"""Functions implementing LILAC's download_input_data command"""

import argparse
import logging
import os
import re

from CIME.case import Case  # pylint: disable=import-error

from ctsm.ctsm_logging import (
    setup_logging_pre_config,
    add_logging_args,
    process_logging_args,
)

logger = logging.getLogger(__name__)

# ========================================================================
# Define some constants
# ========================================================================

# In lilac_in, file names match this pattern: The variable name ends with 'filename', so
# that is the last thing before the equals sign on the line.
_LILAC_FILENAME = r"filename *="

# ========================================================================
# Public functions
# ========================================================================


def main():
    """Main function called when download_input_data is run from the command-line"""
    setup_logging_pre_config()
    args = _commandline_args()
    process_logging_args(args)

    download_input_data(rundir=args.rundir)


def download_input_data(rundir):
    """Implementation of the download_input_data command

    Args:
    rundir: str - path to directory containing input_data_list files
    """
    _create_lilac_input_data_list(rundir)
    case = Case(os.path.realpath(os.path.join(rundir, os.pardir, "case")))
    case.check_all_input_data(data_list_dir=rundir, download=True, chksum=False)
    os.remove(os.path.join(rundir, "lilac.input_data_list"))


# ========================================================================
# Private functions
# ========================================================================


def _commandline_args():
    """Parse and return command-line arguments"""

    description = """
Script to download any missing input data for CTSM and LILAC
"""

    parser = argparse.ArgumentParser(
        description=description, formatter_class=argparse.RawTextHelpFormatter
    )

    parser.add_argument(
        "--rundir",
        default=os.getcwd(),
        help="Full path of the run directory\n"
        "(This directory should contain clm.input_data_list and lilac_in,\n"
        "among other files.)\n"
        "(Note: it is assumed that this directory exists alongside the other\n"
        "directories created by build_ctsm: 'case' and 'inputdata'.)",
    )

    add_logging_args(parser)

    args = parser.parse_args()

    return args


def _create_lilac_input_data_list(rundir):
    with open(os.path.join(rundir, "lilac_in")) as lilac_in:
        with open(os.path.join(rundir, "lilac.input_data_list"), "w") as input_data_list:
            for line in lilac_in:
                if re.search(_LILAC_FILENAME, line):
                    # Remove quotes from filename, then output this line
                    line = line.replace('"', "")
                    line = line.replace("'", "")
                    input_data_list.write(line)