# -*- coding: utf-8 -*- #
# Copyright 2015 Google LLC. 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.
# 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.
"""Fetch cluster credentials."""

from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals

from googlecloudsdk.api_lib.container import util
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.container import flags
from googlecloudsdk.core import log


NOT_RUNNING_MSG = """\
cluster {0} is not RUNNING. The kubernetes API may or may not be available. \
Check the cluster status for more information."""


def _BaseRun(args, context):
  """Base operations for `get-credentials` run command."""
  util.CheckKubectlInstalled()
  adapter = context['api_adapter']
  location_get = context['location_get']
  location = location_get(args)
  cluster_ref = adapter.ParseCluster(args.name, location)
  log.status.Print('Fetching cluster endpoint and auth data.')
  # Call DescribeCluster to get auth info and cache for next time
  cluster = adapter.GetCluster(cluster_ref)
  auth = cluster.masterAuth
  # TODO(b/70856999) Make this consistent with the checks in
  # api_lib/container/kubeconfig.py.
  missing_creds = not (auth and auth.clientCertificate and auth.clientKey)
  if missing_creds and not util.ClusterConfig.UseGCPAuthProvider():
    raise util.Error(
        'get-credentials requires `container.clusters.getCredentials`'
        ' permission on {0}'.format(cluster_ref.projectId)
    )
  if not adapter.IsRunning(cluster):
    log.warning(NOT_RUNNING_MSG.format(cluster_ref.clusterId))

  return cluster, cluster_ref


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.GA)
class GetCredentials(base.Command):
  """Fetch credentials for a running cluster.

  {command} updates a `kubeconfig` file with appropriate credentials and
  endpoint information to point `kubectl` at a specific cluster in Google
  Kubernetes Engine.

  It takes a project and a zone as parameters, passed through by set
  defaults or flags. By default, credentials are written to `HOME/.kube/config`.
  You can provide an alternate path by setting the `KUBECONFIG` environment
  variable. If `KUBECONFIG` contains multiple paths, the first one is used.

  This command enables switching to a specific cluster, when working
  with multiple clusters. It can also be used to access a previously created
  cluster from a new workstation.

  By default, {command} will configure kubectl to automatically refresh its
  credentials using the same identity as gcloud. If you are running kubectl as
  part of an application, it is recommended to use [application default
  credentials](https://cloud.google.com/docs/authentication/production).
  To configure a `kubeconfig` file to use application default credentials, set
  the container/use_application_default_credentials
  [Cloud SDK property](https://cloud.google.com/sdk/docs/properties) to true
  before running {command}

  See
  [](https://cloud.google.com/kubernetes-engine/docs/how-to/cluster-access-for-kubectl)
  for kubectl usage with Google Kubernetes Engine and
  [](https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands)
  for available kubectl commands.
  """
  detailed_help = {
      'EXAMPLES': """\
          To switch to working on your cluster 'sample-cluster', run:

            $ {command} sample-cluster --location=us-central1-f
      """,
  }

  @staticmethod
  def Args(parser):
    """Register flags for this command.

    Args:
      parser: An argparse.ArgumentParser-like object. It is mocked out in order
        to capture some information, but behaves like an ArgumentParser.
    """
    flags.AddGetCredentialsArgs(parser)
    flags.AddDnsEndpointFlag(parser)
    flags.AddKubecontextOverrideFlag(parser)
    flags.AddUseIamTokenFlag(parser)

  def Run(self, args):
    """This is what gets called when the user runs this command.

    Args:
      args: an argparse namespace. All the arguments that were provided to this
        command invocation.

    Raises:
      util.Error: if the cluster is unreachable or not running.
    """
    cluster, cluster_ref = _BaseRun(args, self.context)
    util.ClusterConfig.Persist(
        cluster,
        cluster_ref.projectId,
        args.internal_ip,
        use_dns_endpoint=args.dns_endpoint,
        impersonate_service_account=args.impersonate_service_account,
        kubecontext_override=args.kubecontext_override,
        use_iam_token=args.use_iam_token,
    )


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.BETA)
class GetCredentialsBeta(base.Command):
  """Fetch credentials for a running cluster.

  {command} updates a `kubeconfig` file with appropriate credentials and
  endpoint information to point `kubectl` at a specific cluster in Google
  Kubernetes Engine.

  It takes a project and a zone as parameters, passed through by set
  defaults or flags. By default, credentials are written to `HOME/.kube/config`.
  You can provide an alternate path by setting the `KUBECONFIG` environment
  variable. If `KUBECONFIG` contains multiple paths, the first one is used.

  This command enables switching to a specific cluster, when working
  with multiple clusters. It can also be used to access a previously created
  cluster from a new workstation.

  By default, {command} will configure kubectl to automatically refresh its
  credentials using the same identity as gcloud. If you are running kubectl as
  part of an application, it is recommended to use [application default
  credentials](https://cloud.google.com/docs/authentication/production).
  To configure a `kubeconfig` file to use application default credentials, set
  the container/use_application_default_credentials
  [Cloud SDK property](https://cloud.google.com/sdk/docs/properties) to true
  before running {command}

  See [](https://cloud.google.com/kubernetes-engine/docs/kubectl) for
  kubectl documentation.
  """
  detailed_help = {
      'EXAMPLES': """\
          To switch to working on your cluster 'sample-cluster', run:

            $ {command} sample-cluster --location=us-central1-f
      """,
  }

  @staticmethod
  def Args(parser):
    """Register flags for this command."""
    flags.AddGetCredentialsArgs(parser)
    flags.AddCrossConnectSubnetworkFlag(parser)
    flags.AddPrivateEndpointFQDNFlag(parser)
    flags.AddDnsEndpointFlag(parser)
    flags.AddKubecontextOverrideFlag(parser)
    flags.AddUseIamTokenFlag(parser)

  def Run(self, args):
    """This is what gets called when the user runs this command.

    Args:
      args: an argparse namespace. All the arguments that were provided to this
        command invocation.

    Raises:
      util.Error: if the cluster is unreachable or not running.
    """
    flags.VerifyGetCredentialsFlags(args)
    cluster, cluster_ref = _BaseRun(args, self.context)
    util.ClusterConfig.Persist(
        cluster,
        cluster_ref.projectId,
        args.internal_ip,
        args.cross_connect_subnetwork,
        args.private_endpoint_fqdn,
        args.dns_endpoint,
        kubecontext_override=args.kubecontext_override,
        use_iam_token=args.use_iam_token,
    )


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.ALPHA)
class GetCredentialsAlpha(base.Command):
  """Fetch credentials for a running cluster.

  {command} updates a `kubeconfig` file with appropriate credentials and
  endpoint information to point `kubectl` at a specific cluster in Google
  Kubernetes Engine.

  It takes a project and a zone as parameters, passed through by set
  defaults or flags. By default, credentials are written to `HOME/.kube/config`.
  You can provide an alternate path by setting the `KUBECONFIG` environment
  variable. If `KUBECONFIG` contains multiple paths, the first one is used.

  This command enables switching to a specific cluster, when working
  with multiple clusters. It can also be used to access a previously created
  cluster from a new workstation.

  By default, {command} will configure kubectl to automatically refresh its
  credentials using the same identity as gcloud. If you are running kubectl as
  part of an application, it is recommended to use [application default
  credentials](https://cloud.google.com/docs/authentication/production).
  To configure a `kubeconfig` file to use application default credentials, set
  the container/use_application_default_credentials
  [Cloud SDK property](https://cloud.google.com/sdk/docs/properties) to true
  before running {command}

  See [](https://cloud.google.com/kubernetes-engine/docs/kubectl) for
  kubectl documentation.
  """
  detailed_help = {
      'EXAMPLES': """\
          To switch to working on your cluster 'sample-cluster', run:

            $ {command} sample-cluster --location=us-central1-f
      """,
  }

  @staticmethod
  def Args(parser):
    """Register flags for this command.

    Args:
      parser: An argparse.ArgumentParser-like object. It is mocked out in order
        to capture some information, but behaves like an ArgumentParser.
    """
    flags.AddGetCredentialsArgs(parser)
    flags.AddCrossConnectSubnetworkFlag(parser)
    flags.AddPrivateEndpointFQDNFlag(parser)
    flags.AddDnsEndpointFlag(parser)
    flags.AddKubecontextOverrideFlag(parser)
    flags.AddUseIamTokenFlag(parser)

  def Run(self, args):
    """This is what gets called when the user runs this command.

    Args:
      args: an argparse namespace. All the arguments that were provided to this
        command invocation.

    Raises:
      util.Error: if the cluster is unreachable or not running.
    """
    flags.VerifyGetCredentialsFlags(args)
    cluster, cluster_ref = _BaseRun(args, self.context)
    util.ClusterConfig.Persist(
        cluster,
        cluster_ref.projectId,
        args.internal_ip,
        args.cross_connect_subnetwork,
        args.private_endpoint_fqdn,
        args.dns_endpoint,
        kubecontext_override=args.kubecontext_override,
        use_iam_token=args.use_iam_token,
    )
