import argparse
import datetime
import numpy as np
import dnstool
from pycompact import CompactScheme

# Commandline argument parser
parser = argparse.ArgumentParser()
parser.add_argument("-c", "--case", help="target case name", required=True)
args = parser.parse_args()
params = vars(args)

casename = params["case"]
field_idx = 4

cases = dnstool.case_library()

case = cases[casename]

nx, ny, nz = case.shape

cs = CompactScheme(nx, ny, nz, False, True, True, 4, 2, 2)

ufile = "ddxc.dat"

storage = np.memmap(ufile, mode='w+', dtype=np.double, shape=(nx, len(case.data_files), ny, nz))

for i, fname in enumerate(case.data_files):
    print(datetime.datetime.now(), i, fname)
    time, y = case.read_single_field(fname, field_idx)
    storage[:,i,:,:] = cs.ddx(1. - y).T

storage.flush()