import { expect, test } from "bun:test";
import type { ApiCustomerV3 } from "@autumn/shared";
import { expectLatestInvoiceCorrect } from "@tests/integration/billing/utils/expectLatestInvoiceCorrect.js";
import { TestFeature } from "@tests/setup/v2Features.js";
import { items } from "@tests/utils/fixtures/items.js";
import { products } from "@tests/utils/fixtures/products.js";
import { initScenario, s } from "@tests/utils/testInitUtils/initScenario.js";
import chalk from "chalk";

/**
 * Subscription Update - Decrease Quantity Tests
 *
 * These tests verify quantity downgrades:
 * - Basic single-feature downgrade (20 → 5 units)
 */

test.concurrent(`${chalk.yellowBright("update-quantity: downgrade 20 to 5 units")}`, async () => {
	const customerId = "dec-qty-basic-downgrade";
	const billingUnits = 12;
	const pricePerUnit = 8;

	const prepaidItem = items.prepaid({
		featureId: TestFeature.Messages,
		billingUnits,
		price: pricePerUnit,
	});

	const product = products.base({
		id: "prepaid",
		items: [prepaidItem],
	});

	const { autumnV1 } = await initScenario({
		customerId,
		setup: [
			s.customer({ paymentMethod: "success" }),
			s.products({ list: [product] }),
		],
		actions: [
			s.attach({
				productId: product.id,
				options: [
					{ feature_id: TestFeature.Messages, quantity: 20 * billingUnits },
				],
			}),
		],
	});

	// Preview the downgrade
	const preview = await autumnV1.subscriptions.previewUpdate({
		customer_id: customerId,
		product_id: product.id,
		options: [{ feature_id: TestFeature.Messages, quantity: 5 * billingUnits }],
	});

	// Verify preview total matches expected (20 -> 5 = -15 units * $8)
	expect(preview.total).toBe(-15 * pricePerUnit);

	// Downgrade from 20 to 5 units
	await autumnV1.subscriptions.update({
		customer_id: customerId,
		product_id: product.id,
		options: [{ feature_id: TestFeature.Messages, quantity: 5 * billingUnits }],
	});

	const customer = await autumnV1.customers.get<ApiCustomerV3>(customerId);
	const feature = customer.features?.[TestFeature.Messages];

	// Should have 60 messages (5 units × 12 billing_units)
	expect(feature?.balance).toBe(60);

	// Expect credit invoice for downgrade (20 -> 5 = -15 units * $8)
	expectLatestInvoiceCorrect({
		customer,
		productId: product.id,
		amount: -15 * pricePerUnit,
	});
});