#!/usr/bin/env impala-python
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF 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.
#
# This script waits for the Hive HiveServer2 service to become available by attempting
# to create a new session until the session creation succeeds, or a timeout is reached.
# TODO: Consider combining this with wait-for-metastore.py. A TCLIService client
# can perhaps also talk to the metastore.

import os
import time
import getpass
from optparse import OptionParser
from tests.util.thrift_util import create_transport

# Imports required for HiveServer2 Client
from TCLIService import TCLIService
from thrift.transport import TTransport, TSocket
from thrift.protocol import TBinaryProtocol

# Disable buffering to get "print" output on the console immediately.
os.environ["PYTHONUNBUFFERED"] = "1"

parser = OptionParser()
parser.add_option("--hs2_hostport", dest="hs2_hostport",
                  default="localhost:11050", help="HiveServer2 hostport to wait for.")
parser.add_option("--transport", dest="transport", default="buffered",
                  help="Transport to use for connecting to HiveServer2. Valid values: "
                  "'buffered', 'kerberos', 'plain_sasl'.")
options, args = parser.parse_args()

hs2_host, hs2_port = options.hs2_hostport.split(':')

if options.transport == "plain_sasl":
  # Here we supply a bogus username of "foo" and a bogus password of "bar".
  # We just have to supply *something*, else HS2 will block waiting for user
  # input.  Any bogus username and password are accepted.
  hs2_transport = create_transport(hs2_host, hs2_port, "hive", options.transport,
                                   "foo", "bar")
else:
  hs2_transport = create_transport(hs2_host, hs2_port, "hive", options.transport)

protocol = TBinaryProtocol.TBinaryProtocol(hs2_transport)
hs2_client = TCLIService.Client(protocol)

# Try to connect to the HiveServer2 service and create a session
now = time.time()
TIMEOUT_SECONDS = 300.0
while time.time() - now < TIMEOUT_SECONDS:
  try:
    hs2_transport.open()
    open_session_req = TCLIService.TOpenSessionReq()
    open_session_req.username = getpass.getuser()
    resp = hs2_client.OpenSession(open_session_req)
    if resp.status.statusCode == TCLIService.TStatusCode.SUCCESS_STATUS:
      close_session_req = TCLIService.TCloseSessionReq()
      close_session_req.sessionHandle = resp.sessionHandle
      hs2_client.CloseSession(close_session_req)
      print "HiveServer2 service is up at %s." % options.hs2_hostport
      exit(0)
  except Exception as e:
    if "SASL" in e.message:  # Bail out on SASL failures
      print "SASL failure when attempting connection:"
      raise
    if "GSS" in e.message:   # Other GSSAPI failures
      print "GSS failure when attempting connection:"
      raise
    print "Waiting for HiveServer2 at %s..." % options.hs2_hostport
    print e
  finally:
    hs2_transport.close()
    time.sleep(0.5)

print "HiveServer2 service failed to start within %s seconds." % TIMEOUT_SECONDS
exit(1)