#!/usr/bin/env python

# Uses 'scp' to copy local files to all slaves reported by the master.

import json
import signal
import subprocess
import sys

from optparse import OptionParser

from mesos import http
from mesos.cli import *
from mesos.futures import *


if sys.version_info < (2,6,0):
    fatal('Expecting Python >= 2.6')


def scp(host, src, dst):
    cmd = 'scp -pr %s %s' % (src, host + ':' + dst)
    try:
        process = subprocess.Popen(
            cmd,
            stdin=None,
            stdout=None,
            stderr=None,
            shell=True)
        return process.wait() == 0
    except Exception as e:
        sys.stderr.write('Exception %s when doing %s\n' % (e, cmd))
        return False


def main():
    # Parse options for this script.
    parser = OptionParser()
    parser.add_option('--master')
    parser.usage = '%prog [options] local-file(s) remote-directory'
    parser.epilog = ('This command uploads the specifeid local file(s) '
                     'to a remote directory on all slaves known by the '
                     'master. The current implementation assumes '
                     'passwordless scp')
    (options, args) = parser.parse_args(sys.argv)

    if options.master is None:
        usage('Missing --master', parser)

    # Get master info.
    try:
      master = resolve(options.master)
    except Exception as e:
      fatal('Failed to get the master: %s' % str(e))

    # Get the master's state.
    try:
        state = json.loads(http.get(master, '/master/state'))
    except Exception as e:
        fatal('Failed to get the master state: %s' % str(e))

    # all slaves that the master is aware of
    slaves = set(slave['hostname'] for slave in state['slaves'])

    if len(args) < 3:
        usage('Missing arguments', parser)

    # All arguments after args[0] until the last argument are the
    # local files.
    src = " ".join(args[1:-1])

    # Remote directory is the very last argument.
    dst = args[-1]

    success = set()
    with ThreadingExecutor() as executor:
        futures = dict((executor.submit(scp, slave, src, dst), slave)
                       for slave in slaves)
        for future in as_completed(futures):
            slave = futures[future]
            try:
                status = future.result()
                if status:
                    success.add(slave)
            except Exception as e:
                sys.stderr.write('Failed to copy to %s: %s\n' % (slave, e))

    print

    for slave in success:
        print '%s\t%s' % (slave, 'uploaded')

    print

    failed = slaves - success
    for slave in failed:
        print '%s\t%s' % (slave, 'failed')

    print

    print ('----- %d uploaded, %d failed of total %d slaves'
           % (len(success), len(failed), len(slaves)))

    print


if __name__ == '__main__':
    def handler(signal, frame):
        sys.stdout.write('\n')
        sys.exit(130)

    signal.signal(signal.SIGINT, handler)

    main()