downloadModelWithProgress static method

Stream<DownloadProgress> downloadModelWithProgress(ModelSpec spec, { String? token, })

Downloads a model specification with progress tracking

Implementation

static Stream<DownloadProgress> downloadModelWithProgress(
  ModelSpec spec, {
  String? token,
}) async* {
  // print('Starting download for model: ${spec.name} (${spec.files.length} files)');

  try {
    final totalFiles = spec.files.length;

    for (int i = 0; i < spec.files.length; i++) {
      final file = spec.files[i];
      final filePath = await ModelFileSystemManager.getModelFilePath(file.filename);

      // print('Downloading file ${i + 1}/$totalFiles: ${file.filename}');

      // Emit progress for current file start
      yield DownloadProgress(
        currentFileIndex: i,
        totalFiles: totalFiles,
        currentFileProgress: 0,
        currentFileName: file.filename,
      );

      // Download current file with progress
      await for (final progress in _downloadSingleFileWithProgress(
        url: file.url,
        targetPath: filePath,
        token: token,
      )) {
        yield DownloadProgress(
          currentFileIndex: i,
          totalFiles: totalFiles,
          currentFileProgress: progress,
          currentFileName: file.filename,
        );
      }

      // Validate downloaded file
      final minSize = file.extension == '.json' ? 1024 : 1024 * 1024; // 1KB for JSON, 1MB for others
      if (!await ModelFileSystemManager.isFileValid(filePath, minSizeBytes: minSize)) {
        throw ModelValidationException(
          'Downloaded file failed validation: ${file.filename}',
          null,
          filePath,
        );
      }

      // print('Completed file ${i + 1}/$totalFiles: ${file.filename}');
    }

    // Save to SharedPreferences ONLY after ALL files are successfully downloaded
    await ModelPreferencesManager.saveModelFiles(spec);

    // Emit final progress
    yield DownloadProgress(
      currentFileIndex: totalFiles,
      totalFiles: totalFiles,
      currentFileProgress: 100,
      currentFileName: 'Complete',
    );

    // print('Successfully downloaded model: ${spec.name}');
  } catch (e) {
    // print('Download failed for model ${spec.name}: $e');

    // Cleanup any partial files
    await ModelFileSystemManager.cleanupFailedDownload(spec);

    if (e is ModelException) {
      rethrow;
    } else {
      throw ModelDownloadException(
        'Failed to download model: ${spec.name}',
        e,
      );
    }
  }
}