# Copyright 2015 gRPC authors.
#
# 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 __future__ import print_function

from . import jobset

import six.moves.urllib.request as request
import logging
import os
import socket
import subprocess
import sys
import tempfile
import time

# must be synchronized with test/core/utils/port_server_client.h
_PORT_SERVER_PORT = 32766


def start_port_server():
    # check if a compatible port server is running
    # if incompatible (version mismatch) ==> start a new one
    # if not running ==> start a new one
    # otherwise, leave it up
    try:
        version = int(
            request.urlopen('http://localhost:%d/version_number' %
                            _PORT_SERVER_PORT).read())
        logging.info('detected port server running version %d', version)
        running = True
    except Exception as e:
        logging.exception('failed to detect port server')
        running = False
    if running:
        current_version = int(
            subprocess.check_output([
                sys.executable,  # use the same python binary as this process
                os.path.abspath('tools/run_tests/python_utils/port_server.py'),
                'dump_version'
            ]))
        logging.info('my port server is version %d', current_version)
        running = (version >= current_version)
        if not running:
            logging.info('port_server version mismatch: killing the old one')
            request.urlopen('http://localhost:%d/quitquitquit' %
                            _PORT_SERVER_PORT).read()
            time.sleep(1)
    if not running:
        fd, logfile = tempfile.mkstemp()
        os.close(fd)
        logging.info('starting port_server, with log file %s', logfile)
        args = [
            sys.executable,
            os.path.abspath('tools/run_tests/python_utils/port_server.py'),
            '-p',
            '%d' % _PORT_SERVER_PORT, '-l', logfile
        ]
        env = dict(os.environ)
        env['BUILD_ID'] = 'pleaseDontKillMeJenkins'
        if jobset.platform_string() == 'windows':
            # Working directory of port server needs to be outside of Jenkins
            # workspace to prevent file lock issues.
            tempdir = tempfile.mkdtemp()
            if sys.version_info.major == 2:
                creationflags = 0x00000008  # detached process
            else:
                creationflags = 0  # DETACHED_PROCESS doesn't seem to work with python3
            port_server = subprocess.Popen(args,
                                           env=env,
                                           cwd=tempdir,
                                           creationflags=creationflags,
                                           close_fds=True)
        else:
            port_server = subprocess.Popen(args,
                                           env=env,
                                           preexec_fn=os.setsid,
                                           close_fds=True)
        time.sleep(1)
        # ensure port server is up
        waits = 0
        while True:
            if waits > 10:
                logging.warning(
                    'killing port server due to excessive start up waits')
                port_server.kill()
            if port_server.poll() is not None:
                logging.error('port_server failed to start')
                # try one final time: maybe another build managed to start one
                time.sleep(1)
                try:
                    request.urlopen('http://localhost:%d/get' %
                                    _PORT_SERVER_PORT).read()
                    logging.info(
                        'last ditch attempt to contact port server succeeded')
                    break
                except:
                    logging.exception(
                        'final attempt to contact port server failed')
                    port_log = open(logfile, 'r').read()
                    print(port_log)
                    sys.exit(1)
            try:
                port_server_url = 'http://localhost:%d/get' % _PORT_SERVER_PORT
                request.urlopen(port_server_url).read()
                logging.info('port server is up and ready')
                break
            except socket.timeout:
                logging.exception('while waiting for port_server')
                time.sleep(1)
                waits += 1
            except IOError:
                logging.exception('while waiting for port_server')
                time.sleep(1)
                waits += 1
            except:
                logging.exception(
                    'error while contacting port server at "%s".'
                    'Will try killing it.', port_server_url)
                port_server.kill()
                raise
