shutdown

#!/usr/bin/env python
import time
import os
import sys
import platform
from datetime import datetime as dt
from datetime import timedelta
from dateutil.relativedelta import relativedelta


#a dictionary is far neater and more verbose than using a long conditional block
shutdown_cmds = {"Windows" : "shutdown -s -f -t 0", "Linux" : "systemctl poweroff",
                 "Darwin" : "osascript -e 'tell app \"System Events\" to shut down'",
                 "Windows reboot" : "shutdown -r -f -t 0", "Linux reboot" : "systemctl reboot",
                 "Darwin reboot" : "osascript -e 'tell app \"System Events\" to restart'"}


#now let's write a function that return the exact name of the os (portability)
def getOS():
    os_list = ["Windows", "Linux", "Darwin"]
    os_name = platform.system()
    for item in os_list:
        if item in os_name:
            return item


#display a pretty countdown
def count_down(future):
    #relative delta takes 2 datetime objects, beginning and end, and returns
    #the difference between them
    diff = relativedelta(dt.now(), future)
    hours = abs(diff.hours)
    mins = abs(diff.minutes)
    secs = abs(diff.seconds)
    return "\r%d hours, %d mins %d seconds left..." % (hours, mins, secs)


#next we need to add a given time string (hours or minutes or seconds or all)
#to datetime.now() to create the destination datetime object
def makeDest(time_str):
    #dictionaries are freaking awesome!
    time_dict = {"hours" : 0, "mins" : 0, "seconds" : 0}
    for unit in time_str.split(" "):
        unit = unit.lower()
        if "h" in unit:
            time_dict["hours"] = int(unit[:-1])
        elif "m" in unit:
            time_dict["mins"] = int(unit[:-1])
        else:
            if "s" in unit:
                unit = unit[:-1]
            time_dict["seconds"] = int(unit)
    return dt.now() + timedelta(hours=time_dict["hours"], minutes=time_dict["mins"],
                                seconds=time_dict["seconds"])


#almost finished! let's write the main function
def main(reboot=False):
    #prompt the user for a time string
    time_str = input("\nPlease enter the countdown duration in seconds, or enter it like this 1h 2m 3s (you don't have to enter more than one): ")
    target = makeDest(time_str)#destination time
    os_task = getOS()#get the name of the os we're running on
    if reboot:
        os_task += " reboot"

    print("Countdown initiated... Press ctrl + c any time to abort...")
    while True:#a while loop is needed to display the countdown to the user
        try:
            diff = target - dt.now()#it is possible to subtract datetime objects

            sys.stdout.write(count_down(target))
            time.sleep(1)
            sys.stdout.flush()

            if diff.total_seconds() <= 0:#break out of the loop when the destination is reached
                break

        except KeyboardInterrupt:
            sys.exit("\nCanceled by user ._.")#give the user the choice to abort
            break
    os.system(shutdown_cmds[os_task])#execute the os specific shutdown command.. did I mention that dicts are awesome?!

if __name__ == "__main__":
    print("\nBrought to you by Monro Coury...\n\n")
    if input("Would you like to (s)hutdown or (r)eboot? ").lower() in ("r", "reboot"):
        main(reboot=True)
    else:
        main()