###################################################################################################################### 
#  Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.                                           # 
#                                                                                                                    # 
#  Licensed under the Apache License Version 2.0 (the "License"). You may not use this file except in compliance     # 
#  with the License. A copy of the License is located at                                                             # 
#                                                                                                                    # 
#      http://www.apache.org/licenses/                                                                               # 
#                                                                                                                    # 
#  or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES # 
#  OR CONDITIONS OF ANY KIND, express or implied. See the License for the specific language governing permissions    # 
#  and limitations under the License.                                                                                # 
######################################################################################################################
import boto_retry
from services.aws_service import AwsService

ACCOUNT_LIMITS = "AccountLimits"
LOAD_BALANCER_ATTRIBUTES = "LoadBalancerAttributes"
LISTENER_CERTIFICATES = "ListenerCertificates"
LISTENERS = "Listeners"
LOAD_BALANCERS = "LoadBalancers"
TARGET_GROUPS = "TargetGroups"
TARGET_HEALTH = "TargetHealth"
TARGET_GROUP_ATTRIBUTES = "TargetGroupAttributes"
RULES = "Rules"
SSL_POLICIES = "SslPolicies"
TAGS = "Tags"

MAPPED_PARAMETERS = {
    "MaxResults": "PageSize"
}

NEXT_TOKEN_ARGUMENT = "Marker"
NEXT_TOKEN_RESULT = "NextMarker"

CUSTOM_RESULT_PATHS = {
    ACCOUNT_LIMITS: "Limits",
    LOAD_BALANCER_ATTRIBUTES: "Attributes",
    LISTENER_CERTIFICATES: "Certificates",
    TARGET_HEALTH: "TargetHealthDescriptions",
    TAGS: "TagDescriptions"
}

RESOURCE_NAMES = [
    ACCOUNT_LIMITS,
    LISTENER_CERTIFICATES,
    LISTENERS,
    LOAD_BALANCER_ATTRIBUTES,
    LOAD_BALANCERS,
    RULES,
    SSL_POLICIES,
    TAGS,
    TARGET_GROUP_ATTRIBUTES,
    TARGET_GROUPS,
    TARGET_HEALTH
]

RESOURCES_WITH_TAGS = [
    LOAD_BALANCERS,
    TARGET_GROUPS,
    LISTENERS
]


class Elbv2Service(AwsService):
    def __init__(self, role_arn=None, session=None, tags_as_dict=True, as_named_tuple=False, service_retry_strategy=None):
        """
        :param role_arn: Optional (cross account) role to use to retrieve services
        :param session: Optional session to use to retrieve services
        :param tags_as_dict: Set to True true to convert resource tags to dictionaries
        :param as_named_tuple: Set to True to return resources as named tuples instead of a dictionary
        :param service_retry_strategy: service retry strategy for making boto api calls
        """

        AwsService.__init__(self,
                            service_name="elbv2",
                            resource_names=RESOURCE_NAMES,
                            resources_with_tags=RESOURCES_WITH_TAGS,
                            role_arn=role_arn,
                            session=session,
                            tags_as_dict=tags_as_dict,
                            as_named_tuple=as_named_tuple,
                            custom_result_paths=CUSTOM_RESULT_PATHS,
                            mapped_parameters=MAPPED_PARAMETERS,
                            next_token_argument=NEXT_TOKEN_ARGUMENT,
                            next_token_result=NEXT_TOKEN_RESULT,
                            service_retry_strategy=service_retry_strategy)

    def _get_tags_for_resource(self, client, resource):
        """
        Returns the tags for specific resources that require additional boto calls to retrieve their tags.
        Tags are not supported for this service.
        :param client: Client that can be used to make the boto call to retrieve the tags
        :param resource: The resource for which to retrieve the tags
        :return: Tags
        """
        if self._resource_name not in RESOURCES_WITH_TAGS:
            raise ValueError("Resource type {] does not support tags".format(self._resource_name))

        arn_name = self._resource_name[0:-1] + "Arn"

        if self._service_retry_strategy is not None:
            if getattr(self._service_client, "list_tags_for_resource" + boto_retry.DEFAULT_SUFFIX, None) is None:
                boto_retry.make_method_with_retries(boto_client_or_resource=self._service_client,
                                                    name="describe_tags",
                                                    service_retry_strategy=self._service_retry_strategy)
            tag_list = client.describe_tags_with_retries(LoadBalancerNames=[resource[arn_name]]).get("TagDescriptions")

        else:
            tag_list = client.describe_tags(ResourceArns=[resource[arn_name]]).get("TagDescriptions")

        if len(tag_list) > 0:
            return [{"Key": t["Key"], "Value": t["Value"]} for t in tag_list[0].get("Tags", [])]
        else:
            return {}