# vi: ts=4 expandtab
#
#    Copyright (C) 2012 Yahoo! Inc.
#
#    Author: Joshua Harlow <harlowja@yahoo-inc.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3, as
#    published by the Free Software Foundation.
#
#    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 General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import shutil

from cloudinit import helpers
from cloudinit import util

from cloudinit.settings import PER_ALWAYS

frequency = PER_ALWAYS


def _migrate_canon_sems(cloud):
    sem_path = cloud.paths.get_ipath('sem')
    if not sem_path or not os.path.exists(sem_path):
        return 0
    am_adjusted = 0
    for p in os.listdir(sem_path):
        full_path = os.path.join(sem_path, p)
        if os.path.isfile(full_path):
            (name, ext) = os.path.splitext(p)
            canon_name = helpers.canon_sem_name(name)
            if canon_name != name:
                new_path = os.path.join(sem_path, canon_name + ext)
                shutil.move(full_path, new_path)
                am_adjusted += 1
    return am_adjusted


def _migrate_legacy_sems(cloud, log):
    sem_path = cloud.paths.get_ipath('sem')
    if not sem_path or not os.path.exists(sem_path):
        return
    legacy_adjust = {
        'apt-update-upgrade': [
            'apt-configure',
            'package-update-upgrade-install',
        ],
    }
    sem_helper = helpers.FileSemaphores(sem_path)
    for (mod_name, migrate_to) in legacy_adjust.items():
        possibles = [mod_name, helpers.canon_sem_name(mod_name)]
        old_exists = []
        for p in os.listdir(sem_path):
            (name, _ext) = os.path.splitext(p)
            if name in possibles and os.path.isfile(p):
                old_exists.append(p)
        for p in old_exists:
            util.del_file(os.path.join(sem_path, p))
            (_name, freq) = os.path.splitext(p)
            for m in migrate_to:
                log.debug("Migrating %s => %s with the same frequency",
                          p, m)
                with sem_helper.lock(m, freq):
                    pass


def handle(name, cfg, cloud, log, _args):
    do_migrate = util.get_cfg_option_str(cfg, "migrate", True)
    if not util.translate_bool(do_migrate):
        log.debug("Skipping module named %s, migration disabled", name)
        return
    sems_moved = _migrate_canon_sems(cloud)
    log.debug("Migrated %s semaphore files to there canonicalized names",
              sems_moved)
    _migrate_legacy_sems(cloud, log)