fix(download): download multipart

lib/service/feralfile_service.dart

@@ -347,7 +347,7 @@ class FeralFileServiceImpl extends FeralFileService {
         signature: signatureHex,
         owner: ownerAddress,
       );
-      final file = await FileHelper.downloadFile(url);
+      final file = await FileHelper.downloadFileMultipart(url);
       return file;
     } catch (e) {
       log.info('Error downloading artwork: $e');

lib/util/file_helper.dart

@@ -1,14 +1,21 @@
 import 'dart:io';
 import 'dart:typed_data';
 
+import 'package:autonomy_flutter/util/log.dart';
 import 'package:collection/collection.dart';
+import 'package:dio/dio.dart';
 import 'package:http/http.dart' as http;
 import 'package:image_gallery_saver/image_gallery_saver.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:share_plus/share_plus.dart';
 
 class FileHelper {
+  static final dio = Dio();
+
+  static Future<Directory> getDownloadDir() async =>
+      await getApplicationDocumentsDirectory();
+
   static Future<bool> saveImageToGallery(Uint8List data, String name) async {
     final response = await ImageGallerySaver.saveImage(data,
         name: name, isReturnImagePathOfIOS: true);
@@ -33,6 +40,82 @@ class FileHelper {
     return file;
   }
 
+  static Future<int> _getFileSize(Map<String, String> headers) async =>
+      int.parse(headers['content-length'] ?? '0');
+
+  static Future<String> _getFileName(Map<String, String> headers) async {
+    final fileName = headers['content-disposition']
+            ?.split(';')
+            .firstWhereOrNull((element) => element.contains('filename'))
+            ?.split('=')[1]
+            .replaceAll('"', '') ??
+        'file';
+    return fileName;
+  }
+
+  static String _getPartFilePath(String filePath, int partNum) =>
+      '$filePath.part$partNum';
+
+  static Future<void> _clearPartFiles(String filePath, int numParts) async {
+    for (int i = 0; i < numParts; i++) {
+      final partFile = File(_getPartFilePath(filePath, i));
+      if (partFile.existsSync()) {
+        await partFile.delete();
+      }
+    }
+  }
+
+  static Future<File?> downloadFileMultipart(String fullUrl) async {
+    log.info('Downloading file: $fullUrl');
+    final dir = await getDownloadDir();
+    final savePath = '${dir.path}/Downloads/';
+    final request = http.MultipartRequest('GET', Uri.parse(fullUrl));
+    final response = await request.send();
+
+    // Get the file size
+    final int fileSize = await _getFileSize(response.headers);
+    final String fileName = await _getFileName(response.headers);
+    final filePath = savePath + fileName;
+
+    // Calculate the number of parts
+    const partSize = 5 * 1024 * 1024;
+
+    final int numParts = (fileSize / partSize).ceil();
+    try {
+      // Perform multipart download
+      await Future.wait(List.generate(numParts, (i) => i).map((i) async {
+        final int start = i * partSize;
+        final int end = (i + 1) * partSize - 1;
+
+        await dio.download(
+          fullUrl,
+          _getPartFilePath(filePath, i),
+          options: Options(
+            headers: {
+              HttpHeaders.rangeHeader: 'bytes=$start-$end',
+            },
+          ),
+        );
+        log.info('Downloaded part $i/$numParts');
+      }));
+
+      // Concatenate parts to create the final file
+      final outputFile = File(filePath);
+      final IOSink sink = outputFile.openWrite(mode: FileMode.writeOnlyAppend);
+      for (int i = 0; i < numParts; i++) {
+        final File partFile = File(_getPartFilePath(filePath, i));
+        await sink.addStream(partFile.openRead());
+      }
+      await sink.close();
+      await _clearPartFiles(filePath, numParts);
+      return outputFile;
+    } catch (e) {
+      log.info('Error downloading file: $e');
+      await _clearPartFiles(filePath, numParts);
+    }
+    return null;
+  }
+
   static Future<File> downloadFile(
     String fullUrl,
   ) async {