Behaviors

billsdk({
  behaviors: {
    onRefund: async (ctx, params, defaultBehavior) => {
      // Option 1: Custom logic
      await ctx.paymentAdapter.refund({ ... });
      return { refund, originalPayment };

      // Option 2: Run default + side effects
      const result = await defaultBehavior();
      await sendEmail("Refund processed");
      return result;
    },
  },
});

onRefund: async (ctx, params) => {
  const payment = await ctx.internalAdapter.findOne("payment", {
    where: [{ field: "id", operator: "eq", value: params.paymentId }],
  });

  await ctx.paymentAdapter.refund({
    providerPaymentId: payment.providerPaymentId!,
  });

  // Don't cancel subscription
  return { refund: payment, originalPayment: payment };
},

onSubscriptionCancel: async (ctx, params) => {
  await ctx.internalAdapter.update("subscription", {
    where: [{ field: "customerId", operator: "eq", value: params.customerId }],
    data: { planCode: "free" },
  });

  return { subscription, canceledImmediately: false };
},

onTrialEnd: async (ctx, params, defaultBehavior) => {
  const subscription = await ctx.internalAdapter.findSubscriptionById(
    params.subscriptionId,
  );

  // Extend trial by 7 more days for engaged users
  if (await isEngagedUser(subscription.customerId)) {
    const newTrialEnd = new Date(subscription.trialEnd!);
    newTrialEnd.setDate(newTrialEnd.getDate() + 7);

    const updated = await ctx.internalAdapter.updateSubscription(
      subscription.id,
      { trialEnd: newTrialEnd },
    );

    return { subscription: updated, converted: false };
  }

  // Otherwise, run default (charge or cancel)
  return defaultBehavior();
},

onTrialEnd: async (ctx, params) => {
  const subscription = await ctx.internalAdapter.findSubscriptionById(
    params.subscriptionId,
  );

  // Instead of charging, downgrade to free plan
  const updated = await ctx.internalAdapter.updateSubscription(
    subscription.id,
    { planCode: "free", status: "active" },
  );

  return { subscription: updated, converted: false };
},