from data_structure import Tree

class Ai:
    def __init__(self):
        self.path = []
    
    def start(self,snake,apple,settings):
        openlist = []
        closelist = []
        starting_point = snake.coords[0]
        ending_point = apple.coords


        def calculate_f():
            """计算openlist各格子的f值"""
            for cell in openlist:
                g = abs(cell['x'] - starting_point['x']) + abs(cell['y'] - starting_point['y'])
                h = abs(cell['x'] - ending_point['x']) + abs(cell['y'] - ending_point['y'])
                f = g + h
                cell['f'] = f

        
        def is_wall():
            # 碰到左右墙壁
            if (cell['x'] == -1 or cell['x'] == settings.cell_w):
                return True
            # 碰到上下墙壁
            if (cell['y'] == -1 or cell['y'] == settings.cell_h):
                return True
            # 碰到自己
            if (cell in snake.coords[1:]):
                return True
            return False
        

        #记得做openlist用尽、苹果在蛇里面的解决办法
        while ending_point not in openlist:
            if not openlist:
                openlist.append(starting_point)
                path_tree = Tree(starting_point)
            #查找Openlist中F最小的格子并弹入Closelist
            #《这里也有问题 假设下面出现的列表同步更改的错误解决了》
            #《那么本来就被计算过的格子不需要再次计算 但这里依然算了》
            calculate_f()
            min_f = min(f['f'] for f in openlist)
            for cell in openlist:
                if cell['f'] == min_f:
                    closelist.append(cell)
                    openlist.remove(cell)
                    break
            #《这里有问题 不应该for 应该只检查刚丢进closelist的那一个》
            #《检查过的格子又检查一遍 也是openlist有重复格子的根本原因》
            for close_cell in closelist:
                near_cells = [{'x': close_cell['x'], 'y': close_cell['y'] + 1},   #获取旁边的格子上右下左
                            {'x': close_cell['x'] + 1, 'y': close_cell['y']},
                            {'x': close_cell['x'], 'y': close_cell['y'] - 1},
                            {'x': close_cell['x'] - 1, 'y': close_cell['y']}]
                #不考虑蛇的身体或墙壁
                for cell in near_cells:
                    if is_wall():
                        near_cells.remove(cell)
                #排除F键值对的影响
                #《？为什么使用切片后copy的更改还是能影响到原openlist？》
                #《搞得我openlist的f值全弹出了》
                openlist_copy = openlist[:]
                for cell_copy in openlist_copy:
                    cell_copy.pop('f',None)
                #找出不在openlist的格子并加进openlist
                #《filter疑似用错 没有筛选功能 openlist依然有重复格子》
                not_in_list = filter(lambda x: x != (cell_copy for cell_copy in openlist_copy), near_cells)
                openlist.extend(not_in_list)
                #《这里再用一次filter查教程后是因为filter只能迭代一次》
                #《filter好jb难用 我是因为看它性能消耗少才用的QAQ 换一个吧》
                not_in_list = filter(lambda x: x != (cell_copy for cell_copy in openlist_copy), near_cells)
                
                #《这里的添加节点能运行但是加不进去 只有一开始的父节点加得进去》
                for not_in_cell in not_in_list:
                    path_tree.add_child(path_tree.find(close_cell),not_in_cell)


        ending_nodes = path_tree.find(ending_point)
        for node in ending_nodes.get_ancestors()[::-1]:
            self.path.append(node)
            self.iterator = snake.create_iterator(self.path)