import abc
import random
from copy import deepcopy
from itertools import chain

from funcy import rpartial, juxt

from image_prediction.info import Info


class SplitKeyMapper(abc.ABC):
    def __init__(self, box: dict, keymap: dict):
        self.box = box
        self.keymap = keymap

    def __getitem__(self, item):
        return self.box[self.keymap[item]]

    def __setitem__(self, key, value):
        self.box[self.keymap[key]] = value


class HorizontalKeyMapper(SplitKeyMapper):
    def __init__(self, box: dict):
        super().__init__(box, {"dim": Info.WIDTH, "c1": Info.X1, "c2": Info.X2})


class VerticalKeyMapper(SplitKeyMapper):
    def __init__(self, box: dict):
        super().__init__(box, {"dim": Info.HEIGHT, "c1": Info.Y1, "c2": Info.Y2})


class BoxSplitter:
    def __init__(self):
        self.__steps = None

    def split_box(self, box, steps=5):
        self.__steps = steps
        return self.__split_recursively(box, 0)

    def __split_recursively(self, box, step):
        return self.__split_and_recurse(box, step) if self.__steps_left(step) else self.__base_case(box)

    def __steps_left(self, step):
        return step < self.__steps

    @staticmethod
    def __base_case(box):
        return [box]

    def __split_and_recurse(self, box, step):
        new_boxes = self.__random_split(box)
        new_boxes_per_branch = self.__tree_recurse(new_boxes, step + 1)
        return chain.from_iterable(new_boxes_per_branch)

    def __random_split(self, box):
        splitter = random.choice([self.__split_horizontal, self.__split_vertical])
        new_boxes = splitter(box)
        return new_boxes

    def __tree_recurse(self, boxes, step):
        return map(rpartial(self.__split_recursively, step + 1), boxes)

    def __split_horizontal(self, box):
        return self.__split_if_large_enough(HorizontalKeyMapper(box))

    def __split_vertical(self, box):
        return self.__split_if_large_enough(VerticalKeyMapper(box))

    def __split_if_large_enough(self, wrapped_box: SplitKeyMapper):
        return (
            self.__get_child_boxes(wrapped_box)
            if self.__large_enough(wrapped_box)
            else self.__base_case(wrapped_box.box)
        )

    @staticmethod
    def __large_enough(box):
        return box["dim"] >= 10

    @staticmethod
    def __get_child_boxes(wrapped_box: SplitKeyMapper):

        split_len = random.randint(5, wrapped_box["dim"] - 5)
        split_point = wrapped_box["c1"] + split_len

        box_left, box_right = juxt(deepcopy, deepcopy)(wrapped_box)

        box_left["dim"] = split_len
        box_right["dim"] = wrapped_box["dim"] - split_len

        box_left["c2"] = split_point
        box_right["c1"] = split_point

        return box_left.box, box_right.box