import argparse

import numpy as np
import vtk

from python_vtk.vtkService.vtkService import writeDataArrayToNewVtkFile


def main():
    #    try:
    parser = argparse.ArgumentParser()
    parser.add_argument("invtkfile", help="filename of input vtk mesh (VTK XML unstructured grid")
    parser.add_argument("varname", help="name of cell data variable")
    parser.add_argument("outvtkfile", help="filename of output vtk mesh (VTK XML unstructured grid")
    args = parser.parse_args()

    # deserialize raw bytes into VarDataAdd
    reader = vtk.vtkXMLUnstructuredGridReader()
    reader.SetFileName(args.invtkfile)
    reader.Update()
    mesh = reader.GetOutput()
    assert isinstance(mesh, vtk.vtkUnstructuredGrid)
    num_cells = mesh.GetCells().GetSize()

    # write 0..N-1 into data
    npdata = np.arange(0, num_cells, 0.1)

    writeDataArrayToNewVtkFile(args.invtkfile, args.varname, npdata, args.outvtkfile)
    print("done")


# except:
#     e = sys.exc_info()[0]
#     print("exception "+e)
#     sys.exit(-1)
# else:
#     sys.exit(0)


if __name__ == '__main__':
    main()