Ghost/ghost/admin/app/components/gh-billing-iframe.js

import Component from '@ember/component';
import {htmlSafe} from '@ember/template';
import {inject as service} from '@ember/service';

export default Component.extend({
    billing: service(),
    config: service(),
    ghostPaths: service(),
    ajax: service(),
    notifications: service(),

    isOwner: null,
    fetchingSubscription: false,

    didInsertElement() {
        this._super(...arguments);

        this.billing.getBillingIframe().src = this.billing.getIframeURL();

        window.addEventListener('message', (event) => {
            if (event?.data) {
                if (event.data?.request === 'token') {
                    this._handleTokenRequest();
                }

                if (event.data?.request === 'forceUpgradeInfo') {
                    this._handleForceUpgradeRequest();
                }

                if (event.data?.subscription) {
                    this._handleSubscriptionUpdate(event.data);
                }
            }
        });
    },

    _handleTokenRequest() {
        this.set('fetchingSubscription', false);
        let token;
        const ghostIdentityUrl = this.get('ghostPaths.url').api('identities');

        this.ajax.request(ghostIdentityUrl).then((response) => {
            token = response && response.identities && response.identities[0] && response.identities[0].token;
            this.billing.getBillingIframe().contentWindow.postMessage({
                request: 'token',
                response: token
            }, '*');

            this.set('isOwner', true);
        }).catch((error) => {
            if (error.payload?.errors && error.payload.errors[0]?.type === 'NoPermissionError') {
                // no permission means the current user requesting the token is not the owner of the site.
                this.set('isOwner', false);

                // Avoid letting the BMA waiting for a message and send an empty token response instead
                this.billing.getBillingIframe().contentWindow.postMessage({
                    request: 'token',
                    response: null
                }, '*');
            } else {
                throw error;
            }
        });

        // NOTE: the handler is placed here to avoid additional logic to check if iframe has loaded
        //       receiving a 'token' request is an indication that page is ready
        if (!this.fetchingSubscription && !this.billing.get('subscription') && token) {
            this.set('fetchingSubscription', true);
            this.billing.getBillingIframe().contentWindow.postMessage({
                query: 'getSubscription',
                response: 'subscription'
            }, '*');
        }
    },

    _handleForceUpgradeRequest() {
        // Send BMA requested information about forceUpgrade and owner name/email
        let ownerUser = null;
        const owner = this.billing.ownerUser;

        if (owner) {
            ownerUser = {
                name: owner?.name,
                email: owner?.email
            };
        }
        this.billing.getBillingIframe().contentWindow.postMessage({
            request: 'forceUpgradeInfo',
            response: {
                forceUpgrade: this.config.get('hostSettings.forceUpgrade'),
                isOwner: this.isOwner,
                ownerUser
            }
        }, '*');
    },

    _handleSubscriptionUpdate(data) {
        this.billing.set('subscription', data.subscription);
        this.billing.set('checkoutRoute', data?.checkoutRoute || '/plans');

        if (data.subscription.status === 'active' && this.config.get('hostSettings.forceUpgrade')) {
            // config might not be updated after a subscription has been set to active.
            // Until then assume the forceUpgrade is over and the subscription
            // was activated successfully.
            this.config.set('hostSettings.forceUpgrade', false);
        }

        // Detect if the current subscription is in a grace state and render a notification
        if (data.subscription.status === 'past_due' || data.subscription.status === 'unpaid') {
            // This notification needs to be shown to every user regardless their permissions to see billing
            this.notifications.showAlert('Billing error: This site is queued for suspension. The owner of this site must update payment information.', {type: 'error', key: 'billing.overdue'});
        } else {
            this.notifications.closeAlerts('billing.overdue');
        }
        // Detect if the current member limits are exceeded and render a notification
        if (
            data?.exceededLimits
            && data?.exceededLimits.length
            && data?.exceededLimits.indexOf('members') >= 0
            && data?.checkoutRoute
        ) {
            // The action param will be picked up on a transition from the router and can
            // then send the destination route as a message to the BMA, which then handles the redirect.
            const checkoutAction = this.billing.get('billingRouteRoot') + '?action=checkout';

            this.notifications.showAlert(htmlSafe(`Your audience has grown! To continue publishing, the site owner must confirm pricing for this number of members <a href="${checkoutAction}">here</a>`), {type: 'warn', key: 'billing.exceeded'});
        } else {
            this.notifications.closeAlerts('billing.exceeded');
        }
    }
});