# Licensed to Elasticsearch under one or more contributor
# license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright
# ownership. Elasticsearch 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.

import argparse
import base64
import glob
import logging
import os
import random
import shutil
import subprocess
import sys
import tempfile
import time

DEFAULT_TRANSPORT_TCP_PORT = 9300
DEFAULT_HTTP_TCP_PORT = 9200

if sys.version_info[0] < 3:
  print('%s must use python 3.x (for the ES python client)' % sys.argv[0])

from datetime import datetime
try:
  from elasticsearch import Elasticsearch
  from elasticsearch.exceptions import ConnectionError
  from elasticsearch.exceptions import TransportError
except ImportError as e:
  print('Can\'t import elasticsearch please install `sudo pip3 install elasticsearch`')
  sys.exit(1)

# sometimes returns True
def rarely():
  return random.randint(0, 10) == 0

# usually returns True
def frequently():
  return not rarely()

# asserts the correctness of the given hits given they are sorted asc
def assert_sort(hits):
  values = [hit['sort'] for hit in hits['hits']['hits']]
  assert len(values) > 0, 'expected non emtpy result'
  val = min(values)
  for x in values:
    assert x >= val, '%s >= %s' % (x, val)
    val = x

def random_binary_base64():
  return base64.b64encode(bytearray(random.getrandbits(8) for _ in range(16))).decode('ascii')

# Indexes the given number of document into the given index
# and randomly runs refresh, optimize and flush commands
def index_documents(es, index_name, type, num_docs, supports_compressed_binary_fields):
  logging.info('Indexing %s docs' % num_docs)
  for id in range(0, num_docs):
    body = {'string': str(random.randint(0, 100)),
            'long_sort': random.randint(0, 100),
            'double_sort' : float(random.randint(0, 100)),
            'bool' : random.choice([True, False])}

    body['binary'] = random_binary_base64()
    if supports_compressed_binary_fields:
      body['binary_compressed'] = random_binary_base64()
    es.index(index=index_name, doc_type=type, id=id, body=body)
    if rarely():
      es.indices.refresh(index=index_name)
    if rarely():
      es.indices.flush(index=index_name, force=frequently())
  logging.info('Flushing index')
  es.indices.flush(index=index_name)

def delete_by_query(es, version, index_name, doc_type):

  logging.info('Deleting long_sort:[10..20] docs')

  query = {'query':
           {'range':
            {'long_sort':
             {'gte': 10,
              'lte': 20}}}}

  if version.startswith('0.') or version in ('1.0.0.Beta1', '1.0.0.Beta2'):
    # TODO #10262: we can't write DBQ into the translog for these old versions until we fix this back-compat bug:

    # #4074: these versions don't expect to see the top-level 'query' to count/delete_by_query:
    query = query['query']
    return

  deleted_count = es.count(index=index_name, doc_type=doc_type, body=query)['count']
    
  result = es.delete_by_query(index=index_name,
                              doc_type=doc_type,
                              body=query)

  # make sure no shards failed:
  assert result['_indices'][index_name]['_shards']['failed'] == 0, 'delete by query failed: %s' % result

  logging.info('Deleted %d docs' % deleted_count)

def run_basic_asserts(es, index_name, type, num_docs):
  count = es.count(index=index_name)['count']
  assert count == num_docs, 'Expected %r but got %r documents' % (num_docs, count)
  for _ in range(0, num_docs):
    random_doc_id = random.randint(0, num_docs-1)
    doc = es.get(index=index_name, doc_type=type, id=random_doc_id)
    assert doc, 'Expected document for id %s but got %s' % (random_doc_id, doc)

  assert_sort(es.search(index=index_name,
                  body={
                    'sort': [
                      {'double_sort': {'order': 'asc'}}
                    ]
                  }))

  assert_sort(es.search(index=index_name,
                  body={
                    'sort': [
                      {'long_sort': {'order': 'asc'}}
                    ]
                  }))


def build_version(version_tuple):
  return '.'.join([str(x) for x in version_tuple])

def build_tuple(version_string):
  return [int(x) for x in version_string.split('.')]

def start_node(version, release_dir, data_dir, repo_dir, tcp_port=DEFAULT_TRANSPORT_TCP_PORT, http_port=DEFAULT_HTTP_TCP_PORT, cluster_name=None):
  logging.info('Starting node from %s on port %s/%s, data_dir %s' % (release_dir, tcp_port, http_port, data_dir))
  if cluster_name is None:
    cluster_name = 'bwc_index_' + version
    
  cmd = [
    os.path.join(release_dir, 'bin/elasticsearch'),
    '-Des.path.data=%s' % data_dir,
    '-Des.path.logs=logs',
    '-Des.cluster.name=%s' % cluster_name,
    '-Des.network.host=localhost',
    '-Des.transport.tcp.port=%s' % tcp_port,
    '-Des.http.port=%s' % http_port,
    '-Des.path.repo=%s' % repo_dir
  ]
  if version.startswith('0.') or version.startswith('1.0.0.Beta') :
    cmd.append('-f') # version before 1.0 start in background automatically
  return subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

def install_plugin(version, release_dir, plugin_name):
  run_plugin(version, release_dir, 'install', [plugin_name])

def remove_plugin(version, release_dir, plugin_name):
  run_plugin(version, release_dir, 'remove', [plugin_name])

def run_plugin(version, release_dir, plugin_cmd, args):
  cmd = [os.path.join(release_dir, 'bin/plugin'), plugin_cmd] + args
  subprocess.check_call(cmd)

def create_client(http_port=DEFAULT_HTTP_TCP_PORT, timeout=30):
  logging.info('Waiting for node to startup')
  for _ in range(0, timeout):
    # TODO: ask Honza if there is a better way to do this?
    try:
      client = Elasticsearch([{'host': 'localhost', 'port': http_port}])
      client.cluster.health(wait_for_nodes=1)
      client.count() # can we actually search or do we get a 503? -- anyway retry
      return client
    except (ConnectionError, TransportError):
      pass
    time.sleep(1)
  assert False, 'Timed out waiting for node for %s seconds' % timeout

def generate_index(client, version, index_name):
  client.indices.delete(index=index_name, ignore=404)
  logging.info('Create single shard test index')

  mappings = {}
  mappings['doc'] = {'properties' : {}}
  if not version.startswith('2.'):
    # TODO: we need better "before/onOr/after" logic in python

    # backcompat test for legacy type level analyzer settings, see #8874
    mappings['analyzer_type1'] = {
      'analyzer': 'standard',
      'properties': {
        'string_with_index_analyzer': {
          'type': 'string',
          'index_analyzer': 'standard'
        },
        'string_with_search_analyzer': {
          'type': 'string',
          'search_analyzer': 'keyword'
        }
      }
    }
    # completion type was added in 0.90.3
    if not version.startswith('0.20') and version not in ['0.90.0.Beta1', '0.90.0.RC1', '0.90.0.RC2', '0.90.0', '0.90.1', '0.90.2']:
      mappings['analyzer_type1']['properties']['completion_with_index_analyzer'] = {
        'type': 'completion',
        'index_analyzer': 'standard'
      }

    mappings['analyzer_type2'] = {
      'index_analyzer': 'standard',
      'search_analyzer': 'keyword',
      'search_quote_analyzer': 'english',
    }
    mappings['index_name_and_path'] = {
      'properties': {
        'parent_multi_field': {
          'type': 'string',
          'path': 'just_name',
          'fields': {
            'raw': {'type': 'string', 'index': 'not_analyzed', 'index_name': 'raw_multi_field'}
          }
        },
        'field_with_index_name': {
          'type': 'string',
          'index_name': 'custom_index_name_for_field'
        }
      }
    }
    mappings['meta_fields'] = {
      '_id': {
        'path': 'myid'
      },
      '_routing': {
        'path': 'myrouting'
      },
      '_boost': {
        'null_value': 2.0
      }     
    }
    mappings['custom_formats'] = {
      'properties': {
        'string_with_custom_postings': {
          'type': 'string',
          'postings_format': 'Lucene41'
        },
        'long_with_custom_doc_values': {
          'type': 'long',
          'doc_values_format': 'Lucene42'
        }
      }
    }
    mappings['auto_boost'] = {
      '_all': {
        'auto_boost': True
      }
    }

  # test back-compat of stored binary fields
  mappings['doc']['properties']['binary'] = {
    'type': 'binary',
    'store': True,
    }

  supports_compressed_binary_fields = version.startswith('0.') or version.startswith('1.')  

  if supports_compressed_binary_fields:
    mappings['doc']['properties']['binary_compressed'] = {
      'type': 'binary',
      'compress': True,
      'store': True,
      }
    
  settings = {
    'number_of_shards': 1,
    'number_of_replicas': 0,
  }
  if version.startswith('0.') or version.startswith('1.'):
    # Same as ES default (60 seconds), but missing the units to make sure they are inserted on upgrade:
    settings['gc_deletes'] = '60000',
    # Same as ES default (5 GB), but missing the units to make sure they are inserted on upgrade:
    settings['merge.policy.max_merged_segment'] = '5368709120'
    

  client.indices.create(index=index_name, body={
      'settings': settings,
      'mappings': mappings
  })
  health = client.cluster.health(wait_for_status='green')
  assert health['timed_out'] == False, 'cluster health timed out %s' % health

  num_docs = random.randint(2000, 3000)
  if version == "1.1.0":
    # 1.1.0 is buggy and creates lots and lots of segments, so we create a
    # lighter index for it to keep bw tests reasonable
    # see https://github.com/elastic/elasticsearch/issues/5817
    num_docs = int(num_docs / 10)
  index_documents(client, index_name, 'doc', num_docs, supports_compressed_binary_fields)
  logging.info('Running basic asserts on the data added')
  run_basic_asserts(client, index_name, 'doc', num_docs)

def snapshot_index(client, version, repo_dir):
  # Add bogus persistent settings to make sure they can be restored
  client.cluster.put_settings(body={
    'persistent': {
      'cluster.routing.allocation.exclude.version_attr': version,
      # Same as ES default (30 seconds), but missing the units to make sure they are inserted on upgrade:
      'discovery.zen.publish_timeout': '30000',
      # Same as ES default (512 KB), but missing the units to make sure they are inserted on upgrade:
      'indices.recovery.file_chunk_size': '524288',
    }
  })
  client.indices.put_template(name='template_' + version.lower(), order=0, body={
    "template": "te*",
    "settings": {
      "number_of_shards" : 1
    },
    "mappings": {
      "type1": {
        "_source": { "enabled" : False }
      }
    },
    "aliases": {
      "alias1": {},
      "alias2": {
        "filter": {
          "term": {"version" : version }
        },
        "routing": "kimchy"
      },
      "{index}-alias": {}
    }
  })
  client.snapshot.create_repository(repository='test_repo', body={
    'type': 'fs',
    'settings': {
      'location': repo_dir
    }
  })
  client.snapshot.create(repository='test_repo', snapshot='test_1', wait_for_completion=True)
  client.snapshot.delete_repository(repository='test_repo')

def compress_index(version, tmp_dir, output_dir):
  compress(tmp_dir, output_dir, 'index-%s.zip' % version, 'data')

def compress_repo(version, tmp_dir, output_dir):
  compress(tmp_dir, output_dir, 'repo-%s.zip' % version, 'repo')

def compress(tmp_dir, output_dir, zipfile, directory):
  abs_output_dir = os.path.abspath(output_dir)
  zipfile = os.path.join(abs_output_dir, zipfile)
  if os.path.exists(zipfile):
    os.remove(zipfile)
  logging.info('Compressing index into %s, tmpDir %s', zipfile, tmp_dir)
  olddir = os.getcwd()
  os.chdir(tmp_dir)
  subprocess.check_call('zip -r %s %s' % (zipfile, directory), shell=True)
  os.chdir(olddir)


def parse_config():
  parser = argparse.ArgumentParser(description='Builds an elasticsearch index for backwards compatibility tests')
  required = parser.add_mutually_exclusive_group(required=True)
  required.add_argument('versions', metavar='X.Y.Z', nargs='*', default=[],
                        help='The elasticsearch version to build an index for')
  required.add_argument('--all', action='store_true', default=False,
                        help='Recreate all existing backwards compatibility indexes')
  parser.add_argument('--releases-dir', '-d', default='backwards', metavar='DIR',
                      help='The directory containing elasticsearch releases')
  parser.add_argument('--output-dir', '-o', default='core/src/test/resources/indices/bwc',
                      help='The directory to write the zipped index into')
  parser.add_argument('--tcp-port', default=DEFAULT_TRANSPORT_TCP_PORT, type=int,
                      help='The port to use as the minimum port for TCP communication')
  parser.add_argument('--http-port', default=DEFAULT_HTTP_TCP_PORT, type=int,
                      help='The port to use as the minimum port for HTTP communication')
  cfg = parser.parse_args()

  if not os.path.exists(cfg.output_dir):
    parser.error('Output directory does not exist: %s' % cfg.output_dir)

  if not cfg.versions:
    # --all
    for bwc_index in glob.glob(os.path.join(cfg.output_dir, 'index-*.zip')):
      version = os.path.basename(bwc_index)[len('index-'):-len('.zip')]
      cfg.versions.append(version)

  return cfg

def create_bwc_index(cfg, version):
  logging.info('--> Creating bwc index for %s' % version)
  release_dir = os.path.join(cfg.releases_dir, 'elasticsearch-%s' % version)
  if not os.path.exists(release_dir):
    raise RuntimeError('ES version %s does not exist in %s' % (version, cfg.releases_dir))
  snapshot_supported = not (version.startswith('0.') or version == '1.0.0.Beta1')
  tmp_dir = tempfile.mkdtemp()

  data_dir = os.path.join(tmp_dir, 'data')
  repo_dir = os.path.join(tmp_dir, 'repo')
  logging.info('Temp data dir: %s' % data_dir)
  logging.info('Temp repo dir: %s' % repo_dir)

  node = None

  try:
    node = start_node(version, release_dir, data_dir, repo_dir, cfg.tcp_port, cfg.http_port)
    client = create_client(cfg.http_port)
    index_name = 'index-%s' % version.lower()
    generate_index(client, version, index_name)
    if snapshot_supported:
      snapshot_index(client, version, repo_dir)

    # 10067: get a delete-by-query into the translog on upgrade.  We must do
    # this after the snapshot, because it calls flush.  Otherwise the index
    # will already have the deletions applied on upgrade.
    if version.startswith('0.') or version.startswith('1.'):
      delete_by_query(client, version, index_name, 'doc')

    shutdown_node(node)
    node = None

    compress_index(version, tmp_dir, cfg.output_dir)
    if snapshot_supported:
      compress_repo(version, tmp_dir, cfg.output_dir)
  finally:

    if node is not None:
      # This only happens if we've hit an exception:
      shutdown_node(node)
      
    shutil.rmtree(tmp_dir)

def shutdown_node(node):
  logging.info('Shutting down node with pid %d', node.pid)
  node.terminate()
  node.wait()
    
def main():
  logging.basicConfig(format='[%(levelname)s] [%(asctime)s] %(message)s', level=logging.INFO,
                      datefmt='%Y-%m-%d %I:%M:%S %p')
  logging.getLogger('elasticsearch').setLevel(logging.ERROR)
  logging.getLogger('urllib3').setLevel(logging.WARN)
  cfg = parse_config()
  for version in cfg.versions:
    create_bwc_index(cfg, version)

if __name__ == '__main__':
  try:
    main()
  except KeyboardInterrupt:
    print('Caught keyboard interrupt, exiting...')