from queue import Queue
from Engine.Point import Point
from Engine.State import State
from Constants import RIGHT, LEFT, DOWN, UP, DEFUSE, REST
class BfsPathFinder:

    def __init__(self, board):
        self.board = board
        self.goal = None
    def findBomb(self,startState):

        frontier = Queue()
        frontier.put(startState)
        cameFrom = dict()
        cameFrom[startState] = None

        while not frontier.empty():
            current = frontier.get()

            if self.checkGoal(current):
                return self.constructPath(cameFrom,startState)

            for next in self.getNeighbour(current):
                if next not in cameFrom:
                    frontier.put(next)
                    cameFrom[next] = current
        return []

    def constructPath(self,cameFrom,startState):
        current = cameFrom[self.goal]
        path = []
        path.append(self.goal)
        while current.getAction != startState:
            path.append(current)
            current = cameFrom[current]
        path.append(startState)
        path.reverse()
        return path

    def getNeighbour(self, current):
        neighbourlist = []
        state1 = State(LEFT,Point(current.getX() + 1, current.getY()))
        state2 = State(RIGHT,Point(current.getX(), current.getY() + 1))
        state3 = State(UP,Point(current.getX(), current.getY() - 1))
        state4 = State(DOWN,Point(current.getX() - 1, current.getY()))
        if self.checkField(current.getPoint(),state1.getPoint()):
            neighbourlist.append(state1.getPoint())
        if self.checkField(current.getPoint(), state2.getPoint()):
            neighbourlist.append(state2.getPoint())
        if self.checkField(current.getPoint(),state3.getPoint()):
            neighbourlist.append(state3)
        if self.checkField(current.getPoint(),state4.getPoint()):
            neighbourlist.append(state4)
        return neighbourlist

    def checkGoal(self, current):
        if current.getPoint() in self.board.bombMap:
            self.goal = current
            return True
        return False