# FRINGE - struktura danych przechowująca wierzchołki do odwiedzenia
# EXPLORED - lista odwiedzonych stanów
# istate - stan początkowy
# Succ - funkcja następnika
# Goaltest -test spełnienia celu


def breadth_first_search(istate, goal, agent_direction):  # COORDINATES OF A START PLACE
    fringe = []
    explored = []
    start = Node(istate, agent_direction)
    fringe.append(start)
    path = []

    while True:
        if not fringe:
            return False

        elem = fringe.pop(0)

        if elem.state == goal:
            # return ciag akcji zbudowany z wykorzystaniem pol parent i action
            while elem.parent is not None:
                if type(elem.action) == list:
                    elem.action.reverse()
                    for each_action in elem.action:
                        path.append(each_action)
                else:
                    path.append(elem.action)
                elem = elem.parent

            path.reverse()
            return path

        explored.append(elem)

        for action, state, direction in elem.successor():
            fringe_states = []
            explored_states = []
            for node in fringe:
                fringe_states.append(node.state)
            for node2 in explored:
                explored_states.append(node2.state)

            if state not in fringe_states and state not in explored_states:
                x = Node(state, direction)
                x.parent = elem
                x.action = action
                fringe.append(x)


class Node:
    def __init__(self, state, agent_direction, action=None, parent=None):
        self.state = state
        self.action = action
        self.parent = parent
        self.agent_direction = agent_direction

    def successor(self):
        neighbours = []
        x = self.state[0]
        y = self.state[1]

        if x < 8:  # RIGHT NEIGHBOUR
            if self.agent_direction == "right":
                actions = "move"
            elif self.agent_direction == "left":
                actions = ["rotate_right", "rotate_right", "move"]
            elif self.agent_direction == "up":
                actions = ["rotate_right", "move"]
            elif self.agent_direction == "down":
                actions = ["rotate_left", "move"]

            neighbours.append((actions, (x + 1, y), "right"))

        if x > 0:  # LEFT NEIGHBOUR
            if self.agent_direction == "right":
                actions = ["rotate_left", "rotate_left", "move"]
            elif self.agent_direction == "left":
                actions = "move"
            elif self.agent_direction == "up":
                actions = ["rotate_left", "move"]
            elif self.agent_direction == "down":
                actions = ["rotate_right", "move"]

            neighbours.append((actions, (x - 1, y), "left"))

        if y > 0:  # UP NEIGHBOUR
            if self.agent_direction == "right":
                actions = ["rotate_left", "move"]
            elif self.agent_direction == "left":
                actions = ["rotate_right", "move"]
            elif self.agent_direction == "up":
                actions = "move"
            elif self.agent_direction == "down":
                actions = ["rotate_left", "rotate_left", "move"]

            neighbours.append((actions, (x, y - 1), "up"))

        if y < 8:  # DOWN NEIGHBOUR
            if self.agent_direction == "right":
                actions = ["rotate_right", "move"]
            elif self.agent_direction == "left":
                actions = ["rotate_left", "move"]
            elif self.agent_direction == "up":
                actions = ["rotate_left", "rotate_left", "move"]
            elif self.agent_direction == "down":
                actions = "move"

            neighbours.append((actions, (x, y + 1), "down"))

        return neighbours