from abc import ABC, abstractclassmethod
from collections import deque
import heapq
import time
import os
import time
import csv
import random
class Cell:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.isWall = False
        self.isStart = False
        self.isExit = False
    
    
    def __eq__(self, other):
        if other is None:
            return False
        return self.x == other.x and self.y == other.y
    def __lt__(self, other):
        
        if other is None:
            return False
        return (self.x, self.y) < (other.x, other.y)
    def __hash__(self):
        
        return hash((self.x, self.y))
    
    def __repr__(self):
        return f"Cell({self.x}, {self.y})"
    def isPassable(self):
        return not self.isWall

class Maze:
    def __init__(self, width, height):
        self.width = width
        self.height = height
        self.grid = [[Cell(x, y) for y in range(height)] for x in range(width)]
        self.start = None
        self.exit = None
    
    def getCell(self, x, y):
        if 0 <= x < self.width and 0 <= y < self.height:
            return self.grid[x][y]
        return None
    
    def getNeighbors(self, cell):
        neighbors = []
        directions = [(0, 1), (0, -1), (1, 0), (-1, 0)]  
        for dx, dy in directions:
            neighbor = self.getCell(cell.x + dx, cell.y + dy)
            if neighbor and neighbor.isPassable():
                neighbors.append(neighbor)
        return neighbors
    
    def setStart(self, x, y):
        cell = self.getCell(x, y)
        if cell:
            cell.isStart = True
            self.start = cell
    
    def setExit(self, x, y):
        cell = self.getCell(x, y)
        if cell:
            cell.isExit = True
            self.exit = cell

class MazeBuilder(ABC):
    
    def buildFromFile(self, filename):
        pass

class TextileMazeBuilder(MazeBuilder):
    def buildFromFile(self, filename):
        with open(filename, 'r', encoding='utf-8') as f:
            lines = f.readlines()
        
        
        lines = [line.rstrip('\n\r') for line in lines]
        
        height = len(lines)
        width = len(lines[0]) if height > 0 else 0
        
        
        for line in lines:
            if len(line) != width:
                raise ValueError("все строки одинаковой длины")
        
       
        maze = Maze(width, height)
        
        
        for y in range(height):
            for x in range(width):
                char = lines[y][x]
                cell = maze.getCell(x, y)
                
                if char == '#':
                    cell.isWall = True
                elif char == ' ':
                    cell.isWall = False
                elif char == 's':
                    cell.isWall = False
                    cell.isStart = True
                    maze.start = cell
                elif char == 'e':
                    cell.isWall = False
                    cell.isExit = True
                    maze.exit = cell
                else:
                    raise ValueError(f"неизв сим")
        
        
        if maze.start is None:
            raise ValueError("в лабиринте не найден старт")
        if maze.exit is None:
            raise ValueError("в лабиринте не найден выход")
        
        return maze

class PathFindingStrategy:
    def findPath(self, maze, start, exit):
        pass


class BFSStrategy(PathFindingStrategy):
    def findPath(self, maze, start, exit):
        if exit is None:
            return []
        queue = deque([start])
        visited = {start}
        parent = {start: None}
        
        while queue:
            current = queue.popleft()
            
            if current == exit:
                return self._reconstruct_path(parent, start, exit)
            
            for neighbor in maze.getNeighbors(current):
                if neighbor not in visited:
                    visited.add(neighbor)
                    parent[neighbor] = current
                    queue.append(neighbor)
        
        return []  
    
    def _reconstruct_path(self, parent, start, exit):
        path = []
        current = exit
        while current is not None:
            path.append(current)
            current = parent[current]
        path.reverse()
        return path


class DFSStrategy(PathFindingStrategy):
    def findPath(self, maze, start, exit):
        if exit is None:
            return []
        stack = [start]
        visited = {start}
        parent = {start: None}
        
        while stack:
            current = stack.pop()
            
            if current == exit:
                return self._reconstruct_path(parent, start, exit)
            
            for neighbor in maze.getNeighbors(current):
                if neighbor not in visited:
                    visited.add(neighbor)
                    parent[neighbor] = current
                    stack.append(neighbor)
        
        return []
    
    def _reconstruct_path(self, parent, start, exit):
        path = []
        current = exit
        while current is not None:
            path.append(current)
            current = parent[current]
        path.reverse()
        return path


class AStrategy(PathFindingStrategy):
    def _heuristic(self, cell, exit):
        if exit is None:
            return 0
        return abs(cell.x - exit.x) + abs(cell.y - exit.y)
    
    def findPath(self, maze, start, exit):
        if exit is None:
            return []
        open_set = []
        heapq.heappush(open_set, (0, start))
        
        came_from = {start: None}
        g_score = {start: 0}
        
        while open_set:
            current = heapq.heappop(open_set)[1]
            
            if current == exit:
                return self._reconstruct_path(came_from, start, exit)
            
            for neighbor in maze.getNeighbors(current):
                tentative_g = g_score[current] + 1
                
                if neighbor not in g_score or tentative_g < g_score[neighbor]:
                    came_from[neighbor] = current
                    g_score[neighbor] = tentative_g
                    f_score = tentative_g + self._heuristic(neighbor, exit)
                    heapq.heappush(open_set, (f_score, neighbor))
        
        return []
    
    def _reconstruct_path(self, came_from, start, exit):
        path = []
        current = exit
        while current is not None:
            path.append(current)
            current = came_from[current]
        path.reverse()
        return path


class SearchStats:
    def __init__(self, time_ms=0, visited_cells=0, path_length=0):
        self.time_ms = time_ms
        self.visited_cells = visited_cells
        self.path_length = path_length
    
    def __str__(self):
        return f"Время: {self.time_ms:.3f} мс | Посещено: {self.visited_cells} | Длина пути: {self.path_length}"


class MazeSolver:
    def __init__(self, maze):
        self.maze = maze
        self.strategy = None
    
    def setStrategy(self, strategy):
        self.strategy = strategy
    
    def solve(self):
        if self.strategy is None:
            raise ValueError("Стратегия не установлена")
        
        
        start_time = time.perf_counter()
        path = self.strategy.findPath(self.maze, self.maze.start, self.maze.exit)
        
        end_time = time.perf_counter()
        elapsed_ms = (end_time - start_time) * 1000
        
       
        stats = SearchStats(
            time_ms=elapsed_ms,
            visited_cells=len(path),  
            path_length=len(path)
        )
        
        return path, stats

class Observer:
    def update(self, event):
        pass

class ConsoleView(Observer):
    def render(self, maze, player_position=None, path=None):
        """отрисовка"""
        os.system('cls' if os.name == 'nt' else 'clear')
        
        path_set = set(path) if path else set()
        
        for y in range(maze.height):
            for x in range(maze.width):
                cell = maze.getCell(x, y)
                
                if player_position and cell == player_position:
                    print('P', end='')
                elif cell == maze.start:
                    print('S', end='')
                elif cell == maze.exit:
                    print('E', end='')
                elif cell in path_set:
                    print('.', end='')
                elif cell.isWall:
                    print('#', end='')
                else:
                    print(' ', end='')
            print()
    
    def update(self, event):
        if event['type'] == 'path_found':
            print(f"длина пути {len(event['path'])}")
            self.render(event['maze'], path=event['path'])
        elif event['type'] == 'move':
            print(f"шаг {event['step']}")
            self.render(event['maze'], event['player'], event['path'])
        elif event['type'] == 'maze_loaded':
            print("перегрузка")
            self.render(event['maze'])


class ObservableMazeSolver:
    def __init__(self, maze):
        self.maze = maze
        self.strategy = None
        self.observers = []
    
    def attach(self, observer):
        self.observers.append(observer)
    
    def notify(self, event):
        for observer in self.observers:
            observer.update(event)
    
    def setStrategy(self, strategy):
        self.strategy = strategy
    
    def solve(self):
        if self.strategy is None:
            raise ValueError("")
        
        
        path = self.strategy.findPath(self.maze, self.maze.start, self.maze.exit)
        
        self.notify({
            'type': 'path_found',
            'maze': self.maze,
            'path': path
        })
        
        return path

class Player:
    def __init__(self, start_cell):
        self.currentCell = start_cell
        self.previousCell = None
    
    def moveTo(self, cell):
        self.previousCell = self.currentCell
        self.currentCell = cell
    
    def undoMove(self):
        if self.previousCell:
            self.currentCell, self.previousCell = self.previousCell, None
            return True
        return False


class Command:
    def execute(self):
        pass
    
    def undo(self):
        pass

class MoveCommand(Command):
    def __init__(self, player, direction, maze):
        self.player = player
        self.dx, self.dy = direction
        self.maze = maze
        self.executed = False
    
    def execute(self):
        new_x = self.player.currentCell.x + self.dx
        new_y = self.player.currentCell.y + self.dy
        new_cell = self.maze.getCell(new_x, new_y)
        
        if new_cell and new_cell.isPassable():
            self.player.moveTo(new_cell)
            self.executed = True
            return True
        return False
    
    def undo(self):
        if self.executed:
            self.player.undoMove()
            self.executed = False
            return True
        return False

def clear_console():
    os.system('cls' if os.name == 'nt' else 'clear')

def render_maze_with_player(maze, player, path=None):
    path_set = set(path) if path else set()
    
    for y in range(maze.height):
        for x in range(maze.width):
            cell = maze.getCell(x, y)
            
            if cell == player.currentCell:
                print('P', end='')
            elif cell == maze.start:
                print('S', end='')
            elif cell == maze.exit:
                print('E', end='')
            elif cell in path_set:
                print('.', end='')
            elif cell.isWall:
                print('#', end='')
            else:
                print(' ', end='')
        print()


def run_game(maze, path=None):
    player = Player(maze.start)
    history = []
    
    directions = {
        'w': (0, -1),   
        's': (0, 1),    
        'a': (-1, 0),   
        'd': (1, 0)     
    }
    
    print(" W/A/S/D - движение, U - отмена, Q - выход")
    if path:
        print(f"мин путь {len(path)} шагов")
    
    while True:
        print()
        render_maze_with_player(maze, player, path)
        
        if player.currentCell == maze.exit:
            print("\n*** выход ***")
            break
        
        key = input("\n> ").lower()
        
        if key == 'q':
            print("выход из игры")
            break
        elif key == 'u':
            if history:
                cmd = history.pop()
                cmd.undo()
                print("отмена хода")
            else:
                print("нет ходов")
        elif key in directions:
            cmd = MoveCommand(player, directions[key], maze)
            if cmd.execute():
                history.append(cmd)
            else:
                print("стена")
        else:
            print("неизвестно")