"""

Name:

Author: Eugen Sawin <sawine@informatik.uni-freiburg.de>

"""

def main():    

    goal = ((0, 0, 0), (3, 3, 1))

    node = Node(((3, 3, 1), (0, 0, 0)))

    frontier = [node]

    explored = set()

    solutions = set()

    while len(frontier):

        node = frontier.pop()

        explored.add(node.state)      

        for action in actions(node.state):            

            child = Node(apply(node.state, action), node, action)      

            if child.state == child.parent.state:

                print child

                return

            if child.state not in explored and child not in frontier:

                if child.state == goal:

                    solutions.add(child)

                else:

                    frontier.append(child) 

    for i, s in enumerate(solutions):

        print "solution ", i

        parent = s.parent

        parents = []

        while parent:

            parents.append(parent)            

            parent = parent.parent

        print [p.state for p in reversed(parents)]

def negate(action):

    return (-action[0], -action[1], -action[2]) 

def apply(state, action):

    if len(state) == 2:

        return (apply(state[0], action), apply(state[1], negate(action)))

    return (state[0] + action[0], state[1] + action[1], state[2] + action[2])

def actions(state):      

    actions = [(-2, 0, -1), (-1, 0, -1), (-1, -1, -1), (0, -2, -1), (0, -1, -1)]

    actions.extend([negate(a)for a in actions])

    states = [apply(state, a) for a in actions]   

    good_states = [s[0] for s in states if s[0][2] >= 0 and s[1][2] >= 0 

                   and (s[0][0] >= s[0][1] or not s[0][0]) 

                   and (s[1][0] >= s[1][1] or not s[1][0])

                   and s[0][1] >= 0 and s[1][1] >= 0

                   and s[0][2] >= 0 and s[1][2] >= 0]

    return [a for a in actions if apply(state[0], a) in good_states]

class Node(object):

    def __init__(self, state, parent=None, action=None, cost=None):

        self.state = state

        self.parent = parent

        self.action = action

        self.cost = cost

from argparse import ArgumentParser

def parse_arguments():

    parser = ArgumentParser(description="Parses simple modal logic syntax.")

    parser.add_argument("-f", "--formula", help="your formula") 

    return parser.parse_args()

if __name__ == "__main__":

    main()