/**
 * utils/tree 的单元测试。
 *
 * 移植自 fms-vue 的 tests/unit/utils.spec.js（删掉其中的 utils/theme 段——本项目无关），
 * 并按 TS strict 做了类型标注；另补 fms 未覆盖的六个函数的用例
 * （findTreeNode / collectAllKeys / expandAncestors / filterTreeByText / insertTreeNode / removeTreeNode）。
 */

import { describe, it, expect } from 'vitest'
import {
  addRowUpdate,
  applyTreePosition,
  buildSortedTree,
  buildTree,
  collectAllKeys,
  collectDescendantIds,
  computeTreeMove,
  decorateTreeNodes,
  expandAncestors,
  filterTreeByText,
  findNodePosition,
  findTreeNode,
  insertTreeNode,
  rebuildTreePositions,
  removeTreeNode,
  renumberSiblings,
  sortTree,
} from '@/utils/tree'
import type { TreeMoveResult, TreeRow } from '@/utils/tree'

describe('utils/tree buildTree', () => {
  it('空数组返回空树', () => {
    expect(buildTree([])).toEqual([])
  })

  it('无父节点的节点成为根', () => {
    const list = [
      { b_id: 1, b_parent_id: null },
      { b_id: 2, b_parent_id: null },
    ]
    const tree = buildTree(list)
    expect(tree).toHaveLength(2)
    expect(tree.map((n) => n.b_id)).toEqual([1, 2])
  })

  it('按 parentKey 挂载子节点', () => {
    const list = [
      { b_id: 1, b_parent_id: null },
      { b_id: 2, b_parent_id: 1 },
      { b_id: 3, b_parent_id: 2 },
    ]
    const tree = buildTree(list)
    expect(tree).toHaveLength(1)
    expect(tree[0].b_id).toBe(1)
    expect(tree[0].children).toHaveLength(1)
    expect(tree[0].children?.[0].b_id).toBe(2)
    expect(tree[0].children?.[0].children?.[0].b_id).toBe(3)
  })

  it('父节点不存在的子节点提升为根（孤儿节点）', () => {
    const list = [
      { b_id: 2, b_parent_id: 999 },
      { b_id: 3, b_parent_id: null },
    ]
    const tree = buildTree(list)
    expect(tree).toHaveLength(2)
  })

  it('支持自定义 idKey / parentKey / childrenKey', () => {
    const list = [
      { id: 'a', pid: null },
      { id: 'b', pid: 'a' },
    ]
    const tree = buildTree(list, 'id', 'pid', 'kids')
    expect((tree[0].kids as TreeRow[])[0].id).toBe('b')
  })

  it('副作用说明：向父节点对象注入 children 属性（当前实现行为）', () => {
    const list: TreeRow[] = [
      { b_id: 1, b_parent_id: null },
      { b_id: 2, b_parent_id: 1 },
    ]
    buildTree(list)
    // 当前实现直接修改传入的节点对象（parent[childrenKey] = []），
    // 调用方若复用原数组需注意此副作用；需要纯函数请用 buildSortedTree
    expect(Array.isArray(list[0].children)).toBe(true)
    expect(list[0].children).toHaveLength(1)
  })
})

describe('utils/tree sortTree', () => {
  it('按 b_xh 升序排序', () => {
    const tree = [{ b_xh: 3 }, { b_xh: 1 }, { b_xh: 2 }]
    sortTree(tree)
    expect(tree.map((n) => n.b_xh)).toEqual([1, 2, 3])
  })

  it('b_xh 相同按 b_id 排序', () => {
    const tree = [
      { b_xh: 1, b_id: 'b' },
      { b_xh: 1, b_id: 'a' },
    ]
    sortTree(tree)
    expect(tree.map((n) => n.b_id)).toEqual(['a', 'b'])
  })

  it('递归排序子节点', () => {
    const tree: TreeRow[] = [
      {
        b_xh: 1,
        children: [{ b_xh: 2 }, { b_xh: 1 }],
      },
    ]
    sortTree(tree)
    expect(tree[0].children?.map((n) => n.b_xh)).toEqual([1, 2])
  })

  it('返回原数组引用', () => {
    const tree = [{ b_xh: 2 }, { b_xh: 1 }]
    expect(sortTree(tree)).toBe(tree)
  })
})

/** 两层示例树：a（含 a1，a1 含 a1x）、b */
function makeQueryTree(): TreeRow[] {
  return [
    {
      b_id: 'a',
      b_name: '甲',
      b_code: 'alpha',
      children: [
        {
          b_id: 'a1',
          b_name: '甲一',
          b_code: 'alpha-1',
          children: [{ b_id: 'a1x', b_name: '子节点', b_code: 'alpha-1-x', children: [] }],
        },
      ],
    },
    { b_id: 'b', b_name: '乙', b_code: 'beta', children: [] },
  ]
}

describe('utils/tree 查询与过滤', () => {
  it('findTreeNode 递归查找并返回树中的活节点', () => {
    const tree = makeQueryTree()
    const found = findTreeNode(tree, 'a1x')

    expect(found?.b_name).toBe('子节点')
    // 返回的是原节点引用，业务可以继续改它
    expect(found).toBe(tree[0].children?.[0].children?.[0])
    expect(findTreeNode(tree, 'ghost')).toBe(null)
  })

  it('findTreeNode 支持自定义 idKey / childrenKey', () => {
    const tree: TreeRow[] = [{ code: 'p', kids: [{ code: 'c' }] }]
    expect(findTreeNode(tree, 'c', 'code', 'kids')?.code).toBe('c')
  })

  it('collectAllKeys 收集全部层级 key 并统一转字符串', () => {
    const tree: TreeRow[] = [
      { b_id: 1, children: [{ b_id: 2, children: [] }] },
      { b_id: 3, children: [] },
    ]
    expect(collectAllKeys(tree)).toEqual(['1', '2', '3'])
    expect(collectAllKeys([])).toEqual([])
  })

  it('expandAncestors 返回根到目标节点的祖先路径（不含自身）', () => {
    const tree = makeQueryTree()
    expect(expandAncestors(tree, 'a1x')).toEqual(['a', 'a1'])
    // 根节点没有祖先
    expect(expandAncestors(tree, 'a')).toEqual([])
    expect(expandAncestors(tree, 'ghost')).toEqual([])
  })

  it('filterTreeByText 命中深层节点时保留祖先链路（剪掉兄弟）', () => {
    const tree = makeQueryTree()
    // a1x 的 b_code 独有；b_id 不参与匹配（默认只匹配 b_name / b_code）
    const filtered = filterTreeByText(tree, 'alpha-1-x')

    // 只保留 a → a1 → a1x 这条链路，兄弟节点被剪掉
    expect(filtered).toHaveLength(1)
    expect(filtered[0].b_id).toBe('a')
    expect(filtered[0].children?.[0].b_id).toBe('a1')
    expect(filtered[0].children?.[0].children?.[0].b_id).toBe('a1x')
  })

  it('filterTreeByText 命中父节点但子树未命中时，子树被剪空（命中不豁免后代过滤）', () => {
    const tree = makeQueryTree()
    // '甲一' 只命中 a1 的名字；a1x 未命中被剪掉，a1 自身保留
    const filtered = filterTreeByText(tree, '甲一')

    expect(filtered[0].children?.[0].b_id).toBe('a1')
    expect(filtered[0].children?.[0].children).toEqual([])
  })

  it('filterTreeByText 匹配 b_code，空关键字返回原引用', () => {
    const tree = makeQueryTree()
    expect(filterTreeByText(tree, 'beta')[0].b_id).toBe('b')
    expect(filterTreeByText(tree, '  ')).toBe(tree)
  })

  it('filterTreeByText 未命中返回空数组，且结果是浅拷贝视图', () => {
    const tree = makeQueryTree()
    expect(filterTreeByText(tree, '不存在的关键字')).toEqual([])

    const filtered = filterTreeByText(tree, 'beta')
    // 克隆节点、children 指向克隆後的数组：不是原始行对象
    expect(filtered[0]).not.toBe(tree[1])
  })

  it('insertTreeNode 顶级插入（parentIdKey 为空）', () => {
    const tree: TreeRow[] = [{ b_id: 'a', b_parent_id: null }]
    insertTreeNode(tree, { b_id: 'b', b_parent_id: null })
    expect(tree.map((n) => n.b_id)).toEqual(['a', 'b'])
  })

  it('insertTreeNode 挂到指定父节点下并按 sort 排序', () => {
    const tree: TreeRow[] = [
      {
        b_id: 'a',
        b_parent_id: null,
        children: [{ b_id: 'a1', b_parent_id: 'a', b_xh: 10, children: [] }],
      },
    ]
    insertTreeNode(tree, { b_id: 'a2', b_parent_id: 'a', b_xh: 5 }, { sort: sortTree })
    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a2', 'a1'])
  })

  it('removeTreeNode 移除根级与深层节点', () => {
    const tree = makeQueryTree()
    removeTreeNode(tree, 'b')
    expect(tree.map((n) => n.b_id)).toEqual(['a'])

    removeTreeNode(tree, 'a1x')
    expect(tree[0].children?.[0].children).toHaveLength(0)
  })
})

describe('utils/tree 可编辑树：建树与节点装饰', () => {
  it('buildSortedTree 建树并排序，且不污染原始行（重复构建不累积子节点）', () => {
    const rows: TreeRow[] = [
      { b_id: 'a', b_parent_id: null, b_xh: 20 },
      { b_id: 'b', b_parent_id: null, b_xh: 10 },
      { b_id: 'a1', b_parent_id: 'a', b_xh: 10 },
    ]

    const tree = buildSortedTree(rows)

    expect(tree.map((node) => node.b_id)).toEqual(['b', 'a'])
    expect(tree[1].children?.map((node) => node.b_id)).toEqual(['a1'])
    // children 挂在浅拷贝上，原始行保持干净
    expect(rows[0].children).toBeUndefined()
    expect(buildSortedTree(rows)[1].children).toHaveLength(1)
  })

  it('decorateTreeNodes 预载类型图标，并强制指定类型非叶子', () => {
    const tree: TreeRow[] = [
      {
        b_id: 'a',
        b_module_type: 'module',
        children: [{ b_id: 'a1', b_module_type: 'data', children: [] }],
      },
    ]

    decorateTreeNodes(tree, {
      typeField: 'b_module_type',
      nonLeafValues: ['module'],
      iconMap: { module: FolderIcon },
    })

    expect(tree[0].isLeaf).toBe(false)
    expect(tree[0].icon).toBe(FolderIcon)
    // 非 module 类型不改 isLeaf，图标表里没有的类型不写 icon
    expect(tree[0].children?.[0].isLeaf).toBeUndefined()
    expect(tree[0].children?.[0].icon).toBeUndefined()
  })
})

describe('utils/tree 可编辑树：位置派生与就地变更', () => {
  it('applyTreePosition 根节点的 b_depth 为 0、b_path 为 /编码/', () => {
    const row = { b_id: 'a' }
    applyTreePosition(row, null)
    expect(row).toMatchObject({ b_depth: 0, b_path: '/a/' })
  })

  it('applyTreePosition 子节点继承父级路径并递增层级', () => {
    const row = { b_id: 'a1' }
    applyTreePosition(row, { b_depth: 2, b_path: '/a/b/' })
    expect(row).toMatchObject({ b_depth: 3, b_path: '/a/b/a1/' })
  })

  it('findNodePosition 返回所在父数组与索引', () => {
    const tree: TreeRow[] = [{ b_id: 'a', children: [{ b_id: 'a1' }, { b_id: 'a2' }] }]

    expect(findNodePosition(tree, 'a')).toMatchObject({ index: 0 })
    const found = findNodePosition(tree, 'a2')
    expect(found?.index).toBe(1)
    expect(found?.list.map((node) => node.b_id)).toEqual(['a1', 'a2'])
    expect(findNodePosition(tree, 'not-exist')).toBe(null)
  })

  it('addRowUpdate 按 b_id 合并字段，避免同节点多条 update', () => {
    const updated: TreeRow[] = []
    addRowUpdate(updated, { b_id: 'a', b_xh: 20 })
    addRowUpdate(updated, { b_id: 'a', b_parent_id: 'p' })
    addRowUpdate(updated, { b_id: 'b', b_xh: 10 })

    expect(updated).toEqual([
      { b_id: 'a', b_xh: 20, b_parent_id: 'p' },
      { b_id: 'b', b_xh: 10 },
    ])
  })

  it('renumberSiblings 按 10 步长重排并只收集变化的行', () => {
    const a = { b_id: 'a', b_xh: 30 }
    const b = { b_id: 'b', b_xh: 10 }
    const updated: TreeRow[] = []

    renumberSiblings([a, b], updated)

    expect([a.b_xh, b.b_xh]).toEqual([10, 20])
    expect(updated).toEqual([
      { b_id: 'a', b_xh: 10 },
      { b_id: 'b', b_xh: 20 },
    ])
  })

  it('rebuildTreePositions 整树收敛 b_depth / b_path，未变化的不重复收集', () => {
    const tree: TreeRow[] = [
      {
        b_id: 'a',
        b_depth: 0,
        b_path: '/a/',
        children: [{ b_id: 'a1', b_depth: 9, b_path: '/stale/', children: [] }],
      },
    ]
    const updated: TreeRow[] = []

    rebuildTreePositions(tree, updated)

    expect(tree[0].children?.[0]).toMatchObject({ b_depth: 1, b_path: '/a/a1/' })
    // 根节点本来就是 0 / '/a/'，不该产生一条无意义的 update
    expect(updated).toEqual([{ b_id: 'a1', b_depth: 1, b_path: '/a/a1/' }])
  })

  it('rebuildTreePositions 根节点路径保留前导斜杠（回归：三份实现曾漂移）', () => {
    const tree: TreeRow[] = [
      {
        b_id: 'base',
        b_depth: 0,
        b_path: '/base/',
        children: [
          { b_id: 'base_otherdata', b_depth: 1, b_path: '/base/base_otherdata/', children: [] },
        ],
      },
    ]
    const updated: TreeRow[] = []

    rebuildTreePositions(tree, updated)

    expect(tree[0].b_path).toBe('/base/')
    expect(tree[0].children?.[0].b_path).toBe('/base/base_otherdata/')
    // 与库中既有格式一致，整棵树都不该被改动
    expect(updated).toEqual([])
  })

  it('rebuildTreePositions 修正过期路径时补全前导斜杠', () => {
    const tree: TreeRow[] = [{ b_id: 'base', b_depth: 3, b_path: 'stale/', children: [] }]
    const updated: TreeRow[] = []

    rebuildTreePositions(tree, updated)

    expect(tree[0]).toMatchObject({ b_depth: 0, b_path: '/base/' })
    expect(updated).toEqual([{ b_id: 'base', b_depth: 0, b_path: '/base/' }])
  })
})

/** decorateTreeNodes 用的占位图标组件 */
const FolderIcon = () => null

/** 三层扁平行：a（含 a1、a2）；a1 含 a1x；b 独立 */
function makeDescendantRows(): TreeRow[] {
  return [
    { b_id: 'a', b_parent_id: null },
    { b_id: 'a1', b_parent_id: 'a' },
    { b_id: 'a2', b_parent_id: 'a' },
    { b_id: 'a1x', b_parent_id: 'a1' },
    { b_id: 'b', b_parent_id: null },
  ]
}

const asSet = (list: string[]) => new Set(list)

/** 造一棵两级树：a（含 a1 / a2）、b */
function makeMoveTree(): TreeRow[] {
  return [
    {
      b_id: 'a',
      b_parent_id: null,
      b_xh: 10,
      b_depth: 0,
      b_path: '/a/',
      children: [
        { b_id: 'a1', b_parent_id: 'a', b_xh: 10, b_depth: 1, b_path: '/a/a1/', children: [] },
        { b_id: 'a2', b_parent_id: 'a', b_xh: 20, b_depth: 1, b_path: '/a/a2/', children: [] },
      ],
    },
    { b_id: 'b', b_parent_id: null, b_xh: 20, b_depth: 0, b_path: '/b/', children: [] },
  ]
}

/** 在 updatedRows 里按 b_id 取那一行 */
function rowById(rows: TreeRow[], id: string): TreeRow | undefined {
  return rows.find((row) => String(row.b_id) === id)
}

type MoveOk = Extract<TreeMoveResult, { ok: true }>
type MoveFail = Extract<TreeMoveResult, { ok: false }>

/** 断言拖拽成功并收窄联合类型（strict 下后续可直接取 updatedRows / moved） */
function mustOk(result: TreeMoveResult): MoveOk {
  expect(result.ok).toBe(true)
  if (!result.ok) throw new Error(`期望拖拽成功，实际被拦截：${result.reason}`)
  return result
}

/** 断言拖拽被拦截并收窄联合类型 */
function mustFail(result: TreeMoveResult): MoveFail {
  expect(result.ok).toBe(false)
  if (result.ok) throw new Error('期望拖拽被拦截，实际成功')
  return result
}

describe('utils/tree collectDescendantIds：按父级关联展开整棵子树', () => {
  it('收集自身与全部层级的下级，不限深度', () => {
    const ids = collectDescendantIds(makeDescendantRows(), 'a')

    expect(asSet(ids)).toEqual(new Set(['a', 'a1', 'a2', 'a1x']))
    expect(ids).toHaveLength(4)
  })

  it('叶子节点只返回自身', () => {
    expect(collectDescendantIds(makeDescendantRows(), 'a1x')).toEqual(['a1x'])
    expect(collectDescendantIds(makeDescendantRows(), 'b')).toEqual(['b'])
  })

  it('结果含自身（选中一个节点 = 选中整棵子树）', () => {
    const ids = collectDescendantIds(makeDescendantRows(), 'a1')

    expect(ids).toContain('a1')
    expect(asSet(ids)).toEqual(new Set(['a1', 'a1x']))
  })

  it('ID 数值与字符串混用时不漏（统一按字符串比较）', () => {
    const rows = [
      { b_id: 1, b_parent_id: null },
      { b_id: 2, b_parent_id: 1 },
      { b_id: 3, b_parent_id: '2' },
    ]

    // 数值 1 起头，也要能顺着字符串 '2' 找到 3
    expect(asSet(collectDescendantIds(rows, 1))).toEqual(new Set(['1', '2', '3']))
  })

  it('rootId 不在数据中时返回只含自身的集合，不抛错', () => {
    // 语义安全：拼成 IN ('不存在') 自然查不到数据，调用方无需额外判空
    expect(collectDescendantIds(makeDescendantRows(), 'ghost')).toEqual(['ghost'])
    expect(collectDescendantIds([], 'ghost')).toEqual(['ghost'])
    expect(collectDescendantIds(null, 'ghost')).toEqual(['ghost'])
  })

  it('b_parent_id 成环的脏数据不会死循环（visited 兜底）', () => {
    const rows = [
      { b_id: 'x', b_parent_id: 'y' },
      { b_id: 'y', b_parent_id: 'x' },
    ]

    expect(asSet(collectDescendantIds(rows, 'x'))).toEqual(new Set(['x', 'y']))
  })

  it('自引用的脏数据也不会死循环', () => {
    const rows = [{ b_id: 'z', b_parent_id: 'z' }]

    expect(collectDescendantIds(rows, 'z')).toEqual(['z'])
  })

  it('字段名可用 options 覆盖（非 b_id / b_parent_id 的数据）', () => {
    const rows = [
      { code: 'p', parent: null },
      { code: 'c', parent: 'p' },
    ]

    const ids = collectDescendantIds(rows, 'p', { idKey: 'code', parentKey: 'parent' })
    expect(asSet(ids)).toEqual(new Set(['p', 'c']))
  })
})

describe('utils/tree computeTreeMove：拖拽移动的守卫与落库行', () => {
  const makeTree = makeMoveTree
  it('拖到自己身上被拒绝，且不产生任何变更', () => {
    const tree = makeTree()
    const result = mustFail(
      computeTreeMove(tree, { dragKey: 'a', dropKey: 'a', dropPosition: 'inside' }),
    )

    expect(result.reason).toBe('self')
    expect('updatedRows' in result).toBe(false)
    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a1', 'a2'])
  })

  it('拖拽或落点节点不存在时返回 notFound', () => {
    const tree = makeTree()

    expect(
      mustFail(computeTreeMove(tree, { dragKey: 'ghost', dropKey: 'a', dropPosition: 'inside' }))
        .reason,
    ).toBe('notFound')
    expect(
      mustFail(computeTreeMove(tree, { dragKey: 'a', dropKey: 'ghost', dropPosition: 'inside' }))
        .reason,
    ).toBe('notFound')
  })

  it('把节点拖进自己的后代被判成环，回带调用方传入的提示文案', () => {
    const tree = makeTree()
    const result = mustFail(
      computeTreeMove(tree, {
        dragKey: 'a',
        dropKey: 'a1',
        dropPosition: 'inside',
        messages: { cycle: '不能把模块移动到它自己的下级' },
      }),
    )

    expect(result.reason).toBe('cycle')
    expect(result.message).toBe('不能把模块移动到它自己的下级')
    // 树未被破坏
    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a1', 'a2'])
  })

  it('inside 落到非容器类型上被拒绝', () => {
    const tree = makeTree()
    const result = mustFail(
      computeTreeMove(tree, {
        dragKey: 'b',
        dropKey: 'a1',
        dropPosition: 'inside',
        typeField: 'b_module_type',
        nonLeafValues: ['module'],
        messages: { notContainer: '只能把模块放入模块类型的节点下' },
      }),
    )

    expect(result.reason).toBe('notContainer')
    expect(result.message).toBe('只能把模块放入模块类型的节点下')
  })

  it('inside 落到未保存的草稿节点上被拒绝', () => {
    const tree = makeTree()
    const result = mustFail(
      computeTreeMove(tree, {
        dragKey: 'b',
        dropKey: '-1',
        dropPosition: 'inside',
        isUnsaved: (id) => id === '-1',
        messages: { unsavedTarget: '请先保存目标模块，再调整层级' },
      }),
    )

    expect(result.reason).toBe('notFound') // -1 不在树里

    // 真正放进树里再验一次
    const tree2 = makeTree()
    tree2[0].children?.push({ b_id: '-1', b_parent_id: 'a', b_xh: 30, children: [] })
    const result2 = mustFail(
      computeTreeMove(tree2, {
        dragKey: 'b',
        dropKey: '-1',
        dropPosition: 'inside',
        isUnsaved: (id) => id === '-1',
        messages: { unsavedTarget: '请先保存目标模块，再调整层级' },
      }),
    )

    expect(result2.reason).toBe('unsavedTarget')
    expect(result2.message).toBe('请先保存目标模块，再调整层级')
  })

  it('inside：换父成功，重算 b_parent_id / b_depth / b_path，父级子集与原子级都重排 b_xh', () => {
    const tree = makeTree()
    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'b', dropKey: 'a1', dropPosition: 'inside' }),
    )

    expect(result.parentChanged).toBe(true)

    // a1 收下 b 作为子节点
    const a1 = tree[0].children?.find((n) => n.b_id === 'a1')
    expect(a1?.children?.map((n) => n.b_id)).toEqual(['b'])

    // a 下不再有 b
    expect(tree.map((n) => n.b_id)).toEqual(['a'])

    // 迁移后的位置字段随新父级收敛
    expect(result.moved).toMatchObject({
      b_id: 'b',
      b_parent_id: 'a1',
      b_depth: 2,
      b_path: '/a/a1/b/',
    })

    // b_parent_id 变化会单独补一条 update
    expect(rowById(result.updatedRows, 'b')?.b_parent_id).toBe('a1')
    // b 落到 a1 下成为唯一子节点 → 位置 10；a 下只剩 a1（原 10）、a2（原 20），
    // 重排后取值不变，因此不再产生 update
    expect(rowById(result.updatedRows, 'b')?.b_xh).toBe(10)
    expect(rowById(result.updatedRows, 'a2')).toBeUndefined()
  })

  it('inside：落点原本没有 children 字段时补出空数组并摘掉 isLeaf', () => {
    const tree: TreeRow[] = [
      { b_id: 'a', b_parent_id: null, b_xh: 10, b_depth: 0, b_path: '/a/', children: [] },
      { b_id: 'b', b_parent_id: null, b_xh: 20, b_depth: 0, b_path: '/b/', isLeaf: true },
    ]

    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'a', dropKey: 'b', dropPosition: 'inside' }),
    )

    expect(result.ok).toBe(true)
    const b = tree.find((n) => n.b_id === 'b')
    expect(b?.children?.map((n) => n.b_id)).toEqual(['a'])
    expect(b?.isLeaf).toBe(false)
  })

  it('after：同级换序，父级不变时不再产生 b_parent_id 更新', () => {
    const tree = makeTree()
    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'a2', dropKey: 'a1', dropPosition: 'after' }),
    )

    expect(result.parentChanged).toBe(false)
    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a1', 'a2'])
    // 位置本就是 10 / 20，重排后无变化 → 该节点不产生 update
    expect(rowById(result.updatedRows, 'a2')).toBeUndefined()
    expect(result.updatedRows).toEqual([])
  })

  it('before：跨父拖到目标之前，落到目标同级并接管目标父级', () => {
    const tree = makeTree()
    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'b', dropKey: 'a2', dropPosition: 'before' }),
    )

    expect(result.parentChanged).toBe(true)
    expect(tree.map((n) => n.b_id)).toEqual(['a'])
    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a1', 'b', 'a2'])
    expect(result.moved).toMatchObject({ b_parent_id: 'a', b_depth: 1, b_path: '/a/b/' })
    expect(rowById(result.updatedRows, 'b')?.b_parent_id).toBe('a')
  })

  it('同级 after 且拖到自身之后：索引修正后位置不变', () => {
    const tree = makeTree()
    // a1 拖到 a2 之后 => a1 落到末尾
    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'a1', dropKey: 'a2', dropPosition: 'after' }),
    )

    expect(result.ok).toBe(true)
    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a2', 'a1'])
  })

  it('同级 before 且拖到自身之前：索引修正后位置不变', () => {
    const tree = makeTree()
    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'a2', dropKey: 'a1', dropPosition: 'before' }),
    )

    expect(tree[0].children?.map((n) => n.b_id)).toEqual(['a2', 'a1'])
    expect(rowById(result.updatedRows, 'a2')?.b_xh).toBe(10)
  })

  it('无变化场景给出空 updatedRows 而不是报错', () => {
    const tree = makeTree()
    // 把 a1 拖到 a2 之前，本来就是该位置
    const result = mustOk(
      computeTreeMove(tree, { dragKey: 'a1', dropKey: 'a2', dropPosition: 'before' }),
    )

    expect(result.updatedRows).toEqual([])
  })
})