cn-rdms-web/src/views/system/shared/menu-tree.ts

type TreeNodeId = string | number;

type TreeNode = {
  id: TreeNodeId;
  parentId: TreeNodeId;
  sort?: number | null;
  children?: TreeNode[] | null;
};

export function buildMenuTree<T extends TreeNode>(list: T[]) {
  const nodeMap = new Map<TreeNodeId, T>();
  const roots: T[] = [];

  list.forEach(item => {
    nodeMap.set(item.id, {
      ...item,
      children: []
    });
  });

  nodeMap.forEach(node => {
    if (isRootParentId(node.parentId)) {
      roots.push(node);
      return;
    }

    const parent = nodeMap.get(node.parentId);

    if (!parent) {
      roots.push(node);
      return;
    }

    parent.children = [...(parent.children ?? []), node];
  });

  return sortMenuTree(roots);
}

export function collectDescendantIds<T extends Pick<TreeNode, 'id' | 'children'>>(nodes: T[], targetId: T['id']) {
  const target = findTreeNode(nodes, targetId);

  if (!target?.children?.length) {
    return [];
  }

  const ids: T['id'][] = [];

  walkTree(target.children, item => {
    ids.push(item.id as T['id']);
  });

  return ids;
}

function sortMenuTree<T extends TreeNode>(nodes: T[]) {
  const sortedNodes = [...nodes].sort((prev, next) => Number(prev.sort ?? 0) - Number(next.sort ?? 0));

  sortedNodes.forEach(node => {
    if (node.children?.length) {
      node.children = sortMenuTree(node.children as T[]);
    }
  });

  return sortedNodes;
}

function findTreeNode<T extends Pick<TreeNode, 'id' | 'children'>>(nodes: T[], targetId: T['id']): T | null {
  for (const node of nodes) {
    if (node.id === targetId) {
      return node;
    }

    if (node.children?.length) {
      const target = findTreeNode(node.children as unknown as T[], targetId);

      if (target) {
        return target;
      }
    }
  }

  return null;
}

function isRootParentId(parentId: TreeNodeId) {
  return parentId === 0 || parentId === '0';
}

function walkTree<T extends Pick<TreeNode, 'id' | 'children'>>(nodes: T[], callback: (node: T) => void) {
  for (const node of nodes) {
    callback(node);

    if (node.children?.length) {
      walkTree(node.children as unknown as T[], callback);
    }
  }
}