#!/usr/bin/env python3
# -*- mode: python -*-
#
# Copyright (c) 2016-2017 Weitian LI <weitian@aaronly.me>
# MIT license

"""
Recover the sky map in HPX projection format back into HEALPix table format,
i.e., the reverse of `healpix2hpx.py`.
"""

import os
import sys
import argparse
import logging

import fg21sim
from fg21sim.share import CONFIGS
from fg21sim.utils import setup_logging


def main():
    parser = argparse.ArgumentParser(
        description="Recover the image in HPX projection to HEALPix data")
    parser.add_argument("infile", help="input FITS image in HPX projection")
    parser.add_argument("outfile", help="output HEALPix data file")
    parser.add_argument("-C", "--clobber", action="store_true",
                        help="overwrite the existing output file")
    parser.add_argument("-l", "--log", dest="loglevel", default=None,
                        choices=["debug", "info", "warning",
                                 "error", "critical"],
                        help="set the log level")
    parser.add_argument("-L", "--logfile", default=None,
                        help="filename where to save the log messages")
    parser.add_argument("-Q", "--quiet", action="store_true",
                        help="be quiet so do not log messages to screen")
    args = parser.parse_args()

    tool = os.path.basename(sys.argv[0])
    pkgname = fg21sim.__pkgname__

    log_stream = "" if args.quiet else None
    setup_logging(dict_config=CONFIGS.logging,
                  level=args.loglevel,
                  stream=log_stream,
                  logfile=args.logfile)
    logger = logging.getLogger(tool)
    logger.info("COMMAND: {0}".format(" ".join(sys.argv)))

    history = [
        "TOOL: {0}".format(tool),
        "PARAM: {0}".format(" ".join(sys.argv[1:])),
    ]
    comments = [
        'Tool "{0}" is part of the "{1}" package'.format(tool, pkgname),
        'distributed under {0} license.'.format(fg21sim.__license__),
        'See also {0}'.format(fg21sim.__url__)
    ]

    if os.path.exists(args.outfile):
        if args.clobber:
            logger.warning("Remove existing output file: %s" % args.outfile)
            os.remove(args.outfile)
        else:
            raise OSError("Output file already exists: %s" % args.outfile)

    logger.info("Importing modules + Numba JIT, waiting ...")
    from fg21sim.utils.healpix import hpx2healpix
    from fg21sim.utils.io import write_fits_healpix
    hp_data, hp_header = hpx2healpix(args.infile,
                                     append_history=history,
                                     append_comment=comments)
    write_fits_healpix(args.outfile, hpmap=hp_data, header=hp_header)
    logger.info("HEALPix data write to FITS file: %s" % args.outfile)


if __name__ == "__main__":
    main()