from __future__ import print_function
from argparse import ArgumentParser
import os
from subprocess import CalledProcessError
import sys

from borgmatic import borg
from borgmatic.config import parse_configuration, CONFIG_FORMAT


DEFAULT_CONFIG_FILENAME = '/etc/borgmatic/config'
DEFAULT_EXCLUDES_FILENAME = '/etc/borgmatic/excludes'


def parse_arguments(*arguments):
    '''
    Given the name of the command with which this script was invoked and command-line arguments,
    parse the arguments and return them as an ArgumentParser instance. Use the command name to
    determine the default configuration and excludes paths.
    '''
    parser = ArgumentParser()
    parser.add_argument(
        '-c', '--config',
        dest='config_filename',
        default=DEFAULT_CONFIG_FILENAME,
        help='Configuration filename',
    )
    parser.add_argument(
        '--excludes',
        dest='excludes_filename',
        default=DEFAULT_EXCLUDES_FILENAME if os.path.exists(DEFAULT_EXCLUDES_FILENAME) else None,
        help='Excludes filename',
    )
    parser.add_argument(
        '-v', '--verbosity',
        type=int,
        help='Display verbose progress (1 for some, 2 for lots)',
    )

    return parser.parse_args(arguments)


def main():
    try:
        args = parse_arguments(*sys.argv[1:])
        config = parse_configuration(args.config_filename, CONFIG_FORMAT)
        repository = config.location['repository']

        borg.initialize(config.storage)
        borg.create_archive(
            args.excludes_filename, args.verbosity, config.storage, **config.location
        )
        borg.prune_archives(args.verbosity, repository, config.retention)
        borg.check_archives(args.verbosity, repository, config.consistency)
    except (ValueError, IOError, CalledProcessError) as error:
        print(error, file=sys.stderr)
        sys.exit(1)