import RPi.GPIO as GPIO
import random
import time

def preparepins():
    GPIO.setmode(GPIO.BCM)
    for pin in options.keys():
        GPIO.setup(pin, GPIO.IN, pull_up_down = GPIO.PUD_DOWN)

def nexttarget():
    target = random.choice(options.keys())
    print options[target]
    return target

def buttonpressed():
    for pin in options.keys():
        if GPIO.input(pin) == GPIO.HIGH:
            return pin
    else:
        return None

def play(duration):
    preparepins()

    start = time.time()
    end = start + duration
    score = 0

    target = nexttarget()
    while time.time() < end:
        button = buttonpressed()
        if button == target:
            score = score + 1
            print "Correct!"
            target = nexttarget()
        elif button != None:
            score = score - 1
            print "Wrong!"
        time.sleep(0.1)

    print "Your final score is", score

options = {22:"A", 23:"B", 24:"C", 25:"D"}

if __name__ == "__main__":
    play(30)