from operator import itemgetter

import constants


class Istate:
    def __init__(self, direction, horizontal_index, vertical_index):
        self.__direction = direction
        self.__horizontal_index = horizontal_index
        self.__vertical_index = vertical_index

    @property
    def direction(self):
        return self.__direction

    @property
    def horizontal_index(self):
        return self.__horizontal_index

    @property
    def vertical_index(self):
        return self.__vertical_index


class Node:
    def __init__(self, action, direction, parent, horizontal_index, vertical_index):
        self.__action = action
        self.__direction = direction
        self.__parent = parent
        self.__horizontal_index = horizontal_index
        self.__vertical_index = vertical_index

    @property
    def action(self):
        return self.__action

    @property
    def direction(self):
        return self.__direction

    @property
    def parent(self):
        return self.__parent

    @property
    def horizontal_index(self):
        return self.__horizontal_index

    @property
    def vertical_index(self):
        return self.__vertical_index


def goal_test(elem, goaltest):
    if elem.horizontal_index == goaltest[0] and elem.vertical_index == goaltest[1]:
        return True
    else:
        # print("Traktor wartosc horizontal_index: ", elem.horizontal_index)
        # print("Traktor wartosc vertical_index: ", elem.vertical_index)
        return False


def print_moves(elem):
    moves_list = []
    while elem.parent is not None:
        moves_list.append(elem.action)
        elem = elem.parent
    moves_list.reverse()
    return moves_list


def cost(board, node):
    cost_value = 0
    while node.parent is not None:
        field = board[node.horizontal_index][node.vertical_index]
        cost_value = cost_value + field.cost + 1
        node = node.parent
    return cost_value


def heuristic(node, goaltest):
    return abs(node.horizontal_index - goaltest[0]) + abs(node.vertical_index - goaltest[1])


def f(board, node, goaltest):
    cost_value = cost(board, node)
    return cost_value + heuristic(node, goaltest)


def succ(elem):
    actions_list = []
    direction = elem.direction
    if direction == "UP":
        direction = "RIGHT"
    elif direction == "RIGHT":
        direction = "DOWN"
    elif direction == "DOWN":
        direction = "LEFT"
    elif direction == "LEFT":
        direction = "UP"
    actions_list.append(("Right_Rotation", (direction, elem.horizontal_index, elem.vertical_index)))

    direction = elem.direction
    if direction == "UP":
        direction = "LEFT"
    elif direction == "LEFT":
        direction = "DOWN"
    elif direction == "DOWN":
        direction = "RIGHT"
    elif direction == "RIGHT":
        direction = "UP"
    actions_list.append(("Left_Rotation", (direction, elem.horizontal_index, elem.vertical_index)))

    horizontal_change = 0
    vertical_change = 0

    if elem.direction == "RIGHT" and elem.horizontal_index < constants.HORIZONTAL_TILES_NUMBER - 1:
        horizontal_change = 1
    elif elem.direction == "LEFT" and elem.horizontal_index > 0:
        horizontal_change = -1
    elif elem.direction == "UP" and elem.vertical_index > 0:
        vertical_change = -1
    elif elem.direction == "DOWN" and elem.vertical_index < constants.VERTICAL_TILES_NUMBER - 1:
        vertical_change = 1

    actions_list.append(("Move", (elem.direction, elem.horizontal_index + horizontal_change,
                                  elem.vertical_index + vertical_change)))

    return actions_list


def graphsearch(fringe, explored, istate, goaltest, board):
    node = Node(None, istate.direction, None, istate.horizontal_index, istate.vertical_index)
    fringe.append((node, 0))
    while True:
        if not fringe:
            return False

        elem = fringe.pop(0)
        temp = elem[0]

        if goal_test(elem[0], goaltest) is True:
            return print_moves(elem[0])

        explored.append(elem)

        for (action, state) in succ(temp):
            fringe_list = []
            fringe_list_priority = []
            explored_list = []

            for (x, y) in fringe:
                fringe_list.append((x.direction, x.horizontal_index, x.vertical_index))
                fringe_list_priority.append(((x.direction, x.horizontal_index, x.vertical_index), y))

            for (x, y) in explored:
                explored_list.append((x.direction, x.horizontal_index, x.vertical_index))

            x = Node(action, state[0], elem[0], state[1], state[2])
            p = f(board, x, goaltest)

            if state not in fringe_list and state not in explored_list:
                fringe.append((x, p))
                fringe = sorted(fringe, key=itemgetter(1))
            elif state in fringe_list:
                index = 0
                for (state_priority, r) in fringe_list_priority:
                    if state_priority == state:
                        if r > p:
                            fringe.insert(index, (x, p))
                            fringe.pop(index + 1)
                            fringe = sorted(fringe, key=itemgetter(1))
                            break
                    index = index + 1