# 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 anyjson
import eventlet
import types
import jsonpath

from conductor.openstack.common import log as logging
import conductor.helpers
from command import CommandBase
import conductor.config
from heatclient.client import Client
import heatclient.exc
from keystoneclient.v2_0 import client as ksclient

log = logging.getLogger(__name__)


class HeatExecutor(CommandBase):
    def __init__(self, stack, token, tenant_id):
        self._update_pending_list = []
        self._delete_pending_list = []
        self._stack = stack
        settings = conductor.config.CONF.heat

        client = ksclient.Client(endpoint=settings.auth_url)
        auth_data = client.tokens.authenticate(
            tenant_id=tenant_id,
            token=token)

        scoped_token = auth_data.id

        heat_url = jsonpath.jsonpath(
            auth_data.serviceCatalog,
            "$[?(@.name == 'heat')].endpoints[0].publicURL")[0]

        self._heat_client = Client(
            '1',
            heat_url,
            token_only=True,
            token=scoped_token)

    def execute(self, command, callback, **kwargs):
        log.debug('Got command {0} on stack {1}'.format(command, self._stack))

        if command == 'CreateOrUpdate':
            return self._execute_create_update(
                kwargs['template'],
                conductor.helpers.str2unicode(kwargs.get('mappings') or {}),
                conductor.helpers.str2unicode(kwargs.get('arguments') or {}),
                callback)
        elif command == 'Delete':
            return self._execute_delete(callback)

    def _execute_create_update(self, template, mappings, arguments, callback):
        with open('data/templates/cf/%s.template' % template) as template_file:
            template_data = template_file.read()

        template_data = conductor.helpers.transform_json(
            anyjson.loads(template_data), mappings)

        self._update_pending_list.append({
            'template': template_data,
            'arguments': arguments,
            'callback': callback
        })

    def _execute_delete(self, callback):
        self._delete_pending_list.append({
            'callback': callback
        })

    def has_pending_commands(self):
        return len(self._update_pending_list) + \
            len(self._delete_pending_list) > 0

    def execute_pending(self):
        r1 = self._execute_pending_updates()
        r2 = self._execute_pending_deletes()
        return r1 or r2

    def _execute_pending_updates(self):
        if not len(self._update_pending_list):
            return False

        template, arguments = self._get_current_template()
        stack_exists = (template != {})

        for t in self._update_pending_list:
            template = conductor.helpers.merge_dicts(
                template, t['template'])
            arguments = conductor.helpers.merge_dicts(
                arguments, t['arguments'], max_levels=1)

        log.info(
            'Executing heat template {0} with arguments {1} on stack {2}'
            .format(anyjson.dumps(template), arguments, self._stack))

        if stack_exists:
            self._heat_client.stacks.update(
                stack_id=self._stack,
                parameters=arguments,
                template=template)
            log.debug(
                'Waiting for the stack {0} to be update'.format(self._stack))
            outs = self._wait_state('UPDATE_COMPLETE')
            log.info('Stack {0} updated'.format(self._stack))
        else:
            self._heat_client.stacks.create(
                stack_name=self._stack,
                parameters=arguments,
                template=template)

            log.debug('Waiting for the stack {0} to be create'.format(
                self._stack))
            outs = self._wait_state('CREATE_COMPLETE')
            log.info('Stack {0} created'.format(self._stack))

        pending_list = self._update_pending_list
        self._update_pending_list = []

        for item in pending_list:
            item['callback'](outs)

        return True

    def _execute_pending_deletes(self):
        if not len(self._delete_pending_list):
            return False

        log.debug('Deleting stack {0}'.format(self._stack))
        try:
            self._heat_client.stacks.delete(
                stack_id=self._stack)
            log.debug(
                'Waiting for the stack {0} to be deleted'.format(self._stack))
            self._wait_state(['DELETE_COMPLETE', ''])
            log.info('Stack {0} deleted'.format(self._stack))
        except Exception as ex:
            log.exception(ex)

        pending_list = self._delete_pending_list
        self._delete_pending_list = []

        for item in pending_list:
            item['callback'](True)
        return True

    def _get_current_template(self):
        try:
            stack_info = self._heat_client.stacks.get(stack_id=self._stack)
            template = self._heat_client.stacks.template(
                stack_id='{0}/{1}'.format(
                    stack_info.stack_name,
                    stack_info.id))
            return template, stack_info.parameters
        except heatclient.exc.HTTPNotFound:
            return {}, {}

    def _wait_state(self, state):
        tries = 4
        delay = 1
        while tries > 0:
            if isinstance(state, types.ListType):
                states = state
            else:
                states = [state]

            while True:
                try:
                    stack_info = self._heat_client.stacks.get(
                        stack_id=self._stack)
                    status = stack_info.stack_status
                    tries = 4
                    delay = 1
                except heatclient.exc.HTTPNotFound:
                    stack_info = None
                    status = ''
                except Exception:
                    tries -= 1
                    delay *= 2
                    eventlet.sleep(delay)
                    break

                if 'IN_PROGRESS' in status:
                    eventlet.sleep(1)
                    continue
                if status not in states:
                    raise EnvironmentError()

                try:
                    return dict([(t['output_key'], t['output_value'])
                                 for t in stack_info.outputs])
                except Exception:
                    return {}
        return {}