install method

@override Future<void> install(ModelSource source, { CancelToken? cancelToken, })

Installs the model from the given source

This method performs the actual installation:

• NetworkSource: downloads from URL
• AssetSource: copies from Flutter assets
• BundledSource: accesses native resources
• FileSource: registers external file path

Parameters:

• source: The model source to install from
• cancelToken: Optional token for cancelling the installation

Throws:

• UnsupportedError if this handler doesn't support the source type
• ArgumentError if the source is invalid
• DownloadCancelledException if cancelled via cancelToken
• Platform-specific exceptions for download/file errors

Implementation

@override
Future<void> install(
  ModelSource source, {
  CancelToken? cancelToken,
}) async {
  if (source is! AssetSource) {
    throw ArgumentError('AssetSourceHandler only supports AssetSource');
  }

  final filename = path.basename(source.path);
  final targetPath = await fileSystem.getTargetPath(filename);

  // LargeFileHandler's `targetName` parameter is *just* a filename — the
  // plugin prepends app docs dir itself. We keep the bare filename here.
  // On platforms where large_file_handler doesn't ship a plugin (desktop:
  // macOS/Windows/Linux, web stub) the channel call throws
  // MissingPluginException — fall back to in-memory loadAsset → writeFile.
  //
  // Lookup keys differ between paths:
  // - `pathForLookupKey` (no `assets/` prefix) for the native channel call
  // - `normalizedPath` (with `assets/` prefix) for the Flutter rootBundle
  //   fallback (#250 Mode 2)
  if (assetLoader is FlutterAssetLoader) {
    try {
      await (assetLoader as FlutterAssetLoader)
          .copyAssetToFile(source.pathForLookupKey, filename);
    } on MissingPluginException {
      final assetData = await assetLoader.loadAsset(source.normalizedPath);
      await fileSystem.writeFile(targetPath, assetData);
    }
  } else {
    final assetData = await assetLoader.loadAsset(source.normalizedPath);
    await fileSystem.writeFile(targetPath, assetData);
  }

  final sizeBytes = await fileSystem.getFileSize(targetPath);

  final modelInfo = ModelInfo(
    id: filename,
    source: source,
    installedAt: DateTime.now(),
    sizeBytes: sizeBytes,
    type: ModelType.inference,
    hasLoraWeights: false,
  );

  await repository.saveModel(modelInfo);
}