#!/usr/bin/env python

'''Connect to a WirelessHART Manager and print data notifications

The connection parameters are taken from the environment variables SMSDK_HOST and SMSDK_PORT.
'''

import os
import sys
sys.path += [
    os.path.join('.'), # path to directory containing SmartMeshSDK
]

import datetime
import threading
import pprint

import SmartMeshSDK.ApiException
from SmartMeshSDK.ApiDefinition import HartMgrDefinition
from SmartMeshSDK.HartMgrConnector import HartMgrConnector

# Configuration parameters

DEFAULT_HOST = '192.168.99.100'
DEFAULT_PORT = 4445

pp = pprint.PrettyPrinter()


class NotifHandler(threading.Thread):
    '''Get notifications from the WirelessHART Manager

    This class is based on Thread, so it can be run asynchronously
    '''

    def __init__(self, mgr):
        threading.Thread.__init__(self)
        self.mgr = mgr

    def run(self):
        while True:
            notif = self.mgr.getNotification(1)
            if not notif:
                continue

            # TODO: detect exit conditions

            # Raw notifications
            #pp.pprint(notif)

            # Structured data
            # notif[0] is the type, notif[1] is the notification
            # the notification time is a timestamp milliseconds
            notif_time = datetime.datetime.fromtimestamp(notif[1].time/1000)
            payload_data = ["{0:02X}".format(b) for b in notif[1].payload]
            fmt = "DATA: mac:{0} time:{1} payload:[{2}]\n  {3}"
            print fmt.format(notif[1].macAddr,
                             notif_time.isoformat(),
                             len(notif[1].payload),
                             " ".join(payload_data))

def main(host, port):
    # Initialize the WirelessHART Manager Connector
    mgr = HartMgrConnector.HartMgrConnector()

    # Connect to the Manager over the XML API
    mgr.connect({'host': host, 'port': int(port), 'use_ssl': False})

    # Subscribe to data notifications
    mgr.dn_subscribe('data')

    # Create an object to receive notifications
    notifier = NotifHandler(mgr)
    notifier.run()  # use notifier.start() to run in a separate thread

    # Disconnect from the Manager
    mgr.disconnect()


if __name__ == '__main__':
    try:
        host = os.environ['SMSDK_HOST']
    except KeyError:
        host = DEFAULT_HOST
    try:
        port = os.environ['SMSDK_PORT']
    except KeyError:
        port = DEFAULT_PORT

    main(host, port)