import _ from "lodash";

export const s3ContentsToTree = (
  s3Contents,
  props = {},
  reducer: (...args: unknown[]) => Record<string, unknown> = () => ({})
) => {
  let __result = [];
  let level = { __result, __prefix: "" };
  props = Object.assign(
    {
      key: "key",
      label: "label",
      children: "children",
    },
    props
  );

  s3Contents.forEach((s3Content) => {
    s3Content.Key.split("/").reduce((r, label, i, a) => {
      if (!r[label]) {
        const __prefix = `${r.__prefix ? r.__prefix + "/" : ""}${label}`;
        r[label] = { __result: [], __prefix };
        r.__result.push({
          [props.key]: __prefix,
          [props.label]: label,
          [props.children]: r[label].__result,
          // NOTE 这里要小心覆盖掉props.key props.label props.children
          ...reducer(r, label, i, a, s3Content),
        });
      }

      return r[label];
    }, level);
  });
  return __result;
};

export const trimTreeForSideBar = (tree) => {};

type TreeNodeLike = {
  children?: TreeNodeLike[];
};

export const getTreeFlatten = <T extends TreeNodeLike>(
  treeNode: T,
  order: "preorder" | "postorder" = "preorder",
  mode: "all" | "leaf" = "leaf"
): T[] => {
  if (treeNode.children?.length) {
    const result = _.flatMap<T, T>(treeNode.children as T[], (node) =>
      getTreeFlatten(node, order, mode)
    )
    if (mode === 'all') {
      if (order === 'preorder') {
        result.unshift(treeNode)
      } else if (order === 'postorder') {
        result.push(treeNode)
      }
    }
    return result
  }
  return [treeNode];
};