public abstract class AbstractGui implements Listener, IGui {
    @Getter private Inventory inventory;
    @Getter @Setter private InventoryType inventoryType = InventoryType.CHEST;
    @Getter @Setter private String title, key;
    @Getter @Setter private int slots;
    @Getter private int maxPages;
    @Getter private int currentPage = 1;
    @Getter private final Map<Integer, Map<Integer, ItemStack>> pages = new HashMap<>();
    @Getter private final HashMap<Integer, ItemStack> items = new HashMap<>();

    public abstract void run(Player player);

    public Inventory initializeInventory() throws InventoryDoesNotExistException {
        if (inventoryType.equals(InventoryType.CHEST)) {
            inventory = Bukkit.createInventory(null, slots, title);

            Map<Integer, ItemStack> items = pages.get(currentPage);

            items.forEach((slot, item) -> inventory.setItem(slot, item));

            return inventory;
        } else if (inventoryType.equals(InventoryType.ANVIL)) {
            return Bukkit.createInventory(null, InventoryType.ANVIL, title);
        } else {
            throw new InventoryDoesNotExistException();
        }
    }

    private void queueItems(Player player) {
        pages.get(currentPage).forEach((slot, item) -> inventory.setItem(slot, item));

        player.openInventory(inventory);
    }

    public void nextPage(Player player) {
        if (currentPage < maxPages) {
            currentPage++;

            this.queueItems(player);
        } else {
            player.closeInventory();
            player.sendMessage(MessagesUtils.getMessage("gui.last-page"));
        }
    }

    public void initializeSlots() {
        if (items.keySet().size() > slots) {
            int pagesEst = items.keySet().size() / slots;
            boolean leftOver = items.keySet().size() % slots > 0;

            if (leftOver || pagesEst == 0) {
                pagesEst++;
            }

            for (int i = 0; i < items.size(); i++) {
                Map<Integer, ItemStack> page = new HashMap<>();
                // finish this please ty
            }

        } else {
            Map<Integer, ItemStack> page = new HashMap<>();

            for (int slot : items.keySet()) {
                page.put(slot, items.get(slot));

                pages.put(1, page);
            }
        }
    }

    @EventHandler
    public void onInventoryClick(final InventoryClickEvent e) {
        if (e.getInventory() == inventory) {
            e.setCancelled(true);

            if (e.getRawSlot() == slots) {

            }
        }
    }

    @EventHandler
    public void onInventoryDrag(final InventoryDragEvent e) {
        if (e.getInventory() == inventory) {
            e.setCancelled(true);
        }
    }

    @EventHandler
    public void onInventoryMoveItem(final InventoryMoveItemEvent e) {
        if (e.getInitiator() == inventory) {
            e.setCancelled(true);
        }
    }
}