import Immutable, { List, Map } from "immutable";

/**

 *构建树

 * @param dataList 数据源，array/Immutable.List

 * @param arg 参数，可选

 * @param arg.rootCode 根节点，默认为#

 * @param arg.parentField 关联父节点key字段 默认为parent

 * @param arg.keyField 当前节点key字段，默认为id

 * @param arg.iconRender 图标渲染 func(item,arg)

 * @param arg.keyRender func key渲染 func(item,arg) //当需要key做处理时使用，默认为keyField字段值，一般不使用

 * @param arg.textRender 文字渲染 func(item,arg) 默认取text字段

 * @param arg.checkableRender 复选框显示 func(item,arg) 当树为checkable时使用 默认为true

 * @returns {Immutable.List<*>}

 */

export const buildTree = (dataList = List([]), arg) => {

  if (!(dataList instanceof List)) {

    dataList = Immutable.fromJS(dataList)

  }

  const config = {

    rootCode: "#",

    parentField: "parent",

    keyField: "id",

    iconRender: undefined,

    keyRender: (nodeInfo, arg) => {

      return nodeInfo.get(arg.keyField)

    },

    textRender: (nodeInfo, arg) => {

      return nodeInfo.get("text")

    },

    checkableRender: (nodeInfo, arg) => {

      return true

    },

    ...arg

  }

  let treeData = List([])

  if (dataList.size === 0) {

    return treeData

  }

  const groupTree = dataList.groupBy(nodeInfo => nodeInfo.get(config.parentField))

  if (groupTree && groupTree.size > 0) {

    let collection = groupTree.get(config.rootCode);

    if (collection && collection.size > 0) {

      collection.forEach(role => {

        let node = creatNode(role, config)

        let list = buildChildren(node, role, groupTree, config);

        if (list && list.size > 0) {

          node = node.set("children", list)

        }

        treeData = treeData.push(node)

      })

    }

  }

  return treeData

}

//构建子树

const buildChildren = (newParent, oldParent, groupTree = Map({}), config) => {

  let childList = groupTree.get(oldParent.get(config.keyField));

  let children = List([]);

  if (childList && childList.size > 0) {

    childList.forEach(role => {

      let node = creatNode(role, config)

      let list = buildChildren(node, role, groupTree, config);

      if (list && list.size > 0) {

        node = node.set("children", list)

      }

      children = children.push(node)

    })

  }

  return children

}

//创建节点,可扩充属性

const creatNode = (nodeInfo, config) => {

  let node = {

    key: config.keyRender(nodeInfo, config),

    title: config.textRender(nodeInfo, config)

  }

  if (config.iconRender) {

    node.icon = config.iconRender(nodeInfo, config)

  }

  if (config.checkableRender) {

    node.checkable = config.checkableRender(nodeInfo, config)

  }

  return Map(node)

}