package com.estate.expert.admin.utils.tree;

import com.estate.expert.admin.enums.BizResultCode;
import com.fasterxml.jackson.annotation.JsonIgnore;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

import javax.persistence.Transient;
import java.util.*;

@ApiModel(value = "树节点")
@Data
public class TreeNode<T> {

    @ApiModelProperty(value = "节点id，在同一层级下唯一")
    private Integer id = 0;

    @ApiModelProperty(value = "节点名称，同一层级下唯一")
    private String name;

    @ApiModelProperty(value = "子节点Id计数器，自增")
    private int childIdCnt = 0;

    @ApiModelProperty(value = "节点中的数据")
    private T data;

    @ApiModelProperty(value = "节点的路径，全局唯一")
    private String path;

    @Transient
    @JsonIgnore
    private TreeNode<T> parent;

    @ApiModelProperty(value = "子节点")
    public SortedMap<Integer, TreeNode<T>> children = new TreeMap<>();

    public TreeNode(){
    }

    public TreeNode(String name) {
        this.name = name;
        this.id = 0;
    }

    public TreeNode(String name, T data) {
        this.name = name;
        this.data = data;
        this.id = 0;
    }

    public TreeNode<T> ShadowNode() {
        TreeNode<T> shadow = new TreeNode<>(this.getName(), this.getData());
        shadow.setId(this.getId());
        shadow.setPath(this.getPath());
        shadow.setData(this.getData());
        shadow.setName(this.getName());
        return shadow;
    }

    public TreeNode<T> addChild(TreeNode<T> child) {
        children.put(child.getId(), child);
        return child;
    }

    public TreeNode<T> addChild(String name) {
        return addChild(name, null);
    }

    public TreeNode<T> addChild(String name, T data) {
        for(TreeNode<T> child : children.values()) {
            BizResultCode.HIERARCHY_NODE_NAME_ALREADY_EXISTS.check(child.getName().equals(name));
        }

        TreeNode<T> child = new TreeNode<>(name, data);
        child.setId(childIdCnt++);
        child.setName(name);
        child.setData(data);
        child.setParent(this);
        this.children.put(child.getId(), child);
        return child;
    }

    public void removeChild(Integer id) {
        children.remove(id);
    }

    /**
     * 获取该节点下所有的路径
     * 以及所在分支的路径
     */
    public List<String> allPaths(){
        var list = new ArrayList<String>();
        for (var child : children.values()){
            list.addAll(child.allPaths());
        }
        list.add(getPath());

        var parent = getParent();
        while (parent != null){
            list.add(parent.getPath());
            parent = parent.getParent();
        }
        return list;
    }

    /**
     * 递归查找节点
     * 这里，由于树的根节点是单一的
     * 根节点的path= "/"
     */
    public void buildPath() {
        StringBuilder builder = new StringBuilder();
        TreeNode<T> node = this;
        while (true) {
            var parent = node.getParent();
            if(parent == null) {
                break;
            }

            builder.insert(0, node.getId());
            builder.insert(0, "/");
            node = parent;
        }
        if(builder.isEmpty()) {
            path = "/";
            return;
        }
        path = builder.toString();
    }

    @JsonIgnore
    public String getNamePath(){
        StringBuilder builder = new StringBuilder();
        TreeNode<T> node = this;
        while (true) {
            var parent = node.getParent();
            if(parent == null)
                break;

            builder.insert(0, node.getName());
            builder.insert(0, "/");
            node = parent;
        }

        if(builder.isEmpty())
            return "/";
        return builder.toString();
    }

    @JsonIgnore
    public List<String> getNames(){
        List<String> names = new ArrayList<>();
        TreeNode<T> node = this;
        while (true) {
            names.add(node.getName());
            var parent = node.getParent();
            if(parent == null)
                break;

            node = parent;
        }
        return names;
    }

    @JsonIgnore
    public int getDepth(){
        // 根节点的深度为0
        int depth = 0;
        TreeNode<T> node = this;
        while (true) {
            var parent = node.getParent();
            if(parent == null)
                break;

            depth++;
            node = parent;
        }
        return depth;
    }

    @JsonIgnore
    public List<TreeNode<T>> getLeafNodes() {
        List<TreeNode<T>> leafNodes = new ArrayList<>();
        getLeafNodes(this, leafNodes);
        return leafNodes;
    }

    private void getLeafNodes(TreeNode<T> node, List<TreeNode<T>> leafNodes) {
        if (node.getChildren().isEmpty()) {
            leafNodes.add(node);
        } else {
            for (TreeNode<T> child : node.getChildren().values()) {
                getLeafNodes(child, leafNodes);
            }
        }
    }

    @Override
    public String toString() {
        return "TreeNode{" +
                "path=" + path +
                ", name='" + name +
                "', data=" + data + "}" ;
    }
}