EpicHeads/main/java/com/songoda/epicheads/menu/CacheHeadsMenu.java

package com.songoda.epicheads.menu;

import com.songoda.epicheads.cache.CacheFile;
import com.songoda.epicheads.cache.CacheHead;
import com.songoda.epicheads.menu.ui.Bounds;
import com.songoda.epicheads.menu.ui.InventoryMenu;
import com.songoda.epicheads.menu.ui.MenuResponse;
import com.songoda.epicheads.menu.ui.element.Element;
import com.songoda.epicheads.menu.ui.item.Button;
import com.songoda.epicheads.menu.ui.item.Item;
import com.songoda.epicheads.util.Checks;
import com.songoda.epicheads.util.Stringify;
import org.bukkit.ChatColor;
import org.bukkit.Material;

import java.util.List;
import java.util.function.Function;

public class CacheHeadsMenu extends Element {

	public static final Item defaultClose = Item.create(Material.REDSTONE_BLOCK).name("&cClose Menu");
	public static final Item defaultBack = Item.create(Material.REDSTONE_BLOCK).name("&cBack to Categories");
	public static final Item defaultSearch = Item.create(Material.COMPASS).name("&7Search Heads");
	public static final String defaultCategoriesTitle = "Categories";
	public static final String defaultCategoryTitle = "%category%";

	public static final Template defaultTemplate = new Template(CategoriesMenu.defaultTemplate, HeadsMenu.defaultTemplate, defaultClose, defaultBack, defaultSearch, defaultCategoriesTitle, defaultCategoryTitle);

	private Template template;

	private final CacheFile cache;
	private final InventoryMenu inventoryMenu;

	private final CategoriesMenu categoriesMenu;
	private final HeadsMenu headsMenu;

	private String selectedCategory = null;

	public CacheHeadsMenu(CacheFile cache, InventoryMenu inventoryMenu, Bounds bounds, Function<CacheHead, MenuResponse> onSelect) {
		super(bounds);

		Checks.ensureNonNull(cache, "cache");
		Checks.ensureNonNull(inventoryMenu, "inventoryMenu");
		Checks.ensureNonNull(onSelect, "onSelect");
		Checks.ensureTrue(bounds.height >= 3, "bounds must have a height of at least 3");

		this.cache = cache;
		this.inventoryMenu = inventoryMenu;

		this.categoriesMenu = new CategoriesMenu(cache, bounds, this::selectCategory);
		this.headsMenu = new HeadsMenu(bounds, onSelect);

		setTemplate(defaultTemplate);
	}

	public boolean onCategoriesScreen() {
		return selectedCategory == null;
	}

	public MenuResponse close() {
		return MenuResponse.CLOSE;
	}

	public MenuResponse back() {
		this.selectedCategory = null;

		inventoryMenu.setTitle(template.getCategoriesTitle());

		return MenuResponse.UPDATE;
	}

	public MenuResponse search() {
		inventoryMenu.getPlayer().sendMessage("Search");

		return MenuResponse.NONE;
	}

	public MenuResponse selectCategory(String category) {
		Checks.ensureNonNull(category, "category");

		List<CacheHead> heads = cache.getCategoryHeads(category);

		if (heads.size() == 0) {
			return back();
		}

		this.selectedCategory = category;
		this.headsMenu.setItems(heads);

		inventoryMenu.setTitle(template.getCategoryTitle(category));

		return MenuResponse.UPDATE;
	}

	@Override
	public Button[] getItems() {
		if (onCategoriesScreen()) {
			return categoriesMenu.getItems();
		} else {
			return headsMenu.getItems();
		}
	}

	public void setTemplate(Template template) {
		Checks.ensureNonNull(template, "template");

		this.template = template;
		this.template.init(this);

		if (onCategoriesScreen()) {
			inventoryMenu.setTitle(template.getCategoriesTitle());
		} else {
			inventoryMenu.setTitle(template.getCategoryTitle(selectedCategory));
		}
	}

	@Override
	public String toString() {
		return Stringify.builder().entry("template", template).entry("cache", cache).entry("headsMenu", headsMenu).entry("categoriesMenu", categoriesMenu).toString();
	}

	public static final class Template {

		private final CategoriesMenu.Template categoriesTemplate;
		private final HeadsMenu.Template headsTemplate;
		private final Item close;
		private final Item back;
		private final Item search;
		private final String categoriesTitle;
		private final String categoryTitle;

		public Template(CategoriesMenu.Template categoriesTemplate, HeadsMenu.Template headsTemplate, Item close, Item back, Item search, String categoriesTitle, String categoryTitle) {

			Checks.ensureNonNull(categoriesTemplate, "categoriesTemplate");
			Checks.ensureNonNull(headsTemplate, "headsTemplate");
			Checks.ensureNonNull(close, "close");
			Checks.ensureNonNull(back, "back");
			Checks.ensureNonNull(search, "search");
			Checks.ensureNonNull(categoriesTemplate, "categoriesTemplate");
			Checks.ensureNonNull(categoryTitle, "categoryTitle");

			this.categoriesTemplate = categoriesTemplate;
			this.headsTemplate = headsTemplate;
			this.close = close;
			this.back = back;
			this.search = search;
			this.categoriesTitle = ChatColor.translateAlternateColorCodes('&', categoriesTitle);
			this.categoryTitle = ChatColor.translateAlternateColorCodes('&', categoryTitle);
		}

		public String getCategoriesTitle() {
			return categoriesTitle;
		}

		public String getCategoryTitle(String category) {
			return categoryTitle.replace("%category%", category);
		}

		private void init(CacheHeadsMenu menu) {
			Button close = this.close.buildButton(menu::close);
			Button back = this.back.buildButton(menu::back);
			Button search = this.search.buildButton(menu::search);

			menu.categoriesMenu.setTemplate(categoriesTemplate, close, search);
			menu.headsMenu.setTemplate(headsTemplate, back, search);
		}

		@Override
		public String toString() {
			return Stringify.builder().entry("categoriesTemplate", categoriesTemplate).entry("headsTemplate", headsTemplate).toString();
		}

	}

}