# Copyright 2022-2023 ETSI TeraFlowSDN - TFS OSG (https://tfs.etsi.org/)
#
# 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 logging
from typing import Any, Dict, Optional, Tuple
from common.proto.kpi_sample_types_pb2 import KpiSampleType
from common.type_checkers.Checkers import chk_attribute, chk_string, chk_type
from device.service.driver_api._Driver import RESOURCE_ENDPOINTS
from .Constants import SPECIAL_RESOURCE_MAPPINGS

LOGGER = logging.getLogger(__name__)

def process_optional_string_field(
    endpoint_data : Dict[str, Any], field_name : str, endpoint_resource_value : Dict[str, Any]
) -> None:
    field_value = chk_attribute(field_name, endpoint_data, 'endpoint_data', default=None)
    if field_value is None: return
    chk_string('endpoint_data.{:s}'.format(field_name), field_value)
    if len(field_value) > 0: endpoint_resource_value[field_name] = field_value

def compose_resource_endpoint(endpoint_data : Dict[str, Any]) -> Optional[Tuple[str, Dict]]:
    try:
        # Check type of endpoint_data
        chk_type('endpoint_data', endpoint_data, dict)

        # Check endpoint UUID (mandatory)
        endpoint_uuid = chk_attribute('uuid', endpoint_data, 'endpoint_data')
        chk_string('endpoint_data.uuid', endpoint_uuid, min_length=1)
        endpoint_resource_path = SPECIAL_RESOURCE_MAPPINGS.get(RESOURCE_ENDPOINTS)
        endpoint_resource_key = '{:s}/endpoint[{:s}]'.format(endpoint_resource_path, endpoint_uuid)
        endpoint_resource_value = {'uuid': endpoint_uuid}

        # Check endpoint optional string fields
        process_optional_string_field(endpoint_data, 'name', endpoint_resource_value)
        process_optional_string_field(endpoint_data, 'type', endpoint_resource_value)
        process_optional_string_field(endpoint_data, 'context_uuid', endpoint_resource_value)
        process_optional_string_field(endpoint_data, 'topology_uuid', endpoint_resource_value)

        # Check endpoint sample types (optional)
        endpoint_sample_types = chk_attribute('sample_types', endpoint_data, 'endpoint_data', default=[])
        chk_type('endpoint_data.sample_types', endpoint_sample_types, list)
        sample_types = {}
        sample_type_errors = []
        for i,endpoint_sample_type in enumerate(endpoint_sample_types):
            field_name = 'endpoint_data.sample_types[{:d}]'.format(i)
            try:
                chk_type(field_name, endpoint_sample_type, (int, str))
                if isinstance(endpoint_sample_type, int):
                    metric_name = KpiSampleType.Name(endpoint_sample_type)
                    metric_id = endpoint_sample_type
                elif isinstance(endpoint_sample_type, str):
                    metric_id = KpiSampleType.Value(endpoint_sample_type)
                    metric_name = endpoint_sample_type
                else:
                    str_type = str(type(endpoint_sample_type))
                    raise Exception('Bad format: {:s}'.format(str_type)) # pylint: disable=broad-exception-raised
            except Exception as e: # pylint: disable=broad-exception-caught
                MSG = 'Unsupported {:s}({:s}) : {:s}'
                sample_type_errors.append(MSG.format(field_name, str(endpoint_sample_type), str(e)))

            metric_name = metric_name.lower().replace('kpisampletype_', '')
            monitoring_resource_key = '{:s}/state/{:s}'.format(endpoint_resource_key, metric_name)
            sample_types[metric_id] = monitoring_resource_key

        if len(sample_type_errors) > 0:
            # pylint: disable=broad-exception-raised
            raise Exception('Malformed Sample Types:\n{:s}'.format('\n'.join(sample_type_errors)))

        if len(sample_types) > 0:
            endpoint_resource_value['sample_types'] = sample_types
    
        if 'location' in endpoint_data:
            endpoint_resource_value['location'] = endpoint_data['location']
            
        return endpoint_resource_key, endpoint_resource_value
    except: # pylint: disable=bare-except
        LOGGER.exception('Problem composing endpoint({:s})'.format(str(endpoint_data)))
        return None
