from js import document, setInterval, clearInterval, alert
from pyodide.ffi import create_proxy
import random
import time

GRID_SIZE = 4

puzzle = []
move_count = 0
start_time = None
timer_interval = None


def create_solvable_puzzle():
    numbers = list(range(1, GRID_SIZE * GRID_SIZE))
    numbers.append(0)

    while True:
        random.shuffle(numbers)
        if is_solvable(numbers):
            return numbers


def is_solvable(numbers):
    inv_count = 0
    for i in range(len(numbers)):
        for j in range(i + 1, len(numbers)):
            if numbers[i] and numbers[j] and numbers[i] > numbers[j]:
                inv_count += 1

    empty_row = GRID_SIZE - (numbers.index(0) // GRID_SIZE)

    if GRID_SIZE % 2 == 1:
        return inv_count % 2 == 0
    else:
        if empty_row % 2 == 0:
            return inv_count % 2 == 1
        else:
            return inv_count % 2 == 0


def draw():
    container = document.getElementById("puzzle-container")
    container.innerHTML = ""

    for i, value in enumerate(puzzle):
        tile = document.createElement("div")

        if value == 0:
            tile.className = "tile empty"
        else:
            tile.className = "tile"
            tile.innerText = str(value)
            tile.addEventListener(
                "click",
                create_proxy(lambda event, idx=i: move_tile(idx))
            )

        container.appendChild(tile)


def move_tile(index):
    global move_count

    empty_index = puzzle.index(0)

    row, col = divmod(index, GRID_SIZE)
    empty_row, empty_col = divmod(empty_index, GRID_SIZE)

    if (abs(row - empty_row) == 1 and col == empty_col) or \
       (abs(col - empty_col) == 1 and row == empty_row):

        puzzle[empty_index], puzzle[index] = puzzle[index], puzzle[empty_index]

        move_count += 1
        document.getElementById("moves").innerText = move_count

        draw()

        if is_winner():
            stop_timer()
            alert(f"You won in {move_count} moves and {int(time.time() - start_time)} seconds!")


def is_winner():
    return puzzle == list(range(1, GRID_SIZE * GRID_SIZE)) + [0]


def start_timer():
    global start_time, timer_interval

    start_time = time.time()

    def update_timer():
        elapsed = int(time.time() - start_time)
        document.getElementById("timer").innerText = elapsed

    timer_interval = setInterval(create_proxy(update_timer), 1000)


def stop_timer():
    global timer_interval
    if timer_interval:
        clearInterval(timer_interval)


def restart_game(event=None):
    global puzzle, move_count

    stop_timer()

    puzzle = create_solvable_puzzle()
    move_count = 0

    document.getElementById("moves").innerText = 0
    document.getElementById("timer").innerText = 0

    draw()
    start_timer()

def set_level(event):
    alert("Level selection not implemented yet!")
    print("Level button clicked")

def show_help(event):
    alert("Help not implemented yet!")

# Bind restart button
restart_button = document.getElementById("restart-btn")
restart_button.addEventListener("click", create_proxy(restart_game))

# Bind level button
level_button = document.getElementById("level-btn")
level_button.addEventListener("click", create_proxy(set_level))

# Bind help button
help_button = document.getElementById("help-btn")
help_button.addEventListener("click", create_proxy(show_help))

# Initialize game
restart_game()