#    Copyright (c) 2013 Mirantis, Inc.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import os
import yaml
from oslo.config import cfg
import logging as log

from muranorepository.manifest import Manifest
from muranorepository.consts import DATA_TYPES, MANIFEST
from muranorepository.openstack.common.gettextutils import _  # noqa
from muranorepository.utils import utils
CONF = cfg.CONF


def serialize(data):
    def convert(data):
        """
        Convert unicode to regular strings.

        Needed in python 2.x to handle differences in str/unicode processing.
        In python 3.x this can be done much more easily:
        yaml.dump(data, allow_unicode=True, encoding='utf-8') call would
        convert all unicode to utf-8 encoded byte-strings.
        """
        if isinstance(data, dict):
            return dict([(convert(key), convert(value))
                         for key, value in data.iteritems()])
        elif isinstance(data, list):
            return [convert(element) for element in data]
        elif isinstance(data, unicode):
            return data.encode('utf-8')
        else:
            return data

    return yaml.dump(convert(data), default_flow_style=False)


class ManifestParser(object):
    def __init__(self, manifest_directory=None):
        if not manifest_directory:
            manifest_directory = utils.get_tenant_folder()
        self.manifest_directory = manifest_directory
        utils.check_tenant_dir_existence(self.manifest_directory)

    def _validate_manifest(self, file, service_manifest_data):
        service_id = service_manifest_data.get('full_service_name')
        if not service_id or '{0}-manifest.yaml'.format(service_id) != file:
            log.error(_("Attribute 'full_service_name' inside manifest '{0}' "
                        "has value '{1}' which doesn't correspond to its "
                        "filename, skipping this manifest completely."
                        "".format(file, service_id)))
            return False, False

        valid_file_info = True
        for key, value in service_manifest_data.iteritems():
            if key in DATA_TYPES:
                if key != MANIFEST:
                    root_directory = os.path.join(self.manifest_directory,
                                                  getattr(CONF, key))
                else:
                    root_directory = self.manifest_directory

                if not isinstance(value, list):
                    log.error(_("'{0}' section should represent a file listing"
                                " in manifest {1}".format(root_directory,
                                                          file)))
                    valid_file_info = False
                    continue
                for filename in value:
                    absolute_path = os.path.join(root_directory,
                                                 filename)

                    if not os.path.exists(absolute_path):
                        valid_file_info = False
                        log.warning(
                            _("File '{0}' specified in manifest '{1}' "
                              "doesn't exist at '{2}'".format(filename,
                                                              file,
                                                              absolute_path)))
        return valid_file_info, True

    def parse(self):
        manifests = []
        if os.path.exists(self.manifest_directory):
            for file in os.listdir(self.manifest_directory):
                manifest_file = os.path.join(self.manifest_directory, file)
                if os.path.isfile(manifest_file):
                    if not file.endswith(".yaml"):
                        log.warning(_("Extension of {0} file is not yaml. "
                                      "Only yaml file supported for "
                                      "service manifest files.".format(file)))
                        continue

                    try:
                        with open(manifest_file) as stream:
                            manifest_data = yaml.load(stream)
                    except yaml.YAMLError:
                            log.exception(_("Failed to load manifest file "
                                            " '{0}'".format(manifest_file)))
                            continue

                    manifest_is_valid, use_manifest = self._validate_manifest(
                        file, manifest_data)
                    if use_manifest:
                        manifest_data["valid"] = manifest_is_valid
                        manifests.append(Manifest(manifest_data))

        return manifests

    def parse_manifest(self, manifest_name):
        manifest_file = os.path.join(self.manifest_directory,
                                     manifest_name + '-manifest.yaml')
        if not os.path.exists(manifest_file):
            log.error(_("There is no manifest file '{0}' for {1} "
                        "service".format(manifest_file, manifest_name)))
            return None
        if not os.path.isfile(manifest_file):
            log.error(_("'{0}' is not file".format(manifest_file)))
            return None

        try:
            with open(manifest_file) as stream:
                manifest_data = yaml.load(stream)
        except yaml.YAMLError:
                log.exception(_("Failed to load manifest file: '{0}'.".format(
                    manifest_file)))

                return None
        return Manifest(manifest_data)

    def _get_manifest_path(self, service_name):
        return os.path.join(self.manifest_directory,
                            '{0}-manifest.yaml'.format(service_name))

    def toggle_enabled(self, service_name):
        """
        :param service_name: string, name of the service
        :return: Status code with operation result
        """
        path_to_manifest = self._get_manifest_path(service_name)
        if not os.path.exists(path_to_manifest):
            msg = _("There is no manifest "
                    "file for '{0}' service".format(service_name))
            log.exception(msg)
            raise NameError(msg)
        try:
            with open(path_to_manifest) as stream:
                service_manifest_data = yaml.load(stream)
            enabled_value = not service_manifest_data.get('enabled')
            service_manifest_data['enabled'] = enabled_value
            with open(path_to_manifest, 'w') as manifest_file:
                manifest_file.write(yaml.dump(service_manifest_data,
                                              default_flow_style=False))
        except IOError:
            msg = _("Error during modifying '{0}'".format(path_to_manifest))
            log.exception(msg)
            raise Exception(msg)

    def update_service(self, service_name, data):
        path_to_manifest = self._get_manifest_path(service_name)
        if not path_to_manifest:
            log.error(_("There is no manifest "
                        "file for '{0}' service".format(service_name)))
            return False
        with open(path_to_manifest) as stream:
            service_manifest_data = yaml.load(stream)
        for key, value in data.iteritems():
            service_manifest_data[key] = data[key]

        with open(path_to_manifest, 'w') as manifest_file:
            manifest_file.write(serialize(service_manifest_data))
        return True