text: # Licensed to the StackStorm, Inc ('StackStorm') under one or more
  # contributor license agreements.  See the NOTICE file distributed with
  # this work for additional information regarding copyright ownership.
  # The ASF licenses this file to You 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.
  
  from oslo_config import cfg
  
  from st2common.models.db import db_setup
  from st2common.runners.base_action import Action as BaseAction
  from st2common.persistence.pack import Pack
  from st2common.persistence.pack import ConfigSchema
  from st2common.persistence.pack import Config
  from st2common.persistence.reactor import SensorType
  from st2common.persistence.reactor import TriggerType
  from st2common.persistence.reactor import Trigger
  from st2common.persistence.reactor import Rule
  from st2common.persistence.action import Action
  from st2common.persistence.action import ActionAlias
  from st2common.persistence.policy import Policy
  from st2common.constants.pack import SYSTEM_PACK_NAMES
  from st2common.services.triggers import cleanup_trigger_db_for_rule
  from st2common.exceptions.db import StackStormDBObjectNotFoundError
  
  BLOCKED_PACKS = frozenset(SYSTEM_PACK_NAMES)
  
  
  class UnregisterPackAction(BaseAction):
      def __init__(self, config=None, action_service=None):
          super(UnregisterPackAction, self).__init__(config=config, action_service=action_service)
          self.initialize()
  
      def initialize(self):
          # 1. Setup db connection
          username = cfg.CONF.database.username if hasattr(cfg.CONF.database, 'username') else None
          password = cfg.CONF.database.password if hasattr(cfg.CONF.database, 'password') else None
          db_setup(cfg.CONF.database.db_name, cfg.CONF.database.host, cfg.CONF.database.port,
                   username=username, password=password,
                   ssl=cfg.CONF.database.ssl,
                   ssl_keyfile=cfg.CONF.database.ssl_keyfile,
                   ssl_certfile=cfg.CONF.database.ssl_certfile,
                   ssl_cert_reqs=cfg.CONF.database.ssl_cert_reqs,
                   ssl_ca_certs=cfg.CONF.database.ssl_ca_certs,
                   ssl_match_hostname=cfg.CONF.database.ssl_match_hostname)
  
      def run(self, packs):
          intersection = BLOCKED_PACKS & frozenset(packs)
          if len(intersection) > 0:
              names = ', '.join(list(intersection))
              raise ValueError('Unregister includes an unregisterable pack - %s.' % (names))
  
          for pack in packs:
              self.logger.debug('Removing pack %s.', pack)
              self._unregister_sensors(pack=pack)
              self._unregister_trigger_types(pack=pack)
              self._unregister_triggers(pack=pack)
              self._unregister_actions(pack=pack)
              self._unregister_rules(pack=pack)
              self._unregister_aliases(pack=pack)
              self._unregister_policies(pack=pack)
              self._unregister_pack(pack=pack)
              self.logger.info('Removed pack %s.', pack)
  
      def _unregister_sensors(self, pack):
          return self._delete_pack_db_objects(pack=pack, access_cls=SensorType)
  
      def _unregister_trigger_types(self, pack):
          deleted_trigger_types_dbs = self._delete_pack_db_objects(pack=pack, access_cls=TriggerType)
  
          # 2. Check if deleted trigger is used by any other rules outside this pack
          for trigger_type_db in deleted_trigger_types_dbs:
              rule_dbs = Rule.query(trigger=trigger_type_db.ref, pack__ne=trigger_type_db.pack)
  
              for rule_db in rule_dbs:
                  self.logger.warning('Rule "%s" references deleted trigger "%s"' %
                                      (rule_db.name, trigger_type_db.ref))
  
          return deleted_trigger_types_dbs
  
      def _unregister_triggers(self, pack):
          return self._delete_pack_db_objects(pack=pack, access_cls=Trigger)
  
      def _unregister_actions(self, pack):
          return self._delete_pack_db_objects(pack=pack, access_cls=Action)
  
      def _unregister_rules(self, pack):
          deleted_rules = self._delete_pack_db_objects(pack=pack, access_cls=Rule)
          for rule_db in deleted_rules:
              cleanup_trigger_db_for_rule(rule_db=rule_db)
  
          return deleted_rules
  
      def _unregister_aliases(self, pack):
          return self._delete_pack_db_objects(pack=pack, access_cls=ActionAlias)
  
      def _unregister_policies(self, pack):
          return self._delete_pack_db_objects(pack=pack, access_cls=Policy)
  
      def _unregister_pack(self, pack):
          # 1. Delete pack
          self._delete_pack_db_object(pack=pack)
  
          # 2. Delete corresponding config schema
          self._delete_config_schema_db_object(pack=pack)
  
          # 3. Delete correponding config object
          self._delete_pack_db_objects(pack=pack, access_cls=Config)
  
          return True
  
      def _delete_pack_db_object(self, pack):
          pack_db = None
  
          # 1. Try by ref
          try:
              pack_db = Pack.get_by_ref(value=pack)
          except StackStormDBObjectNotFoundError:
              pack_db = None
  
          # 2. Try by name (here for backward compatibility)
          # TODO: This shouldn't be needed in the future, remove it in v2.1 or similar
          if not pack_db:
              try:
                  pack_db = Pack.get_by_name(value=pack)
              except StackStormDBObjectNotFoundError:
                  pack_db = None
  
          if not pack_db:
              self.logger.exception('Pack DB object not found')
              return
  
          try:
              Pack.delete(pack_db)
          except:
              self.logger.exception('Failed to remove DB object %s.', pack_db)
  
      def _delete_config_schema_db_object(self, pack):
          try:
              config_schema_db = ConfigSchema.get_by_pack(value=pack)
          except StackStormDBObjectNotFoundError:
              self.logger.exception('ConfigSchemaDB object not found')
              return
  
          try:
              ConfigSchema.delete(config_schema_db)
          except:
              self.logger.exception('Failed to remove DB object %s.', config_schema_db)
  
      def _delete_pack_db_objects(self, pack, access_cls):
          db_objs = access_cls.get_all(pack=pack)
  
          deleted_objs = []
  
          for db_obj in db_objs:
              try:
                  access_cls.delete(db_obj)
                  deleted_objs.append(db_obj)
              except:
                  self.logger.exception('Failed to remove DB object %s.', db_obj)
  
          return deleted_objs
  