1 files changed, 110 insertions, 0 deletions
diff --git a/app/sw.src.js b/app/sw.src.js
new file mode 100644
index 0000000..243e425
--- /dev/null
+++ b/app/sw.src.js
@@ -0,0 +1,110 @@
+// noinspection JSUnresolvedVariable
+
+let cacheName = 'peh-pluralponies-pwa';
+let filesToCache = [["%CacheData%"]];
+
+self.addEventListener('install', function(e) {
+    e.waitUntil(
+        caches.open(cacheName).then(function(cache) {
+            return cache.addAll(filesToCache);
+        })
+    );
+});
+
+self.addEventListener('fetch', function(e) {
+    e.respondWith(
+        caches.match(e.request).then(function(response) {
+            return response || fetch(e.request);
+        })
+    );
+});
+
+self.addEventListener('sync', function(e) {
+    if (e.tag === 'data-sync') {
+        e.waitUntil(repeatRefresh());
+    }
+})
+
+self.addEventListener('periodicsync', function(e) {
+    if (e.tag === 'data-sync') {
+        e.waitUntil(repeatRefresh());
+    }
+})
+
+function sleep(ms) {
+    return new Promise((res, _rej) => {
+        setTimeout(res, ms);
+    })
+}
+
+function repeatRefresh() {
+    return new Promise(async (_res, _rej) => {
+        await repeatRefreshInternal();
+    })
+}
+
+async function repeatRefreshInternal() {
+    await refresh();
+    sleep(300000).then(async () => {
+        await repeatRefreshInternal();
+    });
+}
+
+async function fetchPlus(resource, options = {}) {
+    const { timeout = 8000 } = options;
+
+    const controller = new AbortController();
+    const id = setTimeout(() => controller.abort(), timeout);
+    const response = await fetch(resource, {
+        ...options,
+        signal: controller.signal
+    });
+    clearTimeout(id);
+    return response;
+}
+
+function refresh() {
+    return new Promise(async (res, rej) => {
+        let valuesToGet = JSON.parse(await localforage.getItem("values-to-get"));
+
+        let keys = Object.keys(valuesToGet);
+        let index = 2;
+        await getNewValue(res, keys, index, valuesToGet);
+    })
+}
+
+async function getNewValue(res, keys, index, valuesToGet) {
+    if (!keys[0]) {
+        await localforage.setItem("refresh", new Date().toISOString());
+        console.log("Done refreshing in the background at " + new Date().toISOString())
+        res();
+        return;
+    }
+
+    try {
+        await localforage.setItem(keys[0], (await (await fetchPlus(valuesToGet[keys[0]]["url"], { timeout: 3000 })).text()));
+        keys.shift();
+
+        if (!keys[0]) {
+            await localforage.setItem("refresh", new Date().toISOString());
+            console.log("Done refreshing in the background at " + new Date().toISOString())
+            res();
+            return;
+        }
+
+        setTimeout(async () => {
+            index++;
+            await getNewValue(res, keys, index, valuesToGet);
+        }, valuesToGet[keys[0]]["limited"] ? 550 : 0);
+    } catch (e) {
+        for (let key of Object.keys(valuesToGet)) {
+            if (await localforage.getItem(key) === null) {
+                throw new Error("App requested key '" + key + "' but it can't be retrieved at the moment");
+            }
+        }
+
+        await localforage.setItem("refresh", new Date().toISOString());
+        console.log("Done refreshing in the background at " + new Date().toISOString())
+        res();
+    }
+}
+\ No newline at end of file