# Copyright 2017 by MPI-SWS and Data-Ken Research.
# Licensed under the Apache 2.0 License.
"""Test async version of mqtt libraries. Depends on hbmqtt
(https://github.com/beerfactory/hbmqtt)

"""

import unittest
import sys
import asyncio
import string
from random import choice, seed
from thingflow.base import Scheduler, SensorAsOutputThing, SensorEvent
import thingflow.filters.output
import thingflow.filters.combinators
import thingflow.filters.select
from thingflow.filters.transducer import PeriodicMedianTransducer
from utils import ValueListSensor, ValidateAndStopInputThing

seed()

try:
    import hbmqtt
    from thingflow.adapters.mqtt_async import QueueWriter, QueueReader
    HBMQTT_AVAILABLE = True
except ImportError:
    HBMQTT_AVAILABLE = False

URL = "mqtt://localhost:1883"
    

VALUES = [
    1.0,
    2.5,
    3.7,
    4.1,
    8.1,
    0.5,
    6.5,
    4.5,
    3.9,
    6.5
]

EXPECTED = [
    2.5,
    4.1,
    4.5,
    6.5
]

def msg_to_event(msg):
    return SensorEvent(sensor_id=msg[0], ts=msg[1], val=msg[2])

CHARS=string.ascii_letters+string.digits
def get_topic_name(test_class):
    return  test_class.__class__.__name__ + ''.join([ choice(CHARS) for i in range(5) ])
    
@unittest.skipUnless(HBMQTT_AVAILABLE,
                     "HBMQTT library not installed for python at %s" %
                     sys.executable)
class TestCase(unittest.TestCase):
    def setUp(self):
        # Creating a new event loop each test case does not seem to work.
        # I think it is due to hbmqtt not cleaning up some state in the asyncio
        # layer.
        #self.loop = asyncio.new_event_loop()
        self.loop = asyncio.get_event_loop()
        self.sched = Scheduler(self.loop)
    def tearDown(self):
        pass
        #self.loop.stop()
        #self.loop.close()
        
    def test_client_only(self):
        SENSOR_ID='sensor-1'
        TOPIC=get_topic_name(self)
        sensor = SensorAsOutputThing(ValueListSensor(SENSOR_ID, VALUES))
        td = sensor.transduce(PeriodicMedianTransducer(period=3))
        qw = QueueWriter(td, URL, TOPIC, self.sched)
        qw.output()
        self.sched.schedule_periodic(sensor, 0.5)
        self.sched.run_forever()
        self.assertFalse(qw.has_pending_requests(),
                         "QueueWriter has pending requests: %s" % qw.dump_state())
        print("test_client_only completed")

    def send_and_recv_body(self, sleep_timeout):
        SENSOR_ID='sensor-1'
        TOPIC=get_topic_name(self)
        sensor = SensorAsOutputThing(ValueListSensor(SENSOR_ID, VALUES))
        td = sensor.transduce(PeriodicMedianTransducer(period=3))
        qw = QueueWriter(td, URL, TOPIC, self.sched)
        qw.output()
        qr = QueueReader(URL, TOPIC, self.sched, timeout=sleep_timeout)
        self.sched.schedule_periodic(sensor, 0.5)
        stop_qr = self.sched.schedule_on_main_event_loop(qr)
        vs = ValidateAndStopInputThing(EXPECTED, self, stop_qr)
        qr.select(msg_to_event).connect(vs)
        self.sched.run_forever()
        self.assertFalse(qw.has_pending_requests(),
                         "QueueWriter has pending requests: %s" % qw.dump_state())
        self.assertEqual(qr.state, QueueReader.FINAL_STATE)
        self.assertEqual(vs.next_idx, len(EXPECTED))
        print("send_and_recv_bod(%s) completed" % sleep_timeout)

    def test_short_timeout(self):
        self.send_and_recv_body(0.1)

    def test_long_timeout(self):
        self.send_and_recv_body(3.0)
        

if __name__ == '__main__':
    unittest.main()