#
#    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.

from oslo_log import log as logging

from heat.common import exception
from heat.common.i18n import _
from heat.engine import attributes
from heat.engine import constraints
from heat.engine import properties
from heat.engine import resource
from heat.engine import support
from heat.engine import translation

LOG = logging.getLogger(__name__)


class Instance(resource.Resource):
    """OpenStack cloud database instance resource.

    Trove is Database as a Service for OpenStack. It's designed to run entirely
    on OpenStack, with the goal of allowing users to quickly and easily utilize
    the features of a relational or non-relational database without the burden
    of handling complex administrative tasks.
    """

    support_status = support.SupportStatus(version='2014.1')

    TROVE_STATUS = (
        ERROR, FAILED, ACTIVE,
    ) = (
        'ERROR', 'FAILED', 'ACTIVE',
    )

    TROVE_STATUS_REASON = {
        FAILED: _('The database instance was created, but heat failed to set '
                  'up the datastore. If a database instance is in the FAILED '
                  'state, it should be deleted and a new one should be '
                  'created.'),
        ERROR: _('The last operation for the database instance failed due to '
                 'an error.'),
    }

    BAD_STATUSES = (ERROR, FAILED)
    PROPERTIES = (
        NAME, FLAVOR, SIZE, DATABASES, USERS, AVAILABILITY_ZONE,
        RESTORE_POINT, DATASTORE_TYPE, DATASTORE_VERSION, NICS,
        REPLICA_OF, REPLICA_COUNT,
    ) = (
        'name', 'flavor', 'size', 'databases', 'users', 'availability_zone',
        'restore_point', 'datastore_type', 'datastore_version', 'networks',
        'replica_of', 'replica_count'
    )

    _DATABASE_KEYS = (
        DATABASE_CHARACTER_SET, DATABASE_COLLATE, DATABASE_NAME,
    ) = (
        'character_set', 'collate', 'name',
    )

    _USER_KEYS = (
        USER_NAME, USER_PASSWORD, USER_HOST, USER_DATABASES,
    ) = (
        'name', 'password', 'host', 'databases',
    )

    _NICS_KEYS = (
        NET, PORT, V4_FIXED_IP
    ) = (
        'network', 'port', 'fixed_ip'
    )

    ATTRIBUTES = (
        HOSTNAME, HREF,
    ) = (
        'hostname', 'href',
    )

    properties_schema = {
        NAME: properties.Schema(
            properties.Schema.STRING,
            _('Name of the DB instance to create.'),
            update_allowed=True,
            constraints=[
                constraints.Length(max=255),
            ]
        ),
        FLAVOR: properties.Schema(
            properties.Schema.STRING,
            _('Reference to a flavor for creating DB instance.'),
            required=True,
            update_allowed=True,
            constraints=[
                constraints.CustomConstraint('trove.flavor')
            ]
        ),
        DATASTORE_TYPE: properties.Schema(
            properties.Schema.STRING,
            _("Name of registered datastore type."),
            constraints=[
                constraints.Length(max=255)
            ]
        ),
        DATASTORE_VERSION: properties.Schema(
            properties.Schema.STRING,
            _("Name of the registered datastore version. "
              "It must exist for provided datastore type. "
              "Defaults to using single active version. "
              "If several active versions exist for provided datastore type, "
              "explicit value for this parameter must be specified."),
            constraints=[constraints.Length(max=255)]
        ),
        SIZE: properties.Schema(
            properties.Schema.INTEGER,
            _('Database volume size in GB.'),
            required=True,
            update_allowed=True,
            constraints=[
                constraints.Range(1, 150),
            ]
        ),
        NICS: properties.Schema(
            properties.Schema.LIST,
            _("List of network interfaces to create on instance."),
            default=[],
            schema=properties.Schema(
                properties.Schema.MAP,
                schema={
                    NET: properties.Schema(
                        properties.Schema.STRING,
                        _('Name or UUID of the network to attach this NIC to. '
                          'Either %(port)s or %(net)s must be specified.') % {
                              'port': PORT, 'net': NET},
                        constraints=[
                            constraints.CustomConstraint('neutron.network')
                        ]
                    ),
                    PORT: properties.Schema(
                        properties.Schema.STRING,
                        _('Name or UUID of Neutron port to attach this '
                          'NIC to. '
                          'Either %(port)s or %(net)s must be specified.') % {
                              'port': PORT, 'net': NET},
                        constraints=[
                            constraints.CustomConstraint('neutron.port')
                        ],
                    ),
                    V4_FIXED_IP: properties.Schema(
                        properties.Schema.STRING,
                        _('Fixed IPv4 address for this NIC.'),
                        constraints=[
                            constraints.CustomConstraint('ip_addr')
                        ]
                    ),
                },
            ),
        ),
        DATABASES: properties.Schema(
            properties.Schema.LIST,
            _('List of databases to be created on DB instance creation.'),
            default=[],
            update_allowed=True,
            schema=properties.Schema(
                properties.Schema.MAP,
                schema={
                    DATABASE_CHARACTER_SET: properties.Schema(
                        properties.Schema.STRING,
                        _('Set of symbols and encodings.'),
                        default='utf8'
                    ),
                    DATABASE_COLLATE: properties.Schema(
                        properties.Schema.STRING,
                        _('Set of rules for comparing characters in a '
                          'character set.'),
                        default='utf8_general_ci'
                    ),
                    DATABASE_NAME: properties.Schema(
                        properties.Schema.STRING,
                        _('Specifies database names for creating '
                          'databases on instance creation.'),
                        required=True,
                        constraints=[
                            constraints.Length(max=64),
                            constraints.AllowedPattern(r'[a-zA-Z0-9_\-]+'
                                                       r'[a-zA-Z0-9_@?#\s\-]*'
                                                       r'[a-zA-Z0-9_\-]+'),
                        ]
                    ),
                },
            )
        ),
        USERS: properties.Schema(
            properties.Schema.LIST,
            _('List of users to be created on DB instance creation.'),
            default=[],
            update_allowed=True,
            schema=properties.Schema(
                properties.Schema.MAP,
                schema={
                    USER_NAME: properties.Schema(
                        properties.Schema.STRING,
                        _('User name to create a user on instance '
                          'creation.'),
                        required=True,
                        update_allowed=True,
                        constraints=[
                            constraints.Length(max=16),
                            constraints.AllowedPattern(r'[a-zA-Z0-9_]+'
                                                       r'[a-zA-Z0-9_@?#\s]*'
                                                       r'[a-zA-Z0-9_]+'),
                        ]
                    ),
                    USER_PASSWORD: properties.Schema(
                        properties.Schema.STRING,
                        _('Password for those users on instance '
                          'creation.'),
                        required=True,
                        update_allowed=True,
                        constraints=[
                            constraints.AllowedPattern(r'[a-zA-Z0-9_]+'
                                                       r'[a-zA-Z0-9_@?#\s]*'
                                                       r'[a-zA-Z0-9_]+'),
                        ]
                    ),
                    USER_HOST: properties.Schema(
                        properties.Schema.STRING,
                        _('The host from which a user is allowed to '
                          'connect to the database.'),
                        default='%',
                        update_allowed=True
                    ),
                    USER_DATABASES: properties.Schema(
                        properties.Schema.LIST,
                        _('Names of databases that those users can '
                          'access on instance creation.'),
                        schema=properties.Schema(
                            properties.Schema.STRING,
                        ),
                        required=True,
                        update_allowed=True,
                        constraints=[
                            constraints.Length(min=1),
                        ]
                    ),
                },
            )
        ),
        AVAILABILITY_ZONE: properties.Schema(
            properties.Schema.STRING,
            _('Name of the availability zone for DB instance.')
        ),
        RESTORE_POINT: properties.Schema(
            properties.Schema.STRING,
            _('DB instance restore point.')
        ),
        REPLICA_OF: properties.Schema(
            properties.Schema.STRING,
            _('Identifier of the source instance to replicate.'),
            support_status=support.SupportStatus(version='5.0.0')
        ),
        REPLICA_COUNT: properties.Schema(
            properties.Schema.INTEGER,
            _('The number of replicas to be created.'),
            support_status=support.SupportStatus(version='5.0.0')
        ),
    }

    attributes_schema = {
        HOSTNAME: attributes.Schema(
            _("Hostname of the instance."),
            type=attributes.Schema.STRING
        ),
        HREF: attributes.Schema(
            _("Api endpoint reference of the instance."),
            type=attributes.Schema.STRING
        ),
    }

    default_client_name = 'trove'

    entity = 'instances'

    def translation_rules(self, properties):
        return [
            translation.TranslationRule(
                properties,
                translation.TranslationRule.RESOLVE,
                [self.FLAVOR],
                client_plugin=self.client_plugin(),
                finder='find_flavor_by_name_or_id'
            )
        ]

    def __init__(self, name, json_snippet, stack):
        super(Instance, self).__init__(name, json_snippet, stack)
        self._href = None
        self._dbinstance = None

    @property
    def dbinstance(self):
        """Get the trove dbinstance."""
        if not self._dbinstance and self.resource_id:
            self._dbinstance = self.client().instances.get(self.resource_id)

        return self._dbinstance

    def _dbinstance_name(self):
        name = self.properties[self.NAME]
        if name:
            return name

        return self.physical_resource_name()

    def handle_create(self):
        """Create cloud database instance."""
        self.flavor = self.properties[self.FLAVOR]
        self.volume = {'size': self.properties[self.SIZE]}
        self.databases = self.properties[self.DATABASES]
        self.users = self.properties[self.USERS]
        restore_point = self.properties[self.RESTORE_POINT]
        if restore_point:
            restore_point = {"backupRef": restore_point}
        zone = self.properties[self.AVAILABILITY_ZONE]
        self.datastore_type = self.properties[self.DATASTORE_TYPE]
        self.datastore_version = self.properties[self.DATASTORE_VERSION]
        replica_of = self.properties[self.REPLICA_OF]
        replica_count = self.properties[self.REPLICA_COUNT]

        # convert user databases to format required for troveclient.
        # that is, list of database dictionaries
        for user in self.users:
            dbs = [{'name': db} for db in user.get(self.USER_DATABASES, [])]
            user[self.USER_DATABASES] = dbs

        # convert networks to format required by troveclient
        nics = []
        for nic in self.properties[self.NICS]:
            nic_dict = {}
            net = nic.get(self.NET)
            port = nic.get(self.PORT)
            if net or port:
                neutron = self.client_plugin('neutron')
            if net:
                net_id = neutron.find_resourceid_by_name_or_id(
                    neutron.RES_TYPE_NETWORK,
                    net)
                nic_dict['net-id'] = net_id
            if port:
                port_id = neutron.find_resourceid_by_name_or_id(
                    neutron.RES_TYPE_PORT,
                    port)
                nic_dict['port-id'] = port_id
            ip = nic.get(self.V4_FIXED_IP)
            if ip:
                nic_dict['v4-fixed-ip'] = ip
            nics.append(nic_dict)

        # create DB instance
        instance = self.client().instances.create(
            self._dbinstance_name(),
            self.flavor,
            volume=self.volume,
            databases=self.databases,
            users=self.users,
            restorePoint=restore_point,
            availability_zone=zone,
            datastore=self.datastore_type,
            datastore_version=self.datastore_version,
            nics=nics,
            replica_of=replica_of,
            replica_count=replica_count)
        self.resource_id_set(instance.id)

        return instance.id

    def _refresh_instance(self, instance_id):
        try:
            instance = self.client().instances.get(instance_id)
            return instance
        except Exception as exc:
            if self.client_plugin().is_over_limit(exc):
                LOG.warning("Stack %(name)s (%(id)s) received an "
                            "OverLimit response during instance.get():"
                            " %(exception)s",
                            {'name': self.stack.name,
                             'id': self.stack.id,
                             'exception': exc})
                return None
            else:
                raise

    def check_create_complete(self, instance_id):
        """Check if cloud DB instance creation is complete."""
        instance = self._refresh_instance(instance_id)  # refresh attributes
        if instance is None:
            return False
        if instance.status in self.BAD_STATUSES:
            raise exception.ResourceInError(
                resource_status=instance.status,
                status_reason=self.TROVE_STATUS_REASON.get(instance.status,
                                                           _("Unknown")))

        if instance.status != self.ACTIVE:
            return False
        LOG.info("Database instance %(database)s created "
                 "(flavor:%(flavor)s, volume:%(volume)s, "
                 "datastore:%(datastore_type)s, "
                 "datastore_version:%(datastore_version)s)",
                 {'database': self._dbinstance_name(),
                  'flavor': self.flavor,
                  'volume': self.volume,
                  'datastore_type': self.datastore_type,
                  'datastore_version': self.datastore_version})
        return True

    def handle_check(self):
        instance = self.client().instances.get(self.resource_id)
        status = instance.status
        checks = [
            {'attr': 'status', 'expected': self.ACTIVE, 'current': status},
        ]
        self._verify_check_conditions(checks)

    def handle_update(self, json_snippet, tmpl_diff, prop_diff):
        updates = {}
        if prop_diff:
            instance = self.client().instances.get(self.resource_id)
            if self.NAME in prop_diff:
                updates.update({self.NAME: prop_diff[self.NAME]})
            if self.FLAVOR in prop_diff:
                flv = prop_diff[self.FLAVOR]
                updates.update({self.FLAVOR: flv})
            if self.SIZE in prop_diff:
                updates.update({self.SIZE: prop_diff[self.SIZE]})
            if self.DATABASES in prop_diff:
                current = [d.name
                           for d in self.client().databases.list(instance)]
                desired = [d[self.DATABASE_NAME]
                           for d in prop_diff[self.DATABASES]]
                for db in prop_diff[self.DATABASES]:
                    dbname = db[self.DATABASE_NAME]
                    if dbname not in current:
                        db['ACTION'] = self.CREATE
                for dbname in current:
                    if dbname not in desired:
                        deleted = {self.DATABASE_NAME: dbname,
                                   'ACTION': self.DELETE}
                        prop_diff[self.DATABASES].append(deleted)
                updates.update({self.DATABASES: prop_diff[self.DATABASES]})
            if self.USERS in prop_diff:
                current = [u.name
                           for u in self.client().users.list(instance)]
                desired = [u[self.USER_NAME] for u in prop_diff[self.USERS]]
                for usr in prop_diff[self.USERS]:
                    if usr[self.USER_NAME] not in current:
                        usr['ACTION'] = self.CREATE
                for usr in current:
                    if usr not in desired:
                        prop_diff[self.USERS].append({self.USER_NAME: usr,
                                                      'ACTION': self.DELETE})
                updates.update({self.USERS: prop_diff[self.USERS]})
        return updates

    def check_update_complete(self, updates):
        instance = self.client().instances.get(self.resource_id)
        if instance.status in self.BAD_STATUSES:
            raise exception.ResourceInError(
                resource_status=instance.status,
                status_reason=self.TROVE_STATUS_REASON.get(instance.status,
                                                           _("Unknown")))
        if updates:
            if instance.status != self.ACTIVE:
                dmsg = ("Instance is in status %(now)s. Waiting on status"
                        " %(stat)s")
                LOG.debug(dmsg % {"now": instance.status,
                                  "stat": self.ACTIVE})
                return False
            try:
                return (
                    self._update_name(instance, updates.get(self.NAME)) and
                    self._update_flavor(instance, updates.get(self.FLAVOR)) and
                    self._update_size(instance, updates.get(self.SIZE)) and
                    self._update_databases(instance,
                                           updates.get(self.DATABASES)) and
                    self._update_users(instance, updates.get(self.USERS))
                )
            except Exception as exc:
                if self.client_plugin().is_client_exception(exc):
                    # the instance could have updated between the time
                    # we retrieve it and try to update it so check again
                    if self.client_plugin().is_over_limit(exc):
                        LOG.debug("API rate limit: %(ex)s. Retrying.",
                                  {'ex': str(exc)})
                        return False
                    if "No change was requested" in str(exc):
                        LOG.warning("Unexpected instance state change "
                                    "during update. Retrying.")
                        return False
                raise
        return True

    def _update_name(self, instance, name):
        if name and instance.name != name:
            self.client().instances.edit(instance, name=name)
            return False
        return True

    def _update_flavor(self, instance, new_flavor):
        if new_flavor:
            current_flav = str(instance.flavor['id'])
            new_flav = str(new_flavor)
            if new_flav != current_flav:
                dmsg = "Resizing instance flavor from %(old)s to %(new)s"
                LOG.debug(dmsg % {"old": current_flav, "new": new_flav})
                self.client().instances.resize_instance(instance, new_flavor)
                return False
        return True

    def _update_size(self, instance, new_size):
        if new_size and instance.volume['size'] != new_size:
            dmsg = "Resizing instance storage from %(old)s to %(new)s"
            LOG.debug(dmsg % {"old": instance.volume['size'],
                              "new": new_size})
            self.client().instances.resize_volume(instance, new_size)
            return False
        return True

    def _update_databases(self, instance, databases):
        if databases:
            for db in databases:
                if db.get("ACTION") == self.CREATE:
                    db.pop("ACTION", None)
                    dmsg = "Adding new database %(db)s to instance"
                    LOG.debug(dmsg % {"db": db})
                    self.client().databases.create(instance, [db])
                elif db.get("ACTION") == self.DELETE:
                    dmsg = ("Deleting existing database %(db)s from "
                            "instance")
                    LOG.debug(dmsg % {"db": db['name']})
                    self.client().databases.delete(instance, db['name'])
        return True

    def _update_users(self, instance, users):
        if users:
            for usr in users:
                dbs = [{'name': db} for db in usr.get(self.USER_DATABASES,
                                                      [])]
                usr[self.USER_DATABASES] = dbs
                if usr.get("ACTION") == self.CREATE:
                    usr.pop("ACTION", None)
                    dmsg = "Adding new user %(u)s to instance"
                    LOG.debug(dmsg % {"u": usr})
                    self.client().users.create(instance, [usr])
                elif usr.get("ACTION") == self.DELETE:
                    dmsg = ("Deleting existing user %(u)s from "
                            "instance")
                    LOG.debug(dmsg % {"u": usr['name']})
                    self.client().users.delete(instance, usr['name'])
                else:
                    newattrs = {}
                    if usr.get(self.USER_HOST):
                        newattrs[self.USER_HOST] = usr[self.USER_HOST]
                    if usr.get(self.USER_PASSWORD):
                        newattrs[self.USER_PASSWORD] = usr[self.USER_PASSWORD]
                    if newattrs:
                        self.client().users.update_attributes(
                            instance,
                            usr['name'], newuserattr=newattrs,
                            hostname=instance.hostname)
                    current = self.client().users.get(instance,
                                                      usr[self.USER_NAME])
                    dbs = [db['name'] for db in current.databases]
                    desired = [db['name'] for db in
                               usr.get(self.USER_DATABASES, [])]
                    grants = [db for db in desired if db not in dbs]
                    revokes = [db for db in dbs if db not in desired]
                    if grants:
                        self.client().users.grant(instance,
                                                  usr[self.USER_NAME],
                                                  grants)
                    if revokes:
                        self.client().users.revoke(instance,
                                                   usr[self.USER_NAME],
                                                   revokes)
        return True

    def parse_live_resource_data(self, resource_properties, resource_data):
        """A method to parse live resource data to update current resource.

        NOTE: cannot update users from live resource data in case of
        impossibility to get required user password.
        """
        dbs = [d.name for d in self.client().databases.list(self.resource_id)]
        dbs_reality = []
        for resource_db in resource_properties[self.DATABASES]:
            if resource_db[self.DATABASE_NAME] in dbs:
                dbs_reality.append(resource_db)
                dbs.remove(resource_db[self.DATABASE_NAME])
        # cannot get any property for databases except for name, so update
        # resource with name
        dbs_reality.extend([{self.DATABASE_NAME: db} for db in dbs])
        result = {self.NAME: resource_data.get('name'),
                  self.DATABASES: dbs_reality}
        if resource_data.get('flavor') is not None:
            result[self.FLAVOR] = resource_data['flavor'].get('id')
        if resource_data.get('volume') is not None:
            result[self.SIZE] = resource_data['volume']['size']
        return result

    def handle_delete(self):
        """Delete a cloud database instance."""
        if not self.resource_id:
            return

        try:
            instance = self.client().instances.get(self.resource_id)
        except Exception as ex:
            self.client_plugin().ignore_not_found(ex)
        else:
            instance.delete()
            return instance.id

    def check_delete_complete(self, instance_id):
        """Check for completion of cloud DB instance deletion."""
        if not instance_id:
            return True

        try:
            # For some time trove instance may continue to live
            self._refresh_instance(instance_id)
        except Exception as ex:
            self.client_plugin().ignore_not_found(ex)
            return True

        return False

    def validate(self):
        """Validate any of the provided params."""
        res = super(Instance, self).validate()
        if res:
            return res

        datastore_type = self.properties[self.DATASTORE_TYPE]
        datastore_version = self.properties[self.DATASTORE_VERSION]

        self.client_plugin().validate_datastore(
            datastore_type, datastore_version,
            self.DATASTORE_TYPE, self.DATASTORE_VERSION)

        # check validity of user and databases
        users = self.properties[self.USERS]
        if users:
            databases = self.properties[self.DATABASES]
            if not databases:
                msg = _('Databases property is required if users property '
                        'is provided for resource %s.') % self.name
                raise exception.StackValidationFailed(message=msg)

            db_names = set([db[self.DATABASE_NAME] for db in databases])
            for user in users:
                missing_db = [db_name for db_name in user[self.USER_DATABASES]
                              if db_name not in db_names]

                if missing_db:
                    msg = (_('Database %(dbs)s specified for user does '
                             'not exist in databases for resource %(name)s.')
                           % {'dbs': missing_db, 'name': self.name})
                    raise exception.StackValidationFailed(message=msg)

        nics = self.properties[self.NICS]
        for nic in nics:
            if (nic.get(self.NET) is None) == (nic.get(self.PORT) is None):
                msg = _("Either %(net)s or %(port)s must be provided.") % {
                    'net': self.NET, 'port': self.PORT}
                raise exception.StackValidationFailed(message=msg)

    def href(self):
        if not self._href and self.dbinstance:
            if not self.dbinstance.links:
                self._href = None
            else:
                for link in self.dbinstance.links:
                    if link['rel'] == 'self':
                        self._href = link[self.HREF]
                        break

        return self._href

    def _resolve_attribute(self, name):
        if self.resource_id is None:
            return
        if name == self.HOSTNAME:
            return self.dbinstance.hostname
        elif name == self.HREF:
            return self.href()


def resource_mapping():
    return {
        'OS::Trove::Instance': Instance,
    }
