import random
from typing import List, NamedTuple, Tuple

# Python translation by Frank Palazzolo - 2/2021


class Maze(NamedTuple):
    used: List[List[int]]
    walls: List[List[int]]
    enter_col: int
    width: int
    length: int


def main() -> None:
    welcome_header()
    width, length = get_maze_dimensions()
    maze = build_maze(width, length)
    print_maze(maze)


def welcome_header() -> None:
    print(" " * 28 + "AMAZING PROGRAM")
    print(" " * 15 + "CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY")
    print()
    print()
    print()


def build_maze(width: int, length: int) -> Maze:
    # Build two 2D arrays
    #
    # used:
    #   Initially set to zero, unprocessed cells
    #   Filled in with consecutive non-zero numbers as cells are processed
    #
    # walls:
    #   Initially set to zero, (all paths blocked)
    #   Remains 0 if there is no exit down or right
    #   Set to 1 if there is an exit down
    #   Set to 2 if there is an exit right
    #   Set to 3 if there are exits down and right
    assert width >= 2 and length >= 2

    used = []
    walls = []
    for _ in range(length):
        used.append([0] * width)
        walls.append([0] * width)

    # Use direction variables with nice names
    GO_LEFT, GO_UP, GO_RIGHT, GO_DOWN = [0, 1, 2, 3]
    # Give Exit directions nice names
    EXIT_DOWN = 1
    EXIT_RIGHT = 2

    # Pick a random entrance, mark as used
    enter_col = random.randint(0, width - 1)
    row, col = 0, enter_col
    count = 1
    used[row][col] = count
    count = count + 1

    while count != width * length + 1:
        # remove possible directions that are blocked or
        # hit cells that we have already processed
        possible_dirs = [GO_LEFT, GO_UP, GO_RIGHT, GO_DOWN]
        if col == 0 or used[row][col - 1] != 0:
            possible_dirs.remove(GO_LEFT)
        if row == 0 or used[row - 1][col] != 0:
            possible_dirs.remove(GO_UP)
        if col == width - 1 or used[row][col + 1] != 0:
            possible_dirs.remove(GO_RIGHT)
        if row == length - 1 or used[row + 1][col] != 0:
            possible_dirs.remove(GO_DOWN)

        # If we can move in a direction, move and make opening
        if len(possible_dirs) != 0:
            direction = random.choice(possible_dirs)
            if direction == GO_LEFT:
                col = col - 1
                walls[row][col] = EXIT_RIGHT
            elif direction == GO_UP:
                row = row - 1
                walls[row][col] = EXIT_DOWN
            elif direction == GO_RIGHT:
                walls[row][col] = walls[row][col] + EXIT_RIGHT
                col = col + 1
            elif direction == GO_DOWN:
                walls[row][col] = walls[row][col] + EXIT_DOWN
                row = row + 1
            used[row][col] = count
            count = count + 1
        # otherwise, move to the next used cell, and try again
        else:
            while True:
                if col != width - 1:
                    col = col + 1
                elif row != length - 1:
                    row, col = row + 1, 0
                else:
                    row, col = 0, 0
                if used[row][col] != 0:
                    break

    # Add a random exit
    col = random.randint(0, width - 1)
    row = length - 1
    walls[row][col] = walls[row][col] + 1
    return Maze(used, walls, enter_col, width, length)


def get_maze_dimensions() -> Tuple[int, int]:
    while True:
        width_str, length_str = input("What are your width and length?").split(",")
        width = int(width_str)
        length = int(length_str)
        if width > 1 and length > 1:
            break
        print("Meaningless dimensions. Try again.")
    return width, length


def print_maze(maze: Maze) -> None:
    for col in range(maze.width):
        if col == maze.enter_col:
            print(".  ", end="")
        else:
            print(".--", end="")
    print(".")
    for row in range(maze.length):
        print("I", end="")
        for col in range(maze.width):
            if maze.walls[row][col] < 2:
                print("  I", end="")
            else:
                print("   ", end="")
        print()
        for col in range(maze.width):
            if maze.walls[row][col] == 0 or maze.walls[row][col] == 2:
                print(":--", end="")
            else:
                print(":  ", end="")
        print(".")


if __name__ == "__main__":
    main()