#!/usr/bin/env python3

"""
 Given two lists of fields and a netcdf file, check that one list contains
 the tendencies of the vars listed in the other list (ordered in the same way)
 This means that, given a field F and a (presumed) tendency T, the script
 will check that T(time(k)) is approximately equal to
   (F(k) - F(k-1)) / (time(k)-time(k-1))
 where time is the time variable and k is the time slice index
 (other dims omitted for brevity).
"""

from utils import check_minimum_python_version
check_minimum_python_version(3, 4)

import argparse, sys, pathlib

from check_tendencies import CheckTendencies

###############################################################################
def parse_command_line(args, description):
###############################################################################
    parser = argparse.ArgumentParser(
        usage=" {0} -f <file> -v <variables_names> -t <tendencies_names>"
              .format(pathlib.Path(args[0]).name),
        description=description,
        formatter_class=argparse.RawDescriptionHelpFormatter
    )

    # The name of the nc files where to grab data from
    parser.add_argument("-f",dest="file", type=str, required=True,
            help="Name of the netcdf file")

    # Variables comparison
    parser.add_argument("-v",dest="variables",nargs='+', default=[],
                        help="Name of variables from which to compute tendencies",
                        metavar=("v1","v2"))
    parser.add_argument("-t",dest="tendencies",nargs='+', default=[],
                        help="Name of tendencies variables",
                        metavar=("t1","t2"))

    return parser.parse_args(args[1:])

###############################################################################
def _main_func(description):
###############################################################################
    ct = CheckTendencies(**vars(parse_command_line(sys.argv, description)))

    vars_str  = ','.join(ct._vars)
    tends_str = ','.join(ct._tends)
    print (f" **** Checking tendencies correctness **** \n"
           f"    - nc file: {ct._file}\n"
           f"    - variables  list: {','.join(ct._vars)}\n"
           f"    - tendencies list: {','.join(ct._tends)}\n")
    success = ct.run()

    print(f" ==> Check result: {'SUCCESS' if success else 'FAIL'}!\n")

    sys.exit(0 if success else 1)

###############################################################################

if (__name__ == "__main__"):
    _main_func(__doc__)