package com.upchina.rbac.vo;

import com.google.common.collect.Lists;
import cn.hutool.core.util.StrUtil;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;

public interface IParentChildVO<T extends IParentChildVO, PK> {

    PK getId();

    PK getPid();

    List<T> getChildren();

    void setChildren(List<T> list);

    default void buildParent(IParentChildVO vo, Map<PK, IParentChildVO> allMap, Map<PK, IParentChildVO> rootMap) {
        PK pid = (PK) vo.getPid();
        if (pid != null && ((pid instanceof String && StringUtils.isNotEmpty((String) pid) && !"0".equals(pid) && !"-1".equals(pid))
                || (pid instanceof Integer && (Integer) pid > 0)
                || (pid instanceof Long && (Long) pid > 0))) {
            IParentChildVO parent = allMap.get(vo.getPid());
            if (parent == null) return;
            List<IParentChildVO> children = parent.getChildren();
            if (children != null) {
                if (children.stream().noneMatch(child -> child.getId().equals(vo.getId()))) {
                    children.add(vo);
                }
            } else {
                parent.setChildren(Lists.newArrayList(vo));
            }
            buildParent(parent, allMap, rootMap);
        } else {
            rootMap.put((PK) vo.getId(), vo);
        }
    }

    default List<? extends IParentChildVO> buildTree(List<? extends IParentChildVO> voList, List<? extends IParentChildVO> allList) {
        Map<PK, IParentChildVO> allMap = allList.stream().collect(Collectors.toMap(vo -> (PK) vo.getId(), Function.identity()));
        Map<PK, IParentChildVO> rootMap = new HashMap<>();
        voList.forEach(vo -> buildParent(vo, allMap, rootMap));
        return Lists.newArrayList(rootMap.values());
    }
}