import sys
from collections import deque
import heapq
import time
import os
import csv
import matplotlib.pyplot as plt
import numpy as np


# ----------------------------- Модель клетки -----------------------------
class GridCell:
    def __init__(self, x, y):
        self._x = x
        self._y = y
        self._blocked = False
        self._entry = False
        self._exit_flag = False

    @property
    def x(self):
        return self._x

    @property
    def y(self):
        return self._y

    @property
    def is_wall(self):
        return self._blocked

    @is_wall.setter
    def is_wall(self, value):
        self._blocked = value

    @property
    def is_start(self):
        return self._entry

    @is_start.setter
    def is_start(self, value):
        self._entry = value

    @property
    def is_exit(self):
        return self._exit_flag

    @is_exit.setter
    def is_exit(self, value):
        self._exit_flag = value

    def passable(self):
        return not self._blocked


# ----------------------------- Модель лабиринта -----------------------------
class Labyrinth:
    def __init__(self, width, height):
        self._width = width
        self._height = height
        self._cells = [[GridCell(x, y) for x in range(width)] for y in range(height)]
        self._start_cell = None
        self._exit_cell = None

    @property
    def width(self):
        return self._width

    @property
    def height(self):
        return self._height

    @property
    def start(self):
        return self._start_cell

    @property
    def exit(self):
        return self._exit_cell

    def cell_at(self, x, y):
        if 0 <= x < self._width and 0 <= y < self._height:
            return self._cells[y][x]
        return None

    def configure_cell(self, x, y, cell_type):
        cell = self.cell_at(x, y)
        if cell is None:
            return

        if cell_type == 'wall':
            cell.is_wall = True
        elif cell_type == 'start':
            if self._start_cell:
                self._start_cell.is_start = False
            cell.is_start = True
            cell.is_wall = False
            self._start_cell = cell
        elif cell_type == 'exit':
            if self._exit_cell:
                self._exit_cell.is_exit = False
            cell.is_exit = True
            cell.is_wall = False
            self._exit_cell = cell
        elif cell_type == 'path':
            cell.is_wall = False

    def adjacent_cells(self, cell):
        neighbours = []
        directions = [(0, -1), (0, 1), (-1, 0), (1, 0)]
        for dx, dy in directions:
            nx, ny = cell.x + dx, cell.y + dy
            neighbour = self.cell_at(nx, ny)
            if neighbour and neighbour.passable():
                neighbours.append(neighbour)
        return neighbours


# ----------------------------- Загрузка лабиринта -----------------------------
class LabyrinthBuilder:
    def build_from_file(self, filename):
        raise NotImplementedError


class TxtLabyrinthBuilder(LabyrinthBuilder):
    def build_from_file(self, filename):
        with open(filename, 'r') as f:
            lines = [line.rstrip('\n') for line in f.readlines()]
        height = len(lines)
        width = max(len(line) for line in lines) if height > 0 else 0
        start_cnt = 0
        exit_cnt = 0
        lab = Labyrinth(width, height)

        for y, line in enumerate(lines):
            for x, ch in enumerate(line):
                if ch == "#":
                    lab.configure_cell(x, y, "wall")
                elif ch == "S":
                    lab.configure_cell(x, y, "start")
                    start_cnt += 1
                elif ch == "E":
                    lab.configure_cell(x, y, "exit")
                    exit_cnt += 1
                else:
                    lab.configure_cell(x, y, 'path')
        if start_cnt != 1 or exit_cnt != 1:
            raise ValueError(f"Maze must have exactly one S and one E. Found S={start_cnt}, E={exit_cnt}")
        return lab


if __name__ == "__main__":
    builder = TxtLabyrinthBuilder()
    maze = builder.build_from_file("maze/level1.txt")
    print(f"Maze loaded: {maze.width}x{maze.height}")