import type { AdminMenuNode } from '../types/admin'

export interface SidebarItem {
  key: string
  name: string
  route: string
}

/** 侧边栏渲染项：分组（含子页面）或单页面项（含顶级路由叶节点）。 */
export type SidebarEntry =
  | { kind: 'group'; key: string; name: string; children: SidebarItem[] }
  | { kind: 'item'; key: string; name: string; route: string }

/**
 * 后端菜单树 -> 侧边栏节点映射规则（任务 6）：
 * - 有可路由子节点的节点渲染为分组，只保留带 route 的子项；
 * - 无子节点但有 route 的节点渲染为单页面项（不丢顶级叶菜单）；
 * - 既无子节点也无 route 的节点跳过（点不进去的纯占位不展示）。
 */
export function toSidebarEntries(nodes: AdminMenuNode[] | null | undefined): SidebarEntry[] {
  const entries: SidebarEntry[] = []
  for (const node of nodes || []) {
    const name = node.name || ''
    const key = node.key || ''
    const children: SidebarItem[] = (node.children || [])
      .filter((child): child is AdminMenuNode & { route: string } => Boolean(child.route))
      .map((child) => ({ key: child.key || '', name: child.name || '', route: child.route }))
    if (children.length > 0) {
      entries.push({ kind: 'group', key, name, children })
    } else if (node.route) {
      entries.push({ kind: 'item', key, name, route: node.route })
    }
  }
  return entries
}

/** 计算需默认展开的分组 key：分组下含当前激活路由子项时返回该分组 key。 */
export function groupKeysForActive(entries: SidebarEntry[], activeRoute: string): string[] {
  const keys: string[] = []
  for (const entry of entries) {
    if (entry.kind === 'group' && entry.children.some((child) => child.route === activeRoute)) {
      keys.push(entry.key)
    }
  }
  return keys
}