from typing import Iterable

from PIL import Image

from image_prediction.encoder.encoder import Encoder
from image_prediction.utils import get_logger

logger = get_logger()


class HashEncoder(Encoder):
    def encode(self, images: Iterable[Image.Image]):
        yield from map(_monitored_hashing, images)

    def __call__(self, images: Iterable[Image.Image], batch_size=16):
        yield from self.encode(images)


def _monitored_hashing(image):
    try:  # RED-5170: fails if image is 'broken'
        image_hash = hash_image(image)
    except (OSError, Exception) as err:
        logger.warn(f"{err}: Couldn't hash image, generate dummy hash.")
        image_hash = "F" * 25
    return image_hash


def hash_image(image: Image.Image):
    """See: https://stackoverflow.com/a/49692185/3578468"""
    image = image.resize((10, 10), Image.ANTIALIAS)
    image = image.convert("L")
    pixel_data = list(image.getdata())
    avg_pixel = sum(pixel_data) / len(pixel_data)
    bits = "".join(["1" if (px >= avg_pixel) else "0" for px in pixel_data])
    hex_representation = str(hex(int(bits, 2)))[2:][::-1].upper()
    return hex_representation