import random

from django.urls import reverse

from captcha.conf import settings


def math_challenge():
    operators = ("+", "*", "-")
    operands = (random.randint(1, 10), random.randint(1, 10))
    operator = random.choice(operators)
    if operands[0] < operands[1] and "-" == operator:
        operands = (operands[1], operands[0])
    challenge = "%d%s%d" % (operands[0], operator, operands[1])
    return (
        "{}=".format(challenge.replace("*", settings.CAPTCHA_MATH_CHALLENGE_OPERATOR)),
        str(eval(challenge)),
    )


def random_char_challenge():
    chars, ret = "abcdefghijklmnopqrstuvwxyz", ""
    for i in range(settings.CAPTCHA_LENGTH):
        ret += random.choice(chars)
    return ret.upper(), ret


def unicode_challenge():
    chars, ret = "äàáëéèïíîöóòüúù", ""
    for i in range(settings.CAPTCHA_LENGTH):
        ret += random.choice(chars)
    return ret.upper(), ret


def word_challenge():
    fd = open(settings.CAPTCHA_WORDS_DICTIONARY, "r")
    lines = fd.readlines()
    fd.close()
    while True:
        word = random.choice(lines).strip()
        if (
            len(word) >= settings.CAPTCHA_DICTIONARY_MIN_LENGTH
            and len(word) <= settings.CAPTCHA_DICTIONARY_MAX_LENGTH
        ):
            break
    return word.upper(), word.lower()


def huge_words_and_punctuation_challenge():
    "Yay, undocumneted. Mostly used to test Issue 39 - http://code.google.com/p/django-simple-captcha/issues/detail?id=39"
    fd = open(settings.CAPTCHA_WORDS_DICTIONARY, "rb")
    lines = fd.readlines()
    fd.close()
    word = ""
    while True:
        word1 = random.choice(lines).strip()
        word2 = random.choice(lines).strip()
        punct = random.choice(settings.CAPTCHA_PUNCTUATION)
        word = "%s%s%s" % (word1, punct, word2)
        if (
            len(word) >= settings.CAPTCHA_DICTIONARY_MIN_LENGTH
            and len(word) <= settings.CAPTCHA_DICTIONARY_MAX_LENGTH
        ):
            break
    return word.upper(), word.lower()


def noise_arcs(draw, image):
    size = image.size
    draw.arc([-20, -20, size[0], 20], 0, 295, fill=settings.CAPTCHA_FOREGROUND_COLOR)
    draw.line(
        [-20, 20, size[0] + 20, size[1] - 20], fill=settings.CAPTCHA_FOREGROUND_COLOR
    )
    draw.line([-20, 0, size[0] + 20, size[1]], fill=settings.CAPTCHA_FOREGROUND_COLOR)
    return draw


def noise_dots(draw, image):
    size = image.size
    for p in range(int(size[0] * size[1] * 0.1)):
        draw.point(
            (random.randint(0, size[0]), random.randint(0, size[1])),
            fill=settings.CAPTCHA_FOREGROUND_COLOR,
        )
    return draw


def noise_null(draw, image):
    return draw


def random_letter_color_challenge(idx, plaintext_captcha):
    # Generate colorful but balanced RGB values
    red = random.randint(64, 200)
    green = random.randint(64, 200)
    blue = random.randint(64, 200)

    # Ensure at least one channel is higher to make it colorful
    channels = [red, green, blue]
    random.shuffle(channels)
    channels[0] = random.randint(150, 255)

    # Format the color as a hex string
    return f"#{channels[0]:02X}{channels[1]:02X}{channels[2]:02X}"


def post_smooth(image):
    from PIL import ImageFilter

    return image.filter(ImageFilter.SMOOTH)


def captcha_image_url(key):
    """Return url to image. Need for ajax refresh and, etc"""
    return reverse("captcha-image", args=[key])


def captcha_audio_url(key):
    """Return url to image. Need for ajax refresh and, etc"""
    return reverse("captcha-audio", args=[key])