import logging
from typing import List
from collections import Counter
import copy

logging.basicConfig(level=logging.INFO)


def read_input(filename: str):
    seats: List(str) = []
    with open(filename, 'r') as f:
        for line in f:
            line = line.rstrip()
            seats.append(list(line))
    return seats


def neighbors(row, col, seats):
    max_col = len(seats[0])
    max_row = len(seats)
    neighbors = [(row - 1, col - 1), (row - 1, col), (row - 1, col + 1),
                (row, col - 1),                      (row, col + 1),
                (row + 1, col - 1),  (row + 1, col), (row + 1, col + 1)]
    return list(filter(lambda p: p[0] >= 0 and p[0] < max_row and p[1] >= 0 and p[1] < max_col, neighbors))

def occupy(row, col, seats):
    seats[row][col] = '#'

def unoccupy(row, col, seats):
    seats[row][col] = 'L'

def occupied_neighbors(row, col, seats):
    n = neighbors(row, col, seats)
    return list(filter(lambda x: seats[x[0]][x[1]] == '#', n))


def solution_1(seats):
    loop = 0
    seatcopy = copy.deepcopy(seats)
    while True:
        loop += 1
        changed = False
        for rownum, row in enumerate(seats):
            for col, status in enumerate(row):
                num_occupied_neighbors = len(occupied_neighbors(rownum, col, seats))
                if status == 'L' and num_occupied_neighbors == 0:
                    occupy(rownum, col, seatcopy)
                    changed = True
                elif status == '#' and num_occupied_neighbors >= 4:
                    unoccupy(rownum, col, seatcopy)
                    changed = True
        logging.debug(f'{seatcopy}')
        seats = copy.deepcopy(seatcopy)
        if not changed:
            break
    logging.debug(f'Broke the loop at {loop}')
    count = 0
    for row in seats:
        count += Counter(row)['#']
    return count

####### Part 2 ########
def visible_seats(row, col, seats):
    logging.debug(f'processing {row, col}')
    directions = {
        'NW': lambda row, col, delta: (row - delta, col - delta),
        'N': lambda row, col, delta: (row - delta, col),
        'NE': lambda row, col, delta: (row - delta, col + delta),
        'W': lambda row, col, delta: (row, col - delta),
        'E': lambda row, col, delta: (row, col + delta),
        'SW': lambda row, col, delta: (row + delta, col - delta),
        'S': lambda row, col, delta: (row + delta, col),
        'SE': lambda row, col, delta: (row + delta, col + delta),
    }

    def is_valid(row, col):
        max_col = len(seats[0])
        max_row = len(seats)
        return row in range(0, max_row) and col in range(0, max_col)

    visible = []
    delta = 1
    while dirs := list(directions):
        logging.debug(f'processing {delta} delta')
        for d in dirs:
            nr, nc = directions[d](row, col, delta)
            if not is_valid(nr, nc):
                del directions[d] # Hit the row or column boundary
            elif seats[nr][nc] == 'L':
                del directions[d] # Our view in this direction is an empty seat
            elif seats[nr][nc] == '#':
                visible.append((nr, nc))
                del directions[d] # Our view in this direction is an occupied seat
        delta += 1
    return visible


def solution_2(seats):
    loop = 0
    seatcopy = copy.deepcopy(seats)
    while True:
        loop += 1
        changed = False
        for rownum, row in enumerate(seats):
            for col, status in enumerate(row):
                viscount = len(visible_seats(rownum, col, seats))
                logging.debug(f'Viscount={viscount} for {rownum, col}')
                if status == 'L' and viscount == 0:
                    occupy(rownum, col, seatcopy)
                    changed = True
                elif status == '#' and viscount >= 5:
                    unoccupy(rownum, col, seatcopy)
                    changed = True
        logging.debug(f'{seatcopy}')
        seats = copy.deepcopy(seatcopy)
        if not changed:
            break
    logging.debug(f'Broke the loop at {loop}')
    count = 0
    for row in seats:
        count += Counter(row)['#']
    return count


# main
if __name__ == '__main__':
    seats = read_input('input.txt')
    result_1 = solution_1(seats)
    result_2 = solution_2(seats)
    print(f'Result = {result_1}') # 2470
    print(f'Result2 = {result_2}')