import com.aaa.controller.vm.MenuVM;
import com.aaa.entity.Menu;

import java.util.ArrayList;
import java.util.List;

/**
 * 組裝選單樹工具類
 * Created by cws
 * @author Administrator
 */
public class MenuTreeUtil {

    public static MenuVM getTree(List<Menu> list) {

        //判斷是否有獲取到資料
        if (list == null || list.size() < 1) {
            return null;
        }
        return buildTree(getRoot(list), list);
    }

    private static MenuVM buildTree(MenuVM pnode, List<Menu> nodes) {
        List<MenuVM> childs = new ArrayList<>();
        for (Menu tmp : nodes) {
            if (pnode.getId().equals(tmp.getParentId())) {
                childs.add(new MenuVM(tmp));
            }
        }

        //二次遞迴遍歷子節點
        if (childs.size() > 0) {
            pnode.setSubMenu(childs);
            for (MenuVM ptmp : childs) {
                buildTree(ptmp, nodes);
            }
        }
        return pnode;
    }

    /**
     * 獲取一級目錄
     *
     * @param list
     */
    private static MenuVM getRoot(List<Menu> list) {
        for (Menu po : list) {
            if ("#".equals(po.getParentId())) {
                return new MenuVM(po);
            }
        }
        return null;
    }


    /**
     * @param list
     */
    public static List<MenuVM> getMenu(List<Menu> list) {
        //判斷是否有獲取到資料
        if (list == null || list.size() < 1) {
            return null;
        }

        return getTree(list) == null ? null : getTree(list).getSubMenu();
    }

}