# Copyright (C) 2017  Lars Wirzenius
#
# 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/>.


import glob
import os


import yaml


class ControllerState:

    def __init__(self):
        self._statedir = None

    def get_state_directory(self):
        return self._statedir

    def set_state_directory(self, dirname):
        self._statedir = dirname
        if not os.path.exists(self._statedir):
            os.makedirs(self._statedir)

    def get_resource_directory(self, type_name):
        return os.path.join(self.get_state_directory(), type_name)

    def get_resource_filename(self, type_name, project_name):
        return os.path.join(
            self.get_resource_directory(type_name), project_name + '.yaml')

    def load_resources(self, type_name):
        assert self._statedir is not None
        resources = []
        dirname = self.get_resource_directory(type_name)
        for filename in glob.glob(dirname + '/*.yaml'):
            obj = self.load_resource(filename)
            resources.append(obj)
        return resources

    def load_resource(self, filename):
        with open(filename, 'r') as f:
            return yaml.safe_load(f)

    def get_resources(self, type_name):
        return self.load_resources(type_name)

    def get_resource(self, type_name, resource_name):
        filename = self.get_resource_filename(type_name, resource_name)
        if os.path.exists(filename):
            return self.load_resource(filename)
        raise NotFound()

    def add_resource(self, type_name, resource_name, resource):
        filename = self.get_resource_filename(type_name, resource_name)
        dirname = os.path.dirname(filename)
        if not os.path.exists(dirname):
            os.makedirs(dirname)
        with open(filename, 'w') as f:
            yaml.safe_dump(resource, stream=f)
        return resource

    def update_resource(self, type_name, resource_name, body):
        filename = self.get_resource_filename(type_name, resource_name)
        with open(filename, 'w') as f:
            yaml.safe_dump(body, stream=f)
        return body

    def remove_resource(self, type_name, resource_name):
        filename = self.get_resource_filename(type_name, resource_name)
        if not os.path.exists(filename):
            raise NotFound()
        os.remove(filename)


class NotFound(Exception):

    def __init__(self):
        super().__init__('Resource not found')


class WrongPipelineStatus(Exception):  # pragma: no cover

    def __init__(self, new_state):
        super().__init__('Cannot set pipeline state to {}'.format(new_state))