#!/usr/bin/env python3
from subprocess import run, Popen
from re import search
from time import sleep

# NOTE: you will need to install `brightness` utility
# `brew install brightness`


BRIGHTNESS_STEP = 0.2
MAX_BRIGHTNESS = 1
MIN_BRIGHTNESS = 0

POMODORO_ITERATIONS = 3
POMODORO_WORK_TIME = 0.3 * 60
POMODORO_SWITCH_TIME = 0.3 * 60
POMODORO_REST_TIME = 0.3 * 60


# System utils
def execBackground(command, options):
    return Popen([command] + options)


def execSync(command, options):
    result = run(
        [command] + options, capture_output=True
    )
    if result.returncode:
        exit(result.returncode)
    return result


def lockComputer():
    execSync('pmset', ['displaysleepnow'])


def wakeComputer():
    execBackground('caffeinate', ['-u', '-t', '10'])


def notifyUser(message):
    execSync(
        'osascript',
        ['-e', 'display notification "%s" with title "Pymodoro"' % message],
    )


# Brightness utils
def getCurrentBrightness():
    brightness_call = execSync('brightness', ['-l'])
    brightness_output = brightness_call.stdout.decode('utf8')
    brightness = search("brightness ([0-9.]+)", brightness_output).group(1)
    return float(brightness)


def updateBrightness(birghtness_step):
    current_brightness = getCurrentBrightness()
    calc_brightness = current_brightness + birghtness_step
    next_brightness = max(min(calc_brightness, MAX_BRIGHTNESS), MIN_BRIGHTNESS)
    execSync('brightness', ['-d', '0', str(next_brightness)])


def main():
    for _ in range(POMODORO_ITERATIONS):
        notifyUser('It\'s time to work hard')
        sleep(POMODORO_WORK_TIME)
        notifyUser('Hey man, you need to go rest soon, wrap it up')
        updateBrightness(-BRIGHTNESS_STEP)
        sleep(POMODORO_SWITCH_TIME)
        notifyUser('5')
        sleep(1)
        notifyUser('4')
        sleep(1)
        notifyUser('3')
        sleep(1)
        notifyUser('2')
        sleep(1)
        notifyUser('1')
        sleep(1)
        updateBrightness(BRIGHTNESS_STEP)
        lockComputer()
        sleep(POMODORO_REST_TIME)
        wakeComputer()
    notifyUser('Go and get some reeeealy good rest')


if (__name__ == "__main__"):
    main()