Advent of Code Day 24

"""Day 24 of Advent of Code 2020 Solution"""
from collections import defaultdict, Counter
from itertools import chain
import re


class HexGrid:
    directions = {
        "ne": (1, 0, -1),
        "e": (1, -1, 0),
        "se": (0, -1, 1),
        "sw": (-1, 0, 1),
        "w": (-1, 1, 0),
        "nw": (0, 1, -1),
    }

    def __init__(self):
        self.grid = defaultdict(bool)

    def add_tile(self, move):
        x, y, z = 0, 0, 0
        for d in move:
            x += self.directions[d][0]
            y += self.directions[d][1]
            z += self.directions[d][2]
        if (x, y, z) in self.grid:
            self.flip_tile((x, y, z))
        else:
            self.grid[(x, y, z)] = True

    def flip_tile(self, location):
        if self.grid[location]:
            self.grid[location] = False
        else:
            self.grid[location] = True

    @property
    def black(self):
        return sum([*self.grid.values()])

    def __iter__(self):
        return self

    def __next__(self):
        grid = defaultdict(bool)
        all_adj_tiles = []
        for tile in self.grid:
            if self.grid[tile]:
                adj_tiles = [
                    tuple([_t + _d for _t, _d in zip(tile, d)])
                    for d in self.directions.values()
                ]
                n_adjacent = sum([self.grid[t] for t in adj_tiles if t in self.grid])
                grid[tile] = True if 0 < n_adjacent <= 2 else False
                all_adj_tiles.append(adj_tiles)
        adjacent_count = Counter([*chain.from_iterable(all_adj_tiles)])
        for tile in adjacent_count:
            if not self.grid[tile] and adjacent_count[tile] == 2:
                grid[tile] = True
        self.grid = grid


def directions_io(file_location):
    pattern = r"(ne)|(e)|(se)|(sw)|(w)|(nw)"
    directions = []
    with open(file_location, "r") as f:
        for line in f.readlines():
            directions.append([l.group() for l in re.finditer(pattern, line)])
    return directions


def part_a(file_location):
    directions = directions_io(file_location)
    hex = HexGrid()
    for d in directions:
        hex.add_tile(d)
    return hex.black


def part_b(file_location):
    directions = directions_io(file_location)
    hex = HexGrid()
    for d in directions:
        hex.add_tile(d)
    for _ in range(100):
        next(hex)
    return hex.black


if __name__ == "__main__":
    file_location = r"data\day24.txt"
    print(part_a(file_location))
    print(part_b(file_location))