#!/usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2016-2017 Lenovo
#
# 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 collections import deque
import optparse
import os
import select
import shlex
import signal
import subprocess
import sys

try:
    signal.signal(signal.SIGPIPE, signal.SIG_DFL)
except AttributeError:
    pass
path = os.path.dirname(os.path.realpath(__file__))
path = os.path.realpath(os.path.join(path, '..', 'lib', 'python'))
if path.startswith('/opt'):
    sys.path.append(path)

import confluent.client as client


def run():
    concurrentprocs = 168
    # among other things, FD_SETSIZE limits.  Besides, spawning too many
    # processes can be unkind for the unaware on memory pressure and such...
    argparser = optparse.OptionParser(
        usage="Usage: %prog node commandexpression",
        epilog="Expressions are the same as in attributes, e.g. "
               "'ipmitool -H {hardwaremanagement.manager}' will be expanded.")
    argparser.disable_interspersed_args()
    (options, args) = argparser.parse_args()
    if len(args) < 2:
        argparser.print_help()
        sys.exit(1)
    c = client.Command()
    cmdstr = " ".join(args[1:])

    currprocs = 0
    all = set([])
    pipedesc = {}
    pendingexecs = deque()

    for exp in c.create('/noderange/{0}/attributes/expression'.format(args[0]),
                        {'expression': cmdstr}):
        ex = exp['databynode']
        for node in ex:
            cmd = ex[node]['value'].encode('utf-8')
            cmdv = ['ssh', node] + shlex.split(cmd)
            if currprocs < concurrentprocs:
                currprocs += 1
                run_cmdv(node, cmdv, all, pipedesc)
            else:
                pendingexecs.append((node, cmdv))

    exitcode = 0
    rdy, _, _ = select.select(all, [], [], 10)
    while all:
        for r in rdy:
            data = r.readline()
            desc = pipedesc[r]
            if data:
                node = desc['node']
                if desc['type'] == 'stdout':
                    sys.stdout.write('{0}: {1}'.format(node,data))
                else:
                    sys.stderr.write('{0}: {1}'.format(node, data))
            else:
                pop = desc['popen']
                ret = pop.poll()
                if ret is not None:
                    exitcode = exitcode | ret
                    all.discard(r)
                    if desc['type'] == 'stdout' and pendingexecs:
                        node, cmdv = pendingexecs.popleft()
                        run_cmdv(node, cmdv, all, pipedesc)
        if all:
            rdy, _, _ = select.select(all, [], [], 10)
    sys.exit(exitcode)


def run_cmdv(node, cmdv, all, pipedesc):
    nopen = subprocess.Popen(
        cmdv, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    pipedesc[nopen.stdout] = {'node': node, 'popen': nopen,
                              'type': 'stdout'}
    pipedesc[nopen.stderr] = {'node': node, 'popen': nopen,
                              'type': 'stderr'}
    all.add(nopen.stdout)
    all.add(nopen.stderr)


if __name__ == '__main__':
    run()