applyCustomerLicenseTransitions.ts

import type {
	CustomerLicenseBillingContext,
	CustomerLicenseTransition,
	FullCusProduct,
} from "@autumn/shared";
import { transitionLicenseBillingPriceRows } from "./transitionLicenseBillingPriceRows.js";

/** Mirrors pool transitions in memory for downstream billing computation. */
export const applyCustomerLicenseTransitions = ({
	customerProductsToMutate,
	customerLicenseTransitions,
	customerLicenseBillingContext,
}: {
	customerProductsToMutate: FullCusProduct[];
	customerLicenseTransitions: CustomerLicenseTransition[];
	customerLicenseBillingContext?: CustomerLicenseBillingContext;
}): void => {
	if (customerLicenseTransitions.length === 0) return;

	const transitionByIncomingId = new Map(
		customerLicenseTransitions.map((transition) => [
			transition.incomingCustomerLicense.id,
			transition,
		]),
	);

	for (const customerProduct of customerProductsToMutate) {
		for (const customerLicense of customerProduct.customer_licenses ?? []) {
			const transition = transitionByIncomingId.get(customerLicense.id);
			if (!transition) continue;

			customerLicense.link_id = transition.updates.linkId;
			customerLicense.granted = transition.updates.granted;
			customerLicense.remaining = transition.updates.remaining;
			customerLicense.paid_quantity = transition.updates.paidQuantity;
			// Repoint the definition too: unassigned buffer seats must bill at
			// the incoming (possibly customized) price, not the stock one.
			customerLicense.plan_license_id =
				transition.incomingCustomerLicense.plan_license_id;
			customerLicense.planLicense =
				transition.incomingCustomerLicense.planLicense;
		}
	}

	if (!customerLicenseBillingContext) return;

	// Projected rows append so refund paths can keep reading persisted state.
	const persistedRows = [
		...customerLicenseBillingContext.licenseBillingPriceRows,
	];
	for (const customerLicenseTransition of customerLicenseTransitions) {
		const planLicenseId =
			customerLicenseTransition.incomingCustomerLicense.planLicense?.id;
		if (
			planLicenseId &&
			!customerLicenseBillingContext.projectedPlanLicenseIds.includes(
				planLicenseId,
			)
		) {
			customerLicenseBillingContext.projectedPlanLicenseIds.push(planLicenseId);
		}
		customerLicenseBillingContext.licenseBillingPriceRows.push(
			...transitionLicenseBillingPriceRows({
				licenseBillingPriceRows: persistedRows,
				customerLicenseTransition,
				assignedSeatCount:
					customerLicenseBillingContext.assignedSeatCountByCustomerLicenseId[
						customerLicenseTransition.outgoingCustomerLicense.id
					] ?? 0,
			}),
		);
	}
};