#!/usr/bin/env python3

#    Kosmorro - Compute The Next Ephemerides
#    Copyright (C) 2019  Jérôme Deuchnord <jerome@deuchnord.fr>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <https://www.gnu.org/licenses/>.

import argparse
import sys
from datetime import date

from kosmorrolib.version import VERSION
from kosmorrolib import dumper
from kosmorrolib import core
from kosmorrolib.ephemerides import EphemeridesComputer, Position
from kosmorrolib import events


def main():
    output_formats = get_dumpers()
    args = get_args(list(output_formats.keys()))

    if args.special_action is not None:
        return 0 if args.special_action() else 1

    year = args.year
    month = args.month
    day = args.day

    compute_date = date(year, month, day)

    if day is not None and month is None:
        month = date.today().month

    if args.latitude is None or args.longitude is None:
        position = None
    else:
        position = Position(args.latitude, args.longitude)

    ephemeris = EphemeridesComputer(position)
    ephemerides = ephemeris.compute_ephemerides(year, month, day)

    events_list = events.search_events(compute_date)

    dump = output_formats[args.format](ephemerides, events_list, compute_date)
    print(dump.to_string())

    return 0


def get_dumpers() -> {str: dumper.Dumper}:
    return {
        'text': dumper.TextDumper,
        'json': dumper.JsonDumper
    }


def output_version() -> bool:
    python_version = '%d.%d.%d' % (sys.version_info[0], sys.version_info[1], sys.version_info[2])
    print('Kosmorro %s' % VERSION)
    print('Running on Python %s' % python_version)

    return True


def clear_cache() -> bool:
    confirm = input("Do you really want to clear Kosmorro's cache? [yN] ").upper()
    if confirm == 'Y':
        try:
            core.clear_cache()
        except FileNotFoundError:
            pass
    elif confirm not in ('N', ''):
        print('Answer did not match expected options, cache not cleared.')
        return False

    return True


def get_args(output_formats: [str]):
    today = date.today()

    parser = argparse.ArgumentParser(description='Compute the ephemerides and the events for a given date,'
                                                 ' at a given position on Earth.',
                                     epilog='By default, only the events will be computed for today (%s).\n'
                                            'To compute also the ephemerides, latitude and longitude arguments'
                                            ' are needed.'
                                     % today.strftime('%a %b %d, %Y'))

    parser.add_argument('--version', '-v', dest='special_action', action='store_const', const=output_version,
                        default=None, help='Show the program version')
    parser.add_argument('--clear-cache', dest='special_action', action='store_const', const=clear_cache, default=None,
                        help='Delete all the files Kosmorro stored in the cache.')
    parser.add_argument('--format', '-f', type=str, default=output_formats[0], choices=output_formats,
                        help='The format under which the information have to be output')
    parser.add_argument('--latitude', '-lat', type=float, default=None,
                        help="The observer's latitude on Earth")
    parser.add_argument('--longitude', '-lon', type=float, default=None,
                        help="The observer's longitude on Earth")
    parser.add_argument('--day', '-d', type=int, default=today.day,
                        help='A number between 1 and 28, 29, 30 or 31 (depending on the month). The day you want to '
                             ' compute the ephemerides for. Defaults to %d (the current day).' % today.day)
    parser.add_argument('--month', '-m', type=int, default=today.month,
                        help='A number between 1 and 12. The month you want to compute the ephemerides for. Defaults to'
                             ' %d (the current month).' % today.month)
    parser.add_argument('--year', '-y', type=int, default=today.year,
                        help='The year you want to compute the ephemerides for.'
                             ' Defaults to %d (the current year).' % today.year)

    return parser.parse_args()


if __name__ == '__main__':
    sys.exit(main())