feat: new attach / update subscription params

shared/api/billing/common/customizePlan/mappers/customizePlanV1ToV0.ts

@@ -0,0 +1,62 @@
+import { basePriceToProductItem } from "@api/products/components/basePrice/basePriceToProductItem";
+import { planV1ToProductItems } from "@api/products/mappers/planV1ToProductItems";
+import type { FullProduct } from "@models/productModels/productModels";
+import { isPriceItem, mapToProductItems } from "@utils/index";
+import type { SharedContext } from "../../../../../types/sharedContext";
+import type { CustomizePlanV0 } from "../customizePlanV0";
+import type { CustomizePlanV1 } from "../customizePlanV1";
+
+export const customizePlanV1ToV0 = ({
+	ctx,
+	customizePlanV1,
+	fullProduct,
+}: {
+	ctx: SharedContext;
+	customizePlanV1: CustomizePlanV1;
+	fullProduct: FullProduct;
+}): CustomizePlanV0 => {
+	const currentProductItems = mapToProductItems({
+		prices: fullProduct.prices,
+		entitlements: fullProduct.entitlements,
+		features: ctx.features,
+	});
+
+	if (
+		customizePlanV1.price !== undefined &&
+		customizePlanV1.items !== undefined
+	) {
+		// 1. If price AND items provided, return full items array
+		return planV1ToProductItems({
+			ctx,
+			plan: { price: customizePlanV1.price, items: customizePlanV1.items },
+		});
+	} else if (
+		customizePlanV1.price !== undefined &&
+		customizePlanV1.items === undefined
+	) {
+		// 2. If price provided, but no items, then customize base price and carry over feature items
+		const featureItems = currentProductItems.filter(
+			(item) => !isPriceItem(item),
+		);
+
+		const basePriceItem = customizePlanV1.price
+			? basePriceToProductItem({
+					ctx,
+					basePrice: customizePlanV1.price,
+				})
+			: undefined;
+
+		return basePriceItem ? [basePriceItem, ...featureItems] : featureItems;
+	} else {
+		// 3. If no price provided, then carry over base price
+		const basePriceItem = currentProductItems.filter((item) =>
+			isPriceItem(item),
+		);
+		const featureItems = planV1ToProductItems({
+			ctx,
+			plan: { price: null, items: customizePlanV1.items ?? [] },
+		});
+
+		return [...basePriceItem, ...featureItems];
+	}
+};