1. const STATIC = "static";
2. const RESOURCES = "resources";
3.  
4. self.addEventListener("install", event => event.waitUntil(
5.     Promise.all([
6.         self.skipWaiting(),
7.         caches.delete(STATIC),
8.         caches.delete(RESOURCES),
9.     ]).then(() => Promise.all([
10.         caches.open(STATIC).then(cache => cache.addAll([
11.             "/main.js",
12.             "/index.html",
13.         ])),
14.     ]))));
15.  
16. self.addEventListener("activate", event => event.waitUntil(clients.claim()));
17.  
18. self.addEventListener("sync", event =>
19.     event.waitUntil(
20.         Promise.all([
21.             clients.claim(),
22.             caches.delete(RESOURCES),
23.         ])
24.     )
25. )
26.  
27. const base64Fixer = c => c.charCodeAt(0);
28.  
29. const utf8base64ToUint8Array = payload => {
30.     const brokenPayload = atob(payload);
31.     return Uint8Array.from(brokenPayload, base64Fixer);
32. };
33.  
34. const responseFromBuffer = (
35.     buffer,
36.     contentType,
37.     etag
38. ) => {
39.     const headers = new Headers({
40.         "Content-Length": buffer.length.toString(),
41.         "Content-Type": contentType,
42.     });
43.     if (etag) {
44.         headers.append("ETag", etag);
45.     }
46.     return new Response(buffer, { status: 200, headers });
47. };
48.  
49. const createResponseFromAttachment = (
50.     {
51.         data,
52.         contentType = "application/javascript",
53.     },
54.     etag
55. ) => responseFromBuffer(utf8base64ToUint8Array(data), contentType, etag);
56.  
57. const handleEntryRequest = async event => {
58.     try {
59.         const base = event.request.url.substring(event.request.url.indexOf("/entries/"));
60.         const nextSeparator = base.indexOf("/", 9);
61.         const nextDot = base.indexOf(".", 9);
62.         let endIndex;
63.         if (nextSeparator !== -1 && nextDot !== -1) {
64.             endIndex = Math.min(nextSeparator, nextDot);
65.         } else if (nextSeparator !== -1) {
66.             endIndex = nextSeparator
67.         } else if (nextDot !== -1) {
68.             endIndex = nextDot;
69.         }
70.         const response = await fetch(`${base.substring(0, endIndex).replace("/entries/", "/resources/")}.json`);
71.         const data = await response.json();
72.         const cache = await caches.open(RESOURCES);
73.  
74.         /*for (const requestUrl in data) {
75.             console.log(requestUrl)
76.             const contentType = requestUrl.endsWith(".css") ? "text/css" : "application/javascript";
77.             await cache.put(requestUrl, createResponseFromAttachment({
78.                 data: data[requestUrl],
79.                 contentType,
80.             }, response.headers.get("ETag")));
81.         }*/
82.         console.log('matching', base);
83.         return cache.match(base).then(async resp => {
84.             console.log('opening', base);
85.             if (!resp && data[base]) {
86.                 let requestUrl = base;
87.                 const contentType = requestUrl.endsWith(".css") ? "text/css" : "application/javascript";
88.                 resp = createResponseFromAttachment({
89.                     data: data[requestUrl],
90.                     contentType,
91.                 }, response.headers.get("ETag"));
92.                 cache.put(requestUrl, resp.clone())
93.                 //await cache.put(requestUrl, resp);
94.                // resp = await cache.match(base);
95.  
96.             }
97.             console.log('opened', base);
98.             return resp || new Response(undefined, { status: 404 })
99.         });
100.  
101.        // return cache.then(cache => cache.match(base)).then(resp => resp || new Response(undefined, { status: 404 }));
102.  
103.     } catch (e) {
104.         console.log(e)
105.     }
106. };
107.  
108. self.addEventListener("fetch", event => {
109.     if (event.request.url.includes("/entries/")) {
110.         event.respondWith(handleEntryRequest(event));
111.     } else if (event.request.url.endsWith("/main.js") || event.request.url.endsWith("/index.html")) {
112.         return event.respondWith(
113.             caches.open(STATIC)
114.                 .then(cache => cache.match(event.request))
115.                 .then(match => match || fetch(event.request))
116.         );
117.     } else {
118.         console.log('error', event.request.url)
119.     }
120. });