import sys
import os

class Tile:
    """Клетка лабиринта."""
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.wall = False
        self.start = False
        self.exit = False

    def passable(self):
        return not self.wall


class Labyrinth:
    """Модель лабиринта."""
    def __init__(self, width, height):
        self.width = width
        self.height = height
        self._tiles = [[Tile(x, y) for x in range(width)] for y in range(height)]
        self.start_tile = None
        self.exit_tile = None

    def get_tile(self, x, y):
        if 0 <= x < self.width and 0 <= y < self.height:
            return self._tiles[y][x]
        return None

    def set_tile(self, x, y, kind):
        tile = self.get_tile(x, y)
        if tile is None:
            return
        if kind == 'wall':
            tile.wall = True
        elif kind == 'start':
            if self.start_tile:
                self.start_tile.start = False
            tile.start = True
            tile.wall = False
            self.start_tile = tile
        elif kind == 'exit':
            if self.exit_tile:
                self.exit_tile.exit = False
            tile.exit = True
            tile.wall = False
            self.exit_tile = tile
        elif kind == 'path':
            tile.wall = False

    def neighbours(self, tile):
        dirs = [(0, -1), (0, 1), (-1, 0), (1, 0)]
        result = []
        for dx, dy in dirs:
            nx, ny = tile.x + dx, tile.y + dy
            nb = self.get_tile(nx, ny)
            if nb and nb.passable():
                result.append(nb)
        return result


class LabyrinthLoader:
    def load(self, filename):
        raise NotImplementedError


class TextLabyrinthLoader(LabyrinthLoader):
    def load(self, filename):
        with open(filename, 'r', encoding='utf-8') as f:
            lines = [line.rstrip('\n') for line in f]
        h = len(lines)
        w = max(len(line) for line in lines) if h > 0 else 0
        start_cnt = 0
        exit_cnt = 0
        lab = Labyrinth(w, h)

        for y, line in enumerate(lines):
            for x, ch in enumerate(line):
                if ch == '#':
                    lab.set_tile(x, y, 'wall')
                elif ch == 'S':
                    lab.set_tile(x, y, 'start')
                    start_cnt += 1
                elif ch == 'E':
                    lab.set_tile(x, y, 'exit')
                    exit_cnt += 1
                else:
                    lab.set_tile(x, y, 'path')
        if start_cnt != 1 or exit_cnt != 1:
            raise ValueError(f"Нужны ровно S и E, найдено S={start_cnt}, E={exit_cnt}")
        return lab


if __name__ == "__main__":
    # Простая проверка загрузки и вывода лабиринта
    loader = TextLabyrinthLoader()
    lab = loader.load("maze/maze1.txt")   # временно создадим позже

    os.system('cls' if os.name == 'nt' else 'clear')
    print("=" * (lab.width * 2 + 4))
    print("   ЛАБИРИНТ (загружен)")
    print("=" * (lab.width * 2 + 4))
    for y in range(lab.height):
        print("  ", end='')
        for x in range(lab.width):
            t = lab.get_tile(x, y)
            if t == lab.start_tile:
                print('S', end=' ')
            elif t == lab.exit_tile:
                print('E', end=' ')
            elif t.wall:
                print('#', end=' ')
            else:
                print('.', end=' ')
        print()
    print("=" * (lab.width * 2 + 4))