add enhancedfetch for android <=7

lib/utils.ts

@@ -33,15 +33,15 @@ const ping =
     : async (url: string) => {
         let pingFinished = false;
         return Promise.race([
-          fetch(url, {
+          enhancedFetch(url, {
             method: 'HEAD',
           })
-            .then(({ status, statusText }) => {
+            .then(({ status, statusText, url: finalUrl }) => {
               pingFinished = true;
               if (status === 200) {
-                return url;
+                return finalUrl;
               }
-              logger('ping failed', url, status, statusText);
+              logger('ping failed', finalUrl, status, statusText);
               throw new Error('Ping failed');
             })
             .catch((e) => {
@@ -73,3 +73,26 @@ export const testUrls = async (urls?: string[]) => {
   logger('all ping failed, use first url:', urls[0]);
   return urls[0];
 };
+
+export const isAndroid70AndBelow = () => {
+  // android 7.0 and below devices do not support letsencrypt cert
+  // https://letsencrypt.org/2023/07/10/cross-sign-expiration/
+  return Platform.OS === 'android' && Platform.Version <= 24;
+};
+
+export const enhancedFetch = async (
+  url: string,
+  params: Parameters<typeof fetch>[1],
+) => {
+  return fetch(url, params).catch((e) => {
+    logger('fetch error', url, e);
+    if (isAndroid70AndBelow()) {
+      logger(
+        `try fallback to http because android version: ${Platform.Version}`,
+      );
+      return fetch(url.replace('https', 'http'), params);
+    } else {
+      throw e;
+    }
+  });
+};