# Copyright 2018  Lars Wirzenius
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU 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 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/>.
#
# =*= License: GPL-3+ =*=



import logging
import os
import tempfile

import cliapp

import vmdb


class LuksPlugin(cliapp.Plugin):

    def enable(self):
        self.app.step_runners.add(CryptsetupStepRunner())


class CryptsetupStepRunner(vmdb.StepRunnerInterface):

    def get_required_keys(self):
        return ['cryptsetup']

    def run(self, step, settings, state):
        underlying = step['cryptsetup']
        crypt_name = step['tag']

        state.tmp_key_file = None
        key_file = step.get('key-file')
        key_cmd = step.get('key-cmd')
        if key_file is None and key_cmd is None:
            raise Exception(
                'cryptsetup step MUST define one of key-file or key-cmd')

        if key_file is None:
            output = vmdb.runcmd(['sh', '-c', key_cmd])
            output = output.decode('UTF-8')
            key = output.splitlines()[0]
            fd, key_file = tempfile.mkstemp()
            state.tmp_key_file = key_file
            os.close(fd)
            open(key_file, 'w').write(key)

        dev = state.tags.get_dev(underlying)
        if dev is None:
            for t in state.tags.get_tags():
                logging.debug(
                    'tag %r dev %r mp %r', t, state.tags.get_dev(t),
                    state.tags.get_mount_point(t))
            assert 0

        vmdb.runcmd(['cryptsetup', 'luksFormat', dev, key_file])
        vmdb.runcmd(
            ['cryptsetup', 'open', '--type', 'luks', '--key-file', key_file, dev,
             crypt_name])

        crypt_dev = '/dev/mapper/{}'.format(crypt_name)
        assert os.path.exists(crypt_dev)
        state.tags.append(crypt_name)
        state.tags.set_dev(crypt_name, crypt_dev)

    def teardown(self, step, settings, state):
        x = state.tmp_key_file
        if x is not None and os.path.exists(x):
            os.remove(x)

        crypt_name = step['tag']

        crypt_dev = '/dev/mapper/{}'.format(crypt_name)
        vmdb.runcmd(['cryptsetup', 'close', crypt_dev])