/* global process */
function urlBase64ToUint8Array(base64String) {
  const padding = '='.repeat((4 - (base64String.length % 4)) % 4)
  const base64 = (base64String + padding).replace(/-/g, '+').replace(/_/g, '/')

  const rawData = window.atob(base64)
  return Uint8Array.from([...rawData].map((char) => char.charCodeAt(0)))
}

export function isSWSupported() {
  return 'serviceWorker' in navigator
}

function isPushSupported() {
  return 'PushManager' in window
}

function getOrCreateServiceWorker() {
  if (!isSWSupported()) return
  const swType = process.env.HAS_MODULE_SERVICE_WORKER ? 'module' : 'classic'
  return navigator.serviceWorker
    .register('/sw-pleroma.js', { type: swType })
    .catch((err) =>
      console.error('Unable to get or create a service worker.', err),
    )
}

function subscribePush(registration, isEnabled, vapidPublicKey) {
  if (!isEnabled)
    return Promise.reject(new Error('Web Push is disabled in config'))
  if (!vapidPublicKey)
    return Promise.reject(new Error('VAPID public key is not found'))

  const subscribeOptions = {
    userVisibleOnly: false,
    applicationServerKey: urlBase64ToUint8Array(vapidPublicKey),
  }
  return registration.pushManager.subscribe(subscribeOptions)
}

function unsubscribePush(registration) {
  return registration.pushManager.getSubscription().then((subscription) => {
    if (subscription === null) {
      return Promise.resolve('No subscription')
    }
    return subscription.unsubscribe()
  })
}

function deleteSubscriptionFromBackEnd(token) {
  return fetch('/api/v1/push/subscription/', {
    method: 'DELETE',
    headers: {
      'Content-Type': 'application/json',
      Authorization: `Bearer ${token}`,
    },
  }).then((response) => {
    if (!response.ok) throw new Error('Bad status code from server.')
    return response
  })
}

function sendSubscriptionToBackEnd(
  subscription,
  token,
  notificationVisibility,
) {
  return window
    .fetch('/api/v1/push/subscription/', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        Authorization: `Bearer ${token}`,
      },
      body: JSON.stringify({
        subscription,
        data: {
          alerts: {
            follow: notificationVisibility.follows,
            favourite: notificationVisibility.likes,
            mention: notificationVisibility.mentions,
            reblog: notificationVisibility.repeats,
            move: notificationVisibility.moves,
          },
        },
      }),
    })
    .then((response) => {
      if (!response.ok) throw new Error('Bad status code from server.')
      return response.json()
    })
    .then((responseData) => {
      if (!responseData.id) throw new Error('Bad response from server.')
      return responseData
    })
}
export async function initServiceWorker(store) {
  if (!isSWSupported()) return
  await getOrCreateServiceWorker()
  navigator.serviceWorker.addEventListener('message', (event) => {
    const { dispatch } = store
    const { type, ...rest } = event.data

    switch (type) {
      case 'notificationClicked':
        dispatch('notificationClicked', { id: rest.id })
    }
  })
}

export async function showDesktopNotification(content) {
  if (!isSWSupported) return
  const { active: sw } =
    (await window.navigator.serviceWorker.getRegistration()) || {}
  if (!sw) return console.error('No serviceworker found!')
  sw.postMessage({ type: 'desktopNotification', content })
}

export async function closeDesktopNotification({ id }) {
  if (!isSWSupported) return
  const { active: sw } =
    (await window.navigator.serviceWorker.getRegistration()) || {}
  if (!sw) return console.error('No serviceworker found!')
  if (id >= 0) {
    sw.postMessage({ type: 'desktopNotificationClose', content: { id } })
  } else {
    sw.postMessage({ type: 'desktopNotificationClose', content: { all: true } })
  }
}

export async function updateFocus() {
  if (!isSWSupported) return
  const { active: sw } =
    (await window.navigator.serviceWorker.getRegistration()) || {}
  if (!sw) return console.error('No serviceworker found!')
  sw.postMessage({ type: 'updateFocus' })
}

export function registerPushNotifications(
  isEnabled,
  vapidPublicKey,
  token,
  notificationVisibility,
) {
  if (isPushSupported()) {
    getOrCreateServiceWorker()
      .then((registration) =>
        subscribePush(registration, isEnabled, vapidPublicKey),
      )
      .then((subscription) =>
        sendSubscriptionToBackEnd(subscription, token, notificationVisibility),
      )
      .catch((e) =>
        console.warn(`Failed to setup Web Push Notifications: ${e.message}`),
      )
  }
}

export function unregisterPushNotifications(token) {
  if (isPushSupported()) {
    getOrCreateServiceWorker()
      .then((registration) => {
        return unsubscribePush(registration).then((result) => [
          registration,
          result,
        ])
      })
      .then(([, unsubResult]) => {
        if (unsubResult === 'No subscription') return
        if (!unsubResult) {
          console.warn("Push subscription cancellation wasn't successful")
        }
        return deleteSubscriptionFromBackEnd(token)
      })
      .catch((e) => {
        console.warn(`Failed to disable Web Push Notifications: ${e.message}`)
      })
  }
}

export const shouldCache = process.env.NODE_ENV === 'production'
export const cacheKey = 'pleroma-fe'
export const emojiCacheKey = 'pleroma-fe-emoji'

export const clearCache = (key) => caches.delete(key)

export { getOrCreateServiceWorker }