#!/router/bin/python

import os
import outer_packages
import zmq
import threading
import logging
import CCustomLogger
import zipmsg
from json import JSONDecoder
from common.trex_status_e import TRexStatus

# setup the logger
CCustomLogger.setup_custom_logger('TRexServer')
logger = logging.getLogger('TRexServer')


class ZmqMonitorSession(threading.Thread):
    def __init__(self, trexObj , zmq_port):
        super(ZmqMonitorSession, self).__init__()
        self.stoprequest    = threading.Event()
        self.first_dump     = True
        self.zmq_port       = zmq_port
        self.zmq_publisher  = "tcp://localhost:{port}".format(port=self.zmq_port)
        self.trexObj        = trexObj
        self.expect_trex    = self.trexObj.expect_trex     # used to signal if TRex is expected to run and if data should be considered
        self.decoder        = JSONDecoder()
        self.zipped         = zipmsg.ZippedMsg()
        logger.info("ZMQ monitor initialization finished")

    def run(self):
        try:
            self.context    = zmq.Context()
            self.socket     = self.context.socket(zmq.SUB)
            logger.info("ZMQ monitor started listening @ {pub}".format(pub=self.zmq_publisher))
            self.socket.connect(self.zmq_publisher)
            self.socket.setsockopt(zmq.SUBSCRIBE, b'')

            while not self.stoprequest.is_set():
                try:
                    zmq_dump = self.socket.recv()   # This call is BLOCKING until data received!
                    if self.expect_trex.is_set():
                        self.parse_and_update_zmq_dump(zmq_dump)
                        logger.debug("ZMQ dump received on socket, and saved to trexObject.")
                except Exception as e:
                    if self.stoprequest.is_set():
                        # allow this exception since it comes from ZMQ monitor termination
                        pass
                    else:
                        logger.error("ZMQ monitor thrown an exception. Received exception: {ex}".format(ex=e))
                        self.trexObj.zmq_error = e
        except Exception as e:
            logger.error('ZMQ monitor error: %s' % e)
            self.trexObj.zmq_error = e

    def join(self, timeout=5):
        self.stoprequest.set()
        logger.debug("Handling termination of ZMQ monitor thread") 
        self.socket.close()
        self.context.term()
        logger.info("ZMQ monitor resources has been freed.")
        super(ZmqMonitorSession, self).join(timeout)

    def parse_and_update_zmq_dump(self, zmq_dump):
        unzipped = self.zipped.decompress(zmq_dump)
        if unzipped:
            zmq_dump = unzipped
        dict_obj = self.decoder.decode(zmq_dump.decode(errors = 'replace'))

        if type(dict_obj) is not dict:
            raise Exception('Expected ZMQ dump of type dict, got: %s' % type(dict_obj))

        # add to trex_obj zmq latest dump, based on its 'name' header
        if dict_obj != {}:
            self.trexObj.update_zmq_dump_key(dict_obj['name'], dict_obj)
            if self.first_dump:
                # change TRexStatus from starting to Running once the first ZMQ dump is obtained and parsed successfully
                self.first_dump = False
                self.trexObj.set_status(TRexStatus.Running)
                self.trexObj.set_verbose_status("TRex is Running")
                logger.info("First ZMQ dump received and successfully parsed. TRex running state changed to 'Running'.")


if __name__ == "__main__":
    pass