import { CascaderOption, CascaderConfig, convertConfig } from './types';

export const formatTree = (
  tree: CascaderOption[],
  parent: CascaderOption | null,
  config: CascaderConfig
): CascaderOption[] =>
  tree.map((node: CascaderOption) => {
    const { value: valueKey = 'value', text: textKey = 'text', children: childrenKey = 'children' } = config;

    const { [valueKey]: value, [textKey]: text, [childrenKey]: children, ...others } = node;

    const newNode: CascaderOption = {
      loading: false,
      ...others,
      level: parent ? ((parent && parent.level) || 0) + 1 : 0,
      value,
      text,
      children,
      _parent: parent
    };

    if (newNode.children && newNode.children.length) {
      newNode.children = formatTree(newNode.children, newNode, config);
    }

    return newNode;
  });

export const eachTree = (tree: CascaderOption[], cb: (node: CascaderOption) => any): void => {
  let i = 0;
  let node: CascaderOption;
  while ((node = tree[i++])) {
    if (cb(node) === true) {
      break;
    }

    if (node.children && node.children.length) {
      eachTree(node.children, cb);
    }
  }
};

const defaultConvertConfig = {
  topId: null,
  idKey: 'id',
  pidKey: 'pid',
  sortKey: ''
};
export const convertListToOptions = (list: CascaderOption[], options: convertConfig): CascaderOption[] => {
  const mergedOptions = {
    ...defaultConvertConfig,
    ...(options || {})
  };

  const { topId, idKey, pidKey, sortKey } = mergedOptions;

  let result: CascaderOption[] = [];
  let map: any = {};

  list.forEach((node: CascaderOption) => {
    node = { ...node };
    const { [idKey]: id, [pidKey]: pid } = node;
    const children = (map[pid] = map[pid] || []);

    if (!result.length && pid === topId) {
      result = children;
    }

    children.push(node);

    node.children = map[id] || (map[id] = []);
  });

  if (sortKey) {
    Object.keys(map).forEach((i) => {
      if (map[i].length > 1) {
        map[i].sort((a: CascaderOption, b: CascaderOption) => a[sortKey] - b[sortKey]);
      }
    });
  }

  map = null;

  return result;
};