from PIL import Image

def average_color(x, y, n, image):
    r, g, b = 0, 0, 0
    count = 0
    for s in range(x, x + n + 1):
        for t in range(y, y + n + 1):
            pixlr, pixlg, pixlb = image[s, t]
            r += pixlr
            g += pixlg
            b += pixlb
            count += 1
    return ((r / count), (g / count), (b / count))

def differences(rgb_tuple1, rgb_tuple2):
    r1, g1, b1 = rgb_tuple1
    r2, g2, b2 = rgb_tuple2

    return ((r1-r2), (g1-g2), (b1-b2))

def threshold(diff_tuple, trigger=4):
    dr, dg, db = diff_tuple
    return (((( dr**4 + dg**4 + db**4 ) / 3)**0.25) > trigger)        # Thanks to Thomas Atkins, math whiz

#
# reference_image = Image.open('./lib/test-images/lot-empty.jpg').load()
# compare_image = Image.open('./lib/test-images/lot-1-car.jpg').load()
#
# stall_1 = {
#     'location': (54, 79, 109),
#     'reference': average_color(54, 79, 109, reference_image),
#     'compare': average_color(54, 79, 109, compare_image)
# }
#
# stall_2 = {
#     'location': (186, 81, 116),
#     'reference': average_color(186, 81, 116, reference_image),
#     'compare': average_color(186, 81, 116, compare_image)
# }
#
# stall_3 = {
#     'location': (317, 71, 127),
#     'reference': average_color(317, 71, 127, reference_image),
#     'compare': average_color(317, 71, 127, compare_image)
# }
#
# stall_4 = {
#     'location': (469, 76, 100),
#     'reference': average_color(469, 76, 100, reference_image),
#     'compare': average_color(469, 76, 100, compare_image)
# }
#
# stall_5 = {
#     'location': (27, 237, 119),
#     'reference': average_color(27, 237, 119, reference_image),
#     'compare': average_color(27, 237, 119, compare_image)
# }
#
# stall_6 = {
#     'location': (172, 240, 130),
#     'reference': average_color(172, 240, 130, reference_image),
#     'compare': average_color(172, 240, 130, compare_image)
# }
#
# stall_7 = {
#     'location': (317, 234, 144),
#     'reference': average_color(317, 234, 144, reference_image),
#     'compare': average_color(317, 234, 144, compare_image)
# }
#
# stall_8 = {
#     'location': (481, 233, 112),
#     'reference': average_color(481, 233, 112, reference_image),
#     'compare': average_color(481, 233, 112, compare_image)
# }
#
# print(threshold(differences(stall_1['reference'], stall_1['compare'])))
# print(threshold(differences(stall_2['reference'], stall_2['compare'])))
# print(threshold(differences(stall_3['reference'], stall_3['compare'])))
# print(threshold(differences(stall_4['reference'], stall_4['compare'])))
# print(threshold(differences(stall_5['reference'], stall_5['compare'])))
# print(threshold(differences(stall_6['reference'], stall_6['compare'])))
# print(threshold(differences(stall_7['reference'], stall_7['compare'])))
# print(threshold(differences(stall_8['reference'], stall_8['compare'])))