#!/usr/bin/python3
"Unicode Wang tiles."
import random


chars = '┄┊┌┐└┘┄┊┌┐└┘┄┊┌┐└┘├┤┬┴┼♥☆☽🌔'
left  = '100101100101100101011110000'
right = '101010101010101010101110000'
top   = '010011010011010011110110000'
bot   = '011100011100011100111010000'

def generate(ww, hh, initial=None):
    if initial is None:
        above = [random.choice(bot) for i in range(ww)]
    else:
        above = initial

    for i in range(hh):
        row = []
        prev = random.choice(right)
        for j in range(ww):
            c = random.choice([k for k in range(len(chars))
                               if left[k] == prev and top[k] == above[j]])
            prev = right[c]
            above[j] = bot[c]
            row.append(chars[c])
        yield ''.join(row)

def main():
    for line in generate(80, 50):
        print(line)

if __name__ == '__main__':
    main()