import datetime
import sys, termios, tty
import inputs

frequency = 120 # 120Hz refresh

def countdown(length):
    """countdown timer; length in seconds. returns start and time left (>0 if quit early)"""
    time_left = length
    start = datetime.datetime.now()
    end = start + datetime.timedelta(seconds=time_left) # change to mins in final
    accum = 0
    timeout = 1/frequency

    old_settings = termios.tcgetattr(sys.stdin)
    tty.setcbreak(sys.stdin.fileno())
    while True:
        now = datetime.datetime.now()
        time_left = end - now
        if time_left.total_seconds() <= 0:
            break

        ch = inputs.getch_nb(timeout)
        if ch == 'q':
            print("\nexited early!")
            break

        # see https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
        print("\x1b[2K\r" + inputs.delta_to_HM(time_left), end="", flush=True)

        accum += timeout
        if accum >= 1:
            accum = 0
    termios.tcsetattr(sys.stdin, termios.TCSADRAIN, old_settings)

    return (time_left, start)

def stopwatch():
    """stopwatch timer; returns time elapsed"""
    start = datetime.datetime.now()
    accum = 0
    timeout = 1/frequency

    old_settings = termios.tcgetattr(sys.stdin)
    tty.setcbreak(sys.stdin.fileno())
    while True:
        elapsed = datetime.datetime.now() - start

        ch = inputs.getch_nb(timeout)
        if ch == 'q':
            break

        # see https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
        print("\x1b[2K\r" + inputs.delta_to_HM(elapsed), end="", flush=True)

        accum += timeout
        if accum >= 1:
            accum = 0
    termios.tcsetattr(sys.stdin, termios.TCSADRAIN, old_settings)

    return (elapsed, start)