from PIL import Image
from random import random

class Dungeon:
    def __init__(self, width, height):
        self.WIDTH = width
        self.HEIGHT = height
        self.LENGTH = width * height
        self.N_REVIVE = 5
        self.N_DIE = 2
        self.LIFE_CHANCE = 0.4
        self.reset()

    def generate(self):
        while self.__nextGeneration():
            pass

    def saveAsImage(self, filename):
        wall = (0, 0, 0)
        floor = (200, 200, 200)
        factor = 4
        img = Image.new("RGB", (self.WIDTH, self.HEIGHT))
        for point in range(self.LENGTH):
            picPoint = (point % self.WIDTH, point // self.WIDTH)
            img.putpixel(picPoint, wall if self.map[point] else floor)
        img = img.resize((self.WIDTH * factor, self.HEIGHT * factor))
        img.save(filename)

    def reset(self):
        self.map = [random() < self.LIFE_CHANCE for point in range(self.LENGTH)]

    def __str__(self):
        res = ""
        for point in range(self.LENGTH):
            res += "#" if self.map[point] else "."
            res += "\n" if point % self.WIDTH == 0 else ""
        return res

    def __nextGeneration(self):
        tmp = [False] * self.LENGTH
        for point in range(self.LENGTH):
            neighbors = self.__countNeighbors(point)
            if self.map[point]:
                tmp[point] = neighbors > self.N_DIE
            else:
                tmp[point] = neighbors >= self.N_REVIVE
        self.map, tmp = tmp, self.map
        return self.map != tmp

    def __countNeighbors(self, point):
        cnt = 0
        for i in range(-1, 2):
            for j in range(-1, 2):
                neighPoint = point + i + j * self.WIDTH
                if point == neighPoint:
                    continue
                if 0 <= point % self.WIDTH + i < self.WIDTH and \
                   0 <= point // self.WIDTH + j < self.HEIGHT:
                    cnt += self.map[neighPoint]
                else:
                    cnt += 1
        return cnt

print("Dungeon is generated...")
dungeon = Dungeon(100, 100)
dungeon.generate()
dungeon.saveAsImage("dungeon.png")
print("DONE")