#!/usr/local/sbin/charm-env python3
# 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 typing import List
from charms.reactive import (
    Endpoint,
    toggle_flag,
)

from charmhelpers.core.hookenv import log

try:
    from .models import Taint, Label
except ImportError:
    # when this code is under test...it's not installed in a package
    # so catching this exception is simply for the test framework
    from models import Taint, Label


class KubeControlRequirer(Endpoint):
    """
    Implements the kubernetes-worker side of the kube-control interface.
    """

    def manage_flags(self):
        """
        Set states corresponding to the data we have.
        """
        toggle_flag(self.expand_name("{endpoint_name}.connected"), self.is_joined)
        toggle_flag(
            self.expand_name("{endpoint_name}.dns.available"),
            self.is_joined and self.dns_ready(),
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.auth.available"),
            self.is_joined and self._has_auth_credentials(),
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.cluster_tag.available"),
            self.is_joined and self.get_cluster_tag(),
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.registry_location.available"),
            self.is_joined and self.get_registry_location(),
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.controller_taints.available"),
            self.is_joined and self.get_controller_taints(),
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.controller_labels.available"),
            self.is_joined and self.get_controller_labels(),
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.cohort_keys.available"),
            self.is_joined and self.cohort_keys,
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.default_cni.available"),
            self.is_joined and self.get_default_cni() is not None,
        )
        toggle_flag(
            self.expand_name("{endpoint_name}.api_endpoints.available"),
            self.is_joined and self.get_api_endpoints(),
        )

    def get_auth_credentials(self, user):
        """
        Return the authentication credentials.
        """
        rx = {}
        for unit in self.all_joined_units:
            rx.update(unit.received.get("creds", {}))
        if not rx:
            return None

        if user in rx:
            return {
                "user": user,
                "kubelet_token": rx[user]["kubelet_token"],
                "proxy_token": rx[user]["proxy_token"],
                "client_token": rx[user]["client_token"],
            }
        else:
            return None

    def get_dns(self):
        """
        Return DNS info provided by the control-plane.
        """
        rx = self.all_joined_units.received_raw

        return {
            "port": rx.get("port"),
            "domain": rx.get("domain"),
            "sdn-ip": rx.get("sdn-ip"),
            "enable-kube-dns": rx.get("enable-kube-dns"),
        }

    def dns_ready(self):
        """
        Return True if we have all DNS info from the control-plane.
        """
        keys = ["port", "domain", "sdn-ip", "enable-kube-dns"]
        dns_info = self.get_dns()
        return (
            set(dns_info.keys()) == set(keys)
            and dns_info["enable-kube-dns"] is not None
        )

    def set_auth_request(self, kubelet, group="system:nodes"):
        """
        Tell the control-plane that we are requesting auth, and to use this
        hostname for the kubelet system account.

        Param groups - Determines the level of eleveted privleges of the
        requested user. Can be overridden to request sudo level access on the
        cluster via changing to system:masters.
        """
        for relation in self.relations:
            relation.to_publish_raw.update(
                {"kubelet_user": kubelet, "auth_group": group}
            )

    def set_gpu(self, enabled=True):
        """
        Tell the control-plane that we're gpu-enabled (or not).
        """
        log("Setting gpu={} on kube-control relation".format(enabled))
        for relation in self.relations:
            relation.to_publish_raw.update({"gpu": enabled})

    def _has_auth_credentials(self):
        """
        Predicate method to signal we have authentication credentials.
        """
        if self.all_joined_units.received_raw.get("creds"):
            return True

    def get_cluster_tag(self):
        """
        Tag for identifying resources that are part of the cluster.
        """
        return self.all_joined_units.received_raw.get("cluster-tag")

    def get_registry_location(self):
        """
        URL for container image registry.
        """
        return self.all_joined_units.received_raw.get("registry-location")

    @property
    def cohort_keys(self):
        """
        The cohort snapshot keys sent by the control-planes.
        """
        return self.all_joined_units.received["cohort-keys"]

    def get_default_cni(self):
        """
        Default CNI network to use.
        """
        return self.all_joined_units.received["default-cni"]

    def get_api_endpoints(self):
        """
        Returns a list of API endpoint URLs.
        """
        endpoints = set()
        for unit in self.all_joined_units:
            endpoints.update(unit.received["api-endpoints"] or [])
        return sorted(endpoints)

    @property
    def has_xcp(self):
        """
        The flag indicating whether an external cloud provider is in use.
        """
        return self.all_joined_units.received.get("has-xcp", False)

    def get_controller_taints(self) -> List[Taint]:
        """Returns a list of taints configured on the control-plane nodes."""
        taints = self.all_joined_units.received.get("taints", [])
        return [Taint.decode(_) for _ in taints]

    def get_controller_labels(self) -> List[Label]:
        """Returns a list of lables configured on the control-plane nodes."""
        labels = self.all_joined_units.received.get("labels", [])
        return [Label.decode(_) for _ in labels]