autoimport: Fix file extensions from redirects

devtools_options.yaml

@@ -0,0 +1,3 @@
+description: This file stores settings for Dart & Flutter DevTools.
+documentation: https://docs.flutter.dev/tools/devtools/extensions#configure-extension-enablement-states
+extensions:

lib/api/preset/autodownload/single/generic.dart

@@ -2,9 +2,10 @@ part of preset;
 
 // twitter: fxtwitter offers a url to give only the image. getting the artist is as easy as reading the first path segment
 Future<PresetImage> twitterToPresetImage(Uri uri) async {
-    // final res = await http.get(Uri.parse(["https://d.fxtwitter.com", uri.path].join()));
+    // final res = await lbHttp.get(Uri.parse(["https://d.fxtwitter.com", uri.path].join()));
 
     final downloadedFileInfo = await downloadFile(Uri.parse(["https://d.fxtwitter.com", uri.path].join()));
+    debugPrint(downloadedFileInfo.path);
 
     return PresetImage(
         image: downloadedFileInfo,

lib/utils/download_image.dart

@@ -9,13 +9,24 @@ import 'package:path_provider/path_provider.dart';
 typedef HandleChunk = Function(List<int> chunk, http.StreamedResponse response);
 
 int hasDownloaded = 0;
-Future<File> downloadFile(Uri uri, {HandleChunk? handleChunk}) async {
+Future<File> downloadFile(Uri uri, {HandleChunk? handleChunk, bool followRedirects = true}) async {
+    http.Request request;
+    http.StreamedResponse response;
+    do { // lazy work for redirects; do-while because it'll run once if followRedirects = false
+        request = http.Request("GET", uri);
+        request.followRedirects = false;
+        response = await lbHttp.send(request);   
+        if(response.isRedirect) {
+            final String? newUrl = response.headers['location'];
+            if(newUrl != null) uri = Uri.parse(newUrl);
+            else throw "Redirect does not have 'location' header";
+        } else break;
+    } while (followRedirects);
+
     final downloadDir = await getTemporaryDirectory();
-    final file = File(p.join(downloadDir.path, uri.pathSegments.last));
-
-    final request = http.Request("GET", uri);
-    final response = await lbHttp.send(request);
-    final sink = file.openWrite();
+    final name = uri.pathSegments.last;
+    final file = File(p.join(downloadDir.path, name));
+    IOSink sink = file.openWrite();
 
     await response.stream.map((chunk) {
         if(handleChunk == null) {