import { PaymentsErrorEnum } from '../../enum/payments-error.enum';
import { DOMException } from '../../error/dom.exception';

import type { PaymentDetailsUpdate } from '../../@standard/w3c/payment-details-update';
import type { PaymentRequestEventType } from '../../type/payment-request-event.type';
import type { PaymentRequestUpdateHandler } from '../../type/payment-request-update-handler.type';

/**
 * The W3C `PaymentRequestUpdateEvent` interface.
 *
 * @see https://www.w3.org/TR/payment-request/#dom-paymentrequestupdateevent
 */
export class PaymentRequestUpdateEvent {
    readonly type: PaymentRequestEventType;

    private isUpdated = false;
    private readonly onUpdateWith: PaymentRequestUpdateHandler;

    constructor(type: PaymentRequestEventType, onUpdateWith: PaymentRequestUpdateHandler) {
        this.type = type;
        this.onUpdateWith = onUpdateWith;
    }

    /**
     * Whether `updateWith()` was already called for this event, so a later listener can skip an answered one.
     *
     * @see https://github.com/rnw-community/rnw-community/blob/master/packages/react-native-payments/docs/api/payment-request-update-event.md
     */
    get isAnswered(): boolean {
        return this.isUpdated;
    }

    /**
     * The W3C `PaymentRequestUpdateEvent.updateWith()` method answering the change event with updated details.
     *
     * @see https://github.com/rnw-community/rnw-community/blob/master/packages/react-native-payments/docs/api/payment-request-update-event.md
     * @see https://www.w3.org/TR/payment-request/#dom-paymentrequestupdateevent-updatewith
     */
    updateWith(detailsUpdate: PaymentDetailsUpdate | Promise<PaymentDetailsUpdate>): void {
        if (this.isUpdated) {
            throw new DOMException(PaymentsErrorEnum.InvalidStateError);
        }

        this.onUpdateWith(Promise.resolve(detailsUpdate));
        this.isUpdated = true;
    }
}