import copy

width = 0
height = 0


def nextSeat(x, y, grid):
    if grid[x][y] == '.':
        return '.'

    occupied = 0

    forbidden = [-1, height, width]
    xs = [a for a in [x - 1, x, x + 1] if a not in forbidden]
    ys = [a for a in [y - 1, y, y + 1] if a not in forbidden]

    for xz in xs:
        for yz in ys:
            if x is xz and y is yz:
                continue
            if grid[xz][yz] == '#':
                occupied += 1

    if grid[x][y] == 'L' and occupied == 0:
        return '#'
    elif grid[x][y] == '#' and occupied >= 4:
        return 'L'
    else:
        return grid[x][y]


def nextRound(grid):
    next_grid = copy.deepcopy(grid)

    for x in range(0, width):
        for y in range(0, height):
            next_grid[x][y] = nextSeat(x, y, grid)

    return next_grid, grid


def countSeats(grid1):
    count = 0
    for x in range(0, width):
        for y in range(0, height):
            if grid1[x][y] == '#':
                count += 1
    return count


def equals(grid1, grid2):
    for x in range(0, width):
        for y in range(0, height):
            if grid1[x][y] != grid2[x][y]:
                return False
    return True


def part1():
    file = open("input.txt")
    lines = file.readlines()

    grid = []

    for line in lines:
        row = []
        for spot in line.strip():
            row.append(spot)
        grid.append(row)

    global width, height
    width = len(grid[0])
    height = len(grid)

    while True:
        grid, oldGrid = nextRound(grid)
        if equals(grid, oldGrid):
            seats = countSeats(grid)
            break

    print(f"Part 1: {seats}")


def part2():
    file = open("input.txt")


if __name__ == "__main__":
    part1()
    part2()