import React, { useState } from "react";
import { useEffect } from "react";
import { Tree } from "antd";
import type { DataNode, TreeProps } from "antd/es/tree";

type TreeNodeData = {
  key: string;
  title: string;
  children: TreeNodeData[];
  level: number;
};
export type ListNodeData = {
  key: string;
  title: string;
  level: number;
};

var tocActivePath: TreeNodeData[] = [];
function tocGetTreeData(articles: ListNodeData[], active = "") {
  let treeData = [];

  let treeParents = [];
  let rootNode: TreeNodeData = {
    key: "0",
    title: "root",
    level: 0,
    children: [],
  };
  treeData.push(rootNode);
  let lastInsNode: TreeNodeData = rootNode;

  let iCurrLevel = 0;
  for (let index = 0; index < articles.length; index++) {
    const element = articles[index];

    let newNode: TreeNodeData = {
      key: element.key,
      title: element.title,
      children: [],
      level: element.level,
    };
    /*
		if (active == element.article) {
			newNode["extraClasses"] = "active";
		}
*/
    if (newNode.level > iCurrLevel) {
      //新的层级比较大，为上一个的子目录
      treeParents.push(lastInsNode);
      lastInsNode.children.push(newNode);
    } else if (newNode.level === iCurrLevel) {
      //目录层级相同，为平级
      treeParents[treeParents.length - 1].children.push(newNode);
    } else {
      // 小于 挂在上一个层级
      while (treeParents.length > 1) {
        treeParents.pop();
        if (treeParents[treeParents.length - 1].level < newNode.level) {
          break;
        }
      }
      treeParents[treeParents.length - 1].children.push(newNode);
    }
    lastInsNode = newNode;
    iCurrLevel = newNode.level;

    if (active === element.key) {
      tocActivePath = [];
      for (let index = 1; index < treeParents.length; index++) {
        tocActivePath.push(treeParents[index]);
      }
    }
  }
  return treeData[0].children;
}

function treeToList(treeNode: TreeNodeData[]): ListNodeData[] {
  let iTocTreeCurrLevel = 1;

  let arrTocTree: ListNodeData[] = [];

  for (const iterator of treeNode) {
    getTreeNodeData(iterator);
  }

  function getTreeNodeData(node: TreeNodeData) {
    let children = 0;
    if (typeof node.children != "undefined") {
      children = node.children.length;
    }
    arrTocTree.push({
      key: node.key,
      title: node.title,
      level: iTocTreeCurrLevel,
    });
    if (children > 0) {
      iTocTreeCurrLevel++;
      for (const iterator of node.children) {
        getTreeNodeData(iterator);
      }
      iTocTreeCurrLevel--;
    }
  }

  return arrTocTree;
}
interface IWidgetEditableTree {
  treeData: ListNodeData[];
  onChange?: Function;
}
const Widget = ({ treeData, onChange }: IWidgetEditableTree) => {
  const data = tocGetTreeData(treeData);
  console.log("treedata", data);
  const [gData, setGData] = useState(data);
  useEffect(() => {
    const data = tocGetTreeData(treeData);
    setGData(data);
  }, [treeData]);

  const onDragEnter: TreeProps["onDragEnter"] = (info) => {
    console.log(info);
    // expandedKeys 需要受控时设置
    // setExpandedKeys(info.expandedKeys)
  };

  const onDrop: TreeProps["onDrop"] = (info) => {
    console.log(info);
    const dropKey = info.node.key;
    const dragKey = info.dragNode.key;
    const dropPos = info.node.pos.split("-");
    const dropPosition =
      info.dropPosition - Number(dropPos[dropPos.length - 1]);

    const loop = (
      data: DataNode[],
      key: React.Key,
      callback: (node: DataNode, i: number, data: DataNode[]) => void
    ) => {
      for (let i = 0; i < data.length; i++) {
        if (data[i].key === key) {
          return callback(data[i], i, data);
        }
        if (data[i].children) {
          loop(data[i].children!, key, callback);
        }
      }
    };
    const data = [...gData];

    // Find dragObject
    let dragObj: DataNode;
    loop(data, dragKey, (item, index, arr) => {
      arr.splice(index, 1);
      dragObj = item;
    });

    if (!info.dropToGap) {
      // Drop on the content
      loop(data, dropKey, (item) => {
        item.children = item.children || [];
        // where to insert 示例添加到头部，可以是随意位置
        item.children.unshift(dragObj);
      });
    } else if (
      ((info.node as any).props.children || []).length > 0 && // Has children
      (info.node as any).props.expanded && // Is expanded
      dropPosition === 1 // On the bottom gap
    ) {
      loop(data, dropKey, (item) => {
        item.children = item.children || [];
        // where to insert 示例添加到头部，可以是随意位置
        item.children.unshift(dragObj);
        // in previous version, we use item.children.push(dragObj) to insert the
        // item to the tail of the children
      });
    } else {
      let ar: DataNode[] = [];
      let i: number;
      loop(data, dropKey, (_item, index, arr) => {
        ar = arr;
        i = index;
      });
      if (dropPosition === -1) {
        ar.splice(i!, 0, dragObj!);
      } else {
        ar.splice(i! + 1, 0, dragObj!);
      }
    }
    setGData(data);
    if (typeof onChange !== "undefined") {
      onChange(treeToList(data));
    }
  };

  return (
    <>
      <Tree
        rootClassName="draggable-tree"
        draggable
        blockNode
        onDragEnter={onDragEnter}
        onDrop={onDrop}
        treeData={gData}
      />
    </>
  );
};

export default Widget;