request calculated prices.
- We won't accept `currency_code` anymore, as that will come from the region info (since ultimately a cart and its currency are tied to a region)

REF CORE-2376
DEPENDS ON #8003

packages/core/types/src/http/pricing/common.ts

@@ -0,0 +1,105 @@
+export interface BaseCalculatedPriceSet {
+  /**
+   * The ID of the price set.
+   */
+  id: string
+
+  /**
+   * Whether the calculated price is associated with a price list. During the calculation process, if no valid price list is found,
+   * the calculated price is set to the original price, which doesn't belong to a price list. In that case, the value of this property is `false`.
+   */
+  is_calculated_price_price_list?: boolean
+
+  /**
+   * Whether the calculated price is tax inclusive.
+   */
+  is_calculated_price_tax_inclusive?: boolean
+
+  /**
+   * The amount of the calculated price, or `null` if there isn't a calculated price.
+   */
+  calculated_amount: number | null
+
+  /**
+   * The amount of the calculated price with taxes included. If the calculated price is tax inclusive, this field will be the same as `calculated_amount`.
+   */
+  calculated_amount_with_tax?: number | null
+
+  /**
+   * The amount of the calculated price without taxes included. If the calculated price is tax exclusive, this field will be the same as `calculated_amount`.
+   */
+  calculated_amount_without_tax?: number | null
+
+  /**
+   * Whether the original price is associated with a price list. During the calculation process, if the price list of the calculated price is of type override,
+   * the original price will be the same as the calculated price. In that case, the value of this property is `true`.
+   */
+  is_original_price_price_list?: boolean
+
+  /**
+   * Whether the original price is tax inclusive.
+   */
+  is_original_price_tax_inclusive?: boolean
+
+  /**
+   * The amount of the original price, or `null` if there isn't a calculated price.
+   */
+  original_amount: number | null
+
+  /**
+   * The currency code of the calculated price, or null if there isn't a calculated price.
+   */
+  currency_code: string | null
+
+  /**
+   * The details of the calculated price.
+   */
+  calculated_price?: {
+    /**
+     * The ID of the price selected as the calculated price.
+     */
+    id: string | null
+    /**
+     * The ID of the associated price list, if any.
+     */
+    price_list_id: string | null
+    /**
+     * The type of the associated price list, if any.
+     */
+    price_list_type: string | null
+    /**
+     * The `min_quantity` field defined on a price.
+     */
+    min_quantity: number | null
+    /**
+     * The `max_quantity` field defined on a price.
+     */
+    max_quantity: number | null
+  }
+
+  /**
+   * The details of the original price.
+   */
+  original_price?: {
+    /**
+     * The ID of the price selected as the original price.
+     */
+    id: string | null
+    /**
+     * The ID of the associated price list, if any.
+     */
+    price_list_id: string | null
+    /**
+     * The type of the associated price list, if any.
+     */
+    price_list_type: string | null
+    /**
+     * The `min_quantity` field defined on a price.
+     */
+    min_quantity: number | null
+    /**
+     * The `max_quantity` field defined on a price.
+     */
+    max_quantity: number | null
+  }
+}

packages/core/types/src/http/product/admin/payloads.ts

@@ -22,6 +22,8 @@ export interface AdminCreateProductVariantPrice {
   amount: number
   min_quantity?: number | null
   max_quantity?: number | null
+  // Note: Although the BE is generic, we only use region_id for price rules for now, so it's better to keep the typings stricter.
+  rules?: { region_id: string } | null
 }
 
 export interface AdminCreateProductVariant {

packages/core/types/src/http/product/common.ts

@@ -1,6 +1,7 @@
 import { BaseFilterable, OperatorMap } from "../../dal"
 import { BaseCollection } from "../collection/common"
 import { FindParams } from "../common"
+import { BaseCalculatedPriceSet } from "../pricing/common"
 import { BaseProductCategory } from "../product-category/common"
 import { BaseProductType } from "../product-type/common"
 
@@ -56,10 +57,11 @@ export interface BaseProductVariant {
   length: number | null
   height: number | null
   width: number | null
+  variant_rank?: number | null
   options: BaseProductOptionValue[] | null
   product?: BaseProduct | null
   product_id?: string
-  variant_rank?: number | null
+  calculated_price?: BaseCalculatedPriceSet
   created_at: string
   updated_at: string
   deleted_at: string | null

packages/core/types/src/product/common.ts

@@ -305,11 +305,11 @@ export interface ProductCategoryDTO {
    *
    * @expandable
    */
-  parent_category?: ProductCategoryDTO | null
+  parent_category: ProductCategoryDTO | null
   /**
    * The associated parent category id.
    */
-  parent_category_id?: string | null
+  parent_category_id: string | null
   /**
    * The associated child categories.
    *
@@ -330,6 +330,10 @@ export interface ProductCategoryDTO {
    * When the product category was updated.
    */
   updated_at: string | Date
+  /**
+   * When the product category was deleted.
+   */
+  deleted_at?: string | Date
 }
 
 /**

packages/core/types/src/tax/common.ts

@@ -513,7 +513,7 @@ interface TaxLineDTO {
   /**
    * The rate of the tax line.
    */
-  rate: number | null
+  rate: number
 
   /**
    * The code of the tax line.

packages/core/utils/src/totals/index.ts

@@ -2,6 +2,7 @@ export * from "./cart"
 export * from "./create-raw-properties-from-bignumber"
 export * from "./line-item"
 export * from "./math"
+export * from "./tax"
 export * from "./promotion"
 export * from "./shipping-method"
 export * from "./transform-properties-to-bignumber"

packages/core/utils/src/totals/tax/index.ts

@@ -31,3 +31,24 @@ export function calculateTaxTotal({
 
   return taxTotal
 }
+
+export function calculateAmountsWithTax({
+  taxLines,
+  amount,
+  includesTax,
+}: {
+  taxLines: Pick<TaxLineDTO, "rate">[]
+  amount: number
+  includesTax?: boolean
+}) {
+  const tax = calculateTaxTotal({
+    taxLines,
+    includesTax,
+    taxableAmount: amount,
+  })
+
+  return {
+    priceWithTax: includesTax ? amount : MathBN.add(tax, amount).toNumber(),
+    priceWithoutTax: includesTax ? MathBN.sub(amount, tax).toNumber() : amount,
+  }
+}