improved error handling

lib/Globals.dart

@@ -3,27 +3,33 @@ import 'dart:io' show Platform;
 import 'package:audio_service/audio_service.dart';
 import 'package:audio_session/audio_session.dart';
 import 'package:audioplayers/audioplayers.dart';
-import 'package:http/http.dart' as http;
 import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:http/http.dart' as http;
 
 import 'ListenHandler.dart';
 
 late final ListenHandler _listenHandler;
 late final AudioSession _session;
 
-const String _fallback =
-    "https://generic.ything.app/music/separation-185196.mp3";
+final _fallbackSource =
+    Uri.parse("https://generic.ything.app/music/fallback.url");
 final _urlSource = Uri.parse("https://generic.ything.app/music/player.url");
-late final String _radioUrl;
 
-Future<void> loadCurrentUrl() async {
-  final resp = await http.get(_urlSource);
+Future<String?> loadStringFromUrl(Uri remote) async {
+  try {
+    final resp = await http.get(remote);
     if (resp.statusCode == 200) {
-    _radioUrl = resp.body.trim();
-    print('Loaded remote url');
+      var ret = resp.body.trim();
+      print('Loaded remote url: $remote - $ret');
+      return ret;
     } else {
-    _radioUrl = _fallback;
-    print('Request for current streaming url failed, using fallback url');
+      print(
+          'Request to load remote url: $remote - failed - Status Code: ${resp.statusCode} - Body: ${resp.body}');
+      return null;
+    }
+  } catch (e) {
+    print("Exception - unable to load remote url: $remote - $e");
+    return null;
   }
 }
 
@@ -35,21 +41,21 @@ final _urlAbout =
 final _urlAboutIOS =
     Uri.parse("https://generic.ything.app/ything_radio/about_ios.txt");
 
-late final String _remoteAbout;
+late final String _displayAbout;
 
 Future<void> loadAboutUrl() async {
-  final resp = await http.get(kIsWeb || !Platform.isIOS ? _urlAbout : _urlAboutIOS);
+  final reqUrl = kIsWeb || !Platform.isIOS ? _urlAbout : _urlAboutIOS;
 
-  if (resp.statusCode == 200) {
-    _remoteAbout = resp.body;
-    print('Loaded remote about');
+  var about = await loadStringFromUrl(reqUrl);
+
+  if (about != null) {
+    _displayAbout = about;
   } else {
-    _remoteAbout = _fallbackAbout;
-    print('Request for remote about failed, using fallback about');
+    _displayAbout = _fallbackAbout;
   }
 }
 
-String getAboutText() => _remoteAbout;
+String getAboutText() => _displayAbout;
 
 Future<void> setupListenHandler() async {
   _listenHandler = await AudioService.init(
@@ -96,9 +102,19 @@ Future<void> setupListenHandler() async {
 
 ListenHandler getListenHandlder() => _listenHandler;
 
-UrlSource getUrlSource() {
-  return UrlSource(_radioUrl, mimeType: "audio/mpeg");
+Future<Source> getSource({bool fallback = false}) async {
+  var radioUrl = fallback == false
+      ? await loadStringFromUrl(_urlSource)
+      : await loadStringFromUrl(_fallbackSource);
+  if (radioUrl != null) {
+    return UrlSource(radioUrl, mimeType: "audio/mpeg");
+  } else {
+    return getInternetError();
   }
+}
+
+Source getInternetError() =>
+    AssetSource("audio/internet_error.mp3", mimeType: "audio/mpeg");
 
 Future<bool> startAudioSession() async {
   return await _session.setActive(true);

lib/ListenHandler.dart

@@ -5,8 +5,6 @@ import 'package:ything_radio/Globals.dart';
 class ListenHandler extends BaseAudioHandler {
   final _player = AudioPlayer();
 
-  final UrlSource _radioSource = getUrlSource();
-
   setup_player() {
     _player.setReleaseMode(ReleaseMode.release);
     _player.onPlayerStateChanged.listen((event) {
@@ -64,10 +62,22 @@ class ListenHandler extends BaseAudioHandler {
 
   @override
   Future<void> play() async {
+    print('Starting playback');
     if (await startAudioSession()) {
+      try {
         //setSource followed by resume does not work on Android or web
         //play works everywhere though
-      _player.play(_radioSource, mode: PlayerMode.mediaPlayer);
+        await _player.play(await getSource(), mode: PlayerMode.mediaPlayer);
+      } catch (e) {
+        print("Exception $e - loading fallback");
+        try {
+          await _player.play(await getSource(fallback: true),
+              mode: PlayerMode.mediaPlayer);
+        } catch (e) {
+          print("Exception $e - playing internet connectivity problem");
+          await _player.play(getInternetError());
+        }
+      }
     }
   }
 

lib/main.dart

@@ -1,10 +1,11 @@
+import 'package:audioplayers/audioplayers.dart';
 import 'package:flutter/material.dart';
 
 import 'Globals.dart';
 import 'YthingRadio.dart';
 
 Future<void> main() async {
-  await loadCurrentUrl();
+  AudioLogger.logLevel = AudioLogLevel.info;
   await loadAboutUrl();
   await setupListenHandler();
   runApp(const YthingRadio());

pubspec.yaml

@@ -73,6 +73,8 @@ flutter:
     - assets/images/app-background.jpg
     - assets/images/app-background2.jpg
     - assets/images/app-background3.jpg
+    - assets/images/app-background4.jpg
+    - assets/audio/internet_error.mp3
 
   # An image asset can refer to one or more resolution-specific "variants", see
   # https://flutter.dev/to/resolution-aware-images