from collections import OrderedDict

import cv2 as cv


class ExposureErrorCompensator:
    """https://docs.opencv.org/4.x/d2/d37/classcv_1_1detail_1_1ExposureCompensator.html"""  # noqa: E501

    COMPENSATOR_CHOICES = OrderedDict()
    COMPENSATOR_CHOICES["gain_blocks"] = cv.detail.ExposureCompensator_GAIN_BLOCKS
    COMPENSATOR_CHOICES["gain"] = cv.detail.ExposureCompensator_GAIN
    COMPENSATOR_CHOICES["channel"] = cv.detail.ExposureCompensator_CHANNELS
    COMPENSATOR_CHOICES[
        "channel_blocks"
    ] = cv.detail.ExposureCompensator_CHANNELS_BLOCKS
    COMPENSATOR_CHOICES["no"] = cv.detail.ExposureCompensator_NO

    DEFAULT_COMPENSATOR = list(COMPENSATOR_CHOICES.keys())[0]
    DEFAULT_NR_FEEDS = 1
    DEFAULT_BLOCK_SIZE = 32

    def __init__(
        self,
        compensator=DEFAULT_COMPENSATOR,
        nr_feeds=DEFAULT_NR_FEEDS,
        block_size=DEFAULT_BLOCK_SIZE,
    ):

        if compensator == "channel":
            self.compensator = cv.detail_ChannelsCompensator(nr_feeds)
        elif compensator == "channel_blocks":
            self.compensator = cv.detail_BlocksChannelsCompensator(
                block_size, block_size, nr_feeds
            )
        else:
            self.compensator = cv.detail.ExposureCompensator_createDefault(
                ExposureErrorCompensator.COMPENSATOR_CHOICES[compensator]
            )

    def feed(self, *args):
        """https://docs.opencv.org/4.x/d2/d37/classcv_1_1detail_1_1ExposureCompensator.html#ae6b0cc69a7bc53818ddea53eddb6bdba"""  # noqa
        self.compensator.feed(*args)

    def apply(self, *args):
        """https://docs.opencv.org/4.x/d2/d37/classcv_1_1detail_1_1ExposureCompensator.html#a473eaf1e585804c08d77c91e004f93aa"""  # noqa
        return self.compensator.apply(*args)