#!/usr/bin/env python2

from subprocess import call, Popen, PIPE, STDOUT, check_output
import paho.mqtt.client as mqtt
import argparse
import sys
from uuid import getnode as get_mac
import ast
import threading
import shlex

MQTT_SERVER = 'mqtt.suanzi.ai'
MQTT_PORT = 1883
URI = 'debug@autossh.suanzi.ai'

def get_all_connected(host, port, user, password):
    command = 'sshpass -p' + password + ' ssh -q -o "StrictHostKeyChecking=no"  -o "UserKnownHostsFile /dev/null" ' + user + '@' + host + '  netstat -tn | grep ' + str(port) + ' | grep ESTABLISHED | wc -l'
    output = check_output(shlex.split(command), shell=False)
    return int(output)

def on_connect(client, userdata, flags, rc):
    client.subscribe(userdata['id'])
    print "Connected with result code " + str(rc) +'\n'
    if userdata['action'] == 'connect':
        payload = {'from':userdata['id'], 'type':'request', 'command':'ssh'}
        client.publish(userdata['to'], str(payload))
    elif userdata['action'] == 'list':
        payload = {'from':userdata['id'], 'type':'request', 'command':'list'}
        client.publish(userdata['to'], str(payload))
        print'{0}\t\t{1}'.format(' Device ID ', 'Data')
        print '-' * 30

def on_message(client, userdata, msg):
#    print('Receive topic:' + msg.topic + ' payload: ' +str(msg.payload))
    payload = ast.literal_eval(str(msg.payload))
    from_id = payload['from']
    if payload['type'] == 'response':
        if payload['command'] == 'ssh':
            port = payload['data']
            print 'run "ssh ' + URI + ' -p ' + str(port) + '" to connect to device (%s)' % from_id
            client.disconnect()
            sys.exit(0)
        elif payload['command'] == 'list':
            print '{0}\t\t{1}'.format(payload['from'], payload['data'])
            client.total = client.total - 1
            if client.total == 0:
                client.disconnect()
                sys.exit(0)

def get_mac_str():
    mac = hex(get_mac())
    return '{:0>12}'.format(mac[2:-1])

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Choose an avaiable port and run ssh.', add_help=False)
    parser.add_argument('--help', action='help')
    parser.add_argument('-h', '--host', help='the mqtt server', default=MQTT_SERVER)
    parser.add_argument('-p', '--port', type=int, help='the mqtt port', default=MQTT_PORT)
    subparsers = parser.add_subparsers(title='subcommands', dest='action', help='xxx')
    parser_conn = subparsers.add_parser('connect', help='Connect to the specific device')
    parser_conn.add_argument('device', help='the MAC address of remote device, in the form of 080027a6f8dc')
    parser_lsit = subparsers.add_parser('list', help='list all connected devices')
    args = parser.parse_args()
    id = get_mac_str()
    print 'Mac: ', id
    device = args.device if args.action == 'connect' else 'all'

    total = get_all_connected(MQTT_SERVER, MQTT_PORT, 'autossh', 'hard2guess')
    print '\nFound %s connected devices: ' % total

    client = mqtt.Client(userdata={'id':id, 'action':args.action, 'to': device})
    client.total = total
    client.on_connect = on_connect
    client.on_message = on_message
    client.connect(args.host, args.port, 60)
    client.loop_forever()