# Copyright 2016 by MPI-SWS and Data-Ken Research.
# Licensed under the Apache 2.0 License.
"""Cancel an active schedule. Since this is the last active schedule, it
should cleanly stop the scheduler.
"""
from thingflow.base import *
from utils import make_test_output_thing

import asyncio
import unittest

class CallAfter(InputThing):
    def __init__(self, num_events, fn):
        self.events_left = num_events
        self.fn = fn

    def on_next(self, x):
        self.events_left -= 1
        if self.events_left == 0:
            print("calling fn %s" % self.fn)
            self.fn()

class TestSchedulerCancel(unittest.TestCase):
    def test_case(self):
        sensor = make_test_output_thing(1)
        sensor.connect(print)
        s = Scheduler(asyncio.get_event_loop())
        cancel_schedule = s.schedule_periodic(sensor, 1)
        sensor.connect(CallAfter(4, cancel_schedule))
        sensor.print_downstream()
        s.run_forever()
        print("got to end")

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