import { path } from 'ramda';

import { IRemoteConfig } from '../types/index.js';
import { postAPI } from './ajax.js';

function stringToUint8Array(plainString: string) {
  const padding = '='.repeat((4 - (plainString.length % 4)) % 4);
  const base64 = (plainString + padding).replace(/-/g, '+').replace(/_/g, '/');

  const rawData = window.atob(base64);
  const outputArray = new Uint8Array(rawData.length);

  for (let i = 0; i < rawData.length; ++i) {
    outputArray[i] = rawData.charCodeAt(i);
  }

  return outputArray;
}

/**
 * Store a subscription in the backend so we can notify this user later.
 *
 * @param subscription The push subscription
 */
function storeSubscription(subscription) {
  const data = {
    web_push_subscription: {
      data: subscription,
    },
  };

  return postAPI('/web_push_subscriptions', data);
}

/**
 * Request permission to send push notifications.
 *
 * @param pushManager
 * @param publicKey VAPID public key
 */
export function subscribeToPushNotifications(pushManager: PushManager, publicKey: string) {
  const applicationServerKey = stringToUint8Array(publicKey);
  return pushManager.subscribe({ userVisibleOnly: true, applicationServerKey });
}

/**
 * Request permission to send push notifications and store the subscription in
 * the backend.
 *
 * @param pushManager
 * @param user
 * @param project
 */
export async function createPushSubscription(pushManager: PushManager, config: IRemoteConfig) {
  const vapidPublicKey = path(['webPush', 'config', 'vapidAuthentication', 'publicKey'], config.channels) as string;
  const subscription = await subscribeToPushNotifications(pushManager, vapidPublicKey);

  return storeSubscription(subscription.toJSON());
}

/**
 * Request permission to send push notifications in Safari and store the
 * subscription in the backend.
 *
 * @param authenticationToken A string that helps you identify the user
 * @param webServiceUrl URL of the Safari web push service
 * @param websitePushID Apple identifier of the website push service
 */
export function createSafariPushSubscription(
  authenticationToken: string,
  webServiceUrl: string,
  websitePushID = 'web.com.magicbell-notifications',
) {
  const permissionData = window['safari'].pushNotification.permission(websitePushID);
  if (permissionData.permission === 'granted') return Promise.resolve(permissionData);
  if (permissionData.permission === 'denied') return Promise.reject(false);

  return new Promise(function (resolve, reject) {
    window['safari'].pushNotification.requestPermission(
      webServiceUrl,
      websitePushID,
      { authenticationToken },
      function (permissionData) {
        if (permissionData.deviceToken) {
          const subscriptionData = {
            endpoint: permissionData.deviceToken,
            keys: { websitePushID },
            platform: 'safari',
          };

          storeSubscription(subscriptionData)
            .then((subscription) => {
              resolve(subscription);
            })
            .catch((error) => {
              reject(error);
            });
        } else {
          const error = new Error('Permission was denied');
          reject(error);
        }
      },
    );
  });
}