from strategy import PathFindingStrategy
from Maze import Maze, Cell


class BFSStrategy(PathFindingStrategy):
    def findPath(maze: Maze, start: Cell, exit: Cell):

        if not start or not exit:
            return []
        # очерель: перывй вошел - первый вышел
        queue = [start]
        # будем хранить откуда в какую клетку пришли
        parents = {start: None}

        while (len(queue) != 0):
            u = queue.pop(0)
            if u == exit:
                path = []
                current = exit
                while current is not None:
                    path.append(current)
                    current = parents[current]
                path.reverse()
                return path, len(parents)

            childs = maze.getNeighbors(u)
            for child in childs:
                if child not in parents:
                    parents[child] = u
                    queue.append(child)
        return []