import random as rand
from pathlib import Path


def generate_grid(height: int, width: int, fill_percent: int = 70):
    """
    Generates grid with a simple maze. Path is signed as 'p' and walls as 'w'. It always has walls surrounding it.
    :param height: height of the grid.
    :param width: width of the grid.
    :param fill_percent: percentage of walls in the maze (not counting surrounding walls).
    :return:
    """
    grid = []
    for i in range(height):
        grid.append([])
        for j in range(width):
            grid[i].append('w')

    path_percent = (100. - float(fill_percent)) / 100.
    grid_size = float((height-2) * (width-2))
    paths_number = int(path_percent * grid_size)

    start_point_y = height // 2
    start_point_x = width // 2
    grid[start_point_y][start_point_x] = 'p'
    set_paths = 1
    path_list = [(start_point_y, start_point_x)]

    while set_paths < paths_number:
        chosen_position = rand.randint(0, len(path_list)-1)
        random_growth = rand.randint(0, 3)
        if random_growth == 0:
            if path_list[chosen_position][0]+1 == height-1:
                continue
            else:
                new_y = path_list[chosen_position][0] + 1
                new_x = path_list[chosen_position][1]
                if grid[new_y][new_x] == 'w':
                    if grid[new_y][new_x-1] == 'p' or grid[new_y][new_x+1] == 'p' or grid[new_y+1][new_x] == 'p':
                        if rand.randint(0, 100) < 1:
                            grid[new_y][new_x] = 'p'
                            set_paths += 1
                            path_list.append((new_y, new_x))
                    else:
                        grid[new_y][new_x] = 'p'
                        set_paths += 1
                        path_list.append((new_y, new_x))

        elif random_growth == 1:
            if path_list[chosen_position][1]-1 == 0:
                continue
            else:
                new_y = path_list[chosen_position][0]
                new_x = path_list[chosen_position][1] - 1
                if grid[new_y][new_x] == 'w':
                    if grid[new_y][new_x-1] == 'p' or grid[new_y-1][new_x] == 'p' or grid[new_y+1][new_x] == 'p':
                        if rand.randint(0, 100) < 1:
                            grid[new_y][new_x] = 'p'
                            set_paths += 1
                            path_list.append((new_y, new_x))
                    else:
                        grid[new_y][new_x] = 'p'
                        set_paths += 1
                        path_list.append((new_y, new_x))

        elif random_growth == 2:
            if path_list[chosen_position][0]-1 == 0:
                continue
            else:
                new_y = path_list[chosen_position][0]-1
                new_x = path_list[chosen_position][1]
                if grid[new_y][new_x] == 'w':
                    if grid[new_y][new_x+1] == 'p' or grid[new_y][new_x-1] == 'p' or grid[new_y-1][new_x] == 'p':
                        if rand.randint(0, 100) < 1:
                            grid[new_y][new_x] = 'p'
                            set_paths += 1
                            path_list.append((new_y, new_x))
                    else:
                        grid[new_y][new_x] = 'p'
                        set_paths += 1
                        path_list.append((new_y, new_x))

        elif random_growth == 3:
            if path_list[chosen_position][1] + 1 == width-1:
                continue
            else:
                new_y = path_list[chosen_position][0]
                new_x = path_list[chosen_position][1] + 1
                if grid[new_y][new_x] == 'w':
                    if grid[new_y][new_x+1] == 'p' or grid[new_y-1][new_x] == 'p' or grid[new_y+1][new_x] == 'p':
                        if rand.randint(0, 100) < 1:
                            grid[new_y][new_x] = 'p'
                            set_paths += 1
                            path_list.append((new_y, new_x))
                    else:
                        grid[new_y][new_x] = 'p'
                        set_paths += 1
                        path_list.append((new_y, new_x))
    return grid


def write_grid_as_graph_to_file(grid, filename, path="grids/"):
    """
    Writes generated grid to file as a graph with weights
    :param grid: grid generated by function generate_grid
    :param filename: name of the file to save the graph to
    :param path: path to save the file in
    :return: None
    """
    with open(path + filename, 'w') as file:
        for i in range(1, len(grid)-1):
            for j in range(1, len(grid[i])-1):
                if grid[i][j] == 'p':
                    if grid[i-1][j] == 'p':
                        file.write(str(i) + " " + str(j) + "," + str(i-1) + " " + str(j) + "," + "1" + "\n")
                    if grid[i+1][j] == 'p':
                        file.write(str(i) + " " + str(j) + "," + str(i+1) + " " + str(j) + "," + "1" + "\n")
                    if grid[i][j-1] == 'p':
                        file.write(str(i) + " " + str(j) + "," + str(i) + " " + str(j-1) + "," + "1" + "\n")
                    if grid[i][j+1] == 'p':
                        file.write(str(i) + " " + str(j) + "," + str(i) + " " + str(j+1) + "," + "1" + "\n")


def read_grid_graph_from_file(filename, path="grids/"):
    N = set()
    A = {}
    A_b = {}
    w = {}
    with open(path + filename, "r") as file:
        line = file.readline()
        while line != '':
            split = line.strip("\n").split(",")

            fist_node_str_list = split[0].split(" ")
            second_node_str_list = split[1].split(" ")
            weight = int(split[2])

            first_node = (int(fist_node_str_list[0]), int(fist_node_str_list[1]))
            second_node = (int(second_node_str_list[0]), int(second_node_str_list[1]))

            N.add(first_node)
            N.add(second_node)
            if first_node not in A.keys():
                A[first_node] = [second_node]
            else:
                A[first_node].append(second_node)

            if second_node not in A_b.keys():
                A_b[second_node] = [first_node]
            else:
                A_b[second_node].append(first_node)

            w[(first_node, second_node)] = weight
            line = file.readline()
    return N, A, A_b, w


if __name__ == "__main__":
    n = [(20, 20), (50, 50), (100, 100), (150, 150), (250, 250), (500, 500)]
    for i in range(1, len(n)+1):
        p = "grids/" + str(n[i-1][0]) + "x" + str(n[i-1][1]) + "/"
        print("generating graphs group:", n[i - 1])
        for j in range(1, 51):
            f = "grid" + str(j)
            print(f)
            g = generate_grid(n[i-1][0]+2, n[i-1][1]+2)
            Path(p).mkdir(parents=True, exist_ok=True)
            write_grid_as_graph_to_file(g, f, p)
        print()