# Copyright 2021 The Kubernetes Authors.
#
# 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 json
import logging
from typing import Any

from kubernetes.aio import client
from kubernetes.aio.client.api_client import ApiClient
from kubernetes.aio.client.rest import ApiException
from kubernetes.aio.leaderelection.leaderelectionrecord import (
    LeaderElectionRecord,
)
from kubernetes.aio.leaderelection.resourcelock.baselock import BaseLock

logger = logging.getLogger(__name__)


class ConfigMapLock(BaseLock):
    def __init__(self, name: str, namespace: str, identity: str, api_client: ApiClient):
        """
        :param name: name of the lock
        :param namespace: namespace
        :param identity: A unique identifier that the candidate is using
        """
        super().__init__(name, namespace, identity)

        # self._api_instance = None # See api_instance property
        self.api_instance = client.CoreV1Api(api_client=api_client)
        self.leader_electionrecord_annotationkey = (
            "control-plane.alpha.kubernetes.io/leader"
        )
        self.configmap_reference: client.V1ConfigMap | None = None
        self.lock_record: dict[str, Any] = {
            "holderIdentity": None,
            "leaseDurationSeconds": None,
            "acquireTime": None,
            "renewTime": None,
        }

    # get returns the election record from a ConfigMap Annotation
    async def get(
        self, name: str, namespace: str
    ) -> tuple[bool, LeaderElectionRecord] | tuple[bool, Exception] | tuple[bool, None]:
        """
        :param name: Name of the configmap object information to get
        :param namespace: Namespace in which the configmap object is to be searched
        :return: 'True, election record' if object found else 'False, exception response'
        """
        try:
            api_response = await self.api_instance.read_namespaced_config_map(
                name, namespace
            )

            # If an annotation does not exist - add the leader_electionrecord_annotationkey
            annotations = api_response.metadata.annotations
            if annotations is None or annotations == "":
                api_response.metadata.annotations = {
                    self.leader_electionrecord_annotationkey: ""
                }
                self.configmap_reference = api_response
                return True, None

            # If an annotation exists but, the leader_electionrecord_annotationkey does not then add it as a key
            if not annotations.get(self.leader_electionrecord_annotationkey):
                api_response.metadata.annotations = {
                    self.leader_electionrecord_annotationkey: ""
                }
                self.configmap_reference = api_response
                return True, None

            # A corrupted annotation must not take the elector down: treat it
            # like a missing one so the next update rewrites a clean record.
            try:
                annotation_record = json.loads(
                    annotations[self.leader_electionrecord_annotationkey]
                )
            except ValueError:
                logger.warning(
                    "Leader election annotation on ConfigMap %s/%s is not valid "
                    "JSON; treating the lock as unheld",
                    name,
                    namespace,
                )
                api_response.metadata.annotations = {
                    self.leader_electionrecord_annotationkey: ""
                }
                self.configmap_reference = api_response
                return True, None

            lock_record = self.get_lock_object(annotation_record)

            self.configmap_reference = api_response
            return True, lock_record
        except ApiException as e:
            return False, e

    async def create(
        self, name: str, namespace: str, election_record: LeaderElectionRecord
    ) -> bool:
        """
        :param electionRecord: Annotation string
        :param name: Name of the configmap object to be created
        :param namespace: Namespace in which the configmap object is to be created
        :return: 'True' if object is created else 'False' if failed
        """
        body = client.V1ConfigMap(
            metadata=client.V1ObjectMeta(
                name=name,
                annotations={
                    self.leader_electionrecord_annotationkey: json.dumps(
                        self.get_lock_dict(election_record)
                    )
                },
            )
        )

        try:
            await self.api_instance.create_namespaced_config_map(
                namespace, body, pretty=True
            )
            return True
        except ApiException:
            logger.exception("Failed to create lock")
            return False

    async def update(
        self, name: str, namespace: str, updated_record: LeaderElectionRecord
    ) -> bool:
        """
        :param name: name of the lock to be updated
        :param namespace: namespace the lock is in
        :param updated_record: the updated election record
        :return: True if update is successful False if it fails
        """
        try:
            # Set the updated record
            assert self.configmap_reference is not None
            self.configmap_reference.metadata.annotations[
                self.leader_electionrecord_annotationkey
            ] = json.dumps(self.get_lock_dict(updated_record))
            await self.api_instance.replace_namespaced_config_map(
                name=name, namespace=namespace, body=self.configmap_reference
            )
            return True
        except ApiException:
            logger.exception("Failed to update lock")
            return False

    def get_lock_object(self, lock_record: dict) -> LeaderElectionRecord:
        leader_election_record = LeaderElectionRecord(None, None, None, None)

        if lock_record.get("holderIdentity"):
            leader_election_record.holder_identity = lock_record["holderIdentity"]
        if lock_record.get("leaseDurationSeconds"):
            leader_election_record.lease_duration = lock_record["leaseDurationSeconds"]
        if lock_record.get("acquireTime"):
            leader_election_record.acquire_time = lock_record["acquireTime"]
        if lock_record.get("renewTime"):
            leader_election_record.renew_time = lock_record["renewTime"]

        return leader_election_record

    def get_lock_dict(
        self, leader_election_record: LeaderElectionRecord
    ) -> dict[str, Any]:
        self.lock_record["holderIdentity"] = leader_election_record.holder_identity
        self.lock_record["leaseDurationSeconds"] = leader_election_record.lease_duration
        self.lock_record["acquireTime"] = leader_election_record.acquire_time
        self.lock_record["renewTime"] = leader_election_record.renew_time

        return self.lock_record