From 4607863b6d26dd0d3728336dcfae1e89dddd6aa7 Mon Sep 17 00:00:00 2001
From: Friedjoff Trautwein <friedjoff.trautwein@geops.de>
Date: Mon, 27 Apr 2020 16:00:35 +0200
Subject: [PATCH] feat: add tiles service worker for offline map

---
 src/tilesServiceWorker.js | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 src/tilesServiceWorker.js

diff --git a/src/tilesServiceWorker.js b/src/tilesServiceWorker.js
new file mode 100644
index 00000000..aaab8461
--- /dev/null
+++ b/src/tilesServiceWorker.js
@@ -0,0 +1,26 @@
+const CACHE_NAME = 'tree-app-tiles-v1';
+const { REACT_APP_VECTOR_TILES_ENDPOINT: endpoint } = process.env;
+
+// eslint-disable-next-line no-restricted-globals
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => {
+      return fetch(`${endpoint}/tiles.txt`)
+        .then((response) => response.text())
+        .then(async (response) => {
+          const tiles = response.split(/\r?\n/);
+          // eslint-disable-next-line no-plusplus
+          for (let index = 0; index < tiles.length; index++) {
+            const tileUrl = `${endpoint}/${tiles[index]}`;
+            try {
+              // eslint-disable-next-line no-await-in-loop
+              const tileResponse = await fetch(tileUrl);
+              cache.put(tileUrl, tileResponse);
+            } catch (error) {
+              // Some tiles do not exist.
+            }
+          }
+        });
+    }),
+  );
+});