# coding: utf-8
"""
ディスプレイの輝度を計測するため，入力されたグレースケール値 (8ビット) に対応する背景を表示する．
"""

from __future__ import division, unicode_literals, print_function
import numpy as np
from PIL import Image
from psychopy import visual, event

FULLSCR = True
DEFAULT_MESSAGE = 'Input brightness'
MESSAGE_COLOR = (1, -1, -1)
CONFIRM_KEY = 'return'
ESCAPE_KEY = 'escape'


class Rectangle(object):
    def __init__(self, win):
        self._win = win
        self._size = win.size  # in (W, H)
        self.set_brightness(128)

    def set_brightness(self, brightness):
        arr = np.tile(brightness, tuple(reversed(self._size)))  # in (H, W)
        img = Image.fromarray(np.uint8(arr))
        self._rect = visual.ImageStim(win, img)
        self.current_brightness = brightness

    def draw(self):
        self._rect.draw()


def check_brightness(win):
    msg = visual.TextStim(win, DEFAULT_MESSAGE, color=MESSAGE_COLOR)
    rect = Rectangle(win)
    key_list = [str(i) for i in range(10)] + [CONFIRM_KEY, ESCAPE_KEY]
    inputted_digits = []
    while True:
        rect.draw()
        msg.draw()
        win.flip()

        keys = event.getKeys(keyList=key_list)
        if not keys:
            continue
        else:
            key = keys[0]

        if key == ESCAPE_KEY:
            break
        elif key == CONFIRM_KEY:
            if inputted_digits:
                new_brightness = ''.join(inputted_digits)
                rect.set_brightness(new_brightness)
                msg.setText(DEFAULT_MESSAGE)
                inputted_digits = []
            print('current brightness: {}'.format(rect.current_brightness))
        else:
            inputted_digits.append(key)
            inputted_digits = inputted_digits[-3:]
            msg.setText(''.join(inputted_digits))


if __name__ == '__main__':
    win = visual.Window(units='pix', allowGUI=not(FULLSCR), fullscr=FULLSCR)
    check_brightness(win)
    win.close()