Refactor adapter example for cache to map old one

snippets/adapters/cache-lifetime/new.js

@@ -4,9 +4,40 @@ import DataStore from '@ember-data/store';
 export default class Store extends DataStore {
   constructor(args) {
     super(args);
-    this.lifetimes = new LifetimesService(this, {
-      apiCacheSoftExpires: 30_000,
-      apiCacheHardExpires: 60_000
-    });
+    // This is default configuration that would be set automatically be Ember Data
+    // this.lifetimes = new LifetimesService(this, {
+    //   apiCacheSoftExpires: 30_000,
+    //   apiCacheHardExpires: 60_000
+    // });
+    this.lifetimes = {
+      isHardExpired(identifier) {
+        const cached = this.store.cache.peekRequest(identifier);
+        const twentyMinutesInMs = 20 * 60 * 1000;
+
+        function isStale(headers, expirationTime) {
+          const date = headers.get('date');
+
+          if (!date) {
+            return true;
+          }
+
+          const time = new Date(date).getTime();
+          const now = Date.now();
+          const deadline = time + expirationTime;
+
+          const result = now > deadline;
+
+          return result;
+        }
+
+        return !cached || !cached.response || isStale(cached.response.headers, twentyMinutesInMs);
+      },
+
+      isSoftExpired(identifier) {
+        const { downlink, effectiveType } = navigator.connection;
+
+        return downlink > 0 && effectiveType === '4g';
+      }
+    }
   }
 }