timer.py

from datetime import datetime
import time
from task import Task
from task_queue import TaskQueue
from dispatcher import Dispatcher

# note: we do not really need a Timer instance when queue is empty


class Timer:
    def __init__(self, task_queue):
        self.dispatcher = Dispatcher()
        self.task_q = task_queue

    def get_curr_datetime():
        return {  # convert str to int and then again to str
            'time': ':'.join(list(map(
                lambda x: str(x),
                list(map(
                    lambda x: int(x),
                    str(datetime.now().time()).split(':')[:2]
                ))
            ))),
            'date': '-'.join(list(map(
                lambda x: str(x),
                list(map(
                    lambda x: int(x),
                    str(datetime.now().date()).split('-')
                ))
            )))
        }
        # note:
        # the final int to str conversion might not be needed
        # if the Task objects remind_time dictionary has int values

    def start(self):
        print("Timer started.")

        while True:
            # the timer stops as soon as the above while loop is exited
            # and can be restarted again using start()
            # if self.task_q.isEmpty():
            #     break

            if not self.task_q.isEmpty():
                # get a dictionary containing current datetime
                curr = Timer.get_curr_datetime()

                remind_time = self.task_q.peek().remind_time

                if (curr['date'] == remind_time['date'] and
                        curr['time'] == remind_time['time']):
                    self.dispatcher.dispatch_reminder(self.task_q.dequeue())

            # the number of seconds to sleep (could be user specifiable)
            time.sleep(10)

        print("Timer stopped.")


if __name__ == "__main__":
    timer = Timer()
    q = TaskQueue()

    q.insert(Task("20:28", "T 1"))
    # q.insert(Task("16:43", "T 2"))
    # q.insert(Task("16:50", "T 3"))
    # q.insert(Task("16:40", "T 4"))

    timer.start(q)