#!/usr/bin/env python3

# Contest Management System - http://cms-dev.github.io/
# Copyright © 2015 William Di Luigi <williamdiluigi@gmail.com>
# Copyright © 2016-2018 Stefano Maggiolo <s.maggiolo@gmail.com>
#
# 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 <http://www.gnu.org/licenses/>.

"""This script imports a team from disk using one of the available
loaders.

The data parsed by the loader is used to create a new Team in the
database.

"""

# We enable monkey patching to make many libraries gevent-friendly
# (for instance, urllib3, used by requests)
import gevent.monkey
gevent.monkey.patch_all()  # noqa

import argparse
import logging
import os
import sys

from cms import utf8_decoder
from cms.db import SessionGen, Team
from cms.db.filecacher import FileCacher
from cmscontrib.importing import ImportDataError
from cmscontrib.loaders import choose_loader, build_epilog


logger = logging.getLogger(__name__)


class TeamImporter:
    """Script to create a team in the database."""

    def __init__(self, path, loader_class):
        self.file_cacher = FileCacher()
        self.loader = loader_class(os.path.realpath(path), self.file_cacher)

    def do_import(self):
        """Get the team from the TeamLoader and store it."""
        # Get the team
        team = self.loader.get_team()
        if team is None:
            return False

        # Store
        logger.info("Creating team on the database.")
        with SessionGen() as session:
            try:
                team = self._team_to_db(session, team)
            except ImportDataError as e:
                logger.error(str(e))
                logger.info("Error while importing, no changes were made.")
                return False

            session.commit()
            team_id = team.id

        logger.info("Import finished (new team id: %s).", team_id)
        return True

    def do_import_all(self, base_path, get_loader):
        """Get the participation list from the ContestLoader and then
        try to import the needed teams.

        """
        added = set()

        _, _, participations = self.loader.get_contest()
        for p in participations:
            if "team" in p:
                team_path = os.path.join(base_path, p["team"])

                if team_path not in added:
                    added.add(team_path)
                    importer = TeamImporter(
                        path=team_path,
                        loader_class=get_loader(team_path)
                    )
                    importer.do_import()

        return True

    @staticmethod
    def _team_to_db(session, team):
        old_team = session.query(Team).filter(Team.code == team.code).first()
        if old_team is not None:
            raise ImportDataError("Team \"%s\" already exists." % team.code)
        session.add(team)
        return team


def main():
    """Parse arguments and launch process.

    """
    parser = argparse.ArgumentParser(
        description="Import a team to the database.",
        epilog=build_epilog(),
        formatter_class=argparse.RawDescriptionHelpFormatter
    )

    parser.add_argument(
        "-L", "--loader",
        action="store", type=utf8_decoder,
        default=None,
        help="use the specified loader (default: autodetect)"
    )
    parser.add_argument(
        "target",
        action="store", type=utf8_decoder, nargs="?",
        default=os.getcwd(),
        help="target file/directory from where to import team(s)"
    )
    parser.add_argument(
        "-A", "--all",
        action="store_true",
        help="try to import the needed teams inside target (not "
             "necessarily all of them)"
    )

    args = parser.parse_args()

    def get_loader(path):
        return choose_loader(args.loader, path, parser.error)

    importer = TeamImporter(
        path=args.target,
        loader_class=get_loader(args.target)
    )

    if args.all:
        success = importer.do_import_all(args.target, get_loader)
    else:
        success = importer.do_import()
    return 0 if success is True else 1


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