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# Copyright (c) Microsoft Corporation
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import argparse
import sys
import os
from subprocess import Popen, PIPE
import time
import logging
import shlex
import re
import sys
import select
from pyhdfs import HdfsClient

from .constants import HOME_DIR, LOG_DIR, NNI_PLATFORM, STDOUT_FULL_PATH, STDERR_FULL_PATH
from .hdfsClientUtility import copyDirectoryToHdfs, copyHdfsDirectoryToLocal
from .log_utils import LogType, nni_log, RemoteLogger, PipeLogReader, StdOutputType

logger = logging.getLogger('trial_keeper')

def main_loop(args):
    '''main loop logic for trial keeper'''
    
    if not os.path.exists(LOG_DIR):
        os.makedirs(LOG_DIR)
    
    stdout_file = open(STDOUT_FULL_PATH, 'a+')
    stderr_file = open(STDERR_FULL_PATH, 'a+')
    
    trial_keeper_syslogger = RemoteLogger(args.nnimanager_ip, args.nnimanager_port, 'trial_keeper', StdOutputType.Stdout)
    # redirect trial keeper's stdout and stderr to syslog
    trial_syslogger_stdout = RemoteLogger(args.nnimanager_ip, args.nnimanager_port, 'trial', StdOutputType.Stdout)
    sys.stdout = sys.stderr = trial_keeper_syslogger

    if args.pai_hdfs_host is not None and args.nni_hdfs_exp_dir is not None:
        try:
            hdfs_client = HdfsClient(hosts='{0}:{1}'.format(args.pai_hdfs_host, '50070'), user_name=args.pai_user_name, timeout=5)
        except Exception as e:
            nni_log(LogType.Error, 'Create HDFS client error: ' + str(e))
            raise e
        copyHdfsDirectoryToLocal(args.nni_hdfs_exp_dir, os.getcwd(), hdfs_client)

    # Notice: We don't appoint env, which means subprocess wil inherit current environment and that is expected behavior
    log_pipe_stdout = trial_syslogger_stdout.get_pipelog_reader()
    process = Popen(args.trial_command, shell = True, stdout = log_pipe_stdout, stderr = log_pipe_stdout)
    nni_log(LogType.Info, 'Trial keeper spawns a subprocess (pid {0}) to run command: {1}'.format(process.pid, shlex.split(args.trial_command)))

    while True:
        retCode = process.poll()
        # child worker process exits and all stdout data is read
        if retCode is not None and log_pipe_stdout.is_read_completed == True:
            nni_log(LogType.Info, 'subprocess terminated. Exit code is {}. Quit'.format(retCode))
            if args.pai_hdfs_output_dir is not None:
                # Copy local directory to hdfs for OpenPAI
                nni_local_output_dir = os.environ['NNI_OUTPUT_DIR']
                try:
                    if copyDirectoryToHdfs(nni_local_output_dir, args.pai_hdfs_output_dir, hdfs_client):
                        nni_log(LogType.Info, 'copy directory from {0} to {1} success!'.format(nni_local_output_dir, args.pai_hdfs_output_dir))
                    else:
                        nni_log(LogType.Info, 'copy directory from {0} to {1} failed!'.format(nni_local_output_dir, args.pai_hdfs_output_dir))
                except Exception as e:
                    nni_log(LogType.Error, 'HDFS copy directory got exception: ' + str(e))
                    raise e

            ## Exit as the retCode of subprocess(trial)
            exit(retCode)
            break

        time.sleep(2)

def trial_keeper_help_info(*args):
    print('please run --help to see guidance')

if __name__ == '__main__':
    '''NNI Trial Keeper main function'''
    PARSER = argparse.ArgumentParser()
    PARSER.set_defaults(func=trial_keeper_help_info)
    PARSER.add_argument('--trial_command', type=str, help='Command to launch trial process')
    PARSER.add_argument('--nnimanager_ip', type=str, default='localhost', help='NNI manager rest server IP')
    PARSER.add_argument('--nnimanager_port', type=str, default='8081', help='NNI manager rest server port')
    PARSER.add_argument('--pai_hdfs_output_dir', type=str, help='the output dir of hdfs')
    PARSER.add_argument('--pai_hdfs_host', type=str, help='the host of hdfs')
    PARSER.add_argument('--pai_user_name', type=str, help='the username of hdfs')
    PARSER.add_argument('--nni_hdfs_exp_dir', type=str, help='nni experiment directory in hdfs')
    args, unknown = PARSER.parse_known_args()
    if args.trial_command is None:
        exit(1)

    try:
        main_loop(args)
    except SystemExit as se:
        nni_log(LogType.Info, 'NNI trial keeper exit with code {}'.format(se.code))
        os._exit(se.code)
    except Exception as e:
        nni_log(LogType.Error, 'Exit trial keeper with code 1 because Exception: {} is catched'.format(str(e)))
        os._exit(1)

