# Copyright 2021-2023 H2020 TeraFlow (https://www.teraflow-h2020.eu/)
#
# 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 time
from sqlalchemy import delete
from sqlalchemy.dialects.postgresql import insert
from sqlalchemy.engine import Engine
from sqlalchemy.orm import Session, sessionmaker
from sqlalchemy_cockroachdb import run_transaction
from typing import Dict, List, Optional, Set, Tuple
from common.proto.context_pb2 import Device, DeviceId, DeviceIdList, DeviceList
from common.rpc_method_wrapper.ServiceExceptions import InvalidArgumentException, NotFoundException
from common.tools.grpc.Tools import grpc_message_to_json_string
from context.service.database.models.ConfigRuleModel import ConfigRuleKindEnum, ConfigRuleModel
from context.service.database.models.DeviceModel import DeviceModel
from context.service.database.models.EndPointModel import EndPointModel
from context.service.database.models.RelationModels import TopologyDeviceModel
from context.service.database.models.enums.ConfigAction import grpc_to_enum__config_action
from context.service.database.models.enums.DeviceDriver import grpc_to_enum__device_driver
from context.service.database.models.enums.DeviceOperationalStatus import grpc_to_enum__device_operational_status
from context.service.database.models.enums.KpiSampleType import grpc_to_enum__kpi_sample_type

def device_list_ids(db_engine : Engine) -> DeviceIdList:
    def callback(session : Session) -> List[Dict]:
        obj_list : List[DeviceModel] = session.query(DeviceModel).all()
        #.options(selectinload(DeviceModel.topology)).filter_by(context_uuid=context_uuid).one_or_none()
        return [obj.dump_id() for obj in obj_list]
    return DeviceIdList(device_ids=run_transaction(sessionmaker(bind=db_engine), callback))

def device_list_objs(db_engine : Engine) -> DeviceList:
    def callback(session : Session) -> List[Dict]:
        obj_list : List[DeviceModel] = session.query(DeviceModel).all()
        #.options(selectinload(DeviceModel.topology)).filter_by(context_uuid=context_uuid).one_or_none()
        return [obj.dump() for obj in obj_list]
    return DeviceList(devices=run_transaction(sessionmaker(bind=db_engine), callback))

def device_get(db_engine : Engine, request : DeviceId) -> Device:
    device_uuid = request.device_uuid.uuid
    def callback(session : Session) -> Optional[Dict]:
        obj : Optional[DeviceModel] = session.query(DeviceModel)\
            .filter_by(device_uuid=device_uuid).one_or_none()
        return None if obj is None else obj.dump()
    obj = run_transaction(sessionmaker(bind=db_engine), callback)
    if obj is None: raise NotFoundException('Device', device_uuid)
    return Device(**obj)

def device_set(db_engine : Engine, request : Device) -> bool:
    device_uuid = request.device_id.device_uuid.uuid
    device_name = request.name
    device_type = request.device_type
    oper_status = grpc_to_enum__device_operational_status(request.device_operational_status)
    device_drivers = [grpc_to_enum__device_driver(d) for d in request.device_drivers]

    topology_keys : Set[Tuple[str, str]] = set()
    related_topologies : List[Dict] = list()
    endpoints_data : List[Dict] = list()
    for i, endpoint in enumerate(request.device_endpoints):
        endpoint_device_uuid = endpoint.endpoint_id.device_id.device_uuid.uuid
        if len(endpoint_device_uuid) == 0: endpoint_device_uuid = device_uuid
        if device_uuid != endpoint_device_uuid:
            raise InvalidArgumentException(
                'request.device_endpoints[{:d}].device_id.device_uuid.uuid'.format(i), endpoint_device_uuid,
                ['should be == {:s}({:s})'.format('request.device_id.device_uuid.uuid', device_uuid)])

        endpoint_context_uuid = endpoint.endpoint_id.topology_id.context_id.context_uuid.uuid
        endpoint_topology_uuid = endpoint.endpoint_id.topology_id.topology_uuid.uuid

        kpi_sample_types = [grpc_to_enum__kpi_sample_type(kst) for kst in endpoint.kpi_sample_types]

        endpoints_data.append({
            'context_uuid'    : endpoint_context_uuid,
            'topology_uuid'   : endpoint_topology_uuid,
            'device_uuid'     : endpoint_device_uuid,
            'endpoint_uuid'   : endpoint.endpoint_id.endpoint_uuid.uuid,
            'endpoint_type'   : endpoint.endpoint_type,
            'kpi_sample_types': kpi_sample_types,
        })

        if len(endpoint_context_uuid) > 0 and len(endpoint_topology_uuid) > 0:
            topology_key = (endpoint_context_uuid, endpoint_topology_uuid)
            if topology_key not in topology_keys:
                related_topologies.append({
                    'context_uuid': endpoint_context_uuid,
                    'topology_uuid': endpoint_topology_uuid,
                    'device_uuid': endpoint_device_uuid,
                })
                topology_keys.add(topology_key)

    config_rules : List[Dict] = list()
    for position,config_rule in enumerate(request.device_config.config_rules):
        str_kind = config_rule.WhichOneof('config_rule')
        config_rules.append({
            'device_uuid': device_uuid,
            'kind'       : ConfigRuleKindEnum._member_map_.get(str_kind.upper()), # pylint: disable=no-member
            'action'     : grpc_to_enum__config_action(config_rule.action),
            'position'   : position,
            'data'       : grpc_message_to_json_string(getattr(config_rule, str_kind, {})),
        })

    def callback(session : Session) -> None:
        obj : Optional[DeviceModel] = session.query(DeviceModel).with_for_update()\
            .filter_by(device_uuid=device_uuid).one_or_none()
        is_update = obj is not None
        if is_update:
            obj.device_name = device_name
            obj.device_type = device_type
            obj.device_operational_status = oper_status
            obj.device_drivers = device_drivers
            session.merge(obj)
        else:
            session.add(DeviceModel(
                device_uuid=device_uuid, device_name=device_name, device_type=device_type,
                device_operational_status=oper_status, device_drivers=device_drivers, created_at=time.time()))
        obj : Optional[DeviceModel] = session.query(DeviceModel)\
            .filter_by(device_uuid=device_uuid).one_or_none()

        stmt = insert(EndPointModel).values(endpoints_data)
        stmt = stmt.on_conflict_do_update(
            index_elements=[
                EndPointModel.context_uuid, EndPointModel.topology_uuid, EndPointModel.device_uuid,
                EndPointModel.endpoint_uuid
            ],
            set_=dict(
                endpoint_type = stmt.excluded.endpoint_type,
                kpi_sample_types = stmt.excluded.kpi_sample_types,
            )
        )
        session.execute(stmt)

        session.execute(insert(TopologyDeviceModel).values(related_topologies).on_conflict_do_nothing(
            index_elements=[
                TopologyDeviceModel.context_uuid, TopologyDeviceModel.topology_uuid,
                TopologyDeviceModel.device_uuid
            ]
        ))

        session.execute(delete(ConfigRuleModel).where(ConfigRuleModel.device_uuid == device_uuid))
        session.execute(insert(ConfigRuleModel).values(config_rules))

    run_transaction(sessionmaker(bind=db_engine), callback)
    return False # TODO: improve and check if created/updated

def device_delete(db_engine : Engine, request : DeviceId) -> bool:
    device_uuid = request.device_uuid.uuid
    def callback(session : Session) -> bool:
        session.query(TopologyDeviceModel).filter_by(device_uuid=device_uuid).delete()
        num_deleted = session.query(DeviceModel).filter_by(device_uuid=device_uuid).delete()
        #db_device = session.query(DeviceModel).filter_by(device_uuid=device_uuid).one_or_none()
        #session.query(ConfigRuleModel).filter_by(config_uuid=db_device.device_config_uuid).delete()
        #session.query(ConfigModel).filter_by(config_uuid=db_device.device_config_uuid).delete()
        #session.query(DeviceModel).filter_by(device_uuid=device_uuid).delete()
        return num_deleted > 0
    return run_transaction(sessionmaker(bind=db_engine), callback)




#Union_SpecificConfigRule = Union[
#    ConfigRuleCustomModel, ConfigRuleAclModel
#]
#
#def set_config_rule(
#    database : Database, db_config : ConfigModel, position : int, resource_key : str, resource_value : str,
#): # -> Tuple[ConfigRuleModel, bool]:
#
#    str_rule_key_hash = fast_hasher(resource_key)
#    str_config_rule_key = key_to_str([db_config.config_uuid, str_rule_key_hash], separator=':')
#
#    data = {'config_fk': db_config, 'position': position, 'action': ORM_ConfigActionEnum.SET, 'key': resource_key,
#            'value': resource_value}
#    to_add = ConfigRuleModel(**data)
#
#    result = database.create_or_update(to_add)
#    return result
#Tuple_ConfigRuleSpecs = Tuple[Type, str, Dict, ConfigRuleKindEnum]
#
#def parse_config_rule_custom(database : Database, grpc_config_rule) -> Tuple_ConfigRuleSpecs:
#    config_rule_class = ConfigRuleCustomModel
#    str_config_rule_id = grpc_config_rule.custom.resource_key
#    config_rule_data = {
#        'key'  : grpc_config_rule.custom.resource_key,
#        'value': grpc_config_rule.custom.resource_value,
#    }
#    return config_rule_class, str_config_rule_id, config_rule_data, ConfigRuleKindEnum.CUSTOM
#
#def parse_config_rule_acl(database : Database, grpc_config_rule) -> Tuple_ConfigRuleSpecs:
#    config_rule_class = ConfigRuleAclModel
#    grpc_endpoint_id = grpc_config_rule.acl.endpoint_id
#    grpc_rule_set = grpc_config_rule.acl.rule_set
#    device_uuid = grpc_endpoint_id.device_id.device_uuid.uuid
#    endpoint_uuid = grpc_endpoint_id.endpoint_uuid.uuid
#    str_endpoint_key = '/'.join([device_uuid, endpoint_uuid])
#    #str_endpoint_key, db_endpoint = get_endpoint(database, grpc_endpoint_id)
#    str_config_rule_id = ':'.join([str_endpoint_key, grpc_rule_set.name])
#    config_rule_data = {
#        #'endpoint_fk': db_endpoint,
#        'endpoint_id': grpc_message_to_json_string(grpc_endpoint_id),
#        'acl_data': grpc_message_to_json_string(grpc_rule_set),
#    }
#    return config_rule_class, str_config_rule_id, config_rule_data, ConfigRuleKindEnum.ACL
#
#CONFIGRULE_PARSERS = {
#    'custom': parse_config_rule_custom,
#    'acl'   : parse_config_rule_acl,
#}
#
#Union_ConfigRuleModel = Union[
#    ConfigRuleCustomModel, ConfigRuleAclModel,
#]
#
#def set_config_rule(
#    database : Database, db_config : ConfigModel, grpc_config_rule : ConfigRule, position : int
#) -> Tuple[Union_ConfigRuleModel, bool]:
#    grpc_config_rule_kind = str(grpc_config_rule.WhichOneof('config_rule'))
#    parser = CONFIGRULE_PARSERS.get(grpc_config_rule_kind)
#    if parser is None:
#        raise NotImplementedError('ConfigRule of kind {:s} is not implemented: {:s}'.format(
#            grpc_config_rule_kind, grpc_message_to_json_string(grpc_config_rule)))
#
#    # create specific ConfigRule
#    config_rule_class, str_config_rule_id, config_rule_data, config_rule_kind = parser(database, grpc_config_rule)
#    str_config_rule_key_hash = fast_hasher(':'.join([config_rule_kind.value, str_config_rule_id]))
#    str_config_rule_key = key_to_str([db_config.pk, str_config_rule_key_hash], separator=':')
#    result : Tuple[Union_ConfigRuleModel, bool] = update_or_create_object(
#        database, config_rule_class, str_config_rule_key, config_rule_data)
#    db_specific_config_rule, updated = result
#
#    # create generic ConfigRule
#    config_rule_fk_field_name = 'config_rule_{:s}_fk'.format(config_rule_kind.value)
#    config_rule_data = {
#        'config_fk': db_config, 'kind': config_rule_kind, 'position': position,
#        'action': ORM_ConfigActionEnum.SET,
#        config_rule_fk_field_name: db_specific_config_rule
#    }
#    result : Tuple[ConfigRuleModel, bool] = update_or_create_object(
#        database, ConfigRuleModel, str_config_rule_key, config_rule_data)
#    db_config_rule, updated = result
#
#    return db_config_rule, updated
#
#def delete_config_rule(
#    database : Database, db_config : ConfigModel, grpc_config_rule : ConfigRule
#) -> None:
#    grpc_config_rule_kind = str(grpc_config_rule.WhichOneof('config_rule'))
#    parser = CONFIGRULE_PARSERS.get(grpc_config_rule_kind)
#    if parser is None:
#        raise NotImplementedError('ConfigRule of kind {:s} is not implemented: {:s}'.format(
#            grpc_config_rule_kind, grpc_message_to_json_string(grpc_config_rule)))
#
#    # delete generic config rules; self deletes specific config rule
#    _, str_config_rule_id, _, config_rule_kind = parser(database, grpc_config_rule)
#    str_config_rule_key_hash = fast_hasher(':'.join([config_rule_kind.value, str_config_rule_id]))
#    str_config_rule_key = key_to_str([db_config.pk, str_config_rule_key_hash], separator=':')
#    db_config_rule : Optional[ConfigRuleModel] = get_object(
#        database, ConfigRuleModel, str_config_rule_key, raise_if_not_found=False)
#    if db_config_rule is None: return
#    db_config_rule.delete()
#
#def update_config(
#    database : Database, db_parent_pk : str, config_name : str, grpc_config_rules
#) -> List[Tuple[Union[ConfigModel, ConfigRuleModel], bool]]:
#
#    str_config_key = key_to_str([config_name, db_parent_pk], separator=':')
#    result : Tuple[ConfigModel, bool] = get_or_create_object(database, ConfigModel, str_config_key)
#    db_config, created = result
#
#    db_objects = [(db_config, created)]
#
#    for position,grpc_config_rule in enumerate(grpc_config_rules):
#        action = grpc_to_enum__config_action(grpc_config_rule.action)
#
#        if action == ORM_ConfigActionEnum.SET:
#            result : Tuple[ConfigRuleModel, bool] = set_config_rule(
#                database, db_config, grpc_config_rule, position)
#            db_config_rule, updated = result
#            db_objects.append((db_config_rule, updated))
#        elif action == ORM_ConfigActionEnum.DELETE:
#            delete_config_rule(database, db_config, grpc_config_rule)
#        else:
#            msg = 'Unsupported Action({:s}) for ConfigRule({:s})'
#            str_action = str(ConfigActionEnum.Name(action))
#            str_config_rule = grpc_message_to_json_string(grpc_config_rule)
#            raise AttributeError(msg.format(str_action, str_config_rule))
#
#    return db_objects
