package checkout

import (
	"fmt"
	"time"

	messages "git.k6n.net/go-cart-actor/proto/checkout"
)

// PaymentCompleted registers the completion of a payment for a checkout.
func HandlePaymentCompleted(g *CheckoutGrain, m *messages.PaymentCompleted) error {
	if m == nil {
		return fmt.Errorf("PaymentCompleted: nil payload")
	}
	paymentId := m.PaymentId
	payment, found := g.FindPayment(paymentId)

	if !found {
		return fmt.Errorf("PaymentCompleted: payment not found")
	}

	payment.ProcessorReference = m.ProcessorReference
	payment.Status = PaymentStatusSuccess
	if m.Amount > 0 {
		payment.Amount = m.Amount
	}
	if m.Currency != "" {
		payment.Currency = m.Currency
	}

	if m.CompletedAt != nil {
		payment.CompletedAt = asPointer(m.CompletedAt.AsTime())
	} else {
		payment.CompletedAt = asPointer(time.Now())
	}

	// Update checkout status
	g.PaymentInProgress--
	sum := g.CartState.TotalPrice.IncVat

	for _, payment := range g.SettledPayments() {
		sum -= payment.Amount
	}
	g.AmountInCentsRemaining = sum

	return nil
}