Handle incorrect pause

mobile/lib/module/download/manager.dart

@@ -22,6 +22,7 @@ class DownloadManager {
   final Map<int, Completer<DownloadResult>> _completers = {};
   final Map<int, StreamController<DownloadTask>> _streams = {};
   final Map<int, CancelToken> _cancelTokens = {};
+  final Map<int, int> _downloadStartTimes = {};
 
   DownloadManager(this._dio);
 
@@ -44,6 +45,7 @@ class DownloadManager {
     String filename,
     int totalBytes,
   ) async {
+    _downloadStartTimes[fileId] = DateTime.now().microsecondsSinceEpoch;
     // If already downloading, return existing future
     if (_completers.containsKey(fileId)) {
       return _completers[fileId]!.future;
@@ -97,6 +99,15 @@ class DownloadManager {
 
   /// Pause download
   Future<void> pause(int fileId) async {
+    // ignore cancel if download started less than 1 second ago,
+    // this is to avoid cancellination due to different type of video players, where dispose is called
+    // little later after other video player operations
+    final startTime = _downloadStartTimes[fileId];
+    if (startTime == null ||
+        DateTime.now().microsecondsSinceEpoch - startTime < 1e6) {
+      _logger.info('Download paused too soon, ignoring pause request');
+      return;
+    }
     final token = _cancelTokens[fileId];
     if (token != null && !token.isCancelled) {
       token.cancel('paused');
@@ -151,6 +162,31 @@ class DownloadManager {
       final directory = Configuration.instance.getTempDirectory();
       final basePath = '$directory${task.id}.encrypted';
 
+      // check if base file already exists and is of correct size
+      final baseFile = File(basePath);
+      if (await baseFile.exists()) {
+        final existingSize = await baseFile.length();
+        if (existingSize == task.totalBytes) {
+          _logger.info(
+            'Download already exists for ${task.filename} (${existingSize}/${task.totalBytes} bytes)',
+          );
+          task = task.copyWith(
+            status: DownloadStatus.completed,
+            filePath: basePath,
+            bytesDownloaded: existingSize,
+          );
+          _updateTask(task);
+          completer.complete(DownloadResult(task, true));
+          return;
+        } else {
+          _logger.warning(
+            'Existing file size mismatch for ${task.filename}: '
+            'expected ${task.totalBytes}, but got $existingSize',
+          );
+          await baseFile.delete(); // Remove corrupted file
+        }
+      }
+
       // Check existing chunks and calculate progress
       final totalChunks = (task.totalBytes / downloadChunkSize).ceil();
       final existingChunks =
@@ -169,8 +205,13 @@ class DownloadManager {
         'Resuming download for ${task.filename} (${task.bytesDownloaded}/${task.totalBytes} bytes)',
       );
       for (int i = 0; i < totalChunks; i++) {
-        if (existingChunks[i] || cancelToken.isCancelled) continue;
-        _logger.info('Downloading chunk ${i + 1} of $totalChunks');
+        if (existingChunks[i]) {
+          continue;
+        }
+        if (cancelToken.isCancelled) {
+          _logger.info('Download cancelled for ${task.filename}');
+          break;
+        }
         await _downloadChunk(task, basePath, i, totalChunks, cancelToken);
         existingChunks[i] = true;
       }
@@ -235,7 +276,7 @@ class DownloadManager {
           'but got $actualSize bytes',
         );
         existingChunks[i] = false;
-        await chunkFile.delete(); // Remove corrupted chunk
+        // await chunkFile.delete(); // Remove corrupted chunk
       }
     }
 
@@ -270,7 +311,7 @@ class DownloadManager {
     final endByte = chunkIndex == totalChunks - 1
         ? task.totalBytes - 1
         : (startByte + downloadChunkSize) - 1;
-
+    _logger.info('Downloading chunk ${chunkIndex + 1}/$totalChunks');
     await _dio.download(
       FileUrl.getUrl(task.id, FileUrlType.directDownload),
       chunkPath,