#!/usr/bin/env python
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# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  Cloudera, Inc. licenses this file
# to you 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 builtins import map
import json
import logging

from django.http import Http404
from django.urls import reverse
from django.utils.translation import ugettext as _

from desktop.lib.django_util import JsonResponse, render
from desktop.lib.exceptions_renderable import PopupException

from zookeeper import settings
from zookeeper import stats
from zookeeper.conf import CLUSTERS
from zookeeper.forms import CreateZNodeForm, EditZNodeForm
from zookeeper.rest import ZooKeeper
from zookeeper.utils import get_cluster_or_404

from desktop.auth.backend import is_admin


def _get_global_overview():
  clusters = CLUSTERS.get()
  return dict([(c, _get_overview(clusters[c].HOST_PORTS.get())) for c in clusters])


def _get_overview(host_ports):
  zstats = {}

  for host_port in host_ports.split(','):
    host, port = list(map(str.strip, host_port.split(':')))

    zks = stats.ZooKeeperStats(host, port)
    zstats[host_port] = zks.get_stats() or {}

  return zstats


def _group_stats_by_role(stats):
  leader, followers = None, []
  for host, stats in list(stats.items()):
    stats['host'] = host

    if stats.get('zk_server_state') == 'leader' or stats.get('zk_server_state') == 'standalone':
      leader = stats

    elif stats.get('zk_server_state') == 'follower':
      followers.append(stats)

  return leader, followers


def index(request):
  try:
    overview = _get_global_overview()
  except Exception as e:
    raise PopupException(_('Could not correctly connect to Zookeeper.'), detail=e)

  return render('index.mako', request, {
      'clusters': CLUSTERS.get(),
      'overview': overview
  })


def view(request, id):
  cluster = get_cluster_or_404(id)

  stats = _get_overview(cluster['host_ports'])
  leader, followers = _group_stats_by_role(stats)

  return render('view.mako', request, {
      'cluster': cluster, 'all_stats': stats, 'leader': leader, 'followers': followers,
      'clusters': CLUSTERS.get(),
  })


def clients(request, id, host):
  cluster = get_cluster_or_404(id)

  parts = host.split(':')
  if len(parts) != 2:
    raise Http404

  host, port = parts
  zks = stats.ZooKeeperStats(host, port)
  clients = zks.get_clients()

  return render('clients.mako', request, {
    'clusters': CLUSTERS.get(),
    'cluster': cluster,
    'host': host,
    'port': port,
    'clients': clients
  })


def tree(request, id, path):
  cluster = get_cluster_or_404(id)
  zk = ZooKeeper(cluster['rest_url'])

  znode = zk.get(path)
  children = sorted(zk.get_children_paths(path))

  return render('tree.mako', request, {'cluster': cluster, 'path': path, 'znode': znode, 'children': children, 'clusters': CLUSTERS.get(),})


def delete(request, id, path):
  if not is_admin(request.user):
    raise PopupException(_('You are not a superuser'))
  cluster = get_cluster_or_404(id)

  redir = {}
  if request.method == 'POST':
    zk = ZooKeeper(cluster['rest_url'])
    try:
      zk.recursive_delete(path)
    except ZooKeeper.NotFound:
      pass
    redir = {
      'redirect': reverse('zookeeper:tree', kwargs={'id':id, 'path': path[:path.rindex('/')] or '/'})
    }

  return JsonResponse(redir)


def create(request, id, path):
  if not is_admin(request.user):
    raise PopupException(_('You are not a superuser'))
  cluster = get_cluster_or_404(id)

  if request.method == 'POST':
    form = CreateZNodeForm(request.POST)
    if form.is_valid():
      zk = ZooKeeper(cluster['rest_url'])

      full_path = ("%s/%s" % (path, form.cleaned_data['name'])).replace('//', '/')

      zk.create(full_path, form.cleaned_data['data'], sequence = form.cleaned_data['sequence'])
      return tree(request, id, path)
  else:
    form = CreateZNodeForm()

  return render('create.mako', request, {'cluster': cluster, 'path': path, 'form': form, 'clusters': CLUSTERS.get(),})


def edit_as_base64(request, id, path):
  cluster = get_cluster_or_404(id)
  zk = ZooKeeper(cluster['rest_url'])
  node = zk.get(path)

  if request.method == 'POST':
    if not is_admin(request.user):
      raise PopupException(_('You are not a superuser'))
    form = EditZNodeForm(request.POST)
    if form.is_valid():
      # TODO is valid base64 string?
      data = form.cleaned_data['data'].decode('base64')
      zk.set(path, data, form.cleaned_data['version'])

    return tree(request, id, path)
  else:
    form = EditZNodeForm(dict(\
      data=node.get('data64', ''),
      version=node.get('version', '-1')))

  return render('edit.mako', request, {'cluster': cluster, 'path': path, 'form': form, 'clusters': CLUSTERS.get(),})


def edit_as_text(request, id, path):
  cluster = get_cluster_or_404(id)
  zk = ZooKeeper(cluster['rest_url'])
  node = zk.get(path)

  if request.method == 'POST':
    if not is_admin(request.user):
      raise PopupException(_('You are not a superuser'))
    form = EditZNodeForm(request.POST)
    if form.is_valid():
      zk.set(path, form.cleaned_data['data'])

    return tree(request, id, path)
  else:
    form = EditZNodeForm(dict(data=node.get('data64', '').decode('base64').strip(), version=node.get('version', '-1')))

  return render('edit.mako', request, {'cluster': cluster, 'path': path, 'form': form, 'clusters': CLUSTERS.get(),})
