omnivore/packages/web/public/sw.js

/* global
  globalThis
  self
  Response
*/

'use strict'
;(function () {
  const globalApi = (typeof globalThis !== 'undefined' && globalThis) || self
  const naviApi = globalApi.navigator

  const mainOrigin = 'https://omnivore.app'
  const devOrigin = 'https://dev.omnivore.app'
  const demoOrigin = 'https://demo.omnivore.app'
  const webProdOrigin = 'https://web-prod.omnivore.app'
  const webDemoOrigin = 'https://web-demo.omnivore.app'

  const currentOrigin =
    (globalApi.location && globalApi.location.origin) || mainOrigin

  if (
    currentOrigin !== mainOrigin &&
    currentOrigin !== devOrigin &&
    currentOrigin !== demoOrigin &&
    currentOrigin !== webProdOrigin &&
    currentOrigin !== webDemoOrigin
  )
    return

  const cacheVersion = 'v1.0.0'

  const homeCache = '/?cid=' + cacheVersion

  const initialCacheItems = [
    homeCache,
    '/manifest.webmanifest',
    '/pwa-36.png',
    '/pwa-48.png',
    '/pwa-72.png',
    '/pwa-96.png',
    '/pwa-144.png',
    '/pwa-192.png',
    '/pwa-256.png',
    '/pwa-384.png',
    '/pwa-512.png',
  ]

  function fetchWithCacheBackup(request) {
    return globalApi.fetch(request).then((freshResult) => {
      if (freshResult.status > 199 && freshResult.status < 400)
        return freshResult

      return globalApi.caches
        .match(request, {
          ignoreSearch: true,
          ignoreMethod: true,
          ignoreVary: true,
        })
        .then((cachedResult) => {
          return cachedResult || freshResult
        })
    })
  }

  function findShareUrlInText(formData) {
    const url = formData.get('url') || ''
    const text = formData.get('text') || ''
    const title = formData.get('title') || ''

    const allParts = [url, text, title].join(' ')
    const snippets = allParts.split(/\s+/)

    for (let i = 0; i < snippets.length; i++) {
      try {
        const shareUrl = new URL(snippets[i])
        return shareUrl
      } catch (e) {}
    }
  }

  function saveArticleUrl(url) {
    if (!url) {
      return Promise.reject(new Error('No URL'))
    }

    const requestUrl = currentOrigin + '/api/article/save'

    return globalApi
      .fetch(requestUrl, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
        },
        body: new URLSearchParams({
          url: url,
          v: '0.2.18',
        }),
      })
      .then(function (response) {
        if (response.status === 200) {
          return response.json().then((responseJson) => {
            return currentOrigin + '/article?url=' + url
          })
        }

        if (response.status === 400) {
          return response.json().then((responseJson) => {
            if (responseJson.errorCode === 'UNAUTHORIZED') {
              return currentOrigin + '/login'
            }
          })
        }
      })
  }

  function handleShareTarget(request) {
    return request
      .formData()
      .then((formData) => {
        const shareUrl = findShareUrlInText(formData)

        return saveArticleUrl(shareUrl).catch(() => {
          // generic error redirect
          return currentOrigin + '/'
        })
      })
      .then((responseUrl) => {
        return Response.redirect(responseUrl, 303)
      })
  }

  function handleFetchRequest(ev) {
    const request = ev.request
    if (request.method === 'POST') {
      const requestUrl = new URL(request.url)
      if (requestUrl.pathname === '/share-target') {
        const shareRequest = handleShareTarget(request)
        return shareRequest
      }
    }

    if (naviApi.onLine) {
      return globalApi.fetch(request)
    }

    return fetchWithCacheBackup(request)
  }

  function handleOutdatedCache() {
    return globalApi.caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames.map((cacheName) => {
          if (cacheName !== cacheVersion) {
            return globalApi.caches.delete(cacheName)
          }
        })
      )
    })
  }

  function initCache() {
    return globalApi.caches.open(cacheVersion).then((cache) => {
      if (!cache.addAll || !naviApi.onLine) return
      return cache.addAll(initialCacheItems)
    })
  }

  globalApi.addEventListener('install', (ev) => {
    globalApi.skipWaiting()

    const handler = initCache()
    ev.waitUntil(handler)
  })

  globalApi.addEventListener('activate', (ev) => {
    const handler = handleOutdatedCache()
    ev.waitUntil(handler)
  })

  globalApi.addEventListener('fetch', (ev) => {
    if (ev.request.destination === 'script') {
      return
    }

    const handler = handleFetchRequest(ev)
    ev.respondWith(handler)
  })
})()