package hcsshim

import "github.com/Sirupsen/logrus"

// ExportLayer will create a folder at exportFolderPath and fill that folder with
// the transport format version of the layer identified by layerId. This transport
// format includes any metadata required for later importing the layer (using
// ImportLayer), and requires the full list of parent layer paths in order to
// perform the export.
func ExportLayer(info DriverInfo, layerId string, exportFolderPath string, parentLayerPaths []string) error {
	title := "hcsshim::ExportLayer "
	logrus.Debugf(title+"flavour %d layerId %s folder %s", info.Flavour, layerId, exportFolderPath)

	// Generate layer descriptors
	layers, err := layerPathsToDescriptors(parentLayerPaths)
	if err != nil {
		return err
	}

	// Convert info to API calling convention
	infop, err := convertDriverInfo(info)
	if err != nil {
		logrus.Error(err)
		return err
	}

	err = exportLayer(&infop, layerId, exportFolderPath, layers)
	if err != nil {
		err = makeErrorf(err, title, "layerId=%s flavour=%d folder=%s", layerId, info.Flavour, exportFolderPath)
		logrus.Error(err)
		return err
	}

	logrus.Debugf(title+"succeeded flavour=%d layerId=%s folder=%s", info.Flavour, layerId, exportFolderPath)
	return nil
}